Preparation of magnetic chitosan/reduced graphene oxide nanocomposite for the removal of zinc and lead ions from water

Nowadays, heavy metals contaminating water are considered as serious global concerns due to their deleterious environmental effects and not being biodegradable [1]. Among these toxic ions, zinc and lead species originated from diverse industries such as mining, metals, batteries, etc., could result in brain tissue damage, kidney failure and anemia. So far, different methods like membrane filtration, ion-exchange, adsorption, chemical deposition, advanced electrochemical oxidation processes and so on, have been used to reduce the amount of heavy metals in water. In this regard, using an in-expensive and biodegradable sorbent beseems a promising strategy which was reported on carbon, zeolite, metal oxides etc., in the past years [2,3]. In this work, we prepared a magnetic nanocomposite of chitosan-reduced graphene oxide (thiourea was used as reducing agent) to remove zinc and lead ions from simulated contaminated water. The structural properties of the as-synthesized nanocomposite was analyzed by XRD, FT-IR, FE-SEM, EDX, TEM and Raman spectroscopy characterization methods. The effects of some parameters such as pH, contact time and initial ion concentration were investigated on the Pb2+ and Zn2+ ions removal. The equilibrium and kinetic studies showed that lead and zinc adsorption followed Freundlich isotherm and pseudo-second order kinetic models. Moreover, the maximum adsorption capacities were estimated 169.58 and 421.78 mg/g for Pb2+ and Zn2+, respectively.