Optimization of biogas production from wastewater treatment plant sludge

Abstract

This study aims to improve the efficiency of biogas production by utilizing sludge from the Aïn Bouchakif wastewater treatment plant in Tiaret, along with other organic waste. The research process lasted approximately 37 days and began with the collection of samples from the treatment plant. A laboratory-scale digestion reactor was designed to produce biogas. Physicochemical analysis of the sludge was conducted, as well as microbiological analysis to determine important microbial characteristics contributing to the anaerobic digestion process of the sludge and, consequently, biogas production. These characteristics were monitored to enhance the performance of the fermentation process. Under these conditions, three bacterial types were identified. In addition to mixing the sludge with different components in a studied sequence, the quantity of gas produced throughout digestion was monitored. The results demonstrated the feasibility of gas recovery from the utilized sludge. However, the sludge from the predigester exhibited the highest yield with a volume of 2000 ml, while the dairy sludge showed a volume of 1600 ml, and the mixture of sludge with cereal waste yielded 1200 ml. Lower rates were recorded for the mixture of pre-digester sludge with digester sludge. Analysis of the produced gas mixture revealed a methane content of 13%.