Application of Composite Biogas Tank in Anaerobic Co-digestion Faecal Sludge and Organic Waste

Abstract

The aim of this study was to investigate the efficiency of using composite digester for anaerobic co-digestion of mixed faecal sludge and organic waste. The study was done in four trials (T1, T2, T3, T4) in the composite digester that buried underground on climate condition in Vietnam. The original material was faecal sludge (FS) and organic waste (OW) mixed at ratio FS:OW = 3:1 about the weight. The fresh material was loaded batch and kept for digestion in 30 days. The obtained results during anaerobic digestion indicated that the initial temperature at different experiment trials affected biogas yield. The temperature on the first day in T4 was the highest, so the biogas yield was the biggest and the initial temperature in T3 was the lowest, so the biogas yield also was the smallest. Namely, the yield biogas was 485.23 Nl/kgVS of feed, 455.52 Nl/kgVS of feed, 426.94 Nl/kgVS of feed and 526.12 Nl/kgVS of feed in T1, T2, T3 and T4, respectively. However, with low temperature in the T3, the digestion process was also quite good. This shows that it is entirely possible to use composite biogas tank in anaerobic co-digestion of mixed faecal sludge and organic waste to handle faecal sludge and recovery biogas.