Chitosan-Grafted Carbon for the Sequestration of Heavy Metals in Aqueous Solution

Heavy metals removal from wastewater is totally essential to evade water pollution. The present study showed the performance of chitosan coated carbon for the removal of chromium (VI) and Pb (II) from aqueous solution. The following elements; C, K, Ca, Mg, Al, Si, P and Cl were revealed by Energy dispersive X-ray (EDX) as part of the constituent of the adsorbent while Scanning Electron Microscope (SEM) reveal agglomeration of the adsorbent particle. Batch adsorption experiments were performed in order to examine the removal efficiency under the various factors such as the effects of initial concentration, adsorbent dose, agitation time and particle size. The adsorbent possess good adsorption efficiency for chromium (VI) and lead (II) with optimum agitation time of 90 to 120 min even at low concentration. Experimental data were analysed by Langmuir and Freundlich adsorption isotherms. The characteristic parameters and related correlation coefficients were determined. The isotherm study revealed that the adsorption equilibrium is well-fitted to the Langmuir and Freundlich isotherm. The selectivity order of the adsorbent (modified and unmodified) towards the ions was found: Pb (II) > Cr (VI). The method could be successfully employed for removal of toxic metals from industrial effluents and could solve the problem of disposal of agricultural waste materials.