UJI KINERJA DIGESTER ANAEROB TIPE TUNNEL DENGAN SLUDGE RECYCLE UNTUK PRODUKSI BIOGAS DARI LIMBAH PETERNAKAN SAPI

Biodigester sludge are simpler organic material which undergo a process as digestion. Fresh manure mud and sludge digester which have undergone fermentation have very high organic materials because it contains long chain of protein, fat and carbohydrate. Such characteristic makes the material is easy to digest by microorganism or to be treated biologically. Biogas s gases produce by microbe activities an aerobically on biodegradable organic material. The main components of biogas are methane and carbondioksida. This research used two digester tunnels with the capacity of 1.5 m3 and had a purpose to know the productivity of biogas based on digester dimension and operation technique. The operation technique consisted of the continue of subtract feeding and the use of active biodigester sludge as recycle. sludge percentage as recycle as 20%, 30% and 40%. Supporting parameter which is tested consists of biogas productivity, VS, VFA, TS, in inlet and outlet digester. the material used in the research were manure and water in KP4 UGM, Berbah, Sleman Yogyakarta. The result showed that on the concrete tunnel digester with digester volume 1.5 m3, the velocity of biogas resulted is 0.65 (m3/day)/m3 slurry, while on the PVC with digester volume 0.0365 m3 the velocity of biogas resulted is 0.0036 (m3/day)/m3 slurry. Based on continuity of substrate feeling, the velocity of biogas resulted of 0.66 (m3/day)/m3 slurry while the un continued subtracts feeding was 0.29 (m3/day)/m3 slurry. By the used of sludge as recycle with the percentage 20%, 30% and 40%, the velocity of biogas production resulted was 0.38 (m3/day)/m3 slurry, 0.52(m3/day)/m3 slurry and 0.59(m3/day)/m3 slurry. The resulted showed that digester size and operation technique during the process of anaerobic digestion was able to give influence toward biogas productivity