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 pre-treatment 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 non-biodegradable 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.