Selection of Landfill Leachate Treatment Methods According to the Age of Landfill Leachate

Municipal Solid Waste (MSW) is a major issue in India. San-Pedro, L., Méndez-Novelo, R., Hernández-Núñez, E., Flota-Bañuelos, M., Medina, J., & Giacomán-Vallejos, G. (2020). Selection of the activated carbon type for the treatment of landfill leachate is achieved by the fenton-adsorption process. Molecules, 25(13). https://doi.org/10.3390/molecules25133023-21 ; a total of 160,038.9 TPD solid waste is generated in India, of which 29,427.2 TPD is landfilled. Leachate is commonly a high-strength wastewater generated from landfilling operations and its strength varies over its age in a specific landfill, where treatment technologies are classified according to the age of the landfill (i) Immature leachate (Landfill age is less than 5 years), and (ii) Mature leachate (Landfill age is more than 5 years). Immature leachate contains COD value of more than 10,000 mg/L and biodegradability index is more than 0.5, whereas mature leachate contains COD value of less than 10,000 mg/L and biodegradability index is less than 0.5. This paper provides a general overview of landfill operation, characteristics of landfill leachate, factors affecting the strength of leachate, and available leachate treatment methods and also reviewed the currently applied treatment methods together with different combinations of technologies considered regarding their COD removal efficiency. The objective of this paper is to select various combined alternative treatment methods according to their age in terms of cost-saving and increasing each unit's effectiveness. Treatment technologies are divided into 3 categories that are (i) Physico-chemical process, (ii) Biological process, and (iii) Advanced process. Among these treatment methods a combination of the Physico-chemical and biological process is suitable for immature leachate, whereas to treat mature leachate, an advanced process is required along with the combined Physico-chemical and biological process.