December 2016
Volume 1, Number 1
TABLE OF CONTENT
Lignocellulosic biomass for bioproduct: Its potency and technology development Widya Fatriasari, Euis Hermiati ................................................................. 1-14 Diversifikasi serat pulp untuk produk inovatif Wawan Kartiwa Haroen ................................................................................... 15-25 Preparation of heat-adsorbing materials from coconut shell-tar Riska Surya Ningrum, Bambang Setiadji, Wega Trisunaryanti ....................... 26-31 Pembuatan dan karakterisasi komposit zephyr bambu dengan perekat kempa dingin Subyakto, Mohamad Gopar, Ismadi, Ananto Nugroho, Agung Sumarno, Eko Widodo, Sudarmanto ................................................................................. 32-37 Proximate analysis of lignocellulosic material as alternative bioenergy resources Jauhar Khabibi, Bambang Irawan ................................................................... 38-43 Modification of palm oil empty fruit bunches biosorbent using egg shells for phenol sorption Mamay Maslahat, Mediagmi Paramitha, Supriyono Eko Wardoyo .................. 44-52 Sifat fisis dan mekanis papan partikel dengan menggunakan campuran perekat urea formaldehida dan phenol formaldehida pada berbagai suhu pengempaan Ervi Utari Ginting, Apri Heri Iswanto, Irawati Azhar ........................................ 53-59 Biodegradation optimization of 2,4,8-trichlorodibenzofuran by ligninolytic fungus Ajeng Arum Sari, Kazutaka Itoh, Sanro Tachibana .......................................... 60-67 Utilization of kapok fiber as a natural sorbent in petroleum hydrocarbon biodegradation by Pestalotiopsis sp. Dede Heri Yuli Yanto, Sanro Tachibana ....................................................... 68-73
INTRODUCTION Abbreviation: J. Lignocellulose Technol. A peer-reviewed journal dedicated to foster the science and technology in lignocellulosic materials Home: Description J. Lignocellulose Technol. is published both Online (ISSN: xxxx-xxxx) and Printed (ISSN: xxxx-xxxx). Focus and Scope Focus: The focus of this journal is related to lignocellulosic material including crops residue. J. Lignocellulose Technol. encourage manuscripts reporting unique, innovative contributions to the physics, biology, biochemistry, chemistry, material science and applied mechanics aspects of lignocellulosic material, including wood and other biomass resources. J. Lignocellulose Technol. is a peer-reviewed journal which publishes original articles and review articles. All submitted papers will be reviewed by at least two referees. Scope: Advance in the science and technology of utilization of lignocellulosic materials obtained from wood, crop residues and other materials containing cellulose, lignin, and related biomaterials. Emphasis is placed on bioproducts, bioenergy, papermaking technology, new manufacturing materials, composite structures, and chemicals derived from lignocellulosic biomass. Lignocellulose modification, biorefinery derived from lignocellulose, biodegradation related to lignocellulose materials, wood or lignocellulose preservatives, lignocellulose conversion and plant technology
Editor in Chief: Dr. Dede Heri Yuli Yanto Editorial Board: Prof. Dr. Sulaeman Yusuf Prof. Dr. Subyakto Dr. Wahyu Dwianto Dr. Euis Hermiati Dr. Widya Fatriasari Dr. Titik Kartika Dr. Firda Aulya Syamani Dr. Riksfardini Annisa Ermawar Dr. Lisman Suryanegara Dr. Apri Heri Iswanto Dr. Tati Karliati Dr. Yenny Meliana Editorial Staff: Apriwi Zulfitri Anis Sri Lestari Lillik Astari Fahriya Puspita Sari Ni Putu Ratna Ayu Krishanti Secretariat: Eka Lestari Photographer: Agus Mulyadi Graphic Design: Adik Bahanawan Eko Widodo Website: Faizatul Falah Ismadi Febrina Dwiky Indriyani Fathul Bari Herry Samsi Syam Budi Iryanto BramantyoWikantyoso Publisher & Secretariat: Research Center for Biomaterials Indonesian Institutes of Sciences Jl. Raya Bogor KM 46, (CSC – BG) Cibinong Science Center – Botanical Garden, Cibinong, 16911, Bogor, Indonesia Email :
[email protected] Subscription: Free journal subscription and free hardcopy (postal fee apply)
FOREWORD The term lignocellulose refers to material composed of lignin, cellulose and hemicellulose. Lignocellulosic material is a constituent component of plant cell walls and often found in biomass or waste derived from agricultural products, forests and plantations. Composition of lignocellulose in plant varies and depends on the type of biomass, age and the environment where the plant grows. Generally, plant contains1525% of lignin, 40-50% of cellulose, 25-30% of hemicellulose and 5-10% of extractive and ash (USDE, 2015). Indonesia is a tropical country which rich in lignocellulosic materials. Most of lignocellulosic based-products, such as pulp, paper, furniture and building materials are derived from the natural forest. The exploitation of timber from forest has been increased from time to time along with the increased number of population and demand of the products. The over-exploitation of natural forests can lead to forest destruction and worse to natural disasters such as floods, droughts and land slide. In order to fulfill the continuing demand for raw materials in wood industries, Industrial Plantation Forest (Hutan Tanaman Industri or HTI) is one of the solutions to maintain the preservation of natural forest. However, it may challenge sustainability of other species or biodiversity because of its monoculture system. Other solution is generating valuable products from lesser known fast-growing wood species, industrial lignocellulosic biomass waste, or non-wood lignocellulosic commodities such as bamboo, sisal, kenaf which can be harvested in a relatively short periods of time (2-3 years). Developing technology and materials engineering are of importance to improve durability and physical-mechanical properties of fast-growing wood with low quality. Similarly, fabricating wood substitute materials from forestry industry waste, plantation, agriculture and other natural fibers for building construction materials, furniture, automotive parts and other meaningsis equally critical. In this first issue, Journal of Lignocellulose Technology contains seven original articles and two review articles that have been selected and peer-reviewed to be published in volume 1, 2016. We hope this publication is useful for the advancement of science and technology in the related fields. Dr. Dede Heri Yuli Yanto Editor in Chief
ACKNOWLEDGEMENT
Editorial board would like to acknowledge persons and parties below for their great assistance and valuable support:
Dr. Sri Nugroho Marsoem, Faculty of Forestry, Gadjah Mada University Prof. Wasrin Syafii, Department of Forest Product, Faculty of Forestry, Bogor Agricultural University Dr. Nanang Masruchin, Kyung Pook National University, South Korea Dr. Saptadi Darmawan, Research, Development and Innovation Agency Ministry of Environment and Forestry Republic of Indonesia Dr. Isroi, Indonesian Research Institute for Biotechnology and Bioindustry
Dr. Ade Andriani Ehime University, Japan Dr. Asep Hidayat Research, Development and Innovation Agency Ministry of Environment and Forestry Republic of Indonesia Dr. Ajeng Arum Sari Research Center for Chemistry Indonesian Institutes of Sciences
J. Lignocellulose Technol. 01 (2016), 1-14
Journal of Lignocellulose Technology Journal homepage: http://ejournal.lipi.go.id/index.php/jol/
Review
Lignocellulosic biomass for bioproduct: its potency and technology development Widya Fatriasari1*, Euis Hermiati1 1Research
Center for Biomaterials, Indonesian Institute for Sciences, Jl Raya Bogor km 46,Cibinong,Bogor, 16911 Indonesia *Corresponding author: e-mail:
[email protected]
Received: 1 December 2016. Received in revised form: 14 December 2016. Accepted: 19 December 2016. Published online: 23 December 2016
Abstract Lignocellulosic biomass has high potency to be utilized as materials for bioproducts. Cellulose, hemicellulose and lignin are main polymers which build the biomass structure. To convert the polymers into derived bioproducts, the cell wall structure of biomass must be fractionated. Common fractionation methods include physical, mechanical, biological and chemical process, or the combination between them. In line with the biorefinery concept, i.e. all of polymers can be utilized in creating functional materials, both as final and intermediate bioproducts. Cellulose is main material source for pulp and paper, bioplastic, bioethanol and 5-hydroxyl methylfurfural (HMF) production. Hemicellulose as 5-carbon sugar can be converted into xylitol used in food application as sweetener or in the production of other biochemicals. On the other hand, biosurfactant, activated carbon, and bioadhesives can be obtained from lignin processing. Research Center for Biomaterials LIPI is interested in developing process and technology for the conversion of these polymer into bioproducts, that is derived from wood and non wood material. The bioproducts are bioethanol, bio-adhesive based lignin, biosurfactant based lignin, wood plastic composites (WPC) and bio-composites. To drive the research development in this area, research collaboration among government, private and international research institutes is encouraged. Keywords : bioproducts; biorefinery concept; functional materials; lignocellulosic biomass; intermediate and final products
Introduction The main component of lignocellulosic materials are carbohydrates, including cellulose and hemicellulose, and lignin. In order to utilize each component effeciently, their structures must be altered or broken down. There are many potential biomasses which can be further converted into functional materials for intermediate and final products. Derived bioproducts from
lignocellulosic biomass can be used in wide area of applications, depends on the purposes. The utilization of bioresources should be pay attention to their potencies in each country. It will allow to use biomass resources in more rational method both economically and environmentally. Recently, the upgrading of the low-quality lignocellulosic biomass or ”waste” biomass
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from wood and non woody materials into valuable bioproducts become research of interest worldwide.
biorefinery concept is developed based on the petroleum fractionation with modification in reaction process regarding with low thermal stability and a high degree of functionality (Huber and Dumesic 2006).
Fractionation of lignocellulosic biomass to separate its component for biofuel production has possibility in producing “waste” liquor. The liquor content is affected by the treatment methods and conditions or chemicals used. Ideally, the whole utilization of the main biomass components can render the term waste which has potential to be converted in a by-product stream than waste streams (Kamn and Kamn 2007). This approach meets with application of biorefinery concept to promote biomass conversion into high value products and then diversify the types and applications.
In this paper we focused in investigating the biorefinery concept application for producing bioproducts from lignocellulosic biomass. The biomass feedstock, fractionation methods and and some potential bioproducts are subjects discussed, with special stresses on the the conversian of lignocellulosic of biomass to ethanol and the utilization of lignin as by product of the process. The multi-step processes in Biorefinery Concept
In general, there are many definitions of biorefinery concept. Biorefinery can be defined as the integration between processes (biological, thermomechanical, chemical) and equipment in the biomass conversion for producing biofuel, power, food and feed ingredients, value added chemicals and biomaterials (Diep et al.2012 ). This integrated bio-based industry activities can generate a promising plant to produce various bioproducts for intermediate or final products. Hybrid technologies including polymer chemistry, bioengineering and agriculture invole to realize the biorefinery approach in the biomass fractionation (Ohara 2003). Typically, this concept consist of multi-step processes including feedstock selection, pretreatment, sugar production or chemicals through hydrolysis step, conversion to speciality polymers for energy sources, composite materials (FitzPatrick et al. 2010) and functional bioproducts. The
Nature of biomass feedstock To achieve effective conversion strategy of lignocellulosic biomass, the content of cellulose, hemicellulose and lignin polymer along with smaller amounts of pectin, protein, extractives and ash which build up cell wall of lignocellulosic biomass should be understand previously. Structural and relative abundance of these polymers in lignocellulosic biomass are presented in Fig. 1 and Table 1. There are some variations in chemical compositions of the biomass. The compositons are affected by the types, species, sources of biomass, sites of growth, stages of growth (Fengel and Wegener 1989; Chandra et al. 2007; Bajpai 2016), environmental conditions, silviculture treatments, etc. In general there are three groups of lignocellulosic biomass regarding to the chemical contents, hardwood, softwood, and graminae crops.
Table 1. Variations of chemical components of lignocellulosic materials Lignocellulosic materials Cellulose (%) Hemicellulose (%) Lignin (%) Hardwooda 40-55 24-40 18-25 Softwooda 45-50 25-35 25-35 Corn cobsa 45 35 15 Grassesa 25-40 35-50 10-30 Wheat strawa 30 50 15 Leavesa 15-20 80-85 0 Papera 85-99 0 0-15 Switch grassa 45 31.4 12.0 Coastal bermuda grassa 25 35.7 6.4 Newspapera 40-55 25-40 18-30 Sugarcane bagasseb 52.45 25.97 12.72 Empty oil fruit bunch (EFB)c 43.75 26.22 17.35 Sorgum bagassec,d 41.65-46.5 25.3-33.8 24.98-32.5 Source : aReshamwala et al. (1995), Cheung and Anderson (1997), Boopathu (1998) and Dewes and Hunsche (1998) in Sun and Cheng (2002), bChen, Tu and Shen, 2011, cFatriasari et al. 2016a, d Fatriasari, Supriyanto and Iswanto, 2015a, dSyafwina et al. (2002)
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a
b
Figure 1. Lignocellulosic biomass structure (a) (Kheswani, 2009), Crystalline and amorphous region of cellulose (Borjesson and Westman, 2015)
Cellulose is linear polymer of β-Dglucopyranose moieties via β (1,4) glycosidic bonds (Fig. 2). It is the main constituents of plant cell wall for supporting its cell wall structure. The degree of polymerization (DP) of cellulose chain ranges from 10,000 glucopyranose units in wood to 15,000 in native cotton (Bajpai, 2016). Hardwoods and sofwoods have higher DP in the range of 4000–5500 than that of some of agricultural residues, such as sugarcane bagasse and wheatstraw with DP (~1000) (Hallac and Ragauskas, 2011). The linear cellulose chain has strong bonding in an order packing that interact via inter-molecular and intramolecular hydrogen bonds. The cellulose chain consists of in crystalline region in order form and amorphous region in disorder form. This crystalline structure of cellulose is relatively difficult to be
hydrolyzed (Laureano-Perez et al., 2005; Kheswani, 2009) in producing sugar. About 20-50% of chemical component of biomass is hemicellulose, which has short branches chain consisted of different types of sugars (Fig. 3). There are two bonds in hemicellulose i.e β-(1,4)-glycosidic bonds and β-(1,3)-glycosidic bonds. Hemicellulose has 5-carbon sugars (pentoses) such as xylose, rhamnose, and arabinose and 6carbon sugars (hexoses) including glucose, mannose, and galactose. Besides sugar content, hemicellulose may also contain uronic acid such as 4-O-methylglucuronic, D-glucuronic, and D-galactouronic acids (Bajpai, 2016). It also has lower molecular weight and crystallinity than that of cellulose with short lateral chains (Fengel and Wegener, 1989; Kheswani, 2009).
Figure 2. Structure of cellulose chain (Hallac and Ragauskas, 2011)
a
b
Figure 3. Structure of xylan (a) and glucomannan (b) (Lee, Hamid and Zain, 2014)
Lignin is a highly complex cross linked polymer of aromatic rings which made up of
three phenolic acids or monolignols i.e pcoumaryl alcohol, coniferyl alcohol/guiacyl
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and synapyl alcohol/syringyl (Fig. 4a,b). It presents in plant cell walls and confers a rigid, impermeable resistance to microbial attack and oxidative stress (Bjapai, 2016). Type of lignocellulosic material affects the monolignol proportion (Kheswani, 2009). At least, three kinds of bonds are found in lignin structure such as alkyl-aryl, alkylalkyl, and aryl-aryl ether bonds link (Bjapai, 2016) with β-O-5 ether bond dominated them. In general, herbaceous plants such as grasses have the lowest contents of lignin, whereas softwoods have the highest lignin
contents. Typically, softwood and hardwood lignins consist of two monolignol types i.e syringyl and guiacyl with different proportion. p-coumaryl alcohol monolignol can be found in grasses plants besides syringyl and guiacyl. This complex structure of lignin with the strong carbon-carbon bonding has caused the difficulty in breaking lignocellulosic structure of biomass. Therefore, elimination of lignin by pretreatment can facilitate in providing access to cellulose to be further processed.
b
a
Figure 4. (a) Monolignols of lignin polymer (1) p-coumaryl alcohol, (2) coniferyl alcohol, (3) Synaphyl alcohol, (b) Functional groups of lignin molecules (Harmsen et al., 2010; Werhan, 2013)
Different functional groups of the major components of lignocellulosic biomass are shown in Table 2 (Harmsen et al., 2010). It can be seen that with lignin has the most variations in functional group types. By
understanding this functional groups belongs to each polymer, the reaction during conversion processes can be applied appropriately.
Table 2. Fuctional groups of monomer units within individual polymers and between the polymers Bonds within different components (intrapolymer linkages) Aromatic ring Hydrogen bond Carbon to carbon linkage Ester bond
Lignin Cellulose Lignin Hemicellulose
Bonds connecting different components (interpolymer linkages) Ether (glucosidic) linkage Cellulose-lignin Hemicellulose-lignin Ester bond Hemicellulose-lignin Hydrogen bond* Cellulose-hemicellulose Hemicellulose-lignin Cellulose-lignin Source: Harmsen et al., 2010
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Fractionation of lignocellulosic biomass in biorefinery concept and selected bioproduct production
biomass’ chemical component biomass to choose route process and targeted bioproducts. In prespective of biomass biorefinery of lignocellulosic biomass, RC for Biomaterials LIPI has also focused its research to develop some valuable bioproducts such as bionanocomposites, wood plastic composites, pulp and paper, bioethanol, microfibrillated cellulose from cellulose. Xylitol production has been under development, while bioadhesives and biosurfactant has been converted from isolated lignin.
Various methods can be used to liberate the lignocellulosic biomass structure. In this pathway, many derived functionalized biomaterial can be produced. The process and their bioproducts are represented in Fig. 5. Seeing the possible bioproducts which can be produced by the pretreatment and separation of lignocellulosic biomass, the choice of method will determine the results. It is required to consider the initial of
Lignocellulosic biomass
Main component
Non structural component
Extractives
Bioadhesives Biosurfactant Cellulose Glucose polymer
Lignin Phenol-polymer
Hemicellulose Pentose, Hexose
Activated carbon Sub-bitumious coal
Hydrolysis
Hydrolysis
Sulphur free solid fuel Hexose
Xylose
Glucose Xylite Fermentation
-5 hydroxymethyl furfural (HMF) - Levulinic acid
Furfural -Bioethanol -Organic acid -Solvents
Dispersants
Chemical conversion
Biopolymer based cellulose Bioplastic -Pulp and paper -Bionanocomposite -Microfibrillated cellulose -Wood plastic composites -Rayon
Emulsifiers Antioxidants Plastics Binders Aromatics
Furan resins Chemical
Nylon
Energy
Figure 5. Biorefinery for cellulosic biomass to fuels, chemicals, power, and food
Lignocellulosic pretreatment
physically, chemically, biologically, or using combinations of those processes. In the biorefinery of lignocellulosic to ethanol the aims of the pretreatment are to reduce crystallinity of cellulose, increase porosity of biomass, and achieve the desired fractionation (Sun and Cheng 2002). In cellulose production, the efficient pretreatment can be evaluated by optimizing
The first important step in the fractionation of lignocellulosic biomass is pretreatment. This step usually consists of reduction the sizes of the biomass by means of mechanical processes, such as chopping, cutting, grinding, pulverizing, etc. The biomass then could be further processed
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the cellulose content with minimize the further degradation products and its process cost (Sun and Cheng 2002; Kheswani 2009). The detail effects of pretreatment types on break down the lignocelulosic biomass structures are describes in Table 3.
combination of them can be chosen for optimizing the lignin solubilization in biomass with high lignin content. Even though, lignin is not the single factor which affects improvement of biomass digestibility, the determination of targeted polymer to be removed from the biomass will facilitate maximum cellulose content. In contrast, acid pretreatment or its combination with other pretreatment can be used to gain high yield of hemicellulose, which is usually present in the liquor.
Each pretreatment has advantages and disadvantages, therefore, the pretreatment selection is an important step in conversion of lignocellulosic biomass. For example, biological, alkali pretreatment or
Table 3. The effect of preteatment of lignocellulosic biomass Example Effect Reference Mechanical Reduction of particle Kheswani, 2009; communition size and crystallinity Zhao et al., 2006; Ball mill2 Increase surface area Sun and Cheng, 2002 Microwave Irradiation Lignin reduction Fatriasari et al., Hemicellulose reduction 2016b Electron beam Bak et al., 2009; irradiation Decomposition of Sun and Cheng, Phyrolysis cellulose 2002 Physico-chemical Steam explosion (auto- Hemicellulose Sun and Cheng, hydrolysis) solubilization 2002; Khewani, Lignin transformation 2009 Crystallinity reduction Ammonia fiber Delignification Kheswani, 2009; explosion1 Crystallinity reduction Sun and Cheng, 2002 Microwave-dilute Lignin reduction Fatriasari, Anisa acid/alkaline Hemicellulose reduction and Risanto, 2016a; Anita et al., 2012; Risanto et al., 2011; Conventional heatingLignin reduction Isroi et al., 2012 dilute acid/alkaline Hemicellulose reduction Damage of fiber structure into smaller Liquid hot water particle size Chemical Dilute sulfuric and Hemicellulose Kheswani, 2009; organic acid solubilization Isroi et al., 2012; Dilute NaOH, Ca(OH) Crystallinity reduction Amin et al., 2014 Kraft and soda pulping Delignification Crystallinity reduction Biological White rot fungi Delignification Fatriasari et al., Increase of crystallite 2014a; Isroi et al., size 2012; Risanto et Lateral order index al., 2012; reduction Biological-physicoWhite rot fungiHemicellulose reduction Fatriasari et al., chemical microwave irradiation Lignin reduction 2015b; Isroi et al. Phosporic acid-white Later order index 2012 rot fungi reduction MechanicalKraft pulping-beating Fiber fibrillation Wistara, Pelawi chemical Delignification and Fatriasari, 2016 Pretreatment Physical
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Process assesement to produce bioproducts from fractionated polymers
fiber having more hydropobic properties or an addition of chemicals during the WPC production can be conducted. Up to now, the research development to find out the economic and feasible method in this area is still becoming area of interest for many research groups. To make a broad utilization of cellulose as reinforcement matrix, reducing the cellulose size to nano scale also becomes research interest. By this treatment, a great improvement on the physical and mechanical properties can be resulted.
As the most abundant polymer, cellulose can be further converted into intermediate materials such as pulp. Pretreatment by delignification process is a principal process to remove or disolve lignin from the plant cell wall. It will provide a high cellulose content. Pulp can be utilized as materials for final products, such as paper, bioplastic, microfibrillated cellulose for matrix reinforcement, bionanocellulose, bioethanol, rayon,etc. Understanding cellulose properties can be used to fit the targeted bioproducts production. For example, as reinforcing fibers in wood plastic composites (WPC), a high cellulose content and degree of crystallity are more preferable to produce composites with good mechanical properties. Incompatibility between natural fibers and polymer matrix is the main problem in the WPC production. Cellulose modification to make cellulose
Biomass feedstock
The development of second generation bioethanol production from lignocellulosic biomass is an interesting research subject regarding the depletion of fossil oil reserves. At least, there are four main stages in bioethanol production that have been carried out at RC Biomaterials LIPI (Fig.6). .
Bioplastic Technical Lignin
Disruption of biomass structure
Acetylation
Isolation
Xylose
Hydrolyzate
Pretretment
Microorganisme fermentation
Solid fraction
To break down cellulose into sugar SHF Hydrolysis
Xylitol
Cellulase enzyme
Microfibrilated cellulose
SSF Fermentation
Yeast
Nanocellulose
Plastic polymer mixing
Destillation WPC Bioethanol Figure 6. Conversion process of lignocellulosic into bioethanol and biopolymer: a simple biorefinery concept application at RC Biomaterials LIPI
The first stage is pretreatment to alter the biomass structure for providing more accesible spesific area, and reducing degree of polimerization of cellulose. Lignin and crystalline structure of cellulose are identified as recalcitrances in hydrolysis of cellulose (Mosier et al. 2005; Chandra et al. 2007; Sun and Cheng 2002). In the second stage, the pretreated biomass is subjected for cellulose hydrolysis into sugar
monomers and then this sugars will be yeast fermented to produce bioethanol in third stage. For utilization as biofuel which will be blended with petroleum, the moisture content of bioethanol must be reduced by distillation process in the fourth stage. Even though there are several single or combination of pretreatment methods as present in Fig. 5, determining the appropriate method which resulted in
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satisfacory bioethanol yield is still looked for. Besides that, feedstock types and their properties affected the results. The future challenges in the development of second generation bioethanol production is to find out the efficent and economical method with
less consumption of energy and also low cost production with high bioethanol yield. Preventing the degradation product which can interfere the enzyme and yeast performances becomes researchers’attention as well.
Table 4. Biomass for sugar and bioethanol products and its potential polymers source for bioproducts No
Biomass
Conversion process
Results -The highest RSY per biomass at 1% acid concentration for 12.5 min is 25.09% -The ethanol concentration of SSF for 72 h is 1.26 g/L with ethanol productivity is 0.02 g/L/h, whereas ethanol yield is 0.64 g/g The highest sugar yield (29.15 %) was obtained at power level 550 W for 15 min with sulfuric acid The highest RSY per pulp of pretreated EFB is 16.32%
Potential polymer source for bioproducts Hemicellulose Lignin
Fatriasari et al., 2016b
References
1
OPEFB
Microwave assisted acid-glycerol pretreatment in variation of acid concentration and irradiation time
2
OPEFB
Hemicellulose Lignin
Anita et al., 2012
3
OPEFB
Lignin
Risanto et al., 2012
4
Sugar cane bagasse
Lignin
5
Cassava pulp
Fajriutami, Fatriasari and Hermiati, 2016 Hermiati et al., 2012
6
Bamboo
Lignin Hemicellulose
Fatriasari et. al., 2014b
7
Bamboo
Lignin Hemicellulose
Fatriasari et al., 2014b
8
Bamboo
Lignin Hemicellulose
Fatriasari et al., 2015c
9
Oil palm frond (OPF)
Microwave assisted oxalic and sulfuric acid-glycerol pretreatment Biological pretreatment using coculturing P.crysosporium and T. versicolor for 4 weeks using 10% inoculum loading Alkaline pretreatment The highest RSY (45.69%) is using CaOH and NaOH found in bagasse pretreated NaOH after 48 h of enzymatic hydrolysis Microwave assisted The highest glucose yield of acid hydrolysis for 10 microwave assisted acid min at 550 W using hydrolysis is 80.80% 0.5% sulfuric acid Biological The highest RSY of pretreated pretreatment using bamboo using microwave T.versicolor assisted hydrolysis is 17.06% Microwave The highest RSY of pretreated pretreatment bamboo using microwave assisted acid hydrolysis is 25.81% Biological-microwave The highest RSY of pretreated pretreatment bamboo using microwave assisted acid hydrolysis is 16.65% Biological Pretreatment of OPF fiber pretreatment using incubated T.versicolor for 4 weeks gave the highest RSY (12.61% of dry biomass)
Lignin
Hermiati et al., 2013
10
Kraft pulp of sengon wood
Microwave assisted sulfuric and oxalic acid hydrolysis
Lignin
Fajriutami, Fariasari, and Hermiati, 2012
11
Sengon wood
Microwave assisted oxalic and sulfuric acid-glycerol pretreatment
Lignin
Risanto et al., 2011
12
Bamboo
Biological pretreatment using F.polustris and P.crysosporium
Lignin Hemicellulose
Fatriasari et al., 2012
The highest reducing sugar production by dilute sulfuric acid was 8.58 g/L, while the dilute oxalic acid was 4.94 g/L when the hydrolysis of sengon pulp was conducted over 10 min under 550 of microwave power The highest RSY of pretreated sengon wood by sulfuric acid was 34.68% irradiated for 10 min with 550 W of power level The highest sugar yield is obtained on bamboo pretreated by brown rot (F. polustris) of 11.157%
Some of biomass including wood and non woody materials have been explored to be converted into sugar and bioethanol
production with potential valuable bioproducts at RC Biomaterials LIPI (Table 4). Integrated research program in biorefiery
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concept at RC Biomaterials will build link and match among the research divisions at the research center. In the future, biomass such as oil palm empty fruit bunch (OPEFB) and sugarcane bagasse considering their abundancy and high cellulose content (Table 1) become main biomass to be converted into bioethanol as main products.
Rao, 2010). Xylitol is utilized in pharmaceuticals and food industries application due to high sweetening properties, non-and anticariogenicity property and microbial growth inhibition capacity (Hyvonen, Koivistoinen and Voirol, 1982; Edger, 1998). Xylitol is used as sugar substitute for diabetics (Hyvonen, Koivistoinen and Voirol, 1982) and for preventing acute otitis media (OAM) in children (Uhari, Kontiokari and Nieme la, 1998). Xylitol commanly is produced from xylan-rich biomass of agricultural and wood residues ( Menon , Prakash and Rao, 2010) through chemical and biological methods. The last method receives wider attention caused by utilization of mild process condition during yeast fermentation ( Menon , Prakash and Rao, 2010). Certain microbial species have potential to utilize xylose as carbon source by converting it to xylitol. Yeasts naturally produce xylitol as an intermediate during D-xylose metabolism (Verduyn et al., 1985). In RC for Biomaterials, xylitol has been also tried to be developed by fermentation of hydrolyzate for organic acid pretreatment of empty fruit bunch (OPEFB) using Candida tropicalis yeast.
Bioplastic or biodegradable plastic can be used to reduce the landfill problems caused by conventional plastics (Davis and Song, 2006). Acetylation of cellulose fibers is a common process in biodegradable plastic production. This plastic can be decomposed in soil or water within a few years. Furthermore, the material can be recycled, also, or incinerated without residue (Alexender, 1993). Biodegradable plastic from non wood and woody cellulose fibers has been succesfully approved for its uses as packaging in food and pharmaceutical industries (Mostafa et al. 2015). Since there are many routes to produce various final cellulose based final bioproducts by converting of lignocellulosic biomass, it is important to consider the techno-economic feasibility in the large scale production, and its environmental effects. Besides that, the use of engineered microorganisms in converting glucose and/or xylose into biethanol is a promising approach to increase efficiency and reduce bioethanol production cost (Sun and Cheng, 2002). In the commercial scale of fermentation operation it is important to maintain a stable performance of the genetically engineered yeasts (Dipardo, 2000).
As resulted from fractionation of lignocellulosic biomass, around 5 x 106 m3 tons of lignin has been produced by industry (Mai, Milstein and Huttermann, 2000) with major utilization for generating steam and energy (Mohan et al. 2006). So far industries have not utilized lignin as raw materials for other purposes through chemical conversion. (El Mansouri and Salvado 2006; Dorety Mousaviouna, and Fellows, 2011). To broaden the utilization of lignin, application of biorefinery concept will help to increase its economical prospective. Technical lignin can be obtained from some sources, by separation technique which will determine the properties. To minimize the problem in use of technical lignin, the depth analysis of the structure, composition and lignin features are needed (Vishtal and Kraslawski 20010). Basically, there are five technical lignin types based on the separation process including kraft lignin, soda lignin, organosolv lignin, acid and enzymatic hydrolysis lignin, and ionic liquid lignin. The diverse properties of them are resumed in Table 5.
Utilization of xylose containing in hydroxysate for xylitol production is to make more profitable bioethanol production to compete in commercial markets (Wyman, 1999). Selective separation of hemicellulose from biomass was conducted by using acids, water (liquid or steam), organic solvents and alkaline agents. Besides hemicellulose, biomass pretreatment using organic solvents or alkaline can remove lignin too. Furthermore, lignin or its derived compounds can inhibit the microbial growth during fermentation process ( Menon , Prakash and Rao, 2010). Xylose converted into value added xylitol (five-carbon sugar alcohol) can increase economic feasibility in cellulose bioconversion process (Menon , Prakash and
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Table 5. Technical lignin properties from hardwood, sofwood and non wood Parameter Kraft Soda Lignin* Hydrolysis Organosolv Lignin* Lignin* Lignin* Ash,% 0.5-3.0 0.7-2.3 1.0-3.0 1.7 Moisture content, 3.0-6.0 2.5-5.0 4.0-9.0 7.5 % Carbohydrates, % 1.0-2.3 1.5-3.0 10.0-22.4 1-3 Acid soluble 1-4.9 1.0-11 2.9 1-9 lignin, % Nitrogen, % 0.05 0.2-1.0 0.5-1.4 0-0.3 Sulphur, % 1.0-3.0 0 0-1.0 0 Molecular weight, 1.5001.000-3.000 5.000500-5.000 Mw 5.000 (up (up to 10.000 to 25.000) 15.000) Polydispersity 2.5-3.5 2.5-3.5 4.0-11.0 1.5
sources Ionic liquid Lignin* 0.6-2.0 0.1 1.5 Around 2.000 -
Source: Vishtal and Kraslawski (2011)
Kraft lignin produced from kraft pulping is 85% of total world lignin production (Tajado et al. 2007) which degraded into fragment with the different molecular weight in alkali spent liquor (Chakar and Ragauska 2004). Kraft pulping is the common process used to produce pulp having high yield and viscosity with low lignin content. Only 15.87% of kraft lignin is processed into other products and any application (El Mansouri and Salvado 2006). About 84.13% of kraft lignin is utilized for energy and process steam (Mohan, Pitmann and Steele 2006). Kraft lignin has ash content up to 30% (El Mansouri and Salvado 2006) with molecular weight varies within the range of 200 to 200.000 g per mole (Mork et al 1986; Niemela 1990).
from lignin is delivered in Fig. 7. In point of view of technological aspect in converting various types of technical lignin into bioproducts, it can be identified two major problems i.e heterogenous structure and unique reactivity of lignin (Vishtal and Kraslawski 2011). These problems can be overcome by chemical modifications. Utilization of lignin for biosurfactant such as lignosulphonate or directly application lignin as binder in concretes has been conducted at RC for Biomaterials LIPI (Falah 2012). Besides that, lignin is also incorporated in aqueous polymer isocyanate (API) system with natural rubber latex (NRL) as adhesive polymer (Hermiati et al.2015). This system is used for bioadhesives in laminated board and plywood at low temperature. However, it is still required to improve the composition of bioadhesive system to optimize the shear strength. Creating homogenous mixture between base polymers, filler and crosslinker is one approach to overcome this problem. Recently, we are developing the utilization of kraft lignin from hardwood for biosurfactant such as amphipatic lignin derivatives (A-LD). It will be used for improving the performance of cellulase enzyme to break down cellulose into its sugar monomer. A-LD can be produced by blending epoxylated poly ethylene glicol (PEG) with isolated lignin. Naturally, lignin has hidrophobic properties, and this reaction can facilitate to provide hydrophylic materials. In the future, the other prospective of biosurfactant system to substitute commercial surfactant will be developed.
Compared to the other technical lignin, ionic liquid and organosolv lignin have the lowest molecular weight and can be further dissolved in certain solvents. In certain application, it is needed high molecular weight of lignin. Non-wood lignin usually has lower molecular weight, high polydispersity and higher ash content compared to wood lignin (Vishtal and Kraslawski 2011). In polymer production, lignin should be sugar free, high lignin klason content and sulfur free (Lora and Glesser 2002). To obtain technical lignin, it is needed to separate it from the liquor. The selection method depends on the types of lignin. Precipation/pH change is a method to separate kraft and soda lignin, while ultrafiltration is common separation technique in kraft, soda, and hydrolysis lignin. Extraction by NaOH and filtration is used to recover hydrolysis lignin. To separate organosolv lignin, dissolved air flotation and precipation by addition of nonsolvent has been choosen. The last method is also used to separate ionic liqud lignin (Vishtal and Kraslawski 2011). The main derived bioproducts and their processes
10
Lignin Treatment method and their Bioproducts
Hydrogenolysis
Pyrolysis Thermal treatment No oxigen with or without catalyst
-Solid char -Phyrolysis oil -Gasses (CO, CO2)
Thermal treatment With hydrogen
Liquid monomeric phenol
Oxidation
Gasification
Thermal treatment With oxigen
Aldehyde (vanilin, syringaldehide)
Heat solid lignin breakdown
Biogas H2, CO, CO2, CH4
Combustion With oxygen
-heat -Gasses -Solid char
Figure 7. Lignin process conversion into bioproducts. Source: Welker et al., 2015
Concluding Remaks
References
Fractionation of lignocellulosic biomass for cellulose, hemicellulose and lignin separation is a crucial step before further converted into derived bioproducts. In term of biorefinery concept, these bioproducts derived from biomass will facilitate to obtain the effeciency of conversion process. It also leads in improving value-added of biomass. The selection of the feedstock, methods, and targeted bioproducts are factors which determine feasibility of lignocellulosic biomass conversion. As intermediate bioproducts from cellulose, pulp can be utilized as raw materials for paper, bioethanol, bioplastic, WPC, rayon etc. Different kinds of biomass have been used as feedstocks for producing sugars and bioethanol at RC Biomaterials, LIPI. To increase its efficiency, the utilization of “waste” biomass such as OPEFB is more useful. Kraft lignin dominates technical lignin production which can be converted into aromatics, carbon fiber, bioadhesives, biosurfactant, antioxidants, binders, energy etc. Xylitol is main bioproduct resulting by fermentation of xylose. RC for Biomaterials LIPI will also focus its research in developing the production of valuable bioproducts for applying biorefinery concept in the second generation of bioethanol. In the future, studies in this area will grow intnesively with the main challenge in scaling up the stable process and bring the bioproducts into market.
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J. Lignocellulose Technol. 01 (2016), 15-25
Journal of Lignocellulose Technology Journal homepage: http:/ejournal.lipi.go.id/index.php/jol/
Review
Diversifikasi serat pulp untuk produk inovatif Wawan Kartiwa Haroen* Center for Pulp and Paper- Indonesian, Ministry of Industry, *Corresponding author:
[email protected] Received: 1 Desember 2016. Received in revised form: 16 Desember 2016. Accepted: 21 December 2016. Published online: 23 December 2016
Abstract Fiber pulp from wood or non-wood is generally used as a raw material for cultural paper, special purpose paper, commercial paper industry or similar derivatives. In fact, natural cellulose fiber pulp is free from carsinogenic substance when it is compared to other fibers such as asbestos fiber and glass fiber, so the applications of the pulp fiber into new innovative product provide new eco-friendly advance material. Research on pulp fibers for inovative products in our research group were summarized in this review. Non-asbestos brake linings vehicles were comercially produced from pulp fiber composite and have been patented. Health care products, such as diapers, from kenaf fluff fiber is on going to be patented soon. We also reported here the development of diverse application of pulp fibers as degradable media for seedlings, natural fillers for orthopedic components and energy sources such as briquettes and bio-oil from pyrolisis extraction. These research are of importance to increase the value-added of pulp fibers for various applications Keywords : Brake, diapers, fiber pulp, innovative product, non-asbestos
Pendahuluan Serat pulp diperoleh dari hasil pemisahan serat selulosa berasal dari bahan baku kayu maupun bukan kayu melalui proses pulping secara kimia, semikimia, mekanis atau biologi. Serat pulp terdiri dari selulosa dan hemiselulosa sebagai bahan utama pada pembuatan kertas atau rayon. Perkembangan teknologi serat pulp saat ini dapat dijadikan sebagai bahan produk lainnya yang memiliki nilai manfaat lebih tinggi, namun penggunaan seratnya lebih sedikit sebagai bahan pengisi atau lainnya. Produk serat pulp selain untuk kertas menjadi produk lainnya selanjutnya disebut diversifikasi produk serat pulp.
Beberapa pakar dalam UCEO (2015) menjelaskan pengertian tentang diversifikasi produk : 1. Kotler mendefinisikan diversifikasi produk merupakan cara untuk meningkatkan kinerja bisnis yang ada dengan jalan mengidentifikasi peluang bisnis menarik yang tidak berkaitan dengan bisnis perusahaan saat ini. 2. Effendi menyebutkan diversifikasi produk adalah suatu perluasan pemilihan barang dan jasa oleh perusahaan dengan menambah produk baru dalam rangka memperoleh laba maksimal.
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rock wool, selulosa dan serat karbon yang memiliki serat panjang, sedangkan kampas rem dari bahan asbestos hanya memiliki 1 jenis fiber yaitu asbes dan bahan tersebut dapat memicu pertumbuhan sel kanker (karsinogen). Perbedaan karakteristik serat tersebut menyebabkan kampas rem asbestos memiliki kelemahan pada kondisi basah, karena hanya memiliki 1 jenis fiber. Dalam kondisi basah bahan tersebut akan mengalami efek licin (loss/tidak pakem). Sedangkan kampas rem berbahan non asbestos (serat pulp) memiliki beberapa jenis serat, maka efek licin dapat teratasi. Karena kampas rem asbestos menggunakan campuran maksimal 6 jenis material sedangkan kampas berbahan serat pulp menggunakan 9-10 jenis material. Ketahanan terhadap panas akibat pengereman asbestos bertahan sampai suhu 200 oC sedang non asbestos bertahan lebih 300 oC, berarti asbestos akan blong (fading) pada temperatur 250 oC sedang non asbestos lebih stabil (tidak blong). Harga jual kampas rem asbestos relatif murah, karena bahannya dari 6 jenis material sedangkan non asbestos terbuat dari material yang banyak dan berkualitas seperti serat kevlar atau serat aramid yang bisa mengurangi putaran rotor atau drum kendaraan bermotor secara sempurna. Debu kampas rem asbes sangat ringan dan mudah menempel di pelek dan susah dibersihkan sedang debu non asbestos (serat pulp) lebih berat, tidak menempel di pelek dan mudah dibersihkan. Selain itu, debu asbestos sangat ringan mudah terhirup bersama udara dan akan menempel di tangan dan dimungkinkan dapat masuk dalam sistem pencernaan sehingga dapat menjadi memicu kanker (Paten. ID P0029623). Gambar 1 menunjukkan tipe cakram dan tipe tromol pada kampas rem serat pulp.
3. Tjiptono menjabarkan diversifikasi produk sebagai upaya mencari dan mengembangkan produk atau pasar yang baru, atau keduanya, untuk mengejar pertumbuhan, peningkatan penjualan, profitabilitas dan fleksibilitas. Diversifikasi produk pulp merupakan strategi berkaitan dengan produk utama (kertas), yang dirubah menjadi produk lain atau penganekaragaman produk selulosa untuk memperluas pemanfaatan serat pulp yang memiliki nilai tambah melalui inovasi teknologi sejalan dengan perkembangan Iptek (Ilmu Pengetahuan dan Teknologi). Beberapa pakar dalam UCEO (2015) menjelaskan tentang pengertian mengenai inovasi berikut ini: -
-
Everett M. Rogers mendefinisikan inovasi sebagai sebuah gagasan, ide, rencana, praktek atau benda yang diterima dan disadari sebagai hal yang baru dari seseorang atau kelompok untuk di implementasikan atau diadopsi. Stephen Robbins menjelaskan bahwa inovasi adalah sebuah gagasan atau ide baru yang diterapkan untuk memperbaiki suatu produk dan jasa.
Sifat dari inovasi harus mempunyai 4 ciri utama antara lain : 1. 2. 3. 4.
Ciri yang khas Unsur kebaruan Program yang terencana Mempunyai tujuan akhir yang jelas
Penelitian dasar, laboratorium dan tahap aplikasi skala produksi terhadap diversifikasi serat pulp untuk produkproduk inovatif telah dilakukan sejak tahun 1998 di Balai Besar Pulp dan Kertas, sampai saat ini masih dilanjutkan penelitian dan pengembangan tentang diversifikasi serat pulp untuk produk selain kertas. Walaupun demikian masih terdapat berbagai kendala, diantaranya minimnya dukungan pemegang kebijakan untuk pengaplikasian hasil penelitian kami secara luas. Pada tulisan ini diuraikan sebagian aplikasi serat pulp untuk produk inovatif seperti kampas rem pulp, fluff untuk diapers, media pot pembibitan, pulp semen board, bahan uang kertas uang, pengisi orthopedi, arang briket limbah pulp dan pirolisis cepat.
Kampas rem organik Tipe atau jenis kampas rem yang dibuat pada penelitian ini mengarah kepada kampas rem organik, yaitu kampas rem yang terbuat dari selulosa diinteraksikan bersamaan dengan material lain menggunakan phenolic resin yang tahan panas. Organic pad pada awalnya menggunakan asbestos untuk mendapatkan ketahanan terhadap panas yang lebih baik, namun sejak abestos diketahui dapat menyebabkan timbunya sel kanker, maka serat kevlar, serat gelas dan mineral fillers lebih banyak digunakan sebagai pengganti asbestos. Organic pad
Kampas rem serat pulp Kampas rem yang terbuat dari bahan non asbestos (kampas rem pulp) terdiri dari 4-5 macam fiber seperti kevlar, steel fiber,
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memiliki coefficient of Friction (COF) yang bagus agar pedal menjadi lebih ringan, bekerja secara baik pada temperatur rendah dan tidak menimbulkan kebisingan. Organic pad tidak bekerja dengan baik pada kapasitas pemakaian yang tinggi dimana pada suhu yang tinggi, bahan kampas mudah teroksidasi, mudah menjadi hancur dan akhirnya bahan cepat habis.
Pengujian tahap pertama terhadap daya gesek dan koefisien gesek dengan kuantitas mulai 1 kali sampai dengan 20 kali pemakaian, pada kampas rem jenis 1 dan kampas rem jenis 2 menunjukkan kekuatan yang hampir sama (Table 1). Hal ini menunjukkan bahwa pulp memiliki daya gesek dan koefisien gesek hampir sama pada jumlah pulp yang ditambahkan pada jenis 1 atau jenis 2, walaupun terdapat perbedaan dari kedua jenis tersebut, nilainya tidak berpengaruh terhadap kinerja kampas rem tersebut.
Hasil pengujian kampas rem serat pulp
Tabel 1. Hasil uji kampas rem pulp tahap 1 Tahap (menit)
Daya. (N)
Daya gesek (N)
Suhu (oC)
1
1 584
2 587
1 296
2 256
1 90
2 67
5 10
579 578
518 564
287 291
291 274
88 111
15
585
549
310
289
20
590
540
319
293
Koefisien gesek 1 0,51
2 0.49
Keterangan
68 92
0,50 0.50
0.47 0.49
Kekerasan kampas rem 6,7 – 7,5
90
91
0,53
0.53
95
92
0,54
0.53
Gambar 1. Kampas rem serat pulp tipe cakram (kiri) dan tromol (kanan)
Selanjutnya, pengujian tahap kedua dilakukan pada kampas rem setelah digunakan pada tahap pertama. Pada pengujian ini menunjukkan pemakaian ke1 sampai dengan ke-8 terjadi perbedaan daya gesek jenis 1 lebih baik dari pada jenis 2. Suhu pada jenis 2 lebih tinggi dengan koefisien gesek yang menurun. Kampas rem dengan bahan pulp setelah diistirahatkan pada pemakaian kedua dilakukan pengujian kembali dengan hasil seperti pada Tabel 2.
temperatur. Hasilnya menunjukkan nilai yang sama sehingga dapat disimpulkan bahwa komposisi pulp jenis 1 dan jenis 2 untuk pemakaian ke-100 kali memberikan kinerja pengereman yang baik. Lebih lanjut, dilakukan juga pengujian terhadap kampas rem pulp setelah pemulihan tahap 1 dan 2 dengan 5 kali percobaan. Hasil pengujian memperlihatkan bahwa daya gesek kampas rem jenis 1 dan 2 masih memperlihatkan daya gesek pada suhu 250-311 oC dengan nilai koefisien gesek masih berada pada kisaran 0,4-0,5 (Haroen, Sudarmin dan Triwaskito, 2013). Gambar 2 menunjukkan ilustrasi kampas rem pulp pada penampakkan SEM dan X-ray mapping.
Uji coba pemakaian kampas rem serat pulp dilakukan pada pemakaian ke-1 sampai pemakaian ke-100 terhadap daya gesek, koefisien gesek dan perubahan
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Tabel 2. Hasil pengujian kampas rem serat pulp pemakaian ke-1 sampai pemakaian ke-100 Pengujian Koefisien gesek (100 oC) Koefisien gesek (150 oC) Tingkat kehasusan (100 oC) Tingkat kehasusan (150 oC) Kekerasan Klasifikasi Klasifikasi penggunaan
Jenis 1
Jenis 2
Rem Komersil
SNI 09-0143-1987
0.30 0.27 0.48 0.41 10.2 Tipe 1 1B
0.24 0.23 1.95 0,40 9.5 Tipe 1 1B
0.25 0.21 1.03 0.49 8.7 Tipe 1 1B
0.30-0.60 ±0.10 0.25-0.60 ±0.10 1.02 ±0.10 02.04 ±0.10 Tipe 1 1B
Penggunaan formula resin rendah pada kampas rem menggunakan cetakan positif
senyawa chlorine dan oksigen (ClO2) dengan tidak menggunakan chlorine murni (gas chlorine Cl2). Pada proses ECF, penggunaan senyawa chlorine diminimalisasi sehingga menjadikan proses ini ramah lingkungan dan menghasilkan derajat putih serat fluff yang tinggi dan kekuatan fisik serat fluff baik.
Hasil pengujian untuk pemakaian resin rendah dengan cetakan positif pada rem cakram memperlihatkan kampas remnya tidak terjadi fading saat pengereman. Hal ini berarti cetakan positif (Positive Mold) merupakan cara yang tepat untuk memproduksi rem cakram, proses ini banyak digunakan pabrik kampas rem OEM (asli pabrikan). Selama proses kempa panas cetakan positif, bahan baku kampas rem diletakan ke dalam celah cetakan dari dies kempa panas kemudian dikempa dengan alat penekan untuk mejaga kepadatan pada kampas rem. Beberapa produk kampas rem ada yang mempergunakan sistim proses flash mold karena harga cetakannya yang lebih murah, namun kandungan resin dan material kampas rem harus berlebih supaya resin dapat mengalir keluar. Kandungan resin yang tinggi membuat kampas rem mudah blong pada temperatur tinggi (fading). Proses fading menyebabkan jarak pengereman bertambah lebih dari 50% sehingga menyebabkan kecelakaan. Salah satu penyebabnya adalah karena pemakaian serat asbes dan komposisi resin tinggi 15-20%, sehingga saat suhu pengereman tinggi maka kampas rem menjadi licin. Sedangkan pada kampas rem non asbestos kandungan resinnya lebih rendah 9-10% dan non asbes (selulosa) yang dapat mengurangi suhu pengereman dan mengatasi terjadinya fading (Haroen, 2009; Haroen dan Sudarmin, 2009). Fluff Pembuatan fluff dari serat pulp diperoleh melalui proses pulping secara kimiawi dan selanjutnya diputihkan dengan proses ECF (elementally chlorine free). Proses pemutihan dapat menggunakan
Gambar 2 . Foto SEM dan x-ray mapping kampas rem pulp
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menolak air (hidrofobik). Kandungan lignin yang masih tinggi pada fluff dapat menyebabkan daya serap air yang rendah dan kecerahan pulp gelap karena gugus kromofor. Pemutihan fluff bertujuan untuk meningkatkan kecerahan yang lebih stabil dan terlihat higenis bagi penggunanya (Haroen dan Hidayat 2009; Anonim, 2013). Persyaratan fluff yang baik diantaranya memiliki kandungan ekstraktif yang rendah, derajat putih yang tinggi dan kandungan selulosa alfa diatas 80% (Haroen, 2005). Pulp fluff kenaf memiliki ektraktif 0,01 0,07 % lebih rendah dibandingkan pulp fluff dan diapers komersial 0,1 – 0,3%. Hal ini menunjukkan bahwa fluff kenaf memiliki kualitas setara dengan fluff komersial. Kandungan selulosa alfa fluff dari serat kenaf berada pada kisaran 80 – 90 %. Hal ini mengindikasikan bahwa selulosa pada fluff serat kenaf dapat berfungsi sebagai media penyerap yang baik. Sifat ini juga memperlihatkan bahwa fluff kenaf dapat menyerap cairan secara optimal untuk dipergunakan sebagai diapers. Sisa khlorine pada fluff dari serat kenaf yang rendah, ditunjukan dengan kandungan AOX lebih kecil dari 0,1 yang mengindikasikan bahwa serat fluff ini aman dipergunakan jika bersentuhan dengan kulit, meminimalkan timbulnya iritasi dan alergi pada kulit pemakainya.
Gambar 3. Foto SEM serat fluff kenaf dan lembaran fluff untuk diuji
Gambar 3 memperlihatkan serat fluff kenaf dan contoh lembaran diaper ketebalan 10 mm untuk lakukan pengujian daya serap cairannya. Serat kenaf yang diproses menjadi pulp fluff menghasilkan rendemen 61,83 - 63,10%, dengan bilangan Kappa (KN) 9,08-10,96. Penggunaan alkali aktif yang tinggi akan mempengaruhi rendemen dan bilangan kappanya, karena lignin, selulosa dan hemiselulosa dapat terdegradasi sempurna.
Rendemen dan Bilangan Kappa pulp fluff kenaf 70
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KN menunjukkan tingkat kematangan pulp, nilai KN yang tinggi dapat diasumsikan lignin yang tersisa pada pulp masih tinggi, hal ini dapat berakibat pada proses pemutihan. Pemakaian alkali aktif yang semakin tinggi, lignin yang terdegradasi lebih baik dan nilai KN semakin rendah. Pemasakan optimum serat kenaf untuk fluff diperoleh pada pemakaian alkali aktif 14%. Fluff kenaf 14 seperti terlihat pada Gambar 4 memperlihatkan Rendemen pulp tersaring tinggi, dengan reject dibawah 10% dan tingkat kematangan pulp (KN)10 sesuai untuk pulp fluff. Pemakaian kimia pemasak 14%, tergolong rendah akan sesuai dengan pemakaian energi rendah, biaya produksi lebih ekonomis dan kualitas pulp fluff memenuhi syarat seperti pada Tabel 3.
50 40 R.Total R.Saring
30
Reject KN
20
10 0 PK-12
PK-14
PK-16
Contoh fluff
Gambar 4. Rendemen pulp dan bilangan kappa fluff kenaf Tabel 3. Karakteristik fluff dari senat kenaf Komponen
Kenaf
Fluff Stora Fluff
Extraktif , % 0,01- 0,07 Selulosa α, % 90,11 Viscositas, cp 4,76 PH 6,5 Kadar air , % 9,2 AOX , kg/ton (TOX) 37 ppm Noda , % 5
Pemutihan fluff Lignin pada fluff perlu dihilangkan untuk meningkatkan daya serap cairan, hal ini berhubungan dengan sifat lignin yang
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Diapers Komersil
0,15 - 0,30 82,67- 86,87 6,78- 6,87 6,0 8,0 <0,1
0,1 85 - 90 -
3-8
-
Morfologi fluff dari serat kenaf
dalam rongga selulosa pada jumlah tertentu. Jumlah air yang terjebak di rongga selulosa disebut kemampuan daya serap maksimum selulosa terhadap air (Haroen, 2005). Pengamatan daya serap cairan fluff kenaf hasil dari penelitian kami dikategorikan memiliki daya serap yang sama dengan daya serap fluff kualitas impor (Tabel 4). Kemampuan daya serap fluff kenaf berbeda-beda nilainya, hal ini disebabkan oleh penguraian serat (defiberizing) yang berbeda. Daya serap optimal ditemukan pada pulp fluff yang penguraiannya menggunakan penggaruk (shredder) dibandingkan dengan willeymill. Serat fluff diuraikan oleh willeymill seratnya lebih halus dan banyak terpotong sehingga daya serapnya berkurang, sedangkan penguraian menggunakan penggaruk seratnya lebih terbuka dan utuh. Daya serap fluff kenaf berkisar 7,03-9,20 g/g, setara dengan Stora fluff impor yang berkisar antara 8,0-9,5 g/g. Penambahan super absorbent polymer (SAP) pada fluff sebanyak 10-30% terhadap berat fluff menunjukkan pengaruh terhadap peningkatan daya serap cairan.
Gambar 5 menunjukkan bahwa fluff dari serat kenaf memiliki panjang rata-rata 2,98 mm, berdasakan klasifikasi Klemm (Haroen, 2016) termasuk serat panjang (>1,96 mm). Serat fluff yang dihasilkan dari hasil penelitian ini sebanding dengan serat produk stora fluff dan serat diapers komersial. Panjang Serat Fluff 5 4.5 4
Panjang, mm
3.5 3
Min
2.5
Maks
2
Rata2
1.5 1 0.5 0 Kenaf
Stora fluff
Diapers
Gambar 5. Panjang serat fluff kenaf
Panjang serat adalah salah satu syarat penting untuk produksi bahan fluff dimana fluff dari serat kenaf yang telah diproduksi dapat memenuhi persyaratan sehingga dapat dipertimbangkan sebagai bahan substitusi fluff impor. Selain serat kenaf, serat kapas merupakan pilihan utama sebagai bahan penyerap (diapers), karena memiliki daya serap tinggi dan permukaan kontak dengan air yang lebih luas. Serat dengan panjang > 1,96 mm memberikan permukaan kontak yang luas, ikatan antar serat kuat dan daya serap cairan tinggi (Haroen, 2004a, 2004b, 2004c).
Daya serap sangat berkorelasi positif dengan jumlah SAP yang ditambahkan, karena SAP berfungsi memperbaiki kemampuan daya serap, semakin tinggi kandungan SAP maka daya serap fluff dapat ditingkatkan mencapai 75 %. Penambahan 30% SAP pada fluff kenaf meningkatkan daya serap sampai 95,54 % (Haroen, 2004a, 2004b, 2004c). Sehingga dapat disimpulkan bahwa daya serap fluff dari serat kenaf dikategorikan memiliki prospek yang menjanjikan untuk produk diapers.
Daya serap fluff kenaf
Volume spesific fluff kenaf
Parameter utama fluff adalah kemampuan daya serap cairan tinggi agar dapat dipertimbangkan sebagai substitusi fluff impor. Serat selulosa kering umumnya memiliki kemampuan menyerap air (higroskopis) dari sumber apapun, namun sangat sulit untuk mendapatkan kemurnian selulosa 100%. Untuk menghilangkan kadar air 1% pada serat selulosa akan diikuti kerusakan struktur molekul selulosanya (Anonim, 2013). Penyerapan air pada fluff dikelompokkan menjadi 3 kategori antara lain air yang terikat (adsorpsi), air yang terserap (absorpsi) dan air kapiler jumlah air terikat dan terserap sekitar 30% dari berat, disebut sebagai titik jenuh serat. Fluff serat kenaf memiliki daya serap air yang terbatas, penyerapan cairan diawali oleh interaksi ikatan hidrogen dengan gugus OH selulosa dan molekul air, kemudian air terjebak
Volume spesifik fluff adalah banyaknya serat dalam satuan volume persatuan berat. Semakin tinggi nilainya berarti semakin fluffy (ruah). Volume spesifik fluff kenaf diuraikan dengan willey mill atau penggaruk menghasilkan volume spesifiknya antara 5,80 - 7,84 cm3/g, nilai ini tidak banyak dipengaruhi oleh proses pemasakan atau pemutihan tetapi dipengaruhi oleh penguraian fluffnya (Haroen dan Sudarmin, 2005) (Tabel 5). Penguraian serat fluff menggunakan willeymill volume spesifiknya lebih rendah dibandingkan dengan penguraian menggunakan penggaruk (Haroen, 2004a, 2004b, 2004c); Haroen dan Sudarmin 2012). Pengujian volume spesifik dapat mempengaruhi pembentukan rongga antar serat. Semakin banyak rongga antar serat yang terbentuk maka kemampuan
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daya serap cairannya semakin tinggi (Haroen dan Posma, 2009; Haroen, Panggabean and Wistara, 2009).
penguraian menggunakan penggaruk serat fluff yang terurai masih utuh dan terbuka, sifat ini diperlukan pada lembaran fluff untuk diapers. Volume spesifik fluff lebih tinggi atau ruah akan menghasilkan daya serap yang baik. Sedangkan penguraian fluff menggunakan Willey mill menyebabkan serat banyak terpotong dan berdebu sehingga volumenya lebih padat dan rongga kosong yang terbentuk lebih kecil, hal ini akan berakibat daya serap cairan yang rendah (Tabel 4)
Penguraian fluff menggunakan alat willey mill dan penggaruk, memberikan pengaruh terhadap volume spesifik saat pembentukan lembaran kering sebagai media penyerap. Semakin tinggi nilai volume spesifik menunjukkan fluff memiliki ruang kosong lebih luas dan berfungsi sebagai media penyimpan cairan. Artinya
Tabel 4. Daya serap cairan fluff Absoption capacity (g/g) 30 menit Willeymill + SAP, % 10 20
Contoh 0 Kenaf-12 Kenaf-14 Kenaf-16
30
0
7,03 9,12
10,76 12,10
11,98 14,62
13,78 15,49
9,11
13,63
15,07
16,42
Storafluff Diapers komersil
Penggaruk + SAP , % 10
9,05 9,20
12,17 14,10
9,03
14,63
20 13,08
30
16,62
14,90 17,99
16,47
18,78
8,0 - 9,5 8,6 -15.9
SAP100%
25 – 30
Tabel 5. Volume spesifik fluff serat kenaf Specific volume (cm3/g) Willey mill
Contoh Uji 0 Kenaf-12 Kenaf-14 Kenaf-16 Stora Fluff
5,80 5,85 5,80
+ SAP, % 10 20 6,20 6,22 6,27
6,82 6,87 6,85
Diapers Komersil
Penggaruk + SAP , % 30
0
6,97 7,24 7,01 7,28 6,98 7,27 3/ 6 -19 cm /g
10
20
30
7,58 7,66 7,64
7,69 7,72 7,74
7,73 7,84 7,81
7,3 - 21,2 cm3//g
pembibitan. Hasilnya pot bibit tanaman dapat ditanam bersama tanaman di lokasi hutan atau perkebunan. Produk pot bibit ramah alam karena pot tidak perlu dibuka saat penanaman dan dapat hancur dengan mikroba tanah di lokasi hutan atau perkebunan bahkan media pot dapat dipadukan menjadi media pupuk secara bersamaan sehingga berfungsi sebagai pupuk hijau (Haroen, Sumaryuwono dan Tatang 2012; Kardiansyah, 2015). Kekurangannya saat pengangkutan memerlukan tempat berlebih, karena sifatnya ruah dibandingkan kantong plastik polybag. Hasil produk penelitian ini (Gambar 6) sedang dalam proses penulisan paten.
Media Pot Bibit Tanaman Wadah bibit tanaman ramah alam merupakan salah satu usaha untuk mendukung kelangsungan tanaman di hutan, perkebunan dan pertanian. Saat ini wadah pembibitan menggunakan plastik hitam (polybag) yang terbuat dari bahan polimer umumnya polipropilena atau polietilena yang tidak dapat terdegradasi dengan mudah sehingga penyemaian bibit tanaman memerlukan penanganan pemindahan bibit pada saat bibit siap tumbuh dewasa. Pemindahan bibit dari polybag harus dibuka, limbahnya dibuang atau sebagian dimanfaatkan. Untuk menanggulangi permasalahan polybag tersebut dilakukan upaya pemanfaatan serbuk/limbah kayu menjadi media
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Indonesia, serat alam yang memiliki sifat tersebut belum dimanfaatkan. Data tahun 2014 menyebutkan bahwa bahan kertas uang rupiah yang beredar di Indonesia diperoleh dari Inggris, Perancis, Jerman dan Belanda. Percetakan Uang Republik Indonesia (PERURI) bertugas mendesain, menyediakan tinta cetak dan memproduksi uang pesanan Bank Indonesia. Bahan kertas uang diutamakan memiliki serat panjang, fleksibel, mudah direfining, kekuatan fisik optimal dan tahan lama. Syarat lainnya antara lain diterima secara umum, tahan lama, kualitasnya sama, tidak mudah dipalsukan, mudah dibawa, mudah dibagi tanpa mengurangi nilai. Menurut Direktorat Akunting dan Sistem Pembayaran Bank Indonesia mengimpor kertas uang 5.000 ton/tahun senilai + 475 Milyar dari Inggris, Perancis, Jerman dan Belanda. Indonesia memiliki sumber daya manusia dalam pengolahan pulp kertas dan sumber daya alam penghasil serat kapas atau serat lainnya yang memenuhi syarat sebagai bahan baku kertas uang. Penelitian harus diarahkan dan memenuhi persyaratan kertas uang yang meliputi :
Pulp Cement Board (PCB) Papan partikel merupakan papan buatan sebagai subsitusi papan kayu, papan partikel umumnya digunakan untuk perumahan atau mebel. Papan partikel penganti ini sangat dianjurkan untuk digunakan (eco-green) karena dapat mengurangi penebangan kayu dari hutan
Gambar
6. Media pot bibit tanaman dari lignoselulosa
Papan partikel yang dibuat dari serat pulp mekanis dengan bantuan dari JICA Jepang menghasilkan papan partikel dengan pulp mekanis yang disebut dengan pulp cement board (PCB) atau papan semen pulp (Haroen, Santosa dan Supratman, 2007). Produk ini telah dikembangkan dengan Balai Penelitian Pemukiman yang lebih memiliki kompetensi dalam bidangnya. Penelitian lainnya yaitu pemanfaatan limbah proses penyulingan minyak kayu putih berupa limbah ranting dan daun. Limbah tersebut dibuat papan partikel dengan tambahan aditif pengikat tertentu dan dicetak dengan proses panas hasilnya berupa papan partikel serat kayu putih yang saat ini masih dilakukan penelitian lanjutannya (Haroen, Santosa dan Supratman 2007; Haroen, Sumaryuwono dan Tatang, 2012; Kondo et al., 1993).
1. 2. 3. 4. 5. 6.
Tensile strength (indeks tarik) tinggi Tearing strength (ketahanan sobek) Folding endurance (ketahanan lipat) Tahan lama (durable) Tidak mudah hancur dan luntur Penambahan zat kimia tertentu untuk menghindari pemalsuan
Kertas Uang Kualitas Tinggi Uang kertas menurut penjelasan UU No. 23 tahun 1999 tentang Bank Indonesia adalah uang dalam bentuk lembaran terbuat dari bahan kertas atau bahan lainnya. Kertas uang dan kertas biasa secara spesifik dibedakan dari sifat fisik, bahan dan prosesnya contohnya dapat dilihat pada Gambar 7. Faktanya saat uang kertas terlipat, kertasnya tetap utuh tidak sobek dan tahan sampai 3.500 kali lipat (double folds). Hal ini berarti uang tersebut tahan ditekuk 3.500 kali. Disamping itu uang kertas memiliki aspek keamanan yang sangat kompleks. Kertas uang yang memenuhi syarat dibuat dari 100% serat panjang halus, elastis dan kuat. Di
Gambar 7. Lembaran kertas uang
Pulp Pengisi Orthopedi Serat pulp putih dapat diaplikasikan sebagai pengisi dan penguat orthopedi, untuk menggantikan serat karbon, serat
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gelas, serat asbes atau serat lainnya yang harganya lebih mahal. Penelitian diutamakan pada pemilihan jenis dan komposisi pulp untuk menghasilkan produk layak pakai dan memenuhi standar orthopedi. Standar umum produk orthopedi yaitu ringan, tahan air, mudah dibentuk, berisi serat, kuat menahan beban dan nyaman digunakan. Aplikasi serat pulp untuk bahan pengisi orthopedi dapat menambah kekuatan ikatan dengan perekat, mudah diuraikan, dan harga serat lebih ekonomis dibandingkan serat lainnya. Pembuatan orthopedi pada saat ini umumnya menggunakan bahan serat seperti serat gelas, serat karbon, serat plastik dan serat asbes dengan perekat dari campuran plastik, resin dan HDPE. Produk orthopedi yang berkualitas dan memiliki nilai estetika menyerupai organ tubuh aslinya, masih diimpor dari Amerika, Inggris, jepang dan China. Pengadaan orthopedi untuk memenuhi para penyandang difabel diperlukan. Penelitian diarahkan untuk pembuatan orthopedi berbahan baku serat pulp dengan biaya ekonomis dan kualitas standar (Gambar 8). Kementerian kesehatan menyebutkan bahwa sumber daya manusia Indonesia yang memiliki keterampilan membuat dan mengembangkan prostetik (pengganti anggota tubuh) dan orthosis (penyangga tubuh) masih sangat terbatas.
Gambar 9. Produk briket arang limbah proses minyak kayu putih
Hasil uji briket arang dari kayu dan daun limbah proses detilasi kayu putih yang dibandingkan dengan bahan lainnya (Tabel 6). Nilai kalornya 15 kJ/g dengan unsur karbon yang lebih rendah yaitu 38% dibandingkan dengan kayu normal. Dari segi manfaat, limbah destilasi proses kayu putih mesih memiliki energi yang berguna untuk dimanfaatkan. Sampai saat ini limbah tersebut masih belum dimanfaatkan dan untuk sampah padat menunggu pelapukan secara alami. Tabel 6. Nilai kalor limbah kayu putih Jenis Bahan Bakar Limbah kayu putih Kayu * Arang * Batu bara * Minyak tanah *
Komposisi (%) C H O 38 50 100 77 85
6 0 5 12
Nilai kalor (kJ/gr) 15
44 0 7 0
18 34 32 45
* Sumber : ESDM (2008)
Limbah dari proses pulping kertas yang mengandung palstik dimanfaatkan sebagai bahan bakar. Hasilnya bahwa pelet plastik limbah sisa industri kertas sebanyak 1415% mengandung 85% serat halus pulp kertas. Pelet ini menghasilkan nilai kalor 7,50-8,73 Cal/g dengan kadar sulfur 0,150,17 % (Setiawan et al., 2015)
Gambar 8. Produk orthopedi berpenguat serat pulp
Energi alternatif dan absorben
Briket arang
Limbah padat dari limbah pulp dapat dipergunakan untuk subtitusi energi melalui proses gasifikasi (pirolisis). Tahapan pirolisis meliputi pengeringan, pengempaan dan pengeringan termal. Penambahan serbuk batu-bara dapat memudahkan pengeringan dan manambah nilai kalor. Sludge cake dipirolisis menghasilkan arang dan zat volatil, gasifikasi steam model suplai panas dari luar (alothermal) menghasilkan gas bakar dengan nilai kalor 11 MJ.Nm-3. Hasil penyediaan sekitar 95 kg/ton CaO dan konsumsi gas bumi 218 Nm3/ton CaO untuk lime kiln. Maka bahan bakar hasil gasifikasi sluge cake dapat mengantikan
Pembuatan bahan bakar dari sisa atau limbah tanaman berserat yang dipadatkan, dan ditambah bahan pengikat dan kemudian dikeringkan produknya disebut briket arang. Limbah daun dan ranting kayu putih (Eucalyptus sp) dihancurkan sampai homogen ditambah pengikat tertentu, dicetak bentuk kotak atau bulat kemudian dikeringkan dengan matahari atau oven setelah mengeras produknya menjadi briket arang (Gambar 9). Hasil uji awal briket arang memiliki nilai kalor 13 kJ/g, dibandingkan dengan bahan bakar kayu lebih rendah namun masih memiliki nilai panas yang berarti (Kondo et al., 1993).
23
18% gas bumi di industri pulp kertas ( Syamsudin dan Susanto, 2011)
Sinergisitas dalam mengatasi permasalahan dalam penelitian sesuai dengan program prioritas nasional (produktifitas dan daya saing) Komersialisasi hasil penelitian
Limbah padat berupa serat selulosa dari industri kertas memiliki nilai kalor 5.000-7.000 kal/g berpotensi sebagi bahan bakar. Pembuatan pelet dari limbah padatan industri kertas melalui pemadatan dan solidifikasi menjadi bahan bakar alternatif. Variasi penambahan batu bara 550% pada limbah industri kertas dapat digunakan untuk boiler tanpa terbentuk slagging dan fouling pada boiler. Kualitas emisi hasil pembakaran dengan konsentrasi SO2, NOx dan Cl2 dapat memenuhi baku mutu emisi boiler (Syamsudin dan Susanto, 2014).
Ucapan Terima Kasih Terima kasih penulis sampaikan kepada rekan peneliti dari Balai Besar Pulp dan Kertas, yaitu Dr.Syamsudin, Dr. Hendro Risdianto, Krina Aditya, dan Teddy Kardiansyah. Daftar Pustaka Anonim. (2013). Biodegradable diapers from recycled cardboard. VTT Technical Research Centre of Finland, pp. 34 -40.
Limbah padat industri pulp kertas, selain untuk sumber energi dapat pula digunakan sebagai bahan absorben yang penelitiannya masih berlangsung samapai saat ini. Limbah lumpur serat kertas dimanfaatkan sebagai absoben untuk menyerap tumpahan cairan hidrophobik di perairan seperti minyak. Sebelum dipergunakan untuk absorben, limbah industri kertas diberikan perlakuan awal antara lain: perlakuan mekanis untuk memperluas permukaan dan proses silanisasi untuk meningkatkan sifat hidrofobik limbah sehingga dapat meningkatkan daya serap terhadap material hidrofonik. Hasil yang diperoleh dapat meningkatkan kemampuan penyerapan senyawa hidrophobik mencapai 136-531 %.
Haroen, W. K. (2004a). Pembuatan pulp fluff serat abaca dan rami untuk diapers. Laporan Riset Unggulan Terpadu 2004, pp. 25-40. Haroen, W. K. (2004b). Penerapan standar kualitas pulp fluff sebagai bahan baku diapers. Prosiding Pertemuan dan presentasi ilmiah standardisasi Jakarta , pp. 69-76. Haroen, W. K. (2004c). Pengaruh defiberzing pulp fluff bukan kayu terhadap daya serap cairan sebagai diapers. Prosiding Seminar Nasional Teknik Kimia, pp. C5-1-C5-8. Haroen, W. K. (2005). Penambahan SAP pada pembuatan pulp fluff non kayu untuk meningkatkan daya serap. Berita Selulosa 40(1), pp. 1-9. Haroen, W. K. (2009). Potensi serat pulp untuk kampas otomotif. Prosiding seminar teknologi pulp dan kertas. Bandung, pp.86-95.
Kesimpulan Diversifikasi serat pulp menjadi produk produk lain yang inovatif sudah diterapkan pada skala industri seperti kampas rem pulp, pot/wadah bibit tanaman dan briket arang. Pengembangan produk inovatif lainnya masih dalam pengkajian untuk diaplikasikan pada skala industri dengan mempertimbangkan pasar pengguna yang luas.
Haroen, W. K. (2016). Teknologi serat bahan baku pulp kertas. Cetakan 1. Agung Ilmu. pp.72-79. Haroen, W. K. dan Hidayat, T. (2009). The Possibility of Seaweed Wastes Usage as Raw Material of Papermaking. Proceeding of The First International Symposium of Indonesian Wood Research Society, pp. 258-264. Haroen, W. K. dan Posma, R.P. (2009). The prospect of kenaf fluff pulp for diapers. Jurnal Riset Industri, 3(3), pp 156-182.
Saran Untuk pengembangan dan aplikasi serat pulp untuk diversifikasi produk yang memiliki pengguna yang luas maka diperlukan:
Haroen, W. K. dan Sudarmin A. L. (2009). Optimasi penerapan kampas rem pulp mekanis untuk kendaraan sepeda motor. Laporan Desember 2009, pp. 2-32. Haroen, W. K., Panggabean, P. R. and Wistara, N. (2009). Diapers from Fuff Kenaf. Journal of Industrial Research 3, pp.125-129.
Kerjasama penelitian material produk inovatif dengan pihak industri terkait Peluang kerjasama pengembangan material inovatif berbasis pulp
Haroen, W. K., Santosa, L. dan Supratman, M. (2007). Pemanfaatan limbah padat berserat
24
industri kertas sebagai bahan pembuatan partisi. Berita Selulosa, 42, pp. 29-34.
Seminar Teknologi Pulp dan Kertas 2015,pp. 37.
Haroen, W. K., Sudarmin A.L. (2005). Prospek serat kenaf untuk pulp fluff sebagai bahan diapers. Jurnal Riset Industri dan Perdagangan, 3, pp. 66-78.
Kondo, T., Minowa, T., Sudirdjo, T. S., Haroen, W. K., Susi S, Pratiwi, W. dan Purwati. (1993). Efficient utilization of tropical biomass waste. National Institute for Resources and Enviroment (NIRE), Japan, Report Programme, p.1-15.
Haroen, W. K., Sudarmin. A. L. dan Triwaskito, A. (2013). Pengembangan skala pilot kampas rem serat pulp untuk kendaraan roda dua. Prosiding Seminar Teknologi Pulp dan Kertas 2013, pp.23.
Setiawan, Y., Purwati, S., Aep, S., Reza, B.W. dan Kristaufanm, J.P. (2015). Pemanfaatan plastik limbah rejek industri kertas untuk bahan bakar. Prosiding Seminar Teknologi Pulp dan Kertas, pp.1-8.
Haroen, W. K., Sumaryuwono, T. B. dan Tatang. (2012). Kajian pemanfaatan limbah proses destilasi kayu putih IBM Perhutani III Jawa barat untuk produk bermanfaat. Prosiding Seminar pembangunan Jawa Barat 2012, pp. 330-336.
Syamsudin, H. dan Susanto. (2011). Pemanfaatan slugde cake untuk produksi gas medium heating value. Prosiding Seminar Teknologi Pulp dan Kertas, pp.13-21.
Haroen, W. K. dan Sudarmin, A. L. (2012). Serat rami Jawa Barat berpotensi sebagai bahan baku diapers (pulp fluff). Prosiding Seminar pembangunan Jawa Barat 2012, pp. 323-329.
Syamsudin, H. dan Susanto. (2014). Kaji ulang pemanfaatan slugde cake untuk substitusi enerji di pabrik pulp kraft melalui proses gasifikasi. Prosiding Seminar Teknologi Pulp dan Kertas.Bandung, pp. 95-108.
Kardiansyah, T. (2015). Wadah media tanaman dari serat karton daur ulang”, Prosiding
UCEO. 2015. Couses for eneterpreuneur. Ciputra university.pp.2-5.
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J. Lignocellulose Technol. 01 (2016), 26-31
Journal of Lignocellulose Technology Journal homepage: http://ejournal.lipi.go.id/index.php/jol/
Article
Preparation of heat-adsorbing materials from coconut shell-tar Riska Surya Ningrum1*, Bambang Setiadji2, Wega Trisunaryanti2 2Department
1Institute of Health Science Bhakti Wiyata Kediri, KH. Wachid Hasyim, Kediri, East Java, Indonesia of Chemistry, Faculty of Mathematics and Sciences, Gadjah Mada University, Yogyakarta, Indonesia *Corresponding author: e-mail:
[email protected]
Received: 1 December 2016. Received in revised form: 14 December 2016. Accepted: 19 December 2016. Published online: 23 December 2016
Abstract Asphalt can be used as a good and safe heat-adsorbing material (HAM), however the asphalt consumption for road reconstruction process is increasing nowadays. Therefore, synthesis of HAM from bio-asphalt is needed. In this study, tar that obtained from the pyrolysis of coconut shell was used as bio-asphalt. It has physical and chemical properties similar to the asphalt. Heat-adsorbing material was composed from the mixing of powder coconut shell (PCS), coconut shell charcoal powder (CSCP), bio-asphalt and latex compound. The composition of CSCP and PCS used in this study were 30 : 0, 25 : 5, 20 : 10, 15:15, 10: 20, 5: 25 and 0: 30 % with coconut shell tar 55%, and latex 15% of the total mass, respectively. Characterizations of HAM including thermal conductivity test, penetration and surface morphology using Scanning Electron Microscopy (SEM) were investigated. The results showed that HAM with 0 : 30 composition of CSCP : PCS has the best heat-adsorbing properties. Its thermal conductivity numbers were from 0.045 to 0.0997 W/mK. Its thermal resistance up to 115 ° C, penetration value of 57.6 pen and density of 1.0534 g/cm3. Keywords : coconut shell charcoal powder, coconut shell powder, coconut shell tar, heat-adsorbing, thermal conductivity
Introduction Indonesia is a tropical country that has warm or slightly hot weathered. Hot weather caused a person feel uncomfortable being in the room. Thus air conditioner is commonly used to overcome this situation. However, this utilization can break the ozone because it contains freon as refrigerant which has negative effect on the environment. The alternative solutions to maintain temperature in the building is by installing a heat-adsorbing material (insulator) in the walls or roof.
Asphalts have been reported having the ability as a heat-adsorbing materials. Generally, asphalt is used in the form of tiles, paving or roof tile. Research in producing polymer tile-based asphalt has been conducted (Milawarni, 2012; Suryati, 2012). However, the use of asphalt for road reconstruction process is intensive resulting low availability of asphalt. Therefore, it is necessary to do research on the manufacture of heat-adsorbing material (HAM) made from bio-asphalt.
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Tar from coconut shell pyrolysis process can be referred as bio-asphalt because its major constituent is bitumen which has same component with asphalt (Nuryanto, 2008). Tar also has physical properties similar to asphalt, which has black or dark brown liquid due to the main constituent is carbon, pungent, adhesive and thermoplastic material (in liquid form when heated and in pasta form at room temperature) (Kamulyan, 2008).
Materials and Methods Preparation and Characterization HAM The materials used for the preparation of heat-adsorbing materials are weighed according to variations of percent composition, ratio of CSCP 200 mesh and PCS 100 mesh are (30:00, 25:05, 20:10, 15:15, 10: 20, 05:25, and 00:30) %, tar 55%, and 15% of the latex compound total mass. That samples coded PP-3000, PP 2505, PP2010, PP-1515, PP-1020, PP-0525, and PP0030. Each material (except latex compound) was heated at 110 °C for 30 minutes before it’s mixed by stirring, after that the mixture was pressed into mold. For thermal conductivity test, the dimension of the mold is 4 cm in diameter and two various thicknesses that are 4 mm and 6 mm. For penetration test (hardness) sample was pressed or poured into the penetration cup. Finally samples were stored at room temperature until the sample dried and hard. For density test performed by using Archimedes method.
Tar which is used as HAM should be improved by the addition of filler in order to increase the hardness so fulfill the criteria of a good HAM. Filler that used to increase hardness tar such as coconut shell charcoal powder (CSCP) (Mashuri and Manicar, 2006) or latex (Karacasua and Okur, 2006). Criteria of good HAM are has low value of thermal conductivity, high thermal resistance and compressive strength, low water absorption and density, nonflammable and environmentally friendly (Suwardiyono and Awwaludin, 2011). The low value of thermal conductivity and low density can be achieved by adding a fibrous or porous material in the manufacture of HAM. A high porosity or fibrous materials are able to absorb the heat and reduce the rate of heat transfer by conduction. Porous or fibrous materials were used for heat-absorbing such as rice husk ash (Sunendar, Handoko and Subari, 2008), rice husks (Mulyadi, Adril and Apriono, 2010), pineapple leaves (Tangjuank, 2011), fiber papyrus (Tangjuank and Kumfu, 2011), and the durians skin fibers (Jintakososl and Kumfu, 2012). Furthermore, fibrous or porous materials attached with an elastomeric materials, such as natural rubber (latex) or synthetic rubber that can improve the performance of insulation (Ford et al., 2009).
Results and Discussion Characterization of Heat-Adsorbing Materials
1. Penetration tests Penetration test (hardness) of HAM based on RSNI 06-2456-1991. The results in Fig. 1 shows that the hardness increase as increasing PCS and decreasing CSCP in the sample, evidenced by the lower penetration value. The hardness of HAM caused by high content of lignocellulose in PCS. Lignin is poly-aromatics compound that amorphous shaped, so it has many π bond in the double bonds. The molecule becomes more rigid when it has many phi bonds. Sp2 hybridization at some atoms that have double bond can make a flat triangular molecular shape then the molecules can be rigid and tight. Therefore, increasing PCS in the sample can increase the hardness too. Beside lignin, PCS also contains cellulose and hemicelluloses that can make HAM become elastic. Oxygen atoms in -OH group can form single bond with other atoms. Atom that form single bond or sigma bond (σ) can spin (rotation) then the overall shape of a molecule always change sustainably (Ford et al., 2009). Thus, the addition of PCS will make HAM becomes hard and elastic.
Coconut shell is a fibrous material containing lignocellulose that has been widely used as reinforcement in the manufacture of composite particles. In this study, coconut shell powder (PCS) is used in the manufacture of HAM together with tar, CSCP and latex compound. The function of each ingredient is PCS as a porous material and reinforcement particles, CSCP as adsorbent and reinforcing particles, latex compound as elastomeric, and tar (bioasphalt) as an adhesive for the three other components. The advantages of HAM that made from natural materials are renewable, biodegradable and environmentally friendly (Lee and Choi, 2007).
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Addition CSCP into the sample cannot generate a harder HAM than the addition of PCS because CSCP is an adsorbent. If the amount of adsorbent (CSCP) is not proportional with the amount of adsorbate (tar) so the increase of hardness will not become maximum.
2. The density test The density test performed by using Archimedes method as shown in Figure.2. The density of samples decreases with increasing percentage of PCS and decreasing percentage of CSCP in composition of HAM. Density influences the weight of the HAM, the lower density value the sample getting lighter.
Figure 1. Penetration test of the hat-adsorbing materials
Figure 2. Penetration test of the hat-adsorbing materials
There is no specific connection between lighter and SEM or hardness test result with the density test.
conductivity number. Good insulating ability generated by PP 1515, PP-1020, PP0525 and PP-0030. The thermal absorption ability on sample is influenced by the PCS quantity in the mixture. PCS is filler that has lignocelluloses as the major component. The amorphous structures of lignin and hemicelluloses along with many -OH groups contained in lignocelluloses caused PCS able to absorb the heat treatment. Tetrahedral molecule that formed by the bond between carbon atoms with oxygen atoms in the -OH groups can form threedimensional structure that allows air entering it so the heat absorption can occur.
3. The thermal conductivity test The purpose of thermal conductivity test is to determine a material's ability to conduct heat (thermal). Decreasing of thermal conductivity number (k) in material means the thermal energy will be more difficult to passed the materials, and otherwise. Testing on each sample was carried out at temperature 40, 60 and 80oC. Generally, the temperature has a linear connection with thermal conductivity. Table 1 shows that increasing PCS and decreasing CSCP in HAM will give smaller thermal
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Table 1. The thermal conductivity test
Sample
Thermal conductivity value (W/mK) 40 oC
60 oC
80 oC
PP -3000
0.0668
0.0518
0.1162
PP -2505
0.0638
0.0247
0.0995
PP -2010
0.0917
0.1635
0.0185
PP -1515
0.0828
0.154
0.2024
PP -1020
0.0740
0.1374
0.1550
PP -0525
0.0658
0.0899
0.1318
PP -0030
0.0450
0.0520
0.0997
Addition CSCP in the sample caused the sample tighter because CSCP is absorbent which can absorb tar or latex compound to the pores. However, addition CSCP in the sample caused decreasing heat absorption because CSCP that absorbed into the tar or latex compound pores will close the pores.
Based on the comparison of the binding energy between atoms, hydrogen bond has a binding energy of about 5-10 kcal/mol, while the Van der Waals forces have less than 5 kcal/mol bond energy (Ford et al., 2009). Thus, the thermal resistance of HAM will increase along with the increasing hydrogen bonds formed in PCS.
Besides the heat isolation ability, the thermal resistance ability on the sample is also need to be considered. Thermal resistance of HAM is influenced by the presence of inter-molecular bond that is formed from the addition of PCS and CSCP. PCS composed of lignin, cellulose and hemicelluloses which have many -OH groups that have high potential to form intra molecular and intermolecular hydrogen bonds. In addition, many phi bond and intra molecular or intermolecular Van der Waals forces can be formed between PCS and tar or latex compound. However, addition CSCP on samples only donated intra molecular or intermolecular Van der Waals forces between CSCP and tar or latex compound.
Based on the results of thermal conductivity test, the lowest thermal conductivity value obtained from PP-0030. Therefore, thermal conductivity measurement should do at higher temperatures to determine the thermal resistance. The results can be seen in Fig. 3 that show PP-0030 has a thermal resistance up to 115 oC. At temperatures of 40-115 °C, PP-0030 has thermal conductivity numbers of 0.0552-0.1544 W/mK. The PP-0030’s thermal conductivity is lower than asphalt which has thermal conductivity of 0.5 W/mK. Thus, this sample is potential to be alternative material to substitute asphalt as heat absorber.
Figure 3. The thermal stability test of PP-0030
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will lower the compatibility of material. Fig. 4 shows that the sequence of the samples surface morphology ruggedness are PP-0030 > PP-0525 > PP-1020.
4. The surface morphology test CSCP can absorb tar or latex compound into their pores (Fessenden and Fessenden, 1982), so the more addition CSCP on HAM, the sample’s surface morphology is smoother and spread evenly. Eventhough, PCS is not an absorbent so the interactions between PCS with other components such as tar, CSCP and latex compound are surface interactions. Increasing the percentage of PCS in the sample caused more PCS particles attached to tar surface, then the sample’s surface morphology rougher. In other words increasing PCS and decreasing CSCP into the mixture of HAM
a
The presence of pores between PCS particles that wrapped by tar and latex compound can be shown at Fig. 4c. The pore is formed because PCS patch on the tar surface. This pore is not visible on the PP1020 that has 10% of CSCP and start to seem at PP-0525 which has pore less than PP-0030. This happen because PP-0525 also contains of 5% CSCP which allows CSCP to adsorb tar.
b
c
Figure 4. Morphology of the heat-insulator materials: a. PP-1020 b. PP-0525 c. PP-0030
Jintakosol, T. and Kumfu, S. (2012). Properties of thermal insulation from durian peel fiber and natural rubber latex. Journal of Advanced Material Research, 506, pp. 571574.
Conclusion Sample with high PCS is potential to become as alternative material to substitute asphalt as heat absorber. PCS is fibrous material that can increase the hardness of HAM based on coconut shell-tar.
Kamulyan and Budi. (2008). Isolasi Bahan Bakar (Biofuels) dari Tar-Asap Cair Hasil Pirolisis Tempurung Kelapa, Tesis. Jurusan Kimia FMIPA UGM, Yogyakarta. Karacasua, M. Er. A. and Okur, V. (2012). Energy efficiency of rubberized asphalt concrete under low-temperature conditions. Procedia Social Behavioral Sciences, 54, pp. (1241-1249).
References Athappan, A. (2008). Adsorption Curve Fits for Landfill VOCS on Bituminous Coal Based and Coconut Shell Based Activated Carbon. Thesis. The University of Texas.
Lee, E.K. and Choi, S.Y. (2007). Preparation and characterization of natural rubber foams: effect of foaming temperature and carbon black content. Journal Chemical and Engineering, 24(6), pp. 1070-1075.
Fessenden, J.R. dan Fessenden, S.J. (1982). Kimia Organik, edisi pertama. Alih Bahasa : Aloysius Hadyana Pudjaatmaka Ph. D. Jakarta: Erlangga. Ford, E.T.L.C., Mendes, J.U.L., Nascimento, R.M., Pereira, C.M.C. and Marques, A.T. (2009). Development of composite material from tire scrapes and latex for application in thermal insulation. Thermal Engineering, 8(2), pp. 4-9.
Mashuri dan Manicar, M.H. (2006). Sifat-sifat mekanis aspal yang ditambahkan serbuk arang tempurung kelapa. Mekanika Teknik, 8(1). Milawarni. (2012). Pembuatan dan Karakterisasi Genteng Komposit Polimer dari Campuran Resin Polipropilen, Aspal, Pasir dan Serat Panjang Sabut Kelapa. Tesis. Fakultas
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Matematika dan Ilmu Pengetahuan Alam, Universitas Sumatera Utara, Medan.
Matematika dan Ilmu Pengetahuan Alam, Universitas Sumatera Utara, Medan.
Mulyadi, S., Adril, E. dan Apriono, I. (2010). Uji isolator panas papan sekam dengan variasi ukuran partikel dan kepadatan. Jurnal Teknik Mesin, 7(1).
Suwardiyono, S. P. dan Awwaludin, M. (2011). Perancangan tangki simulasi reaktor untai uji sistem kendali reaktor riset, 1 KW. Dalam : Prosiding Pertemuan Ilmiah Rekayasa Perangkat Nuklir. Serpong: Pusat Rekayasa Perangkat Nuklir, BATAN, 280-288.
Nuryanto, A. (2008). Aspal Buton dan Propelan Padat, Jakarta. Sunendar, B., Handoko, T. dan Subari. (2008). Pembuatan ceramic foam dari limbah gipsum dan abu sekam padi untuk aplikasi isolasi panas dan peredam suara. Jurnal Keramik dan Gelas Indonesia, 17(1).
Tangjuank, S. (2011). Thermal insulation and physical properties of particleboards from pineapple leaves. Journal of Physical Sciences, 6(19), pp. 4528-4532. Tangjuank, S. and Kumfu, S. (2011). Particle boards from papyrus fibers as thermal insulation. Journal of Applied Science, 11(14), pp. 2640-2645.
Suryati. (2012). Pembuatan dan Karakterisasi Genteng Komposit Polimer dari Campuran Resin Poliester, Aspal, Styrofoam Bekas dan Serat Panjang Ijuk. Tesis. Fakultas
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J. Lignocellulose Technol. 01 (2016), 32-37
Journal of Lignocellulose Technology Journal homepage: http://ejournal.lipi.go.id/index.php/jol/
Article
Pembuatan dan karakterisasi komposit zephyr bambu dengan perekat kempa dingin Subyakto1*, Mohamad Gopar1, Ismadi1, Ananto Nugroho1, Agung Sumarno1, Eko Widodo1, Sudarmanto1 1Pusat
Penelitian Biomaterial, Lembaga Ilmu Pengetahuan Indonesia, Jl Raya Bogor KM 46, Cibinong, 16911, Bogor, Indonesia *Corresponding author:
[email protected]
Received: 13 December 2016. Received in revised form: 20 December 2016. Accepted: 20 December 2016. Published online: 23 December 2016
Abstract Preparation and characterization of parallel fiber direction of bamboo zephyr composites using cold press have been conducted. Bamboo zephyr composites were made from Betung (Dendrocalamus asper), Andong (Gigantochloa pseudoarundinacea), and Tali (Gigantochloa apus) bamboos glued with isocyanate cold press type. Zephyr bamboo was firstly made by processed fresh bamboo into flat shape (zephyr) using a bamboo crusher. Zephyr was dried until moisture content reached below 5% then mixed with isocyanate resin using a glue spreader at resin content of 15% of the board dry weight. Two types of resin (i.e. type K and type E) were used. Zephyr was arranged in parallel fiber direction to form a matt and was pressed at room temperature, at pressure of 25 kg/cm2 and kept in the press for 6 hours. The board size was 300 cm x 30 cm x 10 cm, with a target density of 0.7 g/cm3. The tested physical and mechanical properties were density, moisture content, thickness swelling, water absorption, bending strength (modulus of rupture and modulus of elasticity) and compression strength. The result showed that zephyr bamboo composite made from andong exhibited higher physical and mechanical properties than that of betung or tali. Board made with molding was better compared to that without molding. The use of type K resin was better compare to that of Type E resin Keywords : board properties tar, cold press, composite, heat-adsorbing, isocyanate, thermal conductivity, zephyr bamboo
Pendahuluan Tanaman bambu sudah sejak lama digunakan masyarakat Indonesia sebagai bahan bangunan, mebel, kerajinan, alat musik dan lain-lain (Dransfield dan Widjaja, 1995). Penelitian pemanfaatan batang bambu untuk bahan bangunan seperti bambu lapis dan balok bambu telah banyak dilakukan (Subiyanto dan Subyakto, 1995; Sudijono, Subyakto dan Subiyanto, 2001;
Khalil et al., 2012; Subyakto et al., 2016). Pemanfaatan batang bambu untuk produk bambu lapis (ply bamboo) bisa digunakan sebagai pengganti kayu lapis dengan menggunakan perekat memakai kempa panas (Sudijono, Subyakto dan Subiyanto, 2001; Subyakto et al., 2016). Proses pembuatan bambu lapis telah dipatenkan oleh LIPI dengan nomor Paten ID P0028883
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(Subiyanto et al., 2011). Perekat seperti fenol formaldehida (Phenol formaldehyde/PF) adalah tipe perekat yang memerlukan panas untuk proses pematangannya. Penggunaan perekat PF pada pembuatan bambu lapis dengan jenis bambu tali dan gombong telah dilakukan (Subyakto, Subiyanto dan Sudijono, 1995; Sudijono, Subyakto dan Subiyanto, 2000; Gopar et al., 2001; Gopar dan Subyakto, 2002; Sudijono dan Subyakto, 2002; Gopar dan Subyakto, 2003). Penggunaan kempa dingin untuk bambu lamina telah diteliti (Sulastiningsih et al., 2013), tetapi untuk komposit zephyr bambu belum banyak diteliti. Pada penelitian ini dilakukan pembuatan balok bambu komposit zephyr bambu dengan memanfaatkan bagian tengah batang dengan menggunakan perekat kempa dingin. Diharapkan penggunaan perekat tipe ini dapat menghasilkan produk komposit yang memenuhi persyaratan aplikasi untuk penggunaan di luar ruangan, menurunkan biaya produksi dan lebih ramah lingkungan. Tujuan penelitian ini adalah mengembangkan teknologi pembuatan balok komposit dari zephyr dengan perekat kempa dingin dan mengkarakterisasi sifat fisis dan mekanisnya.
andong dan tali dengan perekat tipe E mat form dimasukkan ke dalam cetakan berupa plat besi berbentuk U (dengan cetakan). Percobaan lain dengan menggunakan zephyr bambu tali dengan perekat tipe E dan tipe K tidak dimasukkan ke dalam cetakan (tanpa cetakan). Kemudian mat form dikempa pada suhu ruang dengan tekanan 25 kg/cm2 dan dipertahankan pada tekanan tersebut selama 6 jam. Ukuran papan yang dibuat adalah 300 cm x 30 cm x 10 cm, dengan target kerapatan 0,7 g/cm3. Sifat fisik dan mekanik yang diuji adalah kadar air, kerapatan, pengembangan tebal, penyerapan air, uji bending (modulus of rupture dan modulus of elasticity), dan kuat tekan. Uji bending dilakukan dengan pengujian tree point loading dengan alat Universal Testing Machine (Instron). Pengujian sifat-sifat fisik dilakukan berdasarkan standar JIS A 5908: Particleboard. Hasil dan Pembahasan Hasil pengujian sifat fisik yaitu kadar air, kerapatan, pengembangan tebal, dan penyerapan air berturut-turut disajikan pada Gambar 1, 2, 3, dan 4. Dapat dilihat bahwa kadar air bambu komposit sekitar 13 – 14%. Tidak ada perbedaan kadar air pada perlakuan yang berbeda pada penelitian ini (Gambar 1). Kerapatan yang dihasilkan pada penelitian ini untuk komposit yang dibuat dengan cetakan mendekati target kerapatan yaitu 0,7 g/cm3, sedangkan komposit yang dibuat tanpa cetakan kerapatannya lebih rendah dari kerapatan target (Gambar 2). Hal ini disebabkan dengan menggunakan cetakan berbentuk U maka bahan yang dikempa tidak melebar keluar sehingga dihasilkan komposit yang lebih padat. Jika dibandingkan jenis perekat maka perekat tipe K menghasilkan komposit dengan kerapatan yang lebih tinggi. Pengembangan tebal komposit yang dibuat dengan cetakan menggunakan perekat tipe E dari bambu andong paling kecil dibandingkan dengan bambu betung atau tali (Gambar 3). Sedangkan perekat tipe K menghasilkan penyerapan air lebih kecil dibandingkan dengan perekat tipe E. Data penyerapan air (Gambar 4) memperlihatkan kecenderungan yang sama. Sifat-sifat fisik komposit yaitu kerapatan dan pengembangan tebal sudah memenuhi standar JIS A 5908.
Bahan dan Metode Bahan Bahan penelitian berupa bambu Betung (Dendrocalamus asper), Andong (Gigantochloa pseudoarundinacea), dan Tali (Gigantochloa apus) berumur sekitar 3 tahun berasal dari daerah Bogor. Perekat yang digunakan adalah perekat isosianat tipe kempa dingin yaitu tipe K dan tipe E. Metode Zephyr bambu dibuat dengan memproses bambu segar menggunakan alat penghancur bambu (bamboo crusher) menjadi bentuk datar yang disebut palupuh (zephyr). Zephyr dikeringkan sehingga mencapai kadar air di bawah 5% kemudian dicampur dengan perekat isosianat menggunakan alat pencampur perekat (glue spreader) dengan kadar perekat 15% dari berat kering papan. Zephyr disusun dengan arah sejajar serat dan dibuat cetakan (mat form). Untuk bahan zephyr bambu betung,
33
Dengan cetakan
Kadar air (%)
15,0
Tanpa cetakan
12,0
9,0 6,0 3,0 0,0
E
E
Andong
Tali
E
E
K
Betung
Tali
Tali
Jenis Bambu
Gambar 1. Kadar air komposit bambu zephyr dengan perekat tipe E dan K.
Kerapatan (g/cm3)
0,80
Dengan cetakan
Tanpa cetakan
0,60 0,40 0,20 E
E
0,00
Andong
E
Tali
Betung
E Tali
K Tali
Jenis Bambu
Pengembangan tebal (%)
Gambar 2. Kerapatan komposit bambu zephyr dengan perekat tipe E dan K.
15,0
Dengan cetakan
Tanpa cetakan
12,0 9,0 6,0 3,0 0,0
E Andong
E
E
Tali
Betung
E
K
Tali
Tali
Jenis Bambu
Penyerapan air (%)
Gambar 3. Pengembangan tebal komposit bambu zephyr dengan perekat tipe E dan K.
40,0 35,0 30,0 25,0 20,0 15,0 10,0 5,0 0,0
Tanpa cetakan
Dengan cetakan
E Andong
E
E
Tali
Betung
E
K
Tali
Tali
Jenis Bambu
Gambar 4. Penyerapan air komposit bambu zephyr dengan perekat tipe E dan K.
34
Hasil pengujian sifat-sifat mekanis komposit bambu yaitu modulus of rupture (MOR), modulus of elasticity (MOE), dan kuat tekan berturut-turut dapat dilihat pada Gambar 5, 6, dan 7. Gambar 5 mengindikasikan bahwa penggunaan cetakan menghasilkan MOR lebih tinggi dibandingkan dengan tanpa cetakan. Jenis bambu tali menghasilkan komposit dengan nilai MOR paling tinggi. Tipe perekat K lebih tinggi nilai MOR nya dibandingkan dengan perekat E. Hasil pengujian MOE memperlihatkan kecenderungan yang sama dengan MOR. Hanya pada komposit yang dibuat dengan cetakan, bambu andong
MOR (kgf/cm2)
500
menghasilkan nilai MOR tertinggi. Kuat tekan komposit yang dibuat dengan cetakan dari bambu andong paling tinggi dibandingkan dengan bambu betung atau tali. Pada komposit dari bambu tali yang dibuat tanpa cetakan, tipe perekat K lebih tinggi kuat tekannya dibandingkan dengan perekat E. Dibandingkan dengan hasil penelitian bambu lamina dengan perekat tanin resorsinol formaldehida (Sulastiningsih et al., 2013), MOR yang dihasilkan penelitian ini lebih rendah.
Tanpa cetakan
Dengan cetakan
400 300 200 100 0
E
E
Andong
Tali
E Betung
E
K
Tali
Tali
Jenis Bambu
Gambar 5. Modulus of rupture (MOR) komposit bambu zephyr dengan perekat tipe E dan K.
MOE (kgf/cm2)
200
Tanpa cetakan
Dengan cetakan
150 100 50 0
E
E
E
E
K
Andong
Tali
Betung
Tali
Tali
Jenis Bambu
Kuat tekan (N/mm2)
Gambar 6. Modulus of elasticity (MOE) komposit bambu zephyr dengan perekat tipe E dan K. 50
Dengan cetakan
Tanpa cetakan
40 30 20 10 0
E
E
E
E
K
Andong
Tali
Betung
Tali
Tali
Jenis Bambu
Gambar 7. Kuat tekan (compression strength) komposit bambu zephyr dengan perekat tipe E dan K.
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Bamboo Congress. Bali, June, pp. 155164.
Kesimpulan Komposit zephyr bambu yang dibuat dari bambu andong mempunyai sifat fisik dan mekanik yang paling baik. Pemakaian cetakan menghasilkan sifat-sifat komposit yang lebih baik dibandingkan dengan tanpa cetakan. Sifat-sifat komposit dari bambu tali tanpa cetakan, dengan perekat isosianat tipe K lebih baik dibandingkan dengan perekat tipe E.
Subiyanto, B., Prasetya B., Subyakto, Sudijono dan Gopar, M. (2011). Proses pembuatan papan bambu komposit dan produk yang dihasilkannya. Paten ID P0028883. Subyakto, Romansyah, E., Zakaria, A., Bachtiar, G., Nasution, N. and Prihantono. (2016). Physical and mechanical properties of ply-bamboo made from sembilang and andong. In: Proceedings of The Fourth International Wood Science Symposium. Bandung, Indonesia, 5-6 November 2015. International Wood Science Symposium
Daftar Pustaka Dransfield, S. and Widjaja, E.A. (1995). Plant Resources of South-East Asia No. 7. Bamboos. Leiden: Backhuys Publisher, pp. 189. Gopar, M., Subyakto, Subiyanto, B. dan Firmanti, A. (2001). Sifat Fisis dan Mekanis Panel Zephyr Bambu Skala Pilot. Dalam: Prosiding Seminar Nasional IV Masyarakat Peneliti Kayu Indonesia. Samarinda, 6-9 Agustus 2001, pp. IV.128-IV.134. Masyarakat Peneliti Kayu Indonesia.
Subyakto, Subiyanto, B. dan Sudijono. (1995). Pengaruh Pengeringan Hamparan Palupuh dan Waktu Kempa terhadap Sifat-sifat Papan Bambu Komposit. Dalam: Prosiding Seminar Ilmiah Hasil-hasil Penelitian Puslitbang Fisika Terapan – LIPI. Bandung 2-3 Oktober, pp. 81-90. Pusat Penelitian Fisika- LIPI.
Gopar, M. dan Subyakto. (2003). Pengaruh Ketebalan Panel terhadap Sifat Ketahanan Api Panel Bambu Zephyr dengan Perekat Urea Formaldehida dan Penol Formaldehida. Dalam: Prosiding Seminar Nasional VI Masyarakat Peneliti Kayu Indonesia. Sumatera Barat, Padang, pp. 287-297. Fahutan Universitas Muhammadiyah.
Sudijono, Subyakto and Subiyanto, B. (2000). Manufacture of Bamboo-Zephyr Board as Plywood Substitution for Concrete-Block Pallet Application. In: Proceedings of The Third International Wood Science Symposium. Kyoto, Japan, November 1-2, pp. 90-94. University of Kyoto. Sudijono, Subyakto dan Subiyanto, B. (2001). Pengaruh Jumlah Perekat Phenol Formaldehid terhadap Keteguhan Rekat Papan Lapis Bambu Zephyr dari Bahan Baku Bambu Tali (Gigantochloa apus Kurs). Dalam: Prosiding Seminar Nasional IV Masyarakat Peneliti Kayu Indonesia. Samarinda, 6-9 Agustus 2001, pp. IV.220-IV.224. Masyarakat Peneliti Kayu Indonesia.
Gopar, M. and Subyakto. (2002). Physical and Mechanical Properties of Zephyr Board Made from Gombong Bamboo. In: Proceedings of The Fourth International Wood Science Symposium. Serpong, Indonesia, 2-3 September 2002, pp. 257-261. International Wood Science Symposium. Japanese Standards Association. (2003). JIS A 5908: Particleboard.
Sudijono and Subyakto. (2002). Bending and Shear Properties of ow Density Particleboard Laminated with Zephyr of Tali Bamboo. In: Proceedings of The Fourth International Wood Science Symposium. Serpong, Indonesia, 2-3 September 2002, pp. 219-222. International Wood Science Symposium.
Khalil, H.P.S.A., Bhat, I.U.H., Jawaid, M., Zaidon, A., Hermawan, D. and Hadi, Y.S. (2012). Bamboo fibre reinforced biocomposites: A Review. Materials and Design, 42, pp. 353-368. Subiyanto, B. and Subyakto. (1995). Development of Processing Technology of Semi Fiber Bamboo Board I. Shortening the Press Cycle. In: Proceedings of The IVth International
Sulastiningsih, I.M., Santoso, A., Barly dan Iskandar, M.I. (2013). Karakteristik
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Papan Bambu lamina Direkat dengan Tanin Resorsinol Formaldehida. Jurnal Ilmu dan Teknologi Kayu Tropis, 11(1), pp. 62-72.
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J. Lignocellulose Technol. 01 (2016), 38-43
Journal of Lignocellulose Technology Journal homepage: http://ejournal.lipi.go.id/index.php/jol/
Article
Proximate analysis of lignocellulosic material as alternative bioenergy resources Jauhar Khabibi1*, Bambang Irawan1 1Forestry
Department, Faculty of Forestry, University of Jambi, Mendalo Darat–Jambi 36361, Indonesia *Corresponding
author:
[email protected]
Received:1 December 2016. Received in revised form: 14 December 2016 Accepted: 19 December 2016. Published online: 23 December 2016
Abstract Plant species have different abilities to sequester and to store carbon in a forest ecosystem. The content of fixed carbon in the forest biomass shows its suitability as bioenergy resources. Biomass with a higher fixed carbon content can produce more energy. The proximate analysis was conducted on nine types of lignocellulosic materials, such as Tectona grandis wood, Acacia mangium wood, Toona sureni wood, T. grandis bark, A. mangium bark, T. sureni bark, Gigantochloa verticillata, G. apus, and Dendrocalamus asper. Proximate analysis showed the moisture content and volatile matter of lignocellulosic materials range between 7.93–18.26% and 60.05– 79.60%, respectively. The ash content and fixed carbon showed the range 0.53–7.02% and 21.50–32.93%, respectively. The bark has the highest fixed carbon content than that of the other lignocellulosic materials. T. sureni bark, G. verticillata, and T. grandis wood have the potential to be developed as an alternative source of bioenergy. Keywords: bioenergy; fixed carbon; lignocellulosic; proximate analysis
Keywords Forests have an important role in reducing the effects of greenhouse gasses (GHG) (Sun, Fujimoto and Minowa, 2013). It happens when CO2 in the atmosphere was sequestered and stored in forest biomass (Donate, 2014). Assessment of forest carbon, such as wood, leaves, bark, etc uses generic assumption (such as biomass consisting of 50% carbon on a weight/weight basis) (Martin and Thomas, 2011). Although this value has been supported empirically and has been used universally, but it only uses to simplify calculation in the context of global warming and carbon credit (Lamlon and Savidge, 2003). However, it doesn't accurate enough to predict the carbon
Introduction Utilization of renewable energy resources could reduce the negative environmental effects caused by burning nonrenewable fossil fuels (Serba et al. 2016). Lignocellulosic material is gaining increased industrial application due to abundances and advantages as a raw material for valuable chemical production (Donate, 2014). Lignocellulosic also represents a crucial option as a renewable energy alternative (Mulakhudair et al., 2016). It is also an inexpensive renewable resource that is available on a global scale (Donate, 2014).
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4
content among species and the section of plant tissues (Thomas and Martin, 2012).
research materials. All materials were collected from Bogor, West Java, Indonesia. The sample of wood, bark, and bamboo were reduced to chips (3–5 mm thicknesses, 20– 30 mm length, and 20 mm width), which were air-dried one week, ground using a Wiley mill, and sieved with a 40–60 mesh (TAPPI T 264 om-88, 1988). The sample was then used for the further analysis.
Thomas and Melczewski (2007) and Telmo, Lousada and Moreira (2010) showed the differences in carbon content between hardwoods and softwoods. Lamlon and Savidge (2003) stated hardwoods have lower carbon content than that of softwoods. Fu, Wang and Sun (2013), Arias et al. (2011), and Elias and Wistara (2009) showed the difference of carbon content of plant tissues such as branch, root, stem etc. Bark of same species also has different carbon content compare to wood’s (Almeida, Brito and Perre, 2010). In addition, as a non-wood lignocellulosic material, bamboo has the potential to sequester and to store the carbon too (Suprihanto, Hamidy and Amin, 2012; Hernandez-Mena, Pecora and Beraldo, 2014).
Materials and Methods
Proximate analysis which carried out are (1) moisture content analysis (TAPPI T 264 om-88, 1988), (2) volatile matter analysis (ASTM E872-82, 1988), (3) ash content analysis (TAPPI T 211 om-02 2002), and fixed carbon analysis (Cordero et al., 2001; McKendry, 2002). This analysis has been conducted triplicates. Results and Discussion Moisture content The moisture content variation of lignocellulosic materials has shown in Fig. 1. It ranges of 7.93–18.26% which indicating that all lignocellulosic materials are in airdried condition. In other hand it also between the fiber saturation point (25–30%) and oven-dry (0%) (Unger, Schniewind and Unger, 2001). The characteristics and properties of lignocellulosic material has influenced the moisture content (Barnett and Jeronimidis, 2003). Furthermore, Akowuah et al. (2012) stated that moisture content affects the characteristic of flame and heating value of biomass. The lowest moisture content is demonstrated in the wood (Fig. 1). The similar finding is also supported by Iswanto (2008) which using both wood and bark of Pterocarpus indicus. Moisture content (%)
These differences occurred due to plants include as biological material that have many variations of the species and sections in same individual (Barnett and Jeronimidis, 2003; Haygreen and Bowyer, 1982; Heaton 1999; Stevens, Pavoine and Baguette, 2010). Therefore, the data of fixed carbon content containing in the lignocellulosic materials are required to be collected as an overview of carbon stock and the utilization potency of them as a source of bioenergy. Proximate analysis is one method that can be used to analyze the fixed carbon content (Cordero et al., 2001; Thipkhunthod et al., 2006; Krishnaiah, Lawrence and Dhanuskodi, 2012). This method is relatively inexpensive and easily performed (Krishnaiah, Lawrence and Dhanuskodi, 2012). This research was intended to analyze the fixed carbon content of nine lignocellulosic materials such as Tectona grandis wood, Acacia mangium wood, Toona sureni wood, T. grandis bark, A. mangium bark, T. sureni bark, Gigantochloa verticillata, G. apus, and Dendrocalamus asper using proximate analysis. Furthermore, this approach was also to determine the precise utilization of lignocellulosic materials as a bioenergy resources.
Proximate analysis
25 20 15 10 5 0
Materials preparation About nine types of lignocellulosic materials, (1) T. grandis wood, (2) A. mangium wood, (3) T. sureni wood, (4) T. grandis bark, (5) A. mangium bark, (6) T. sureni bark, (7) G. verticillata, (8) G. apus, and (9) D. asper have been chosen as
Lignocellulosic materials Figure 1. Moisture content of woods, wood barks, and bamboos
39
Nine lignocellulosic materials have the different ash content which varied at range 0.53–7.02% (Fig. 3). Ash content indicates the amount of metal oxides remaining on high heat, such as calcium, potassium, and magnesium. Furthermore, this content can be measured due to the presence of compounds that do not burn at 800–900 0C, such as calcium, magnesium, manganese, and silicon (Haygreen and Bowyer, 1982)
Ash content (%)
The lower moisture content correlates with the easier combustion process. Lignocellulosic materials with lower moisture content will be more easily ignited due to lower evaporation process (FAO, 2004). The reduction of moisture content needs to be done on lignocellulosic materials which are used as a bioenergy source. The moisture content higher than 20% is generally not advisable and may damage the equipment being used and also it invites microbial to decompose lignocellulosic materials (Mills, 2015; Campo, 2010). Akyildiz and Ates (2008) stated that moisture content in biomass can be reduced using temperature treatment such as openair dry, oven-dry, fans blowing etc. Volatile matter The results show volatile matter is ranged between 60.05–79.60% (Fig. 2). Bark has the lowest average of volatile matter. This result is similar with Almeida, Brito and Perre (2010) which showed that Eucalyptus grandis bark and E. saligna bark have lower volatile matter than that of the wood itself. In addition, Márquez-Montesino et al. (2015) have recently shown that a higher volatile content in biomass correlates with hemicellulose content in the biomass. The volatile matter affects the reactivity of burning (Akowuah et al., 2010). However, a higher volatile matter in lignocellulosic materials generates more smoke in burning. This reduces the efficiency of energy resulted from combustion process. In other hand it also produces toxic effluents such as carbon monoxide, carbon dioxide that harmful to the people (Alarie, 2002).
Lignocellulosic materials
Figure 3. Ash content of woods, wood barks, and bamboos
The highest and the lowest average of ash content is found in the bark and bamboo, respectively (Fig. 3). A similar result is reported before by Almeida, Brito and Perre (2010) using bark of E. grandis and E. saligna. Ash content significantly affected the heat transfer. The higher ash content in biomass produces the lower heat (Biedermann and Obernberger, 2005). Considering the lowest ash content, bamboo will be predicted to produce better heat transfer performance.
90
80 Volatile matter (%)
8 7 6 5 4 3 2 1 0
Fixed carbon
70 60
Fig. 4. shows fixed carbon content varied between 21.50–32.93%. The bark has the highest fixed carbon. It correlates with the lignin content in the lignocellulosic materials (Khabibi, Syafii and Sari, 2016; Demirbaş, 2003). Carbon concentration in the lignin was 63–66% (Bert and Danjon, 2006). Wina, Toharmat and Astuti (2001) and Yao et al. (2010) showed the A. mangium bark has higher lignin content than that of A. mangium wood. It correlates to higher fixed carbon containing in A. mangium bark compared to the wood (Khabibi, Syafii and Sari, 2016). Wood has lignin content 20– 24%, while the bark about 25–36% (Wina,
50 40 30 20 10 0
Lignocellulosic materials
Figure 2. Volatile matter of woods, wood barks, and bamboos
Ash content
40
Fixed carbon (%)
Toharmat and Astuti, 2001). The heating value was correlated with their lignin content (Demirbaş, 2001). T. sureni bark, G. verticillata, and T. grandis wood have higher fixed carbon content than that of the others (Fig.4).
higher volatile matter in lignocellulosic materials generates more smoke in burning. Ash content and fixed carbon shows the range 0.53–7.02% and 21.50–32.93%, respectively. The higher ash content in biomass produces the lower heat. The higher fixed carbon in biomass produces the higher heating value. The bark of wood has the highest fixed carbon content. T. sureni bark, G. verticillata, and T. grandis wood have the potential to be developed as an alternative source of bioenergy base on fixed carbon content.
40 35 30 25 20 15 10 5 0
Acknowledgment I would like to express my sincere thanks and deep gratitude to Faculty of Forestry, University of Jambi and Laboratory of Chemical Forest Products, Department of Forest Products, Faculty of Forestry, Bogor Agricultural University for funding this work.
Lignocellulosic materials
References Figure 4. Fixed carbon of woods, wood barks, and bamboos
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Amongst all wood materials, T. grandis wood has the highest fixed carbon (Fig. 4). The similar finding has been reported by Elias and Potvin (2003). T. grandis wood also has higher fixed carbon compared to Ormosia macrolyx. It is includes as one of expensive and fancy wood (Irawari, Melati and Purnomo, 2009). However waste of T.grandis processes, such as felling waste, furniture waste, saw dust, planer waste, carving waste etc (Rahmat et al., 2014; Budiaman and Komalasari, 2012) can be considered to increase its value added. The differences of fixed carbon between species were proven by the interaction of environmental factors with growth factors (Briand et al., 1999). Besides, it also correlates with the specific gravity of the biomass (Elias and Potvin, 2003). The specific gravity of lignocellulosic materials was significantly affected by growing site such as soil, moisture content, weather, and temperature (Woodcock, 2000). At the same location, the differences of specific gravity were affected by the species (Williamson, 1993).
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Conclusion
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J. Lignocellulose Technol. 01 (2016), 44-52
Journal of Lignocellulose Technology Journal homepage: http:/ejournal.lipi.go.id/index.php/jol/
Article
Modification of palm oil empty fruit bunches biosorbent using egg shells for phenol sorption Mamay Maslahat1*, Mediagmi Paramitha1, Supriyono Eko Wardoyo1 1PS
Kimia FMIPA Universitas Nusa Bangsa Bogor, Jl. KH. Sholeh Iskandar KM 4 Cimanggu Tanah sareal Bogor *Corresponding
author:
[email protected]
Received: 1 December 2016. Received in revised form: 15 December 2016. Accepted: 15 December 2016. Published online: 23 December 2016
Abstract Palm oil empty fruit bunches (OPEFB) is the largest solid waste produced by the palm oil Industry. It accounts of 23% of fresh fruit bunches. The major component of palm oil waste are lignin and cellulose, which has potential used as a natural biosorbent for the recovery of phenol waste. Phenol is an organic material which widely used in the plastics industry, lubricants, paints, pharmaceuticals, herbicides, and resin. Phenol is classified as one of the most toxic industrial pollutants. Phenol contamination in low concentration causes water pollution and hazardous to human health. The purpose of study was to use the OPEFB as biosorbent and to investigate its potential in the sorption of phenol. The biosorbent was modified with egg shells (BMC) to increase high sorption power of the phenol. The stages of research were biosorbent production, impregnation using NaOH, modification using egg shells, water analysis content, active functional group analysis using IR spectrophotometer, determination of maximum wavelength and optimum sorption condition. Optimum sorption condition were time of sorption, biosorbent weights, pH and the concentration of phenol. The result showed the biosorbent modified egg shell can be used to absorb phenol. The adsorption capacity of BMC and pH were 1476.046 g and <3, respectively. They were appropriate to the Langmuir isotherm equation. Keywords : BMC; fenol waste; functional groups; langmuir isotherm equation;oil palm empty fruit bunches
Pendahuluan Peningkatan pertumbuhan sektor agroindustri kelapa sawit diikuti oleh dampak lingkungan akibat dihasilkannya limbah cair, gas dari kegiatan perkebunan maupun pabrik kelapa sawit. Oleh karena itu, pencegahan dan penanggulangan dampak negatif dari kegiatan perkebunan kelapa sawit amat penting untuk dilakukan. Perkebunan kelapa sawit
menghasilkan limbah padat berupa batang dan pelepah sawit. Sedangkan proses pengolahan tandan buah segar (TBS) dihasilkan limbah berupa tandan kosong, serat, cangkang, kernel cake, dan POME. Pemanfaatan limbah pelepah dan Tandan Kosong Kelapa Sawit (TKKS) sejauh ini belum maksimal, yakni digunakan umumnya untuk pupuk, arang,
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pulp kertas, papan partikel, dan pakan ternak (Indriyati, 2008). Salah satu pemanfaatan limbah TKKS lain yang berpotensi dikembangkan adalah sebagai biosorben.
seperti TKKS untuk proses sorpsi bukan hanya menguntungkan secara ekonomis, tetapi juga mendukung prinsip zero-waste, khususnya untuk industri- industri yang menghasilkan biomassa sebagai hasil samping.
TKKS merupakan limbah padat terbesar yang dihasilkan oleh industri kelapa sawit yaitu berkisar 23% dari tandan buah segar (TBS), sehingga ketersediaannya melimpah (Indriyati, 2008). Komponen utama dari limbah kelapa sawit berupa lignin dan selulosa sehingga limbah ini disebut sebagai limbah lignoselulosa (Darnoko et al., 1995). Selulosa adalah polisakarida berantai lurus yang mengandung lebih dari 1000 unit glukosa, terikat oleh ikatan beta 1,4 glikosida, dan dapat didegradasi menjadi senyawa C sederhana. Sedangkan lignin merupakan senyawa yang sulit untuk didegradasi (Orth, Royse and Tien, 1993). Dilihat dari strukturnya, selulosa memiliki banyak gugus hidroksil (OH), sehingga dapat digunakan sebagai penjerap yang potensial. Dengan adanya gugus OH ini, selulosa baik digunakan sebagai penjerap zat yang bersifat polar.
Berdasarkan penelitian sebelumnya, biosorben TKKS terimpregnasi basa dan biosorben cangkang telur terbukti mampu digunakan sebagai biosorben fenol (Lestari, 2011). Dengan demikian, perlu dilakukan penelitian mengenai potensi dan optimasi sorpsi biosorben TKKS modifikasi cangkang telur terhadap recovery limbah fenol. Bahan dan Metode Alat dan bahan Peralatan yang dipergunakan dalam penelitian yaitu Spektrofotometer VIS Genesys 20, Spektrofotometer IR, oven Memmert UL50, Neraca analitik, pH meter Eutech Instruments pH 510, dan seperangkat alat gelas. Bahan-bahan yang digunakan yaitu, serbuk TKKS dari PT Perkebunan Nasional Kelapa Sawit VI, Cimulang berukuran 200 mesh, bubuk cangkang telur ayam berasal dari limbah rumah tangga di Bogor berukuran 100 mesh, NH4Cl p.a, NaOH p.a, Fenil alkohol p.a, Kloroform p.a, 4-aminoantipirin 2 %, Kalium Ferrisianida 8%, Natrium Sulfat p.a, Ammonium Hidroksida.
Telur merupakan salah satu jenis bahan makanan yang sering dikonsumsi oleh manusia. Konsumsi telur memberikan hasil samping berupa limbah cangkang telur. Limbah cangkang telur selama ini hanya dianggap sebagai sampah, dan belum banyak diolah secara maksimal. Selama ini cangkang telur hanya dimanfaatkan sebagai pakan unggas, dan baru beberapa industi kecil yang memanfaatkan limbah cangkang telur sebagai bahan baku kerajinan tangan (handicraft). Cangkang telur memiliki kadar kalsium yang cukup tinggi. Dengan demikian, cangkang telur memiliki potensi untuk menjadi penjerap atau sorben.
Metode Penelitian ini terdiri atas beberapa tahap yaitu preparasi sampel tandan kosong kelapa sawit (TKKS) menjadi biosorben, selanjutnya disebut Biosorben Tanpa Modifikasi (BTM). Pembuatan biosorben terimpregnasi basa (BTB) dengan mereaksikan larutan 2 liter NaOH 0,1 N dengan 100 g BTM dengan proses perendaman. Preparasi biosorben cangkang telur (CT) dan pembuatan biosorben modifikasi cangkang telur (BMC) dengan cara mencampurkan antara biosorben terimpregnasi basa (BTB) dengan bubuk cangkang telur pada perbandingan 1:1. Sampel biosorben modifikasi ini selanjutnya disebut sebagai biosorben modifikasi cangkang telur (BMC)
Biosorben yang berasal dari limbah TKKS dapat digunakan untuk pengolahan limbah hasil industri, yaitu limbah fenol (Lestari, 2011). Fenol digolongkan menjadi bahan beracun dan berbahaya (B3), karena bersifat korosif terhadap kulit, beracun, dan karsinogenik, yang jika tidak ditangani akan menyebabkan kerusakan lingkungan. Environmental Protection Agency (EPA) menyatakan konsentrasi fenol yang diizinkan dalam air minum sebesar 0,002 ppm. Penggunaan biomassa
Analisis BMC meliputi penentuan kadar air biosorben, penentuan panjang
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gelombang maksimum dan kalibrasi fenol, dan optimasi kondisi sorpsi. Parameter optimasi terdiri atas waktu kontak, berat BMC, pH sorpsi optimum, konsentrasi fenol (sebagai adsorbat). Adapun penghitungan kapasitas adsorpsi, konsentrasi fenol berdasarkan persamaan 1 dan 2.
Penentuan ukuran partikel biosorben dilakukan agar sampel yang digunakan seragam. Hal ini karena dalam proses sorpsi padatan-cairan ukuran partikel sangat mempengaruhi kapasitas adsorpsi. adsorpsi dipengaruhi oleh ukuran pori dan luas permukaan adsorben (Lynch, 1990). Luas permukaan adsorben dapat diperbesar dengan cara pengecilan ukuran partikelnya. Semakin kecil ukuran partikel akan memperluas permukaan biosorben sehingga ketersediaan sisi aktif biosorben akan meningkat. Bertambahnya sisi-sisi aktif dari permukaan biosorben dapat memungkinkan adsorpsi terjadi di lebih banyak tempat pada permukaan biosorben. Jumlah permukaan biosorben yang meningkat akan meningkatkan jumlah adsorbat yang terjerap.
Rumus-rumus perhitungan Kapasitas adsorpsi (Q) 𝑄=
𝑉 (𝐶𝑜−𝐶𝑎) 𝑚
…………………………….(1)
Q = Kapasitas adsorpsi per bobot biosorben (μg/gram bioremoval) V = Volume larutan (ml) Co = Konsentrasi awal (ppm) Ca = Konsentrasi akhir (ppm) m = Bobot biosoren (gram)
Impregnasi basa Proses impregnasi bertujuan untuk menghilangkan senyawa lignin dari TKKS. Menurut Nevvel dan Zerronian (1985) dalam Darnoko et al. (1995) lignin senyawa polimer aromatik komplek yang terbentuk melalui proses polimerisasi tiga dimensi dari sinapil alkohol yang merupakan turunan dari fenil propana. Adanya ikatan aril eter menyebabkan lignin mudah dihidrolisis oleh basa. Adanya lignin akan menghambat proses penyerapan fenol oleh biosorben.
Konsentrasi fenol ppm Fenol(setimbang) =
𝐴 𝑆𝑙𝑜𝑝𝑒
× 𝑓𝑝................(2)
A = Absorbansi Fp= faktor pengenceran Hasil dan Pembahasan Preparasi sampel Limbah TKKS yang digunakan adalah limbah yang masih segar dan belum ditumbuhi jamur dan sebaiknya memiliki kadar air kurang dari 10%. Beberapa penelitian sebelumnya yang menggunakan agro-waste sebagai biosorben, ukuran partikel yang digunakan yakni 100 mesh. Pada penelitian ini, ukuran partikel diperkecil menjadi 200 mesh dimaksudkan agar diperoleh luas permukaan adsorpsi yang lebih besar.
Kadar air biosorben Analisis kadar air dilakukan terhadap Biosorben Tanpa Modifikasi (BTM), Biosorben Terimpregnasi Basa (BTB), biosorben Cangkang Telur (CT), dan Biosorben Modifikasi Cangkang (BMC) telur (Tabel 1). Tabel 1. Hasil Analisis Kadar Air Biosorben
Limbah cangkang telur yang digunakan diperoleh dari limbah rumah makan dan rumah tangga. Limbah cangkang telur yang digunakan pun merupakan limbah baru, yang belum menghasilkan bau busuk. Cangkang telur yang telah dicuci bersih dikeringkan, kemudian digiling hingga berukuran 100 mesh (Arunlertaree et al., 2007). Selanjutnya bubuk cangkang telur 100 mesh ini kemudian dikeringkan hingga bebas air dengan kadar air sebaiknya kurang dari 10%.
Biosorben
Kadar Air (%)
BTM BTB CT BMC
13,50 7,12 0,82 3,93
Kadar air biosorben berpengaruh pada penyimpanan biosorben sehingga biosorben tidak mudah rusak. Biosorben berbasis selulosa akan mudah ditumbuhi jamur dengan kadar air yang tinggi. Standar maksimum untuk biosorben asal TKKS ataupun cangkang telur sejauh ini
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belum ada. Oleh karena itu, standard kadar air biosorben BMC mengacu pada kadar air maksimum dari karbon aktif yakni sebesar 15%. Hasil kadar air biosorben dibawah 15%.
(BTB), biosorben Cangkang Telur (CT), dan Biosorben Modifikasi Cangkang (BMC) telur setelah dihaluskan, kemudian dianalisis gugus fungsional aktifnya dengan menggunakan spektrofotometer IR. Pengukuran ini bertujuan untuk mengetahui sisi aktif dari biosorben yang digunakan (Gambar 1, 2, 3 dan 4).
Sisi aktif biosorben Sampel Biosorben Tanpa Modifikasi (BTM), Biosorben Terimpregnasi Basa
Gambar 1. Spektrum Infra Merah Biosorben TKKS (BTM)
Gambar 2. Spektrum Infra Merah Biosorben Terimpregnasi Basa (BTB)
Gambar 3. Spektrum Infra Merah Serbuk Cangkang Telur (CT)
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Gambar 4. Spektrum Infra Merah Biosorben Modifikasi dengan Cangkang Telur (BMC)
Hasil interpretasi terhadap spektrum infra merah TKKS memperlihatkan adanya puncak serapan pada daerah 3500-3200 cm-1 yang menunjukkan adanya gugus hidroksil. Pada daerah 3300-3000 cm-1 terjadi penyerapan yang kuat yang menunjukkan adanya regangan C-H aromatik, didukung dengan adanya serapan pada daerah 1650-1500 cm-1 yang merupakan spektrum pendukung untuk mengidentifikasikan senyawa aromatik, puncak serapan juga ditunjukkan pada daerah 850 - 650 cm-1 yang merupakan regangan Ar-H. Serapan yang cukup kuat juga ditunjukkan pada daerah 1900-1650 cm-1 yang merupakan regangan aldehida. Gugus OH dapat diidentifikasikan sebagai senyawa polisakarida seperti selulosa yang merupakan susunan terbesar dari TKKS. Terdapat senyawa aromatik yang kemungkinan besar menunjukkan adanya senyawa lignin (Gambar 1).
Interpretasi spektrum infra merah pada sampel cangkang telur memperlihatkan adanya puncak penyerapan yang signifikan pada 1500–1400 cm-1 yang berasosiasi dengan kuat atas keberadaan mineral karbonat pada matriks cangkang telur (Gambar 3). Hal ini sesuai dengan Ghazy et al. (2008) yang menyatakan puncak serapan pada sekitar 2500 cm-1 dan 1810 cm-1 menunjukkan keberadaan kalsium karbonat. Selain itu pada spektrum tampak bahwa terdapat puncak serapan di sekitar 715 cm-1 dan 875 cm-1 yang masing-masing merupakan pendukung untuk keberadaan kalsium karbonat. Sedangkan pada panjang gelombang 3500 -3200 cm-1 dan 1650 cm-1 yang masing-masing merupakan regangan NH dan –NH-C=O. Hal ini menunjukkan bahwa cangkang telur pun tersusun atas zat organik, yakni membran cangkang telur. Membran cangkang telur ini tersusun dari sejumlah material organik diantaranya kolagen, asam hianulorik, asam amino, dan polipeptida (Yoo et al., 2009). Keberadaan struktur porous alami dan permukaan berporinya yang luas, limbah cangkang telur yang benyak mengandung kalsium mudah untuk digiling dan dihaluskan menjadi bubuk, yang kemudian dapat dimanfaatkan sebagai adsorben yang baik yakni berupa porous adsorbent (Elwakeel and Yousif, 2010).
Berdasarkan analisis dengan spektrofotometer inframerah, spektrum biosorben BTB memiliki spektrum yang tidak jauh berbeda dengan TKKS tanpa impregnasi (BTM). Terlihat puncak serapan pada daerah 3400-3300 cm-1 yang menunjukkan adanya gugus hidroksil. Pada daerah 3000-3300 cm-1 terjadi penyerapan yang kuat yang menunjukkan adanya regangan C-H aromatik, didukung dengan adanya serapan pada daerah 1650-1500 cm1 yang merupakan spektrum pendukung untuk mengidentifikasikan senyawa aromatik, dan pada daerah 1500-1900 cm-1 terjadi penyerapan yang menunjukkan adanya regangan aldehid (Gambar 2).
Interpretasi spektrum infra merah terhadap biosorben BMC terlihat puncak serapan pada 3400–3300 cm-1 yang menunjukkan adanya gugus hidroksil. Terdapat pula regangan pada 3300-3000 cm-1- yang merupakan regangan C-H
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aromatik, dan didukung oleh puncak serapan pada 1650-1500 cm-1. Ketiga spektrum ini diperoleh dari TKKS. Sedangkan cangkang telur memberikan puncak serapan pada 1500 - 1400 cm-1 yang menunjukkan keberadaan mineral karbonat, dan didukung oleh puncak serapan pada 715 cm-1 dan 875 cm-1 (Gambar 4).
waktu tertentu. Saat kapasitas adsorpsi mencapai nilai maksimum, maka lamanya proses adsorpsi tersebut diambil sebagai waktu optimum adsorpsi (Gambar 6, 7, dan 8).
Berdasarkan hasil interpretasi spektrum infra merah dari biosorben BMC, fenol yang memiliki gugus O-H diduga akan berikatan secara kimiawi dengan gugus O-H pada selulosa yang berasal dari BTB. Selain itu, fenol akan mengisi pori-pori kosong yang terdapat pada biosorben yang berasal dari cangkang telur, dan berikatan secara fisik.
Gambar 6. Berat Optimum Adsoprsi Fenol oleh BMC
Panjang gelombang () maksimum fenol Panjang gelombang maksimun untuk fenol berada pada 454 nm. Panjang gelombang ini yang digunakan untuk penentuan konsentrasi fenol selanjutnya. Panjang gelombang yang diperoleh ini sesuai dengan beberapa penelitian yang dilakukan oleh Lestari (2011) yaitu pada panjang gelombang 454 nm, dan Ozkaya (2006) dengan panjang gelombang sekitar 500 nm. Selain menggunakan spektrofotometer dengan panjang gelombang visibel, fenol dapat dianalisis dengan menggunakan spektrofotometer UV, dengan panjang gelombang sekitar 270 nm (Qadeeret al., 2005). Kurva penentuan panjang gelombang maksimum fenol dapat dilihat pada Gambar 5.
Gambar 7. Waktu Optimum Adsorpsi Fenol oleh BMC
Gambar 8. pH Optimum Adsorpsi Fenol oleh BMC
Gambar 5. Panjang Gelombang () Maksimum Fenol
Hasil penelitian menunjukkan bahwa waktu optimum penyerapan fenol oleh biosorben BMC terjadi pada menit ke 40 (Gambar 7), dengan nilai kapasitas adsorpsi (Q) sebesar 278,735 µg fenol/g biosorben. Nilai kapasitas adsorpsi semakin meningkat dari menit ke 5 hingga menit ke 30. Peningkatan kapasitas adsorpsi ini terjadi karena adanya pembukaan tapak aktif yang lebih besar sehingga adsorben lebih banyak
Kondisi optimum adsorpsi fenol oleh biosorben Parameter yang dianalisis pada penentapan kondisi optimum adsorpsi fenol oleh BMC terdiri atas waktu, berat biosorben, dan pH optimum. Lamanya proses adsorpsi ditentukan berdasarkan kapasitas adsorpsinya selama rentang
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menyerap adsorbat, dan pada menit ke 40 terjadi adsorpsi fenol maksimum. Setelah mencapai waktu adsorpsi maksimum, kapasitas adsorpsi cenderung semakin menurun. Hal ini disebabkan oleh jumlah biosorben yang berikatan dengan adsorbat sudah dalam keadaan jenuh, sehingga apabila ditambahkan waktu adsorpsi yang berlebih akan menyebabkan terjadinya proses desorpsi atau pelepasan kembali antara biosorben atau pelepasan kembali antara biosorben dan adsorbat.
keberadaan NaOH (basa) dalam larutan yang mengandung fenol akan membentuk garam natrium dari fenol, yang akan memfasilitasi desorpsi fenol dari permukaan adsorben. Isoterm adsorpsi Tipe isoterm adsorpsi dapat digunakan untuk mempelajari mekanisme penjerapan. Adsorpsi pada fase padat-cair umumnya mengacu pada tipe isoterm Langmuir dan Freundlich (Atkins, 1999). Biosorben BMC memberikan linearitas 0,9994 untuk isoterm Langmuir dan 0,9951 untuk isoterm Freundlich (Gambar 9 dan 10). Adsorpsi fenol oleh biosorben BMC mengikuti persamaan isoterm Langmuir, karena linearitas untuk isoterm Langmuir lebih besar dibandingkan dengan isoterm Freundlich.
Pada sampel BMC, kapasitas adsorpsi optimum diperoleh dengan bobot biosorben sebanyak 0,05 g yakni sebesar 958,891 µg/g. Penambahan biosorben lebih dari 0,05 g tidak memberikan peningkatan kapasitas adsorpsi tehadap fenol, justru terjadi penurunan kapasitas adsorpsi. Kapasitas adsorpsi dapat dipengaruhi oleh pH larutan. Hal ini diperlukan untuk keakuratan parameter adsorpsi. Kondisi pH berpengaruh pada sorpsi karena pH akan mempengaruhi sifat elektrokimia larutan dan muatan partikel atau biosorben (Gambar 8).
Adsorpsi fenol oleh BMC mengikuti isoterm Langmuir, dengan demikian proses adsorpsi dapat diasumsikan bahwa lapisan biosorben membentuk satu lapisan (monolayer), keadaan setimbang bila kecepatan adsorpsi sama dengan kecepatan desorpsi, permukaan adsorbat bersifat homogen, dan fase adsorbat merupakan zat homogen (Anggraningrum, 1996). Jika linearitas kurva untuk kedua isoterm tinggi, maka dapat diasumsikan bahwa adsorpsi dapat berlangsung menurut isoterm Langmuir dan Freundlich sekaligus. Dan dari hasil penelitian yang diperoleh terlihat bahwa linearitas kurva isoterm Langmuir dan Freundlich cukup besar, yakni sebesar 0,9994 untuk isoterm Langmuir dan 0,9951 untuk isoterm Freundlich. Proses adsorpsi menurut isoterm Freundlich dapat diasumsikan bahwa biosorben membentuk lapisan multilayer, permukaan adsorbat bersifat heterogen. Nilai konstanta n, k, α, dan β dapat dihitung dari persamaan Langmuir dan Freundlich yang di dapat dan disajikan pada Tabel 2.
Secara umum kapasitas adsorpsi meningkat seiring dengan peningkatan pH, sampai titik tertentu. Pengaruh pH terhadap adsorpsi ini dipengaruhi oleh jenis adsorben maupun adsorbat. Pada sorpsi fenol oleh BMC, diperoleh hasil pH 3 sebagai pH optimum dengan kapasitas adsorpsi sebesar 1476,046 g/g. Pada pH 5,dan 7 terjadi penurunan kapasitas adsorpsi.Hal ini disebabkan penggunaan basa sebagai bahan aktivasi untuk impregnasi pada biosorben TKKS, sehingga biosorben TKKS memiliki sifat basa pada permukaannya, dan lebih efektif jika penyerapan terjadi pada suasana asam. Selain itu, cangkang telur yang merupakan salah satu penyusun BMC ini mengadung kalsium karbonat (CaCO3) yang bersifat basa. Kalsium karbonat dari cangkang telur ini dapat membuat larutan menjadi basa jika terhidrolisis dalam air, mengikuti mekanisme reaksi sebagai berikut. CaCO3
CO32- + H2O
Nilai konstanta α, β, n dan k yang diperoleh dari persamaan regresi Langmuir dan Freundlich menggambarkan besaran nilai adsorbat yang dapat diadsorpsi pada sisi permukaan biosorben. Nilai k menunjukkan kemampuan proses adsorpsi dan n menunjukkan konsentrasi adsorpsi, semakin naik nilai ini maka akan semakin besar proses adsorpsi.
Ca2+ + CO32
HCO3- + OH-
Sedangkan, proses sorpsi pada pH basa yakni pH 9 tidak dilakukan, karena fenol akan membentuk senyawa natrium fenolat yang akan mengurangi ikatan hidrogen antara fenol dan biosorben. Menurut Ozkaya (2006); Qadeer and Rehan (2002)
Nilai dan dapat diperoleh dari kondisi slope pada garis linear isoterm Langmuir. Slope bernilai 1/ sedangkan perpotongan dengan sumbu 1/x/m bernilai
50
Daftar Pustaka
1/. Nilai n dan k diperoleh dari kondisi slope pada garis linear isoterm Freundlich. Slope bernilai 1/n sedangkan nilai anti log dari perpotongan dengan garis log x/m bernilai k.
Anggraningrum, I. T. (1996). Model Adsorpsi Ion Kompleks Koordinasi Nikel (II) pada Permukaan Alumina. Tesis. Magister Sains Ilmu Kimia. Universitas Indonesia. Depok. Arunlertaree, C., Kaewsomboon, W., Kumsopa, A., Pokethitiyook, P. and Panyawathanakit, P. (2007). Removal of lead from battery manufacturing wastewater by egg shell. Songklanakarin Journal of Science and Technology, 29(3), pp. 857-868. Atkins, P. W. (1999). Kimia Fisik Jilid 1. alih bahasa; Rohadyan T, Hadiyana K. Jakarta: Erlangga. Darnoko, Guritno, P., Sugiharto, A. dan Sugesty, S. (1995). Pembuatan pulp dari tandan kosong sawit dengan penambahan surfaktan. J. Pen. Kelapa Sawit, 3(1), pp. 75-87.
Gambar 9. Isoterm Langmuir Adsorpsi Fenol oleh BMC
Elwakeel, K. Z. and Yousif A. M. (2010). Adsorption of malathion on thermally treated egg shell material. In: Proceeding of Fourteenth International Water Technology Conference. Egypt. Ghazy, S. E., El-Asmy, A. A. and El-Nokrashy, A. M. (2008). Separation of chromium (III) and chromium (VI) from environmental water samples using eggshell sorbent. Indian Journal of Science and Technology, 1(6), pp.1-7. Gambar 10. Isoterm Freundlich Adsorpsi Fenol oleh BMC
Indriyati, (2008). Potensi limbah industri kelapa sawit di Indonesia. M.Tek.Ling, 4(1), pp. 93-103.
Tabel 2. Nilai Konstanta n, K, , dari Persamaan Langmuir dan Freundlich BMC Isoterm Langmuir
Lestari, S. (2011). Pemanfaatan Limbah Tandan Kosong Kelapa Sawit (TKKS) sebagai Biosorben Fenol. Skripsi. Universitas Nusa Bangsa. Bogor.
Isoterm Freundlich
R2
N
K
R2
2,4786
-268,969
0,9994
0,9992
2,5276
0,9951
Lynch, C.T. (1990). Practical Handbook of Material science. 2nd Ed. New York: CRC Pr. Mortaheb, H. R., Amini, M. H., Sadeghian, F., Mokhtarani, B. and Daneshyar, H. (2008). Study on a new surfactant for removal of phenol from wastewater by emulsion liquid membrane. Journal of hazardous materials, 160(2), pp. 582-588.
Kesimpulan Biosorben dari TKKS yang dimodifikasi dengan cangkang telur (BMC) dapat digunakan sebagai biosorben fenol dengan nilai kapasitas adsorpsi sebesar 1476,046 g/g. Kondisi optimum adsoprsi pada waktu kontak 40 menit, bobot biosorben <0,05 g, dan pH <3. Adsorpsi fenol oleh BMC mengikuti persamaan isoterm Langmuir.
Orth A.B., Royse D.J. and M. Tien, M. (1993). Ubiquity of lignin-degrading peroxidases among various wood-degrading fungi. Appl Environ Microbiol, 59, pp. 4017-4023. Ozkaya, B. (2006). Adsorption and desorption of phenol on activated carbon anda comparison of isotherm models. Journal of Hazardous Materials, 129(1), pp. 158-163. Qadeer, R. and Rehan, A. H. (2002). A study of the adsorption of phenol by activated
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carbon from aqueous solutions. Turkish journal of chemistry, 26(3), pp. 357-362.
Yoo, S., Hsieh, J. S., Zou, P. and Kokoszka, J. (2009). Utilization of calcium carbonate particles from eggshell waste as coating pigments for ink-jet printing paper. Bioresource technology, 100(24), pp. 64166421.
Shrihari, V., Madhan, S. and Das, A. (2005). Kinetics of phenol sorption by Raw Agrowastes. Applied Sciences, 6(1), pp. 4750.
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J. Lignocellulose Technol. 01 (2016), 53-59
Journal of Lignocellulose Technology Journal homepage: http:/ejournal.lipi.go.id/index.php/jol/
Article
Sifat fisis dan mekanis papan partikel dengan menggunakan campuran perekat UF dan PF pada berbagai suhu pengempaan Ervi Utari Ginting1, Apri Heri Iswanto1*, Irawati Azhar1 1Fakultas
Kehutanan, Universitas Sumatera Utara
*corresponding author :
[email protected]
Received:1 December 2016. Received in revised form: 20 December 2016. Accepted: 20 December 2016. Published online: 23 December 2016
Abstract The objective of this research was to evaluate the effect of pressing temperature on physical and mechanical properties of the particleboards. Boards made from Durian wood shavings. The particles were dried up to 5.2% moisture content. The size of board was set on 25 by 25 cm2 with thickness and density target were 1 cm and 0.75 g/cm3, respectively. Board has been bonded using a mixture of UF and PF adhesives. Level of adhesives used in this study was 12% based on oven dry weight of the particles. The adhesive ratio of UF and PF was 70/30 (% w/w) with resin solid content of UF and PF were 63% and 50%, respectively. Indirect spraying resin was applied to produce of particleboard. UF was firstly sprayed and followed by PF resin. After mat forming, board was pressed using hot pressing machine. The pressing condition was set on 140, 150, 160, and 170 oC for 10 minutes and 30 kg/cm2 pressure. The results showed that 150oC temperature treatment produced better thickness swelling (TS), water absorption (WA) and internal bond (IB) particleboard compared to other treatments. The increasing of temperature resulted negative effect to those parameters. All of the IB value had met the JIS A 5908 (2003) standard. The temperature of 140oC resulted the best IB value indicating the resin mixture have cured well. Keyword : Pressing temperature, urea formaldehyde, phenol formaldehyde, durian wood shaving, physical-mechanical properties
Pendahuluan Ketidakseimbangan ketersediaan kayu dari hutan alam dengan kebutuhan bahan baku industri perkayuan merupakan fakta. Terjadi peningkatan kebutuhan kayu bulat di Indonesia dari tahun 2013-2014 sebesar 15.38 juta (Kementerian Kehutanan, 2014). Salah satu solusi permasalahan pemenuhan kebutuhan bahan baku bagi
industri papan komposit diantaranya papan partikel adalah melalui pemanfaatan limbah kayu baik yang berasal dari limbah industri penggergajian, pengerjaan maupun limbah kayu dari hutan. Pada pembuatannya, bahan baku tersebut diikat dengan perekat sintetis thermosetting atau thermoplastic melalui proses pengempaan panas (Maloney,
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4
1993). Keterbatasan sifat papan partikel menyebabkan pengggunaannya terbatas untuk keperluan interior seperti furniture, peredam suara, partisi dinding dan lain-lain.
Metode 1. Proses Pembuatan Pada penelitian ini, rasio campuran perekat UF dan PF yang dipergunakan sebesar 70/30 (% w/w) berdasarkan berat kering partikel. Serutan kayu durian dan perekat dicampur dengan menggunakan rotary blending machine. Selanjutnya dilakukan pembuatan lembaran dimana furnish dicetak dengan menggunakan cetakan ukuran 25×25 cm2. Kemudian lembaran dikempa panas pada berbagai variasi suhu (140, 150, 160 dan 170oC) dikempa dalam waktu 10 menit pada tekanan 30 kgf/cm3. Pengkondisian papan partikel dilakukan selama ± 7 hari pada kondisi suhu ruang.
Penelitian ini menggunakan jenis perekat campuran antara urea formaldehida (UF) dengan phenol formaldehida (PF). Sebagaimana dikemukakan oleh Zhang et al. (2015) bahan urea sering dipergunakan sebagai akselerator untuk mempercepat proses pematangan perekat PF serta mengurangi biaya dari perekat PF. Sementara itu PF digunakan untuk memperbaiki ketahanan terhadap air dan mengurangi emisi formaldehida pada perekat UF karena sifat hidrofobik dari cincin benzena serta tingginya konstanta ekuilibrium dari reaksi phenol dan formaldehida. Oleh karena itu pencampuran perekat ini diharapkan dapat memperbaiki kelemahan papan partikel dalam hal stabilitas dimensinya yang rendah. Heygreen dan Bowyer (1996) menyatakan bahwa pengembangan tebal papan partikel berkisar anatara 10-25% dari kondisi basah ke kering melebihi pengembangan kayu utuhnya serta pengembangan liniernya hingga 0.35.
2. Pemotongan Contoh Uji Pola pemotongan contoh uji dan pengujian sifat fisis mekanis dilakukan berdasarkan standar JIS A 5908 (2003) seperti pada Gambar 1. Universal Testing Machine/UTM Instron digunakan untuk menguji sifat mekanis papan partikel.
Tekanan dan suhu kempa merupakan parameter proses pengempaan yang sangat berpengaruh dalam menghasilkan papan yang menghasilkan papan yang berkualitas baik. Kedua parameter ini berperan penting dalam mengoptimalkan laju polimerisasi perekat. Hal ini telah dinyatakan sebelumnya oleh Parida et al. (2001). Selanjutnya Wang dan Dai (2003) mengemukakan bahwa pengaturan kondisi suhu dan waktu pengempaan dapat dilakukan melalui dua mekanisme yaitu peningkatan waktu kempa pada suhu yang konstan atau melalui peningkatan suhu kempa pada waktu kempa yang konstan. Fokus dari penelitian ini adalah untuk memperbaiki stabilisasi dimensi papan partikel dengan menggunakan campuran perekat UF dan PF melalui pengaturan beberapa suhu pengempaan.
Gambar 1. Pola Pemotongan contoh uji papan partikel Keterangan gambar: A = Sampel uji MOE & MOR (5 x 20) cm2 B = Sampel uji kerapatan dan KA (10 x 10) cm2 C = Sampel uji PT dan DSA (5x 5) cm2 D = Sampel uji IB (5 x 5) cm2 3. Analisis data
Bahan dan Metode
Penelitian ini menggunakan analisis Rancangan Acak Lengkap (RAL) dengan 3 ulangan. Perbedaan antar perlakuan dianalisis menggunakan uji wilayah berganda Duncan (Duncan Multiple Range Test/DMRT). Data hasil pengujian untuk setiap parameter yang diuji dianalisis dan dibandingkan dengan persyaratan JIS A 5908 (2003) sebagai standarnya.
Bahan Perekat yang digunakan adalah Urea Formaldehida (UF) dan Phenol Formaldehida (PF) diperoleh dari PT. Palmolite Adhesive Industri (PT. PAI) Probolinggo, Jawa Timur. Serutan kayu durian diperoleh dari tempat penggergajian di Kota Medan.
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variasi suhu kempa tidak memberikan pengaruh yang berbeda nyata pada selang kepercayaan 95% terhadap nilai kerapatan papan partikel yang dihasilkan.
Hasil dan Pembahasan Sifat Fisis Papan Partikel 1. Kerapatan dan Kadar Air
Hasil penelitian menunjukkan bahwa nilai kadar air papan partikel berkisar antara 7,78-11,12% (Gambar 2) dan nilai ini telah memenuhi standar JIS A 5908 (2003) yang mensyaratkan nilai kadar air papan partikel berkisaran 5-13%. Nilai kadar air tertinggi terdapat pada perlakuan suhu kempa 150oC dan terendah pada suhu 160oC. Faktor yang berperan dalam parameter kadar air yaitu kadar air partikel dan kondisi lingkungan pada saat proses pengempaan. Hal ini sesuai dengan pendapat Maloney (1993) yang menyatakan bahwa kadar air awal bahan baku berperan penting dalam menentukan kadar air papan partikel yang dihasilkan.
Nilai kerapatan dan kadar air papan partikel disajikan pada Gambar 2. Nilai kerapatan papan yang dihasilkan berkisar antara 0,57-0,61 g/cm3 dimana nilai tertinggi diperoleh pada perlakuan suhu kempa 140oC dan nilai terendah pada suhu kempa 150 dan 160oC.
Hasil sidik ragam menunjukkan bahwa perlakuan suhu kempa berpengaruh nyata pada selang kepercayaan 95% terhadap parameter kadar air papan partikel. Hasil uji lanjut Duncan Multiple Range Test (DMRT) menunjukkan bahwa perlakuan pengempaan dengan suhu kempa tertinggi 170oC dan terendah 140oC tidak memberikan pengaruh yang berbeda nyata, namun terhadap perlakuan lain memberikan pengaruh yang berbeda. Dengan kata lain penggunaan suhu 1400C secara ekonomis dan teknis bisa dijadikan pertimbangan dalam pembuatan papan partikel dengan menggunakan perekat campuran UF dan PF.
Keterangan: perlakuan yang diikuti oleh huruf yang sama akan menunjukan pengaruh yang tidak berbeda nyata menurut DMRT 5%
Gambar
2.Kerapatan papan partikel berbagai variasi suhu
pada
Kerapatan papan partikel yang dihasilkan tidak sesuai dengan kerapatan target sebesar 0,75 g/cm³ namun sudah memenuhi standar JIS A 5908-2003 yang mensyaratkan nilai kerapatan papan berkisar anatara 0,4 - 0,9 g/cm³ JSA, 2003. Hal ini kemungkinan karena tidak tercapainya tekanan kempa yang ditargetkan, springback papan setelah proses pengkondisian dan adanya partikel yang terbuang selama pembuatan papan. Bufalino et al. (2012) menyatakan bahwa rendahnya nilai kerapatan papan partikel dikarenakan adanya sejumlah partikel yang terbuang selama proses pembuatan. Heygreen dan Bowyer (1996) yang menyatakan bahwa nilai kerapatan sangat tergantung pada kerapatan kayu yang digunakan dan besarnya tegangan kempa yang diberikan dalam pembuatan lembaran. Kelly (1977) melaporkan bahwa beberapa faktor yang mempengaruhi nilai kerapatan papan diantaranya jenis kayu, tekanan kempa, jumlah partikel, jumlah perekat dan bahan aditif yang ditambahkan. Hasil sidik ragam menunjukkan bahwa perlakuan
2. Pengembangan Tebal (PT) Nilai PT papan partikel dengan lama perendaman 2 jam lebih rendah dibandingkan dengan PT 24 jam (Gambar 3). Presentase peningkatan nilai PT berkisar 34,54%-56,33%. Hal ini menunjukkan bahwa papan partikel rentan untuk menyerap air. Hal ini berkaitan dengan ikatan hidrogen dalam komponen utama dinding sel serpih kayu durian yang merupakan salah satu jenis bahan berlignoselulosa. Nilai terendah dan tertinggi pada pengukuran PT 2 jam dan 24 jam terdapat pada papan partikel masing-masing pada suhu kempa 1400C dan 170oC. Semakin tinggi suhu pengempaan menyebabkan nilai PT papan partikel yang dihasilkan semakin besar, hal ini diduga karena perekat UF mengalami overcuring. Nilai PT terkait dengan nilai IB (Gambar 4), dimana nilai IB
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merupakan fungsi dari suhu pengempaan. Peningkatan suhu kempa cenderung menurunkan IB. Pada suhu pengempaan yang terendah, terjadi ikatan yang baik antara partikel dengan perekat. Lebih besarnya rasio UF dibandingkan dengan PF dalam campuran perekat berpengaruh terhadap suhu curing perekat yang optimal. Perekat UF idealnya menggunakan suhu pengempaan maksimal 140oC. Ketidaksesuain suhu pengempaan dengan perekat campuran yang didominasi perekat UF ini berpengaruh terhadap peningkatan nilai pengembangan tebal yang dihasilkan dengan semakin tingginya suhu pengempaan.
Nilai daya serap air papan partikel disajikan pada Gambar 4, dimana nilai DSA papan partikel meningkat dengan semakin lamanya perendaman papan partikel dalam air.
Keterangan: perlakuan yang diikuti oleh huruf yang sama berarti tidak berbeda nyata pengaruhnya menurut DMRT 5%
Gambar 4. Daya Serap Air Papan Partikel
Nilai DSA memiliki kencenderungan yang sama dengan nilai PT dimana semakin tingginya suhu pengempaan berkorelasi linier positip dengan nilai DSA. Hal ini diduga karena terjadi overcuring perekat UF pada suhu pengempaan yang lebih tinggi dari suhu ideal pengempaanya yaitu 1400C. Hal ini menyebabkan terjadinya penurunan daya ikat antara perekat dengan partikel. Mamza et al. (2014) menyatakan bahwa titik melting perekat UF pada suhu 132,7oC. Pada penelitian ini nilai DSA masih tinggi. Bowyer, Shmulsky and Haygreen (2003) menyatakan bahwa penyerapan air terjadi karena adanya gaya absorpsi yang merupakan gaya tarik molekul air pada tempat ikatan hidrogen yang terdapat dalam selulosa, hemiselulosa, dan lignin. Winandy dan Krzysik (2007) menyatakan bahwa peningkatan suhu pengempaan tidak menyebabkan produk medium density fiberboard (MDF) tahan terhadap penyerapan air karena untuk partikel kayu mengandung hemiselulosa dimana komponen ini bersifat hidrofilik dan bertanggung jawab terhadap kemampuan DSA.
Keterangan: perlakuan yang diikuti oleh huruf yang sama menunjukan pengaruh yang tidak berbeda nyata menurut DMRT 5%
Gambar 3. Pengembangan tebal papan partikel pada berbagai variasi suhu
Hasil sidik ragam menunjukkan bahwa perlakuan suhu kempa berpengaruh nyata pada selang kepercayaan 95% terhadap PT papan partikel selama perendaman 2 dan 24 jam. Selain itu, hasil uji DMRT menunjukkan bahwa pada PT 2 jam dengan perlakuan suhu pengempaan 170oC berbeda nyata terhadap perlakuan lainnya. Sementara itu, untuk suhu pengempaan 140, 150 dan 160oC masing-masing tidak berbeda nyata satu dengan yang lainnya. Sementara untuk PT 24 jam menunjukkan bahwa perlakuan suhu pengempaan antara 140 dengan 150oC tidak berbeda nyata, begitu juga dengan perlakuan suhu pengempaan antara 160 dengan 170oC. Secara keseluruhan PT papan partikel yang dihasilkan pada penelitian ini belum memenuhi standar JIS A 5908 (2003) dengan nilai maksimal 12%.
Analisis sidik ragam menunjukkan bahwa perlakuan suhu pengempaan memberikan pengaruh nyata pada selang kepercayaan 95% terhadap DSA papan partikel dengan perendaman 2 jam dan 24 jam. Hasil uji lanjut DMRT menunjukkan bahwa pada DSA 2 jam perlakuan suhu pengempaan masing-masing manunjukkan
3. Daya Serap Air (DSA)
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perbedaan antar perlakuan kecuali antara perlakuan suhu kempa 160 dengan 170oC yang tidak berbeda nyata. Sementara itu untuk DSA 24 jam menunjukkan bahwa perlakuan suhu pengempaan 140 dengan 150oC tidak berbeda nyata, begitu juga dengan perlakuan suhu pengempaan antara 160 dengan 170oC. Meskipun nilai DSA papan partikel tidak dipersyaratkan dalam JIS A 5908 - 2003, namun parameter ini penting untuk diketahui karena mempengaruhi nilai PT papan partikel yang dihasilkan.
pada penelitian ini partikel yang digunakan berupa serutan. Nilai SR akan memberikan pengaruh terhadap kemudahan didalam pengorientasian. Partikel dengan SR yang tinggi akan lebih mudah diorientasikan sehingga terjadi peningkatan kekuatan papan yang dihasilkan dan memerlukan lebih sedikit perekat dalam setiap luasan permukaan kontak untuk mengikat partikel. Lebih lanjut, Maloney (1993) dan Heygreen dan Bowyer (1996) menyatakan bahwa nilai MOE dipengaruhi oleh kandungan dan jenis bahan perekat yang digunakan, kerapatan papan, daya ikat perekat, dan geometri partikel. Hasil analisis sidik ragam menunjukkan bahwa perlakuan variasi suhu kempa tidak berpengaruh nyata terhadap nilai MOE pada selang kepercayaan 95% .
Sifat mekanis papan partikel 1. Modulus of elasticity (MOE) dan Modulus of Rupture (MOR) Nilai MOE dan MOR papan partikel disajikan pada Gambar 5. Nilai MOE pada penelitian berkisar antara 7645 - 9660 kgf/cm2. Nilai rata-rata MOE papan partikel tertinggi dan terendah diperoleh pada papan dengan perlakuan suhu pengempaan 160oC dan 170oC. Hal ini mengindikasikan bahwa peningkatan suhu kempa hingga 160oC masih memberikan respon yang positif terhadap nilai MOE papan. Peningkatan suhu kempa diatas 160oC menunjukkan penurunan nilai MOE yang signifikan. Terjadinya overcuring perekat UF pada pengempaan suhu 1700C menyebabkan papan bersifat lebih rapuh.
Nilai MOR papan partikel yang dihasilkan berkisar antara 67,27 - 94,24 kgf/cm2 (Gambar 5). Nilai MOR tertinggi dan terendah dicapai pada papan dengan perlakuan suhu pengempaan 160oC dan 170oC. Nilai MOR memiliki kecenderungan yang hampir sama dengan MOE. Peningkatan suhu pengempaan diatas 160oC cenderung menurunkan nilai MOR. Hal ini karena penggunaan suhu kempa yang tinggi menyebabkan terjadinya overcuring. Pada kondisi ini ikatan perekat dan partikel yang telah terbentuk menjadi pecah sehingga terjadi penurunan kemampuan menahan beban. Suryadinata (2005) menyatakan bahwa penggunaan suhu kempa yang terlalu tinggi melewati batas suhu kempa optimum menyebabkan penurunan nilai MOR pada papan partikel. MOR papan partikel dengan suhu pengempaan 150 dan 160oC telah memenuhi standar JIS A 5908 (2003) yang mensyaratkan nilai MOR minimal 82 kgf/cm2. 2. Internal Bond (IB) Nilai rata-rata IB papan partikel hasil penelitian ini berkisar antara 1,98 3,65 kgf/cm2 (Gambar 6) dimana IB terendah diproleh pada perlakuan suhu pengempaan 160oC dan yang tertinggi pada suhu pengempaan 140oC. Nilai IB cenderung menurun seiring dengan peningkatan suhu pengempaan. Overcuring perekat UF pada suhu tinggi menyebabkan daya ikat antara partikel dengan perekat mengalami penurunan. Nilai IB yang dihasilkan dari penelitian ini telah memenuhi standar JIS A 5908 (2003) yang mensyaratkan minimum nilai IB dari papan partikel sebesar 1,5 kg/cm2. Proses
Gambar 5. Modulus of elasticity (MOE) dan Modulus of rupture (MOR) pada berbagai variasi suhu
Nilai MOE papan yang dihasilkan masih jauh dibawah nilai standar JIS A 5908 (2003) dengan nilai minimal 20.400 kgf/cm2. Hal ini terkait dengan nilai slenderness ratio (SR) dari partikel serpih kayu durian yaitu sebesar 42,90. Maloney (1993) yang menyatakan bahwa nilai ideal SR untuk partikel sebesar 150 yang dimiliki oleh partikel dalam bentuk flake. Sementara
57
pencampuran, pembentukan, dan pengempaan yang tepat akan menentukan kualitas papan yang dihasilkan. Keberhasilan proses perekatan dipengaruhi oleh penggunaan waktu dan suhu pengempaan. Penggunaan suhu yang terlalu rendah menyebabkan perekat belum matang. Overcuring terjadi jika suhu perekat yang digunakan terlalu tinggi sehingga perekat menjadi rapuh. Kondisi ini dapat menyebabkan penurunan nilai IB. Kecenderungan penurunan nilai IB seiring dengan peningkatan suhu kempa juga telah dilaporkan oleh Widyorini et al. (2005).
Daftar Pustaka Bowyer, J.L., Shmulsky, R. and Haygreen, J. G.(2003). Forest Products and Wood Science: An Introduction. Ed ke-4. Ames, Iowa: Iowa State Press. Bufalino, L., Albino, V.C.S., VA de Sá, Corrêa, A.A.R., Mendes, L.M. and Almeida NA.(2012). Particleboards Made from Australian Red Cedar: Processing Variables and Evaluation of Mixed- Species. J. Tropical Forest Science, 24 (2), pp. 162 Fore. Haygreen, J. G. dan J. L. Bowyer.(1996). Hasil Hutan dan Ilmu Kayu Suatu Pengantar. Gajah Mada University Press. Yogyakarta. Japanese Standards Association.(2003). Japanese Industrial Standard (JIS) A 5908. Particleboard. Tokyo: Japanese Standards Association. Kelly, M.W. (1977). Critical Literature Review of Relationship Between Processing Parameter And Physical Properties of Particleboard. General Technical Report FPL-10. Department of Agriculture Forest. Wisconsin University. Kementrian Kehutanan. (2013). Statistika Kehutanan Indonesia 2013. Kementrian Kehutanan. Jakarta.
Keterangan: perlakuan yang diikuti oleh huruf yang sama menunjukkan pengaruh tidak berbeda nyata menurut DMRT 5%
Kementrian Kehutanan. (2014). Statistika Kehutanan Indonesia 2014. Kementrian Kehutanan. Jakarta.
Gambar 6. Internal Bond (IB) papan partikel pada berbagai variasi suhu
Hasil analisis sidik ragam menunjukkan bahwa variasi suhu pengempaan berpengaruh nyata terhadap nilai IB papan partikel pada selang kepercayaan 95%. Hasil uji DMRT menunjukkan bahwa perlakuan suhu kempa 140oC berbeda nyata pengaruhnya terhadap suhu pengempaan lain. Sementara itu perlakuan suhu pengempaan 150, 160 dan 170oC tidak berbeda nyata satu dengan yang lainnya.
Maloney, T.M. (1993). Modern particleboard and dry-process fiberboard manufacturing (updated edition). Miller Freeman, San Francisco. Paridah, M.T., Chin, A.M.E. and Zaidon A. (2001). Bonding properties of Azadirachta excelsa. Journal of Tropical Forest Products pp. 161– 171. Mamza, P. A., Ezeh, E. C., Gimba, E. C. and Arthur, D. E. (2014). Comparative study of phenol formaldehyde and urea formaldehyde particleboards from wood waste for sustainable environment. International Journal Of Scientific and Technology Research, 3(9), pp. 53-61.
Kesimpulan Perlakuan variasi suhu pengempaan bengaruh terhadap sifat fisis dan mekanis papan partikel yang dihasilkan terutama pengembangan tebal, daya serap air dan internal bond. Meskipun demikian belum diperoleh kondisi yang optimal pengempaan yang dapat memperbaiki karakteristik fisismekanis papan partikel terutama untuk pengembangan tebal. Secara keseluruhan dengan meningkatnya suhu pengempaan menurunkan stabilitas dimensi dan keteguhan rekat internal papan partikel dengan menggunakan campuran perekat PF dan UF dengan rasio 70/30.
Pizzi, A. (1994). Advanced Wood Adhesives Technology. New York: Marcel Dekker Inc. Suryadinata, E. (2005). Determinasi Suhu dan Waktu Kempa Optimum dalam Pembuatan Papan Komposit dari Limbah Kayu dan Karton Gelombang [Skripsi]. Bogor: Fakultas Kehutanan. Institut Pertanian Bogor. Wang, S. and Dai, C. (2003). Press Control for Optimized Wood Composite Processing and
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Properties. Part 2. Properties and Press Control Strategies. Proceeding of a Workshop Fundamental of Composite Processing November 5-6, 2003 in Madison, Wisconsin, USA. Widyorini, R., Xu, J., Watanabe, T. and Kawai, S. (2005). Self-bonding characteristics of binderless kenaf core composites. Wood Sciense and Technology Journal, 39, pp. 651-662. Winandy, J.E. and Krzysik, A.(2007). Thermal degradation of wood fibers during hotpressing of MDF composites: Part I. Relative effects and benefits of thermal exposure. Wood Fiber Sci, 39 (3), pp. 450–46. Yang, H. S., Kim, D. J. and Kim, H. J. (2003). Rice straw–wood particle composite for sound absorbing wooden construction materials. Bioresource Technology, 86(2), pp.117-121. Zhang, Y., Zheng, J., Guo, H., Li, Y. and Lu, M. (2015). Urea formaldehyde resin with low formaldehyde content modified by phenol formaldehyde intermediates and properties of its bamboo particleboards. Journal of Applied Polymer Science, 132(27)
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J. Lignocellulose Technol. 01 (2016), 60-67
Journal of Lignocellulose Technology Journal homepage: http:/ejournal.lipi.go.id/index.php/jol/
Article
Biodegradation optimization of 2,4,8trichlorodibenzofuran by ligninolytic fungus Ajeng Arum Sari1*, Kazutaka Itoh2, Sanro Tachibana2 1Research
Center for Chemistry, Indonesian Institute of Sciences, Kawasan Puspiptek Serpong, Tangerang Selatan, Banten 15314 Indonesia 2Department of Applied Bioscience, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566 Japan *Corresponding
author:
[email protected];
[email protected]
Received:8 December 2016. Received in revised form: 17 December 2016 Accepted: 18 December 2016. Published online: 23 December 2016
Abstract Incineration does have its critical problem if chlorine presence in the solid waste because it may lead to emissions containing highly toxic dioxins and furans. Dioxin is known to be toxic and carcinogenic compounds with long half-lives, and is among the most problematic environmental pollutants. Recently, the biological methods are receiving more attention since they are considered as an environmental friendly method. This study was focused on the biodegradation of 2,4,8-trichlorodibenzofuran in liquid medium and soil by Trametes versicolor U80 for 15 and 30 days. The optimization of 2,4,8-TCDF degradation was conducted by adding glucose as carbon source, surfactant Tween 80, and agitation. In liquid medium, this strain degraded 27 ppm 2,4,8-trichlorodibenzofuran 46.52% at 30 days. Adding glucose 2.5% and 2% Tween 80 were able to improve degradation of 2,4,8-trichlorodibenzofuran as approximately 59%. Wood meal has the highest ability used as lignocellulosic supports for the growth of T.versicolor U80 to degrade 2,4,8-trichlorodibenzofuran in soil. In soil, this strain pre-grown wood meal degraded 10 ppm 2,4,8-trichlorodibenzofuran 46.06% at 30 days. Keywords : 2,4,8-trichlorodibenzofuran; biodegradation; ligninolytic enzymes; Trametes versicolor
Introduction 2,4,8-trichlorodibenzofuran (2,4,8TCDF) that belongs to polychlorinated dibenzofurans (PCDFs) is formed as a result of incineration processes and as byproducts of chemical reactions such as chlorine bleaching of paper and pulp, and from the manufacture of some chlorinated pesticides, herbicides, fungicides, wood preservatives, and textile dyes (Evans and
Dellinger, 2005; Gilpin, Wagel and Solch, 2003; Krizanec et al., 2005) (Fig. 1). PCDFs are a harmful chemical that poses a risk of long-term contamination in soil or bottom sediment because they have a chemically stable structure and accumulates in the environment over a long time. They also pose to the health of humans and animals based on standard toxicity test
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performed on animal revealed differential sensitivity to PCDFs exposure (Kamei, Suhara and Kondo, 2009). The primary human health concerns associated with PCDFs are immunotoxicity, developmental toxicity, neurotoxicity, carcinogenicity, skin, liver, and gastrointestinal toxicity (Kogevinas, 1999; Geusau et al., 2001). Because of their toxicity, how to remove them from polluted environments is one of the most challenging problems in environmental technology. Some physicochemical techniques for detoxifying and degrading dioxins such as thermal remediation, photodegradation, supercritical water with a metal catalyst, have been developed and considered for application. However, physicochemical methods are not feasible to remedy large areas of polluted soils and sediments from both ecological and economic viewpoints (Hiraishi, 2003).
In recent years, some studies of the dioxin using microorganisms, as well as some of their less highly derivatives, have been performed (Hiraishi, 2003). The only evidence for the degradation of chlorinated dioxins by fungi is limited to wood-, or litterdegrading white-rot fungi (Field and SierraAlvarez, 2008). The white-rot fungi constitute the most important group of organisms responsible for the degradation of nature’s most complex polymer, lignin. The white rot fungi such as Phanerochaete chrysosporium, P. Sordida, Bjerkandera, Phlebia and Pleurotus showed the potential ability to degrade dioxin from various environments such as contaminated soils, temperate and tropical forests (Chang, 2008). They use oxidative enzymes to initiate the attack of a variety of xenobiotic pollutants, including chlorinated dioxins. Phanerochaete chrysosporium, P. sordida, Phlebia lindtneri, Phlebia sp. MG-60, unidentified strain MZ-227, Phlebia strains (BMC3014, BMC9152 and BMC9160) and PL1 have able to degrade PCDDs and PCDFs in several concentrations (Valli, Wariishi and Gold, 1992; Takada et al., 1996; Mori and Kondo, 2002a; Mori and Kondo, 2002b; Kamei, Suhara and Kondo, 2005; Tachibana, Kiyota and Koga, 2005). In general, several factors can influence biodegradation by fungi, such as the fungal growth conditions and the chemical structure of the compounds. The fungal growth conditions are affected by carbon source, surfactant, and agitation. Ligninolytic fungi are not able to use lignin as their sole source of energy and carbon. They depend on the more digestible polysaccharides in lignocellulosic substrates. The induction of the chemical compounds degradation, when adding glucose as readily metabolizable carbon source, probably occurs as a result of increasing cell biomass cause faster degradation of that compound. Studies have demonstrated synthetic surfactant such as Tween 80 at low concentrations may be useful for bioremediation of sites contaminated with hydrophobic pollutants. Wong et al., (2004) reported that Pseudomonas aeruginosa when combined with Tween 80 effectively enhanced the solubility and degradation of phenanthrene. By increasing the chemical compound, Tween 80 facilitates the transport of it to microbial cells and improves the metabolism of this hydrocarbon (Hadibarata and Tachibana, 2009). Some research studies have also shown ligninase production in agitated
Figure 1. Structure of 2,4,8-trichlorodibenzofuran
Recently, the biological methods are receiving more attention since they are considered as an environmental friendly way. Using defined microorganisms with the ability to degrade dioxins to eliminate pollution in the environment could have huge advantages over physicochemical methods. Bioremediation uses the microorganisms to degrade environmental pollution into the less toxic compound. The extent of biodegradation is highly dependent on the toxicity and initial concentrations of the contaminants, their biodegradability, the properties of the contaminated soil and the type of microorganism selected (Kulkarni, Crespo and Afonso, 2008). Bioremediation can take place under aerobic and anaerobic conditions. Dioxin degradation has been characterized in aerobic bacteria containing aromatic ring hydrolating dioxygenase enzymes, anaerobic bacteria through reductive chlorination under anaerobic conditions and fungi producing extracellular oxidative enzymes (Chang, 2008).
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pelleted cultures. Stirring could increase the contact between the substrate, oxygen, and biomass. It will enhance mass transfer and finally affect to degradation rate.
and then incubated for 15 and 30 days in dark condition at 25 °C. Positive control was used to support this experiment to quantify the adsorption losses of pollutant caused mycelium in liquid medium. The positive control was sterilized by using autoclave before addition of 2,4,8-TCDF. The optimization of 2,4,8-TCDF degradation was conducted by adding glucose as carbon source (2-10%), surfactant Tween 80 (0.252%), and agitation (80 and 120 rpm).
Compared to bacteria, some white rot species are better able to colonize soil and to compete with microflora. Some fungi were reported to release the target pollutants as they decompose the macromolecular organic matter with which the target pollutants have combined. Moreover, the ability of fungal hyphae to reach the pollutant by penetrating contaminated soil, coupled with the production of extracellular oxidases, gives fungi a significant advantage over bacteria (Pointing, 2001). However, the degradation experiment for PCDFs was carried out commonly under liquid culture conditions and provided little information about the treatment of soil that was contaminated with PCDFs.
Soil culture preparation Soil was collected from a land farming area in Faculty of Agriculture, Ehime University, Japan. It was obtained from the surface layer (0-20 cm) with pH 6.16 (in distilled water ratio 1:5). The soil was airdried, passed through a 3 mm sieve and homogenized. Before its use, the soil was autoclaved 121°C for 180 min to eliminate exist of microorganisms and spiked with 10 ppm 2,4,8-TCDF dissolved in distilled water containing DMF and Tween 80. The water soil content was adjusted 30% with addition distilled water. The several types for inoculation were conducted (Table 1). All treatments were added with 10% shiitake no sato and 10% glucose. The container culture was incubated for 15 and 30 days after adding pollutant at 25°C in the dark condition.
This study was focused on the bioremediation of 2,4,8trichlorodibenzofuran (2,4,8-TCDF) by a white-rot fungus, Trametes versicolor U80. Five enzymes (lignin peroxidase, manganese peroxidase, laccase, 1,2-dioxygenase, and 2,3-dioxygenase) were also measured to know enzyme activities of the fungus. The several treatments were also conducted to obtain the optimum condition during 2,4,8TCDF degradation in liquid and soil media.
Table 1. Experimental design for pre-incubation condition in soil medium
Material and Methods
No.
Chemical reagents
1.
2,4,8-trichlorodibenzofuran (2,4,8TCDF) was purchased from Tokyo Chemical Industry, Ltd (Tokyo, Japan). Agar, glucose, and other chemicals were purchased from Wako Co. Ltd (Osaka, Japan). Malt extract and polypeptone were purchased from Difco.
2. 3.
Inoculum type
Nutrients
Fungi: preincubation in wood meal Fungi: preincubation in paper sludge Fungi: preincubation in liquid medium
Glucose 10%, shiitake no sato 10%, wood meal (5 and 10%) Glucose 10%, shiitake no sato 10%, paper sludge (5 and 10%) Glucose 10% and shiitake no sato 10%
Liquid culture condition
Analytical methods
T. versicolor U80 was tested in a liquid medium to know its ability in degrading 2,4,8-TCDF. Liquid cultures experiments were conducted in 100 mL Erlenmeyer flasks containing 20 ml of malt extract liquid medium (Sari, Tachibana and Itoh 2012). As much as 27 ppm 2,4,8-TCDF was eluted in N, N-Dimethylformamide, Tween 80, and distilled water. The medium was sterilized for 20 min at 121 °C, and then three plugs of each fungus were inoculated into the Erlenmeyer flask and pre-incubated for 7 days. Each of inoculated flasks was supplemented with 27 ppm of 2,4,8-TCDF,
After culture period, the samples in liquid medium were extracted with ethyl acetate for three times and then purified by column chromatography (5 g silica gel C200 and anhydrous Na2SO4) elute with hexane: dichloromethane (3:1). The concentrated samples were analyzed using GC-MS Shimadzu QP-5000. The capillary column used was TC-5 (length: 30 m, diameter 0.24 mm. The carrier gas was helium at constant flow rate 1.5 mL/min with column pressure 100 kPa and interface temperature 260°C. The temperature program was started at 80°C, 20°C/min to 150°C, 25°C/min to
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revealed that P. sordida YK-624 degraded 45-70% of PCDFs (TCDF-HxCDFs) in Kirk’s medium. The ability of fungi to degrade PCDD/Fs depends on the configuration of the isomers and increasing the degree of chlorination of the aromatic rings (Hiraishi, 2003). The rapid PCDF reduction by fungi is occurred when one aromatic ring has free of chlorine substitution or position 1 does not chlorinated. PCDF congeners substituted in position 1 could also degrade rapidly only if the position 4 and 6 are free of chlorine substitution (Schreiner et al., 1997).
300°C which maintained for 10 min to allow eluting peak to exit the column. The injection volume was 1 µL, and the injector was maintained at 260°C. After culture period, the samples in soil medium were extracted using a soxhlet apparatus for 16 hours with dichloromethane, purified using column chromatography (5 g C200 silica gel and anhydrous Na2SO4) eluted with hexane: dichloromethane (3:1), and then analyzed using GC-MS as described above. Enzyme assays
Enzyme activities of T. versicolor U80 were measured when cultivating fungi with and without the addition of 2,4,8-TCDF. The high enzyme activities of T. versicolor U80 during 2,4,8-TCDF degradation were obtained by 1,2-dioxygenase (80.0±13.6 Ul1) and LiP (89.8±25.5 Ul-1) (Fig. 3). On the contrary, the activity of laccase and MnP did not show the constant tendency during the incubation. From these results, it was suggested that the 1,2-dioxygenase and LiP were responsible for the degradation of 2,4,8-TCDF. This result was in line with result from Tachibana, Kiyota and Koga (2005) that LiP and MnP played a role for degradation of 2,4,8-TCDF. Laccase amount during addition of 2,4,8-TCDF was higher than absence of 2,4,8-TCDF. However, laccase did not play a role for degradation because this enzyme has only able to oxidize phenolic compounds (Farnet et al. 2010).
The samples in liquid medium were filtered through a 0.2 µm membrane filter to determine the enzyme activities (laccase, manganese peroxide, lignin peroxidase, 1,2dioxygenase, and 2,3-dioxygenase) using Spectrophotometer Shimadzu UV-1600. The enzyme assays were following methods from Sari et al. (2012). Results and Discussion 2,4,8-trichlorodibenzofuran degradation by T. versicolor U80 in liquid medium T. versicolor U80 degraded 2,4,8-TCDF in exponential phase up to 15 d, and it was followed by a slower rate during the remaining period of incubation. T. versicolor U80 degraded 2,4,8-TCDF 34.69%±3.98 on 15 days and 46.52%±4.71 on 30 days (Fig. 2). The loss of 2,4,8-TCDF approximately 23-24% on 15 and 30 days were may caused by adsorption process in mycelia of fungus during incubation time.
Enzyme activity (U/l)
Addition of TCDF
200
100
100
80 60
Control (+)DegradationControl (+)Degradation 15 day
LiP
MnP
2,3-diox
1,2-diox
LiP
MnP
15 days
0
Laccase
20
2,3-diox
40
1,2-diox
0
Laccase
Degradation rate (%)
Without addition of TCDF
300
30 days
Figure 3. Enzyme activities of T. versicolor U80 during the incubation with or without addition of 2,4,8-TCDF
30 day
Figure 2. Degradation rate of 2,4,8-TCDF (27 ppm) by T. versicolor U80 in malt extract liquid medium
The redox potential of LiP is higher than for most other peroxidases (Cameron, Timofeevski and Aust, 2000). It allows for the oxidation of chemicals that are not easily oxidized. LiP can oxidize series of pollutant which has some similarity structure to the lignin model compounds. The dioxygenase enzyme plays a crucial role in the
White rot fungi capable of degrading lignin are usually capable of degrading a wide variety of aliphatic and aromatic xenobiotics, including PCDD/Fs. A subsequent study by Takada et al., (1996)
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degradation of xenobiotic compounds. By catalyzing the incorporation of two hydroxyl groups into the aromatic ring, these enzymes increase the reactivity of these compounds, making them susceptible to enzymatic ring fission reactions (Erickson and Mondello, 1993). On the other hand, Cordyceps militaris KS-92 has able to degrade 2,4,8-TCDF 25% using P-450 monooxygenase over 30 d in liquid medium (Mori et al. 2005).
polysaccharides in lignocellulosic substrates. The adding glucose as readily metabolizable carbon source increased cell biomass, and then caused the higher degradation of 2,4,8 TCDF. Otherwise, the increasing of glucose concentration resulted in the inhibition of fungus growth and the decreasing of degradation rate. The fungus avoids synthesizing and secreting metabolically ligninolytic agents when substrates more accessible than lignocellulose (such as glucose) were available in medium (Hammel 1997).
Tachibana, Kiyota and Koga (2005) reported that 3,5-dichlorosalicylic acid and 5-chlorosalicylic acid were detected as metabolite products during degradation of 2,4,8-TCDF in soil. On the other hand, degradation of 2,4,8-TCDF using P-450 monooxygenase of C.militaris resulted hydroxyl-triCDFs as metabolite product (Mori et al. 2005). This enzyme was responsible for the hydroxylation of chlorinated dioxins (up to tri-Cl) in the initial step of the metabolic pathway.
Effect of surfactant using Tween 80 was investigated. Tween 80 has no adverse effect on the growth of T. versicolor U80. It was found that 2% concentration of Tween 80 increased 2.8 fold degradation rate at the end of 30 day incubation by T. versicolor U80, compare to the absence of surfactant (Fig. 5).
Degradation rate (%)
100
Evaluating the optimum condition in improving ability for 2,4,8-TCDF degradation in liquid medium by T. versicolor U80 Several treatments were conducted to obtain the optimum condition for 2,4,8TCDF degradation by adding variation of glucose concentration, surfactant concentration and agitation. Variation of glucose concentration has effect for 2,4,8TCDF degradation (Fig. 4).
Degradation rate (%)
80 60
1,50%
60
2,00%
40 20 0 15 day
30 day U80
Surfactants, such as Tween 80, have able to enhance bioremediation processes relate because of increasing the bioavailability of contaminant aqueous insolubility, reducing surface and interfacial tensions, and improving the contaminant inaccessibility in medium (Singh, Van Hamme and Ward, 2007). It has also able to be a ligninase inducer in cultures that protects the enzymes from denaturing and increase the production of ligninolytic enzymes (Zhou et al., 2007). Tween 80 promotes both uptake and exit of compounds from the cell through modification of plasma membrane permeability.
40 20 0 15 day
1,00%
80
Figure 5. Effect of Tween 80 on 2,4,8-TCDF degradation by T. versicolor U80 in the liquid medium
0,50% 1% 2% 2,50% 5% 10%
100
0%
30 day
Figure 4. Effects of glucose on 2,4,8-TCDF degradation by T. versicolor U80 in the liquid medium
The maximum degradation 59% was obtained during the adding 2.5% glucose concentration. The ability to degrade lignocellulose efficiently is associated with a mycellial growth and ability fungus to transport nutrients into the nutrient-poor lignocellulosic substrate (Hammel 1997). Otherwise, ligninolytic fungi are not able to use lignin as their sole source of energy and carbon. They depend on the more digestible
Billingsley, Backus and Ward, (1999) demonstrated that the presence of the anionic surfactant Hostapur SAS 60 increased 2.5 fold the extent of PCB degradation by Pseudomonas LB400. A surfactant, 6˝-O-palmitoylmaltotriose, increased the apparent solubility from 140
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to 305 µg/l and enhanced two folds biodegradation of Aroclor 1242 by Burkholderia cepacia LB400 (Ferrer, Golyshin and Timmis, 2003). Bautista et al., (2009) showed that experiments performed with Tween 80 for degradation PAHs reached >90% in 15 days by bacteria. However, little information about the effects of Tween 80 and other surfactants to degrade PCDFs was provided.
paper sludge only contains cellulose and hemicellulose that could not enhanced 2,4,8-TCDF degradation. To increase the levels of degradation in soil, inoculated polluted soils with various fungal species on different lignocellulosic supports (e.g., wood meal, wood chips, corn cobs and wheat straw) was developed (Quintero, et al., 2008). 100
Degradation rate (%)
100
Degradation rate (%)
Agitation only gave little improvement for biodegradation of 2,4,8-TCDF (Fig. 6). The oxygen concentration is dependent on the air flow rate. Stirring could increase the contact between substrate, oxygen, and biomass. It will enhance mass transfer and finally affect to degradation rate. Jager, Croan and Kirk (1985) showed that ligninase was produced in agitated pelleted cultures at 150 rpm by including detergents Tween 20, Tween 80 or 3--[(3cholamidopropyl)dimethylammonio]-1propanesulfonate (CHAPS) in the culture medium.
60 40 20
15 day
30 day
Figure 7. Degradation rate of 10 ppm 2,4,8-TCDF in soil by bioremediation with T. versicolor U80
Plant residues are a plentiful source of nutrients that favor fungal growth and soil colonization. Additionally, plant residues elicit production of adaptive ligninolytic enzymes (Castillo et al., 2001; Fujian, Hongzang and Zuohu, 2001). However, the lower remediation values obtained in soil than liquid medium because the pollutant is retained in the soil pores thereby impeding transfer to the fungi (Quintero et al., 2005). Further, the structural changes from higher to lower chlorinated congeners was occurred based on support of fungal metabolism.
80 rpm 120 rpm
60 40 20 0 15 day
80
0
0 rpm
80
Liquid no wood meal Liquid + wood meal 10% Paper sludge + fungi 5% Paper sludge + fungi 10% Wood meal + fungi 5% Wood meal + fungi 10%
30 day
Figure 6. Effect of agitation on 2,4,8-TCDF degradation by T. versicolor U80 in the liquid medium
Conclusion In this report, the ability of T. versicolor U80 to degrade 2,4,8-TCDF was studied. In the liquid medium, this strain degraded 46.52% at 30 days. This degradation rate can be enhanced became approximately 59% after addition of glucose 2.5% and 2% Tween 80. Wood meal can be used as lignocellulosic supports for the growth of T. versicolor U80 to degrade 2,4,8-TCDF in soil. T. versicolor U80 degraded 2,4,8-TCDF 46.06% at 30 days in soil. Further investigation of the metabolite pathway involved in 2,4,8-TCDF degradation is still required.
Fungi need lignocellulosic substrates to grow and degrade pollutants in soil. The growth ability of T. versicolor U80 in several pre-grown sources were different. T. versicolor U80 grew well in the wood meal and paper sludge. These results are affected for degradation of 2,4,8-TCDF (Fig. 7).
Investigating of the 2,4,8-TCDF degradation by T. versicolor U80 in soil medium The result showed that 2,4,8-TCDF degradation by T. versicolor U80 pre-grown in 10% wood meal was higher than others. Fungi pre-grown in wood meal could more secreted ligninolytic enzymes thus enhanced 2,4,8-TCDF degradation. On the other hand,
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J. Lignocellulose Technol. 01 (2016), 68-73
Journal of Lignocellulose Technology Journal homepage: http:/ejournal.lipi.go.id/index.php/jol/
Article
Utilization of kapok fiber as a natural sorbent in petroleum hydrocarbon biodegradation by Pestalotiopsis sp. Dede Heri Yuli Yanto 1,*, Sanro Tachibana 1
2
Research Center for Biomaterials, Indonesian Institute of Sciences (LIPI), Jl. Raya Bogor Km. 46, Cibinong 16911, Bogor, Indonesia.
2Department
of Applied Bioscience, Faculty of Agriculture, Ehime University 3-5-7 Tarumi, Matsuyama 790-8566, Ehime, Japan. *Corresponding
author:
[email protected]
Received:1 December 2016. Received in revised form: 20 December 2016. Accepted: 20 December 2016. Published online: 23 December 2016
Abstract Utilization of sorbents is considered have a beneficial effect on crude oil cleanup. In this study, a natural sorbent was used in association with Pestalotiopsis sp. NG007 to enhance the biodegradation of petroleum hydrocarbons (PHCs) in soil. Among six natural sorbents, namely, pulp sheet from softwood (PS), pulp sheet from hardwood (PH), pulp sheet manila (PM), cellulose sponge (CS), polypropylene (PP), and kapok fiber (KF), KF showed high sorption capacity toward asphalt (34.76 g asphalt/g kapok). Addition of 7.5% KF-associated NG007 to crude oilcontaminated soil increased 25.6% degradation compare with no addition of kapok. The effective adsorption of all fractions in PHCs to kapok which induce the high accessibility of fungus and the increasing enzymatic activities by the fungus may responsible to the higher degradation of PHCs. This study suggested that kapok may has the potential to use in bioremediation of crude oil by microorganism. Keywords : Adsorption, Biodegradation, Crude oil, Fiber, Kapok
Introduction Crude oil can cause environmental pollution during various stages of their production, storage, transportation, refining, and utilization. In such cases, PHCs affect aquatic life, human life, local economies, tourism, and leisure activities because of the coating properties of PHCs. The basic methods for oil spill collection and cleanup are chemical, mechanical, and biological
treatments. The mechanical methods involve the transfer of oil from spill site to temporary storage using oil sorbents or skimmers. Oil sorbents can be classified into inorganic mineral, organic synthetic, and natural products (Adebajo et al., 2003). Perlite as a mineral oil sorbent has been
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used by Bastani et al. (2006) but showed lower capacity than that of natural fibers. Most of inorganic oil sorbents include vermiculites, organoclay, zeolite, and diatomite have poor buoyancy, oil sorption capacity, reusability, and oil recovery. In addition, they are difficult to handle on site due to their granular or powder forms. Due to inadequate hydrophobicity, they may also experience collapse of their microstructure due to sorption of water (Adebajo et al., 2003). As an organic synthetic products, polypropylene and polyurethane are recently the most commercially available oil sorbents. However, they have a limited-biodegradable and can be difficult to deal with after use due to their xenobiotic nature. Natural oil sorbents such as rice straw, corn corb, peat moss, cotton, cotton grass, barks, milkweed, kenaf, wool, and kapok have been known to have higher sorption capacities for oil than that of commercially available synthetic (Johnson, Manjreker and Halligan., 1973; Adebajo et al., 2003; Saito et al., 2003; Radetic et al., 2003; Suni et al., 2004). These agricultural products and residues are inexpensive and available locally giving rise an advantages to be used as a low-cost alternative for the removal of oil spilled on water surface.
sorbent were determined by a gravimetric method (Zhu et al. 2011). Pre-incubation of fungal culture in kapok adsorbent Three gram of 2-cm length-air dried kapok was added with 50 mL of malt extract (ME) liquid medium (20 g/L malt extract, 20 g/L glucose, 1 g/L polypeptone in distilled water) and 1% of Tween 80 in an autoclaved plastic box. After all surfaces was wetted, the mixture of kapok was autoclaved at 121oC for 20 min. The fungal culture Pestalotiopsis sp. NG007 was added to kapok adsorbent, then were grown until fully cover the surface of kapok. Effect of kapok adsorbent on biodegradation and enzymatic activities of Pestalotiopsis sp. NG007 Experimental design of addition kapok adsorbent and Pestalotiopsis sp. to asphalt contaminated soil is shown in Fig. 1. Approximately after 1 month pre-incubation in kapok, the kapok containing NG007 with final composition 0, 1, 2.5, 5, 7.5, and 10% was added to soil containing crude oil and incubated for 15 and 30 days in dark condition at 25oC. Non-inoculated NG007 was used as a negative control.
The use of oil sorbent during incubation of Pseudomonas sp. has showed effective biodegradation of crude oil (Setti, Mazzieri and Pifferi., 1999). Naturally, fungi or bacteria capable of using petroleum hydrocarbons can form a colonization in natural oil sorbents. Ali et al. (2011) reported that fungi that associated with sawdust could effectively consume crude oil. The utilization of sorbent that associated with PHC-degrading fungi is projected to not only remove oil pollutants by sorption, but also to simultaneously mineralize this pollutants microbiologically. Therefore, this study aims to investigate the effect of kapok absorbent in enhancing the biodegradation of crude oil in soil. Materials and Methods Adsorption study of sorbents A-100 mL sample of crude oil was placed in a beaker glass before any sorbent was immersed in the ice bath. One piece of sorbent (with initial weight was measured) was place in the system, which was shaken for 3 hours. The wetted sorbent material was weighed after being drained for 1 min in the sustainer. The amounts of oil sorbed by the
Figure 1. Experimental design of biodegradation of crude oil by Pestalotiopsis sp. NG007 in the presence of kapok adsorbent in soil.
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(Ɛ310 nm = 9300 M-1 cm-1) (Tien and Kirk, 1984). All experiments were performed at 25oC. Activities were expressed as units per gram wet soil matter (U g-1), in which one enzyme unit (U) was defined as that forming 1.0 µmol of the product per minute under the assay conditions.
Chemical analysis of crude oil degradation The detailed biodegradation analysis of crude oil and their fractions (aliphatic, aromatic, resin, and asphaltene) were described in our previous study (Yanto and Tachibana, 2013). The biodegradation of total petroleum hydrocarbons (TPHs), resin, and asphaltene fractions were analyzed using the gravimetric method. The biodegradation of aliphatic and aromatic fractions were analyzed using gas chromatography (GC-FID Shimadzu 2014), with a TC-5 capillary column (30 m, id x 0.25 mm x 0.25 μm).
Results and Discussion Adsorption study of the natural fibers The adsorption study of the natural fibers is performed in an ice-container box using crude oil as a model PHCs. The results in Fig. 2 showed that among the fibers tested, kapok has the highest capacity of sorption. Maximum sorption capacity of kapok in crude oil is 34.76 g crude oil/g kapok. The lowest capacity has showed for pulp sheet prepared from softwood (1.00 g crude oil/g sorbent). Polypropilene sheet fibers that widely used commercial sorbent for oil spill cleanup showed lower capacity than kapok in this study. The hollow structure with large lumen in kapok fiber may attribute to the high capacity of kapok to adsorb the oil (Lim and Huang, 2007). The high adsorption capacities of kapok have also been reported by Hori et al. (2000) with 40 g oil/g sorption capacity and by Lim and Huang (2007) with 36–45 g oil/g sorption capacity, at different oils. Other synthetic adsorbent like polyvinyl chloride/polystyrene prepared by electrospinning method has showed a high capacity in oil sorption compare to polypropylene sorbent (Zhu et al., 2011). The mechanism of oil sorption by sorbents can be adsorption, absorption, capillary action, or a combination of these (Radetic et al., 2008).
Aliphatic compounds were identified by gas chromatography-mass spectrometry (GC-MS) using a Shimadzu QP-2010 with a TC-1 capillary column (30 m, id x 0.25 mm x 0.25 μm) (Yanto and Tachibana, 2014). The carrier gas, helium, was delivered at a constant rate of 1.5 mL min-1, with a column pressure of 100 kPa and interface temperature of 280°C. The column temperature was started at 60°C, and increased at 10°C min-1 intervals to 280°C, at which it was maintained for 10 min. The injection volume was 1 µL with a split ratio of 100. The conditions for GC-MS were adjusted to a scan interval of 1.3 eV s-1, a threshold of 100, and a mass range of 40– 900. Each peak was compared with the NIST08 library and results were confirmed with authentic standards. Enzymatic assay Enzymatic activities were assayed using the UV-Vis spectrophotometer (Shimadzu UV-1600). Catechol 1,2-dioxygenase (C12O) activity was assayed using catechol 0.01 M as the substrate by measuring the formation of cis,cis-muconic acid at 260 nm (Ɛ260nm =16000 M-1 cm-1) (Nakazawa and Atsushi, 1970). Catechol 2,3-dioxygenase (C23O) activity was assayed using the same protocols as those for C12O based on changes in absorbance at 375 nm due to the production of 2-hydroxymuconate semialdehyde (Ɛ375 nm = 44000 M-1 cm-1) (Nozaki, 1970). Laccase activity was measured by monitoring the oxidation of syringaldazine at 525 nm (Ɛ525 nm = 6500 M-1 cm-1) (Leonowicz and Grzywnowicz, 1981). Manganese peroxidase (MnP) activity was determined based on the oxidation of 2.6dimethoxyphenol (2,6-DMP) at 470 nm (Ɛ470 -1 cm-1) (Wariishi, Vali and nm = 49600 M Gold., 1992). Lignin peroxidase (LiP) activity was determined by the oxidation of veratryl alcohol to form veratryl aldehyde at 310 nm
Oil sorption (g/g sorbents)
40 35 30 25 20 15
10 5 0 PS
PH
PM
CS
PP
KF
Type of adsorbent Figure 2. Asphalt sorption of different sorbents. PS: pulp sheet from softwood, PH: pulp sheet from hardwood, PM: pulp sheet manila, CS: cellulose sponges, PP: polypropylene sheet, KF: kapok fiber.
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Pestalotiopsis sp. (Fig. 3). All the enzymatic activities such as catechol 1,2-dioxygenase (C12O), catechol 2,3-dioxygenase (C23O), laccase, manganese peroxidase (MnP), and lignin peroxidase (LiP) showed enhanced 1.84-, 2.02-, 6.13-, 4.98-, and 6.25-fold than without kapok addition. 100
6
90
5
COC biodegradation (%)
COC biodegradation (%)
80 70
4
60 50
3
40
2
30 20
1
10 0 100
0 6
90
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60 50
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10 0
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Enzyme activities (U g-1 wet soil mixture)
Effect of kapok composition on biodegradation of COC and enzyme activities of Pestalotiopsis sp. NG007 is shown in Fig. 3. The results showed that addition of kapok enhanced the biodegradation of COC by Pestaloitopsis sp. NG007 in soil. Optimum biodegradation was obtained when 7.5% of dry weight of kapok was used. About 25.6% degradation of COC could be enhanced in kapok-assisted biodegradation by Pestalotiopsis sp. NG007. Comparing with control no addition of kapok, the biodegradation of all fractions in three PHCs, COA, COC, and asphalt were increased in kapok treatment by Pestalotiopsis sp. NG007. The effect of kapok was more significant in degradation of aliphatic, aromatic, and resin fractions in all PHCs than the asphaltene fractions (Fig. 4). However, for overall, the addition of kapok promotes enhancing biodegradation of all fractions in all PHCs. This may indicate that the effective adsorption of all fractions in PHCs to kapok can induce the high accessibility of fungi to degrade and led to higher degradation. Setti, Mazzieri and Pifferi. (1999) reported that utilization of oil sorbents can increase enormously n-alkane biodegradation rate when a Pseudomonas sp. was used in crude oil fermentation as compared with that observed in the absence of the sorbents due to an improved oil and microorganism interaction at the water/cell/oil/sorbent interphase.
Enzyme acitivities (U g-1 wet soil mixture)
Biodegradation of PHCs by Pestalotiopsis sp. NG007 in the presence of kapok
10
Amount of kapok (%)
Figure 3. Biodegradation of Crude oil C (COC) and enzyme activities of Pestalotiopsis sp. NG007 in the presence of kapok in soil.
Addition of kapok also showed an increasing enzymatic activities produced by 100
Absence of kapok
Biodegradation (%)
90
80 70 60 50 40 30 20 10
Aliphatic
Aromatic
Resin
Asphalt
COC
COA
Asphalt
COC
COA
Asphalt
COC
COA
Asphalt
COC
COA
0
Asphaltene
Figure 4. Biodegradation of fractions in COA (Crude oil A), COC (Crude oil C), and asphalt by Pestalotiopsis sp. NG007 in the absence and the presence of kapok in soil.
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Johnson, R. F., Manjreker, T. G. and Halligan, J. E. (1973). Removal of oil from water surfaces by sorption on unstructured fibers. Environmental science & technology, 7(5), pp.439-443.
The study proposes that in addition to improve the oil adsorbed and microorganism interaction, kapok adsorbent can also enhance the production of ligninolytic and non-ligninolytic enzymes of Pestalotiopsis sp. NG007 in the presence of COC. Ligninolytic and non-ligninolytic enzymes have showed a play important role in degradation of PHC fractions. It was reported that dioxygenases or monooxygenases can initiate degradation of PHCs by degrading first the aliphatic fraction via mono-, di-, or sub-terminal oxidation (Yanto and Tachibana, 2013). In addition, both non-ligninolytic and ligninolytic enzymes were needed to improve simultaneously the degradation of PHCs in soil (Yanto and Tachibana, 2014).
Leonowicz, A. and Grzywnowicz, K. (1981). Quantitative estimation of laccase forms in some white-rot fungi using syringaldazine as a substrate. Enzyme and Microbial Technology, 3(1), pp.55-58. Lim, T. T. and Huang, X. (2007). Evaluation of kapok (Ceiba pentandra (L.) Gaertn.) as a natural hollow hydrophobic–oleophilic fibrous sorbent for oil spill cleanup. Chemosphere, 66(5), pp.955-963. Nakazawa, T. and Atsushi, N. (1970). Pyrocatechase (Pseudomonas). In: S. P. Colowick and N. O. Kaplan (Eds.)., Methods in Enzymology, Vol. 17, Part 1. New York: Academic Press,. pp.518–522.
Conclusion Addition of 7.5% KF-associated NG007 to crude oil-contaminated soil increased 25.6% degradation compare with no addition of kapok. Associating Pestalotiopsis sp. NG007 with kapok adsorbent enhanced the biodegradation rate of PHCs in soil due to both facilitating interaction of the fungal culture with PHCs or enhancing enzymatic activities in the presence of PHCs. This technology can be projected to bioremediation of PHCs in contaminated environments.
Nozaki, M. (1970). Metapyrocatechase (Pseudomonas). In : S. P. Colowick and N. O. Kaplan (ed.)., Methods in Enzymology, Vol. 17, Part 1. New York: Academic Press., pp.522–525. Radetic, M., Ilic, V., Radojevic, D., Miladinovic, R., Jocic, D. and Jovancic, P. (2008). Efficiency of recycled wool-based nonwoven material for the removal of oils from water. Chemosphere, 70(3), pp.525-530. Radetic, M. M., Jocic, D. M., Jovancic, P. M., Petrovic, Z. L. and Thomas, H. F. (2003). Recycled wool-based nonwoven material as an oil sorbent.Environmental science & technology, 37(5), pp.1008-1012.
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