Advanced oxidation treatment of composting leachate of municipal solid waste by ozone-hydrogen peroxide

 This research was conducted to investigate the efficacy and feasibility of ozone-hydrogen peroxide advanced oxidation process as a post-treatment step of composting leachate treated by an anaerobic migrating blanket reactor biological treatment system. 

 Leachate samples was collected from the effluent of the biological treatment system and used in an ozone reactor after dilution. The effectiveness of the pH values (4.5-11.5), H2O2 concentrations (0.5-4 g/L), ozone doses (0.2-1 g/h) and reaction times (5-270 min) were evaluated to determine optimum operational conditions. 

 The highest removal efficiencies were achieved 72% and 79% for chemical oxygen demand (COD) and biochemical oxygen demand5 (BOD5), respectively, at pH 8.5, 2.5 g/L H 2 O 2 concentration, and 1 g/h ozone dose, during 270 min reaction time. Furthermore, results indicated that the BOD 5 /COD ratio was decreased from 0.53 to 0.4 after 270 min reaction time. 

 The O 3 /H 2 O 2 was found to oxidize preferably COD and BOD 5 of the leachate samples. In consequence, a decrease in the biodegradability of leachate was observed after oxidation treatment. The O 3 /H 2 O 2 reaction proved to be a feasible technique for the oxidation of the leachate under study, and it can be considered a suitable treatment for this type of wastewater.