Municipal Solid Waste Landfill Leachate Treatment: A Review

One of the main problems posed by municipal solid waste landfills is the generation of leachate and the main issue related to landfill leachate is its treatment, especially in developing countries. Landfill leachate is highly polluted discharge containing high loads of heavy metals, organic compounds, ammonia (NH3-N), chemical oxygen demand (COD), toxic chemicals, pathogens, and various other hazardous chemicals. It must be treated and appropriately disposed in order to avoid the environmental pollution and ecotoxicity caused by its disposal. The type of method selected for treatment depends upon the quality as well as quantity of leachate. The composition as well as quantity of leachate depends upon several factors like type of landfill, age of landfill, seasonal variations, degree of compaction, climatic conditions, precipitation, mode of operation etc. Therefore, the development of an efficient method for treatment of landfill leachate is very crucial. For the treatment process of landfill leachate, several methods including physicochemical, biological, chemical, and physical methods have been used. However, these methods are very complex and costly as they require various processes. Also, due to high pollution loading, complex chemical composition, and seasonally variable volume of leachate the treatment process become very difficult. Therefore, it becomes necessary to implement a combination of different methods including biological, chemical, and physicochemical processes for the effective treatment of leachate. The main objective behind treatment of landfill leachate is to make leachate meet the treatment standards so that it poses least impact on the environment as well as human health after its disposal.