In the present study, the effect of hydrogen peroxide oxidation/alkaline hydrolysis was investigated on waste activated sludge (WAS), to enhance its disintegration and dewaterability. The effects of three operating parameters viz., pH, H2O2 dose and reaction time, on the degree of WAS disintegration and dewaterability were assessed using response surface methodology. The optimum operating variables to achieve VSS removal 20, CST reduction 20, sCOD 6100 mg/L and EPS 455 mg/L were: pH 10.5, 1300 g H2O2/kg TS and 40 min reaction time. Results showed that WAS can be efficiently disintegrated and dewatered by H2O2 oxidation/alkaline hydrolysis for subsequent biological digestion. © The Authors, published by EDP Sciences, 2018.