Functionalised graphene oxide dual nanocomposites for treatment of hazardous environmental contaminants

Abstract

During the past few decades, water contamination has raised a huge concern due to rapid industrialization, agricultural wastes, metal galvanizations, and leather industries as a result of the discharge of organic pollutants, dyes and heavy metals. The present study investigates the synthesis of copper oxide nanoparticles (CuO-NPs) and graphene oxide-copper oxide nanoparticles (GO/CuO-NPs) for heavy metal ions adsorption like Ni2+ and Cd2+ from wastewater. For this purpose, batch and continuous adsorption studies were performed. The chemical and physical characteristics were analyzed by FTIR, XRD, SEM, and AFM. AFM analysis confirmed the hexagonal structure and an average diameter of 79.91, 82.01 and 21.45 nm for GO/CuO-NP, CuOn, and CuOm, respectively. In batch scale, it is concluded that GO/CuO-NPs showed the best adsorption capacity for Ni2+ and Cd2+ than CuOn and CuOm at pH value of 8, adsorbent dose of 250 mg, initial concentration of 50 mg/L, a contact time of 15 min. GO/CuO-NP showed the maximum Ni2+ and Cd2+ removal of 99.16 and 98.84 % respectively at 15 min contact time. Similarly, the maximum Ni2+ and Cd2+ ions removal of about 99.37 and 99.18 % was observed with GO/CuO-NPs at an adsorbent dose of 250 mg and 50 mg/L dye concentration. The adsorbent isotherm and kinetic analysis revealed that the results were best fitted with Langmuir isotherms and the Pseudo-second order model, respectively. While in continuous adsorption analysis, GO/CuO-NPs showed the best adsorption capacity for Ni2+ and Cd2+ than CuOn and CuOm at an initial concentration of 50 to 75 mg/L, a flow rate of 4 mL/min, and a bed height of 1.5 to 2 cm. However, the present study provides valuable insight into novel nanocomposites' development to eliminate Ni2+ and Cd2+ from industrial wastewater.