List the events that lead to the production of biogas from wastewater whose BOD has been reduced significantly
During secondary treatment of wastewater, sewage fungus forms focus. BOD decreases. As it decreases to 10-15% of originaL sewage, the wastewater Is taken to a Large settling tank where the focus of sewage fungus settles down. The supernatant can be passed into water bodies or treated further. The organic sediment is passed into an anaerobic sludge digester where anaerobic microbes methanogens decompose organic matter. It is accompanied by the production of blogs and the formation of manure or compost.
