Enhancement of waste activated sludge disintegration and dewaterability by H2O2 oxidation

This study investigates the effect of hydrogen peroxide (H₂O₂) dose, pH and reaction time on the disintegration of Waste Activated Sludge (WAS) by H₂O₂oxidation alone and H₂O₂ oxidation with acid/alkaline hydrolysis. H₂O₂ oxidation with alkaline hydrolysis enhanced the sludge disintegration and dewaterability. Under the optimum operating conditions (pH 11, 1250 g H₂O₂/kg TS and reaction time 45 min), H₂O₂ oxidation aided with alkaline hydrolysis resulted in good removal of solids (TS 28.1%, VS 25.3%, MLSS 24.6% and MLVSS 21.4%), CST reduction 28.4% and sCOD concentration 8863 mg/L. The current method was shown to be an adequate pretreatment for further treatment of the waste activated sludge by biological digestion.