Leachate Treatment Using Low-Cost Adsorbents: A Comparative Study

Landfill leachate containing potentially harmful substances poses critical concerns for the environment and human health by contaminating groundwater, threatening aquifers, and risking widespread pollution of water sources. This study aimed to assess low-cost activated carbon from sunflower seed husk, pineapple peel, and tea waste in treating stabilized leachate from Lamdeng Khunou Solid Waste Management Plant in Imphal, Manipur State, India, which generates over 8000 mg/L of COD daily. Various physicochemical characteristics including pH, turbidity, conductivity, alkalinity, etc. were examined in treated leachate samples. To study the coagulation-flocculation process, jar test experiments were done using ferric chloride as a coagulant. The adsorbents sunflower seed husk, pineapple peel, and tea waste exhibited high efficiency, reducing COD by 95.4%, 91.7%, and 90.8%, respectively, and lowering BOD with removal efficiencies of 91.4%, 92.5%, and 88.04% correspondingly. Lagergren’s first- and second-order kinetics models were used to analyze the amount of ions adsorbed onto the adsorbent with respect to time. The application of the Langmuir and Freundlich isotherm establishes the functional relationship between the adsorbent and adsorbate. The findings indicate that employing the physicochemical method with the low-cost adsorbents holds promise as an effective treatment approach for landfill leachate in Imphal City.