Removal of organic matter and ammoniacal nitrogen from landfill leachate using the UV/H2O2 photochemical process

This study investigates the effects of pH, H2O2 concentration and reaction time of the UV/H2O2 photochemical process on the removal of organic matter and ammonia from biologically pre-treated landfill leachates in anaerobic stabilization ponds. The results show that the concentration of H2O2 and the initial pH are significant factors, with no significant interaction between them. A pH of 3 is the optimum value for the UV/H2O2 process for the removal of organic matter, resulting in 51.63% chemical oxygen demand (COD) removal in addition to the removal of aromatic compounds. The N-NH3 removal showed little variation between pH values of 1, 5, 7, 11 and 13; the removal was on the order of 16.43 +/- 2.00%. The consumption of H2O2 was elevated at pH 9, 11 and 13; at these pH values, the average removal was 94.56 +/- 0.43%, compared to 43.07% at pH 3. First-order polynomial models and reaction times on the order of 15 min are sufficient for optimization studies and for evaluation of the effects of the studied parameters. The results of this study support the optimization of the UV/H2O2 process for the removal of organic matter and ammonia from landfill leachates.