Ion Cadmium Adsorption from Aqueous Solution Using Nanocomposite Based on Chitosan/Functionalized Nano Graphene Platelet

Toxicities of water sources due to the discharge of industrial effluents is a worldwide environmental problem. Industrial wastewater often contains a considerable amount of heavy metal ions and organic pollutants, which would endanger public health and the environment.Cadmium Cd(II) is a toxic heavy metal, normally found in industrial wastewater, especially from metal plating industries, Cd–Ni batteries, phosphate fertilizer, mining, pigments, stabilizers, and alloys. Cd(II) adversely effects human health because of serious damage to the kidney, renal disturbances, and bones lesions. In this work, heavy metal ions were removed using biodegradable polymer based on chitosan and functionalized graphene with amine groups. Nanocomposite Samples containing 0.5, 1, 2, 5 wt.% of functionalized graphene were obtained via solution method. At first, graphene was oxidized with sulphuric and nitric acid then triethylenetetramine was grafted on the graphene surface. Functionalized graphene was characterized by Fourier Transform Infra-Red (FT-IR) spectroscopy, Thermal Gravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM). Results showed functionalization of graphene was successfully accomplished. The morphology of nanocomposite was monitored by SEM. Adsorbing heavy metal ions (Cadmium) was investigated with Flame Atomic Absorption Spectrometry (FAAS) and results revealed that the nanocomposite samples have a higher potential for ion metals adsorption than that of neat chitosan. The adsorption of nano samples for cadmium was increased around 20% in comparing to neat chitosan. The effect of sorbent concentration, pH, mixing time and heavy metal ion concentration was studied on the adsorption behavior and it was found that the optimum adsorption occurs at pH=7, 50 ppm ion metal concentration, 2h contact time and 25 mg of sorbent.