This study discusses efforts being made to realize energy self-sufficiency in a sewage treatment plant, and to achieve both energy conservation with low-load water treatment based on thorough, intensive solid–liquid separation and ‘energy production’ by using sludge treatment capable of converting recovered biomass into energy with maximum efficiency. Intensive solid–liquid separation resulted in higher suspended solids and Biological Oxygen Demand (BOD) removal rates than those achieved with conventional primary settling tanks. Using thermophilic digestion of raw sludge, recovered by intensive solid–liquid separation, and garbage as substrates, the Volatile Solids (VS) decomposition rate was 70% and generated digestion gas was 759 Nm3/t-loaded VS on average under conditions of Hydraulic Retention Time (HRT) 5 days and a VS load of 6.0 kg-VS/m3/day. The generated digestion gas was totally used to generate power with phosphoric acid fuel cells.

You do not currently have access to this content.