Leachate Treatment Using Wet Air Oxidation Processes

Wet air oxidation (WAO) is One of the advanced oxidation process for reduce organic matter concentration from industrial wastewater, toxic and non biodegradable substance and solid waste leachate. In this study the efficiency of wet air oxidation method in leachate treatment from Esfahan Composing factory was Evaluate. The experiment was carried out by adding 1.5 Lit pretreated leachate sample to 3Lit autoclave reactor and adding 10 bar pressure at temperature 100, 200 and 300 °C with retention time of 30, 60 and 90 min. Leachate sample in 18 stages from composting factory in Isfahan in the volume of 20 Lit was taken and the WAO method, was used for pre-treatments. Removal efficiency of COD, BOD, NH4-N, NO3 and TSS were examined. The result shows removal efficiency of COD more than 35%, BOD5 38%, and TSS 85% was obtained in one hour reaction. The Maximum removal efficiency of NH4-N 53.3% and NO3-N 73.9 % were obtained during the process. This result indicates that the reaction temperatures are the most important factors affecting the degradation of organic matter. The COD, BOD5 removal efficiency of the WAO process was found to vary significantly with the reaction time being the most effective. In additional, BOD5/COD ratios of the effluents, which are generally regarded as an important index of biodegradability of leachate sample, were determined and showed 84% improvement in this factor. The WAO process presented in this paper is efficient process for pretreatment of leachate, as the COD, BOD5 and NO3 reduction for leachate sample.