Landfills leachate generation is the biggest problem faced by M.S.W. departments and Environmental Departments, and it can cause a significant threat to surface water and groundwater. It is the toxic contaminated water generated due to water produced from the biodegradation of wastes in aerobic conditions, a mixture of rainwater percolation through waste, and the inherent water of the waste itself. It carries various pollutants, such as suspended particles, heavy metals, ammonia, and nitrogen. As the age of landfill leachate increases, the toxicity of the leachate also increases. In addition, heavy metals such as cadmium, chromium, lead, mercury, nickel, copper, ferrous, and selenium percolate in soil and water are responsible for the contamination. To protect groundwater, surface water and soil from the toxicity of landfill leachate, physical, chemical, and biological methods were used to treat landfill leachate. The paper discussed the different landfill leachate treatment methods and their merits and demerits. In the current scenario, the membrane processes, especially reverse osmosis, have been effectively used for landfill leachate treatment and found suitable for achieving purification.
