THE EFFECT OF SULPHATE-REDUCTION BACTERIA (SRB) FOR SULPHATE REDUCTION IN THE BIOGAS PRODUCTION FROM BLOTONG Supervisor : 1. Dr. Ir. Sri Rachmania Juliastuti, M.Eng 2. Ir. Nuniek Hendrianie, MT Writen By : 1. Endah Widya Ningrum (NRP. 2306 100 612) 2. Yuana Veronika Setiawan (NRP. 2306 100 615)
ABSTRACT The purpose of this experiment are to advantaged blotong as a raw material to produce biogas and using SRB to reduce the H2S component in the biogas. The methode of this experiment are using blotong and SRB which is Desulfovibrio desulfuricans in a anaerobic digester with continue system. There are 2 steps in this process that is the batch process and continue process. In the batch process, the feed are from the mixing of starter (cow dung : water = 1 : 2, fermented in 5 days), blotong, and water with ratio 1: 2: 4 and SRB addition with 0% and 0,02% variable, then put the feed in the anaerobic digester and fermented for 15 days in a condition for pH 7 and 32–35 °C temperature. The next step is the continue process which is continuing the batch process with adding the feed from mixtured of blotong and water (ratio 1: 2) with 0,5 kg/days and 1 kg/days variable. The continue addition of the feed followed by discarding the digestate from the digester as much as the amount of the feed addition. The condition in the digester need to be controlled in pH 7 and 32–35 °C temperature and also checking the biogas production volume everyday. The fermentation is done until the COD value become constant.
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The parameter that measured are COD, MLVSS, sulphate content, composition and heating value of the biogas. The experiment result in the continue process for the 0% SRB and 0,5 kg/day feed variable obtained that the SO42- removal in the 15th and 35th days are 52,63% dan 63,16%; whereas for the 0,02% SRB and 0,5 kg/day feed variable obtained that the SO42- removal in the 15th and 35th days are 63,16 % dan 68,42%. For the 0% SRB and 1 kg/day feed variable obtained that the SO42- removal in the 15th and 35th days are 52,63% dan 57,89%; whereas for the 0,02% SRB and 1 kg/day feed variable obtained that the SO42removal in the 15th and 35th days are 63,16 % dan 73,68%. The other experiment result in continue operation for the 0,5 kg/day feed variable obtained that the H2S removal in the 15th and 35th days are 71,05% dan 84,62%; whereas for the 1 kg/day feed variable obtained that the H2S removal in the 15th and 35th days are 75% and 81,25%.
Keywords : Desulfovibrio desulfuricans, Sulphate, H2S, Biogas
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KATA PENGANTAR Puji syukur kehadirat Tuhan Yang Maha Esa atas segala rahmat dan ridhoNya sehingga kami dapat menyelesaikan Laporan Skripsi dengan judul “Pengaruh Sulphate-Reducing Bacteria (SRB) terhadap Reduksi Sulfat pada Pembuatan Biogas dari Blotong”. Laporan Skripsi ini merupakan salah satu persyaratan yang harus ditempuh dalam menyelesaikan program studi Strata 1 (S-1) di Jurusan Teknik Kimia FTI – ITS Surabaya. Atas segala bantuan baik moril dan material dalam penyusunan Laporan Skripsi ini, kami menyampaikan terima kasih kepada : 1. Dr. Ir. Tri Widjaja, M.Eng selaku Ketua Jurusan Teknik Kimia FTI – ITS. 2. Prof. Dr. Ir. Kusno Budikarjono, MT, selaku Koordinator Tugas Akhir dan Skripsi Jurusan Teknik Kimia FTI-ITS. 3. Dr. Ir. Sri Rachmania Juliastuti, M.Eng selaku Kepala Laboratorium Pengolahan Limbah Industri dan dosen pembimbing. 4. Ir. Nuniek Hendrianie, MT selaku dosen pembimbing. 5. Bapak / Ibu dosen penguji. 6. Bapak Subchan selaku Laboran Laboratorium Limbah Industri. 7. Seluruh dosen dan karyawan Jurusan Teknik Kimia FTI – ITS. 8. Kedua orang tua kami dan keluarga. 9. Rekan - rekan di Laboratorium Pengolahan Limbah Industri dan teman-teman Lintas Jalur angkatan 2006/2007 Semoga Laporan Skripsi ini bermanfaat bagi kita semua.
Surabaya, Agustus 2009 Penyusun
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DAFTAR ISI
LEMBAR PERSETUJUAN ABSTRAK ABSTRACT KATA PENGANTAR DAFTAR ISI DAFTAR TABEL DAFTAR GAMBAR DAFTAR NOTASI BAB I PENDAHULUAN 1.1 Latar Belakang 1.2 Rumusan Masalah 1.3 Batasan Masalah 1.4 Tujuan Penelitian 1.5 Manfaat Penelitian BAB II TINJAUAN PUSTAKA 2.1 Blotong 2.2 Anaerobic Digestion 2.3 Sulphate-Reduction Bacteria (srb) 2.4 Biogas BAB III METODOLOGI PENELITIAN 3.1 Variabel Penelitian 3.2 Besaran yang Diukur 3.3 Bahan dan Peralatan yang Digunakan 3.4 Prosedur Penelitian 3.4.1 Tahap Persiapan 3.4.2 Prosedur Operasi 3.5 Diagram Alir Penelitian 3.6 Skema Alat BAB IV HASIL DAN PEMBAHASAN BAB V KESIMPULAN DAN SARAN 5.1 Kesimpulan 5.2 Saran
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i ii v vi viii ix x 1 2 2 3 3 5 7 8 10 19 19 20 21 21 22 24 25 27 39 40
DAFTAR PUSTAKA LAMPIRAN A PROSEDUR ANALISA LAMPIRAN B PROSEDUR PERHITUNGAN LAMPIRAN C HASIL ANALISA & PERHITUNGAN LAMPIRAN D GAMBAR ALAT
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41 43 47 51 57
DAFTAR TABEL
Tabel 2.1. Komposisi blotong pabrik gula sulfitasi dan pabrik gula karbonatasi
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Tabel 2.2. Komposisi blotong PT. PG Candi Baru Sidoarjo (dengan proses sulfitasi)
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Tabel 2.3 Komposisi gas dalam biogas (%) antara kotoran sapi dan campuran kotoran ternak dengan sisa pertanian
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Tabel 4.1 Hasil analisa komposisi bahan baku (blotong)
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DAFTAR GAMBAR Gambar 2.1 Bakteri Sulphate-reduction Bacteria (SRB) Gambar 2.2 Bagan ilustrasi pembentukan biogas Gambar 3.5 Diagram Alir Penelitian Gambar 3.6 Skema Alat Grafik 4.1 Hubungan antara waktu fermentasi terhadap COD Grafik 4.2 Hubungan antara waktu fermentasi terhadap MLVSS Grafik 4.3 Hubungan antara waktu fermentasi terhadap volume biogas Grafik 4.4 Hubungan antara waktu fermentasi terhadap % pengikatan SO42- untuk feed 0,5 kg/hari Grafik 4.5 Hubungan antara waktu fermentasi terhadap % pengikatan SO42- untuk feed 1 kg/hari Grafik 4.6 Kadar CH4 untuk feed 0,5 kg/hari Grafik 4.7 Kadar CH4 untuk feed 1 kg/hari Grafik 4.8 Heating Value biogas untuk feed 0,5 kg/hari Grafik 4.9 Heating Value biogas untuk feed 1 kg/hari Grafik 4.10 Kadar H2S untuk feed 0,5 kg/hari Grafik 4.11 Kadar H2S untuk feed 1 kg/hari Grafik 4.12 Hubungan antara waktu fermentasi terhadap removal H2S
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9 16 24 25 28 28 29 30 30 31 32 33 34 35 36 37
DAFTAR NOTASI Simbol
Keterangan
Satuan
COD P V T
Chemical Oxygen Demand Pressure Volume Temperature
mg/liter cmH2O Liter ºC
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