Performance evaluation of polyethersulfone membranes modified with poly (acrylic acid‐co‐N‐vinyl pyrrolidone) grafted mesoporous carbon nitride for effective removal of cadmium(II) from wastewater

Abstract

Industrial pollutants in water streams, such as heavy metals, are among the most important issues for ecosystem and human health. Membrane filtration is an appealing technique for the removal of these contaminants from wastewater. In this study, composite ultrafiltration polyethersulfone (PES) membranes were fabricated by implementing poly (acrylic acid‐co‐N‐vinyl pyrrolidone) grafted mesoporous carbon nitride (MCN) nanoparticles to improve the performance of membranes. Polymer grafted MCN was synthesized through (3‐methacryloxypropyl)trimethoxysilane and (3‐Aminopropyl)triethoxysilane treatment and subsequent in situ radical polymerization on MCN. Modified membranes exhibited significantly improved hydrophilicity; the contact angle decreased from 66° for the PES membrane to 36° for the modified membranes. In addition, the morphology, surface roughness, thermal stability, and mechanical stability of membranes were studied. The results revealed that the pure water flux of membranes was improved from 82.6 to 329. 8 L/m2 h by increasing the nano‐additive content. Moreover, the membranes showed a maximum rejection of 92.3% for Cd2+ metal ions. Studying the fouling resistance of membranes showed a significant increase in fouling ratio recovery from 42.77% to 87.64%. It was also found that the irreversible fouling values were remarkably reduced because of the higher hydrophilicity of fabricated composite membranes.