Energy recovery of sewage sludge treatment by anaerobic co-digestion. Issue 1 (March 2021) - Tran, Thanh
Abstract: Sewage sludge produced from wastewater treatment is one of the challenges facing many countries in their development process; therefore, the sewage sludge needs treating suitably. Besides, recovering energy from waste to save operating costs in treatment plants is also being considered. The study was conducted by mixing urban sludge samples with substrates (agricultural residues) to create different C/N ratios from 16.6 to 32.5, then evaluating the quantity and quality of methane) the gas generated from the test pieces. This method not only solved the environmental problem but also had benefited from biogas produced from the digestion process. The initial results showed that the quantity of biogas from anaerobic co-digestion of sewage sludge and rice husk (ratio 4:1) are 160ml/g VS. Furthermore, the quality of methane can be up to 60% and near twice as much as mono-digestion. The study results estimate that the potential of recovering electricity from the sludge for the wastewater treatment plant of Binh Hung (Vietnam) is about 0.2 MW/year or higher.