Optimization of Sludge Carbon Source Recovery from Waste Activated Sludge Thermo-alkaline Hydrolysis and Short-cut Fermentation Process

Abstract

Organic products generated from waste activated sludge hydrolysis and fermentation process could be used as supplementary carbon source for enhanced biological nutrient removal. However, accompanied with organics production, large amount of ammonia nitrogen (NH4+-N) and soluble orthophosphorus (SOP) released, which would be negative to the reutilization of sludge carbon source. In this study, based on wasted activated sludge thermal-alkaline and short-cut fermentation process, optimal conditions for NH4+-N and SOP removal condition, and sludge carbon source recovery from short-cut fermentation liquid have been investigated systematically using response surface method. Results showed that, the removal rate of NH4+-N and SOP were 72.27% and 85.98% respectively, and the SCOD recovery rate was 80.74%.