Adsorption studies of leachate on cockle shells

Sanitary landfills are important means of disposing municipal solid waste in developing countries. However, these landfills are associated with the generation of leachate, which if untreated may pose severe public health risk and may damage the ecosystem in the long term. In this study, cockle shells were explored as an adsorbent media for the treatment of a stabilized landfill leachate. The optimum shaking speed, pH, and dosage for chemical oxygen demand (COD) parameter removal were investigated using the adsorbent media of particle sizes ranging from 2.00 mm to 3.35 mm. Leachate characteristics were then determined. Results indicated that leachate is non-biodegradable with high concentrations of COD (1763 mg/L), ammonia nitrogen (573 mg/L), and biochemical oxygen demand/COD (0.09). The optimum conditions for shaking were determined at 150 rpm according to the adsorption of COD by the media. Optimum pH and dosage was 5.5 and 35 g/L, respectively. The adsorption isotherms indicated that Langmuir isotherm is better fitted than Freundlich isotherm