Adsorption of nickel ions from electroplating effluent by graphene oxide and reduced graphene oxide

Heavy metal pollution in the water bodies causes a serious threat to all living beings. Extended exposure of heavy metals such as nickel (Ni) ions causes cancer. Henceforth, the current study investigated the removal of Ni ions from the electroplating effluent using nanocomposites namely, Graphene Oxide (GO) and Reduced Graphene Oxide (rGO) in the presence of various factors such as contact time, pH, agitation speed and sorbent dosage. Further, it was determined the rate kinetic model and adsorption equilibrium isotherms. The study also focused on comparing the removal efficiency of two nanocomposites. The maximum sorption efficiency were found to be 90.8% and 84.4% at optimized pH (8), contact time (180-1440 m), RPM (250-300) and adsorbent dosage (0.2 mg/L) for GO and rGO respectively. Furthermore, toxicity of treated and untreated effluent were tested against Phosphobacter and Azospirillium using GO and rGO and found that the treated effluent was non-toxic. The contribution of this study to agriculture in using recycled effluent for crop cultivation was being verified by seed germination of Lablab purpureus seeds watered with treated and untreated effluent. Finally we concluded that the results of treated water can be used for cultivation as there was healthy growth of plants.