PENAMBAHAN AMPAS SAGU (Metroxylon spp.) SEBAGAI SUMBER KARBON PADA PROSES PRODUKSI GASBIO DENGAN SUBSTRAT FESES BABI (Sus sp.)

Daniel Yohanis Seseray, Bapak Prof. Dr. Ir. Suharjono Triatmojo

2012 | Tesis | S2 Ilmu Peternakan

Penelitian ini bertujuan untuk mengetahui produksi gasbio yang dihasilkan dari campuran substrat feses babi dan ampas sagu pada waktu retensi 10, 20 dan 30 hari dengan perlakuan taraf rasio C/N 20, 25 dan 30. Penelitian dilaksanakan selama 3 bulan bertempat di Desa Sidomulyo-Yogyakarta. Materi yang digunakan adalah 27 unit digester tipe batch dengan substrat campuran feses babi, ampas sagu, air dan cairan rumen sebagai inokulum. Variabel yang diamati meliputi kelembaban udara, temperatur udara dan gasbio, volume gas dan produksi gas metana, konsentrasi gas metana dan karbondioksida, pH, kadar VFA, Kadar BOD, COD dan TSS serta kadar bahan organik, N-total, Ptotal dan K-total. Data yang diperoleh dianalisis dengan metode split plot design. Apabila terdapat pengaruh yang signifikan maka dilanjutkan dengan uji DMRT (Duncan’s new multiple range test). Hasil penelitian menunjukkan bahwa produksi gasbio yang dihasilkan belum optimal, karena rerata konsentrasi gas metan yang dihasilkan hingga hari ke-30 rendah yaitu 12,14% pada taraf rasio C/N 20, 11,08% pada taraf rasio C/N 25 dan 5,39% pada taraf rasio C/N 30. Kondisi temperatur gasbio dan pH juga belum optimal yaitu rerata berkisar antara 26,06-29,78oC dan 5,8 - 7,0 dengan kelembaban udara antara 40,5 - 88,5% dan temperatur udara antara 24 - 35o C. Produksi asam lemak volatil (asam asetat, propionat dan butirat) meningkat secara nyata pada hari ke-20 dan menurun hari ke-30, pada taraf rasio C/N 20 produksi lebih tinggi di banding taraf rasio C/N 25 dan taraf rasio C/N 30. Proses fermentasi anaerob menurunkan konsentrasi BOD, COD dan TSS seiring dengan meningkatnya taraf rasio C/N. Kadar bahan organik setelah periode penelitian masih cukup tinggi. Efisiensi penurunan bahan organik pada taraf rasio C/N 20 sebesar 1,1% dari 85,56%, pada taraf rasio C/N 25 sebesar 2,56% dari 88,48% dan taraf rasio C/N 30 sebesar 6,62% dari 91,19%. Ampas sagu dapat dimanfaatkan sebagai sumber karbon dalam campuran substrat gasbio, perlakuan yang diberikan belum menghasilkan produksi gasbio yang optimal, produksi asam lemak volatil pada taraf rasio C/N 20 lebih tinggi dibandingkan taraf rasio C/N 25 dan taraf rasio C/N 30. Fermentasi metanogen pada kondisi anaerob menurunkan konsentrasi BOD, COD dan TSS seiring meningkatnya taraf rasio C/N. Kadar bahan organik pada slurry dan sludge gasbio yang dihasilkan masih cukup tinggi.

This study aimed to determine biogas production resulting from the substrate mixture of pig feaces and sago pulp with C/N ratio 20, 25 and 30 at retention time of 10, 20 and 30 days. The experiment was conducted for 3 months in the Village Sidomulyo-Yogyakarta province. The material used was a 27 units digester batch type substrate mixed with pig feaces, sago pulp, water and rumen fluid as inoculum. The observed variables included air humidity, air temperatures and biogas, the volume of bio-gas and methane production, methane and carbon dioxide concentration, pH value, VFA levels, concentrations of BOD, COD and TSS as well as the levels of organic matter, N, P and K totals. The data obtained were analyzed with a split plot design. If there was a significant influence, the test was followed by DMRT (Duncan's new multiple range test). The results showed that the resulting bio-gas production was not optimal, because the average concentration of methane gas generated by 30 day was low at 12.14% at level C/N ratio 20, 11.08% at level of C/N ratio 25 and 5,39% at the level of C/N ratio 30. Biogas temperature and pH conditions were also not optimal, the averages ranged between 26.06 to 29.78° C and pH 5.8 to 7.0, humidity between 40.5 to 88.5% and temperature between 24 to 35° C. Production of volatile fatty acids (acetic, propionic and butyric acid) increased significantly on 20 day an decreased by 30 day, the level of C/N ratio 20 production was higher compared to the level of the C/N ratio 25 and 30. Anaerobic fermentation process lowered the concentration of BOD, COD and TSS along with the increased level of the C/N ratio. Organic matter levels during the research period were still quite high. The efficiency of organic matter at level C/N ratio 20 decreased is 1.1% from 85.56%, at level C/N ratio 25 is 2.56% from 88.48% and at level C/N ratio 30 is 6.6% from 91.19%. Sago pulp can be used as a source of carbon in the substrate mixture for biogas production, although the treatment did not produce optimal biogas, the production of volatile fatty acids at ratio level C/N 20 was higher than degree C/N ratio of 25 and 30. Methanogens in anaerobic fermentation conditions have lowering concentrations of BOD, COD and TSS with increasing level of C/N ratio. Levels of organic matter in the slurry and sludge generated quite high biogas production.

Kata Kunci : Produksi gasbio, Feses babi, Ampas sagu.