2. Experimental material and methods
The feed sewage sludge was collected from a Sewage Treatment Plant. Palm Oil Mill Effluent
(POME) was collected from Seri Ulu Langat Palm Mill, Dengkil. The POME and SS samples were
collected and sent for characterization studies upon arrival to the laboratory. The laboratory scale 10 L
single stage batch anaerobic digesters were operated under mesophilic conditions at 29°C with a
hydraulic retention time of 12 days. Each anaerobic digester was loaded with 5L’s of the substrate.
Two control systems were fed with 100% POME and 100% SS and its operation is compared to the 2
experimental systems with 60:40 and 70:30 volume ratio of POME: SS. Sample 1 was fed with 60%
POME and 40% SS while Sample 2 was fed with 70% POME and 30% SS. Sludge characteristics
such as MLVSS, TS, TKN, COD and C: N ratio was measured using APHA 2005 standards at third
party laboratory.
Biogas generated was collected in custom fabricated plastic canisters. The volume of gas produced
daily is monitored by reading the amount of displaced water.