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) A B S T R A C T The purpose of this experiment are to advantaged blotong as a raw material to produce biogas and using SRB to reduce the H 2 S 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. iii
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 SO 4 2- removal in the 15 th and 35 th days are 52,63% dan 63,16%; whereas for the 0,02% SRB and 0,5 kg/day feed variable obtained that the SO 4 2- removal in the 15 th and 35 th days are 63,16 % dan 68,42%. For the 0% SRB and 1 kg/day feed variable obtained that the SO 4 2- removal in the 15 th and 35 th days are 52,63% dan 57,89%; whereas for the 0,02% SRB and 1 kg/day feed variable obtained that the SO 4 2- removal in the 15 th and 35 th 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 H 2 S removal in the 15 th and 35 th days are 71,05% dan 84,62%; whereas for the 1 kg/day feed variable obtained that the H 2 S removal in the 15 th and 35 th days are 75% and 81,25%. Keywords : Desulfovibrio desulfuricans, Sulphate, H 2 S, Biogas iv
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 v
DAFTAR ISI LEMBAR PERSETUJUAN ABSTRAK ABSTRACT KATA PENGANTAR DAFTAR ISI DAFTAR TABEL DAFTAR GAMBAR DAFTAR NOTASI BAB I i ii v vi viii ix x PENDAHULUAN 1.1 Latar Belakang 1 1.2 Rumusan Masalah 2 1.3 Batasan Masalah 2 1.4 Tujuan Penelitian 3 1.5 Manfaat Penelitian 3 BAB II TINJAUAN PUSTAKA 2.1 Blotong 5 2.2 Anaerobic Digestion 7 2.3 Sulphate-Reduction Bacteria (srb) 8 2.4 Biogas 10 BAB III METODOLOGI PENELITIAN 3.1 Variabel Penelitian 19 3.2 Besaran yang Diukur 19 3.3 Bahan dan Peralatan yang Digunakan 20 3.4 Prosedur Penelitian 21 3.4.1 Tahap Persiapan 21 3.4.2 Prosedur Operasi 22 3.5 Diagram Alir Penelitian 24 3.6 Skema Alat 25 BAB IV HASIL DAN PEMBAHASAN 27 BAB V KESIMPULAN DAN SARAN 5.1 Kesimpulan 39 5.2 Saran 40 vi
DAFTAR PUSTAKA 41 LAMPIRAN A PROSEDUR ANALISA 43 LAMPIRAN B PROSEDUR PERHITUNGAN 47 LAMPIRAN C HASIL ANALISA & PERHITUNGAN 51 LAMPIRAN D GAMBAR ALAT 57 vii
DAFTAR TABEL Tabel 2.1. Komposisi blotong pabrik gula sulfitasi dan pabrik gula karbonatasi Tabel 2.2. Komposisi blotong PT. PG Candi Baru Sidoarjo (dengan proses sulfitasi) Tabel 2.3 Komposisi gas dalam biogas (%) antara kotoran sapi dan campuran kotoran ternak dengan sisa pertanian Tabel 4.1 Hasil analisa komposisi bahan baku (blotong) 6 6 11 27 viii
DAFTAR GAMBAR Gambar 2.1 Bakteri Sulphate-reduction Bacteria (SRB) 9 Gambar 2.2 Bagan ilustrasi pembentukan biogas 16 Gambar 3.5 Diagram Alir Penelitian 24 Gambar 3.6 Skema Alat 25 Grafik 4.1 Hubungan antara waktu fermentasi terhadap COD 28 Grafik 4.2 Hubungan antara waktu fermentasi terhadap MLVSS 28 Grafik 4.3 Hubungan antara waktu fermentasi terhadap volume biogas 29 Grafik 4.4 Hubungan antara waktu fermentasi terhadap 2- % pengikatan SO 4 untuk feed 0,5 kg/hari 30 Grafik 4.5 Hubungan antara waktu fermentasi terhadap 2- % pengikatan SO 4 untuk feed 1 kg/hari 30 Grafik 4.6 Kadar CH 4 untuk feed 0,5 kg/hari 31 Grafik 4.7 Kadar CH 4 untuk feed 1 kg/hari 32 Grafik 4.8 Heating Value biogas untuk feed 0,5 kg/hari 33 Grafik 4.9 Heating Value biogas untuk feed 1 kg/hari 34 Grafik 4.10 Kadar H 2 S untuk feed 0,5 kg/hari 35 Grafik 4.11 Kadar H 2 S untuk feed 1 kg/hari 36 Grafik 4.12 Hubungan antara waktu fermentasi terhadap removal H 2 S 37 ix
DAFTAR NOTASI Simbol Keterangan Satuan COD Chemical Oxygen Demand mg/liter P Pressure cmh 2 O V Volume Liter T Temperature ºC x