Colour and COD removal from mature landfill leachate using electro-persulphate oxidation process

Abstract

Landfilling is the most common method used to treat municipal solid waste in Malaysia. Landfill leachate (LL) is typically produced by infiltration of precipitation through landfill that contains potential hazards to environment. Only 9 operating landfills in Malaysia can be classified as a modern sanitary landfill. Subsequently, substantial amounts of untreated landfill leachates are regrettably discharged into the surrounding environment. There is a need to treat the generated leachate via an effective process such as electro oxidation. Electro-persulphate oxidation process is introduced to degrade complex organic pollutants exists in mature LL. In this study, the impacts of current density, contact time, S2O82− dosage were investigated and optimized using Response Surface Method (RSM). The optimum performance was obtained at current density 44.66 mA/cm2, contact time 68.3 min and S2O82− dosage of 0.88 g/L, respectively. The optimum removal efficiency was 97.30%, and 45.70% for colour and COD. The final pH was 7.12. The treated LL effluent meet the discharge standard limit of Malaysia.