초록
<P><B>Abstract</B></P> <P>Empty fruit bunches (EFB), palm oil mill effluent (POME), sewage chemical sludge and sewage biological sludge were evaluated for methane production under liquid-state anaerobic digestion (L-AD) and solid-state anaerobic digestion (SS-AD). The highest methane yield of 456 mL CH<SUB>4</SUB> g<SUP>-1</SUP>VS was achieved from co-digestion POME with sewage chemical sludge at a ratio of 99:1 under L-AD. The highest methane yield of 18 mL CH<SUB>4</SUB> g<SUP>-1</SUP>VS was achieved from co-digestion EFB with sewage chemical sludge at a ratio of 95:5 and EFB with sewage biological sludge at a ratio of 95:5 under SS-AD. An increasing of sewage sludge content of 6-42% in both AD systems resulted in decreasing of methane yield. The L-AD system has 2-3 times higher volumetric methane productivity than the SS-AD system. The electricity production from 1-tonne a mixture of POME and sewage chemical sludge or sewage biological sludge would be 218 MJ or 60 kWh of electricity. Anaerobic co-digestion POME with sewage sludge has great potential for biogas production.</P>