Abstract:

This research was conducted to investigate the efficacy and feasibility of a UV/H$_{2}$O$_{2}$ process as a posttreatment step for complete treatment of a biologically treated composting leachate. This study was an experimental study and was conducted during April to September 2013. Leachate samples from the effluent of a multistep biological treatment system were used for further treatment by the UV/H$_{2}$O$_{2}$ process. The effectiveness of the pH values (2-10), H$_{2}$O$_{2}$ concentrations (0.5-4 g/L), and reaction times (15-75 min) were evaluated to determine optimum operational conditions. The highest removal efficiencies were 90%, 92%, 90%, and 88% for chemical oxygen demand (COD), biochemical oxygen demand$_{5}$ (BOD$_{5})$, total organic carbon (TOC), and total suspended solids (TSS) respectively, at the optimum operation conditions (pH 4, 3 g/L H$_{2}$O$_{2}$ concentration, and 75 min reaction time). The UV/H$_{2}$O$_{2}$ was found to oxidize preferably COD and BOD$_{5}$ of the leachate samples and, as a consequence, a decrease in the organic loads of the leachate was observed after oxidation treatment. The UV/H$_{2}$O$_{2}$ process proved to be a feasible posttreatment method for a biologically treated composting leachate and effectively reduced the organic loads.

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