Trends in Physical-Chemical Methods for Landfill Leachate Treatment

Leachate is created while water penetrates through the waste in a landfill, carrying some forms of pollutants. The aims of this study were the review on physical-chemical methods for landfill leachate treatment. The physical-chemical ways for landfill leachate treatment like Chemical precipitation, Chemical Oxidation, Coagulation?Flocculation, Membrane filtration, Ion exchange, Adsorption and Electrochemical treatment are studied. Chemical precipitation is generally used as pretreatment in order to remove high strength of ammonium nitrogen; fenton oxidation is one of these advanced oxidation processes with high efficiency and low capital costs; coagulation?flocculation has been used for the removal of nonbiodegradable organic compounds and heavy metals from landfill leachate; nanofiltration (NF) is one of membrane filter and it has found a place in the removal of recalcitrant organic compounds and heavy metals from landfill leachate; adsorption is the most widely used technique for the removal of recalcitrant organic compounds from landfill leachate; the ion-exchange method offers a number of benefits containing the ability to handle shock loadings and operate over a wider range of temperatures. The landfill leachate properties, technical applicability and constraints, effluent discharge alternatives, cost-effectiveness, regulatory requirements and environmental impact are important factors to selection of the most suitable treatment technique for landfill leachate treatment.