Abstract:Municipal waste landfill leachate was treated with a batch-type supercritical water oxidation process, with hydrogen peroxide as the oxidant. The impacts of reaction temperature, pressure, and retention time on oxidation efficiency were studied. The results show that the COD and TOC removal efficiency of leachate treated with supercritical water oxidation improved with the increase of reaction temperature, pressure, and retention time. After supercritical water oxidation, the efficiencies of removal of COD and TOC reached 98. 8% and 97. 6%, respectively, under the conditions that the concentrations of COD, TOC, and BOD in untreated leachate were 8119 mg/L, 2 289 mg/L, and 971 mg/L, respectively; the reaction temperature was 405℃; pressure was 25 MPa; and the retention time was 37. 1 seconds. The results show that supercritical water oxidation could effectively improve the biodegradability of landfill leachate. The ratio of biodegradability of leachate increased from 0. 12 to 0. 55.