Cd(II) removal from aqueous solution by unmodified sugarcane bagasse and coconut coir: Adsorption equilibrium and kinetics

This paper reports the feasibility of using two Malaysian agricultural residues without modification; unmodified sugarcane bagasse (UMSCB) and unmodified coconut coir (UMCC) for the removal of Cd(II) from aqueous solution under different experimental conditions. Effect of various process parameters; contact time, initial metal ion concentration and pH have been studied. The maximum Cd(II) adsorption capacity was shown by UMSCB and UMCC are 5.322 and 5.870 mg/g respectively at 15 mg/L. Adsorption process was expressed by using Langmuir and Freundlich isotherms. Freundlich isotherm curves were found to be significant compared to Langmuir isotherm. Two simplified kinetic models were tested to investigate the adsorption mechanism. These results indicate that such bagasse and coir without modification could be employed as low cost adsorbents in waste water treatment for the removal of heavy metals.