Abstract: Anaerobic digestion is adapted worldwide to treat sewage sludge, mostly under mesophilic condition and producing methane. The feasibility of anaerobic digestion of aged domestic sewage sludge which was stored for 3 weeks was evaluated under mesophilic condition. Completely mixed batch reactors were used to compare the methane production from aged domestic sewage sludge at inoculum to substrate of 2.0 and 1.5. The tests were carried out at 37°C and run against a control of inoculum without substrate. Modified Gompertz Model was employed to reveal the principle kinetics of methane yield from the anaerobic digestion. The results showed that the methane yield was higher at higher I/S ratio had average value of 1336.6 mL CH4/g VS added. However, the higher cumulative methane production was observed at lower ratio of I/S and had nett average value of 794.23 mL CH4. Model simulation indicated Modified Gompertz model best fitted the laboratory data, showing the value of kinetic equation parameters between model and actual differ slightly.
Roslinda Seswoya and Ahmad Tarmizi Abdul Karim, 2016. Influence of Inoculum to Substrate Ratio on the Biochemical Methane Potential of Domestic Sewage Sludge in Batch Tests. Journal of Engineering and Applied Sciences, 11: 2155-2160.