BIOGAS PRODUCTION FROM SYNTHETIC SAGO WASTEWATER BY ANAEROBIC DIGESTION: OPTIMIZATION AND TREATMENT

Sago processing industries generate a voluminous amount of wastewater with extremely high concentration of organic pollutants, resulting in water pollution. Anaerobic digestion was employed for reduction of COD and maximization of biogas production using synthetic sago wastewater by batch process. Mixed culture obtained from sago industry sludge was used as a source for microorganisms. Response surface methodology was used to optimise the variables, such as pH, initial BOD, temperature and retention time. Statistical results were assessed with various descriptives, such as p-value, lack of fit (F-test), coefficient of R-2 determination, and adequate precision values. Pareto analysis of variance revealed that the coefficients of determination value (R-2) of COD and BOD removal and biogas production were 0.994, 0.993 and 0.988, respectively. The optimum condition in which maximum COD removal (81.85%), BOD removal (91.61%) and biogas production of 99.4 ml/day were achieved was at pH 7 with an initial BOD of 1374 mg/l, and with the retention time of 10 days at 32 degrees C.