Hazardous wastes and management strategies of landfill leachates: A comprehensive review

Leachate usually includes toxic organic and inorganic pollutants, heavy metals, ammonia nitrogen compounds, and other dissolved and suspended contaminants. Careful management of landfill leachate (LFL) is essential to reduce leachate quantity and prevent the unfortunate fate of leachate contamination. In contrast to the management of solid waste incinerators, LFL disposal has serious ecological and health impacts in most developing countries, mainly associated with groundwater, soil, and air pollution. This could be attributed to the absence of cost-effective treatment technology or ideal disposal guidelines by the cities/municipalities. Therefore, ecological evaluation and sustainable managing of LFL collection and disposal treatment are highly recommended. This review describes the classification and composition of leachates, the factors affecting leachate production, and the conventional (current) treatment options for LFLs. Procedures of aerobic and anaerobic biological treatment employing microbial operated separately or in combination along with physiochemical management processes are also discussed. This review examines the prospects of LFL treatment methods/techniques, how to economize LFL treatment methods (e.g., waste pretreatment) using readiness level technology, and recycling sorting technology.