Photocatalytic removal of Chemical Oxygen Demand (COD) from Kg.Wai closed sanitary landfill leachate sample

Abstract

This study was conducted to examine the percentage of Chemical Oxygen Demand (COD) removal from landfill leachate using photocatalytic technique. The absence of catalyst in photocatalytic treatment, the effect of TiO2 and ZnO dosages and solar radiation were investigated. COD removal efficiency becomes lower with the absence of catalyst in photocatalytic. The photocatalytic experiment was performed under different catalyst dosages and also solar radiation exposures. Catalyst dosage of 6 g/L TiO2 and 7 g/L ZnO were found to be optimum for removal of COD up to 64.5 % and 74.5 % respectively for 2 hours photocatalytic duration. The COD leachate can be removed up to 70.4 % by using the optimum TiO2 dosage (6 g/L) under shorter duration (2 hours). However, for 7 g/L of ZnO, the highest degradation of COD at 65.8 % was achieved after 3 hours of solar exposure. Prolonged study to 6 hours shows gradual reduction of COD removal efficiency to 52.1 %. Based on the study, TiO2 was found to be more effective photocatalyst for COD removal up to 60 until 70 % removal efficiency.