Experimental approach for chemical oxygen demand and ammonia nitrogen removal from natural rubber wastewater via adsorption by kaolin

Natural rubber is an important material because of its high strength compared to synthetic rubber. However, the production process of natural rubber discharges a large amount of wastewater containing high concentrations of organic compounds and nitrogen. Therefore, discharging natural rubber processing wastewater without an appropriate treatment can lead to environmental problems such as deterioration of water quality and eutrophication. In this study, the batch adsorption experiment was carried out for the removal of chemical oxygen demand (COD) and ammonia nitrogen from natural rubber wastewater using kaolin as adsorbent. The efficiency of the kaolin was studied by varying the parameters adsorbent dose, pH, shaking speed and contact time. The experimental equilibrium data for this system has been analyzed using the linearized forms of Langmuir and Freundlich isotherms. COD and ammonia nitrogen removal efficiencies were 71.6% and 75.8%, respectively. While, Langmuir isotherm was found to provide the best theoretical correlation of the experimental data.