Optimized Process for Efficiently Extraction Protein from Excess Activated Sludge by Alcalase Hydrolysis

In this paper, we developed the utilization of excess activated sludge (EAS) to extract protein. Firstly, activated sludge was hydrolyzed, using six different commercial proteolytic enzymes by the Kjeldahl method, at their optimal conditions respectively, and Alcalase was chosen as the ideal for further analysis. Secondly, important parameters on protein extraction efficiency(PEE) of EAS by hydrolysis were investigated. Experimental results have been shown that 52.5% of protein was extracted from EAS (accounting for 30.5% of initial dry sludge (DS) weight) and reducing the quality of activated sludge about 35% under optimum hydrolysis conditions. This novel technology is more environmentally friendly than the conventional sludge treatments.