Preparation of an rGO and iron oxide nanoparticle-incorporated polyvinyl acetate based membrane for the removal of Pb2+ from anticorrosive paint industrial wastewater

Abstract

The efficient removal of lead (Pb²⁺) from industrial wastewater is of urgent concern because of its serious environmental and health hazards. Herein, a polyvinyl acetate (PVAc)-based mixed matrix membrane (MMM) embedded with reduced graphene oxide (rGO) and hematite nanoparticles (Fe₂O₃ NPs) by an induced phase inversion method is prepared. The addition of rGO and Fe₂O₃ NPs to the PVAc matrix was confirmed by FTIR and EDX analyses, while morphological, textural, and mechanical features of the membrane were analyzed by SEM, water contact angle and tensile strength tests. The Pb²⁺ remediation efficiency of the membranes was analyzed from model aqueous solution (acidic lead(II) sulfate (PbSO₄)) and anticorrosive paint industrial wastewater in an acrylic cell. Under the optimized conditions of feed, stripping agent (NaOH), acid (H₂SO₄) and carrier (tri-ethanol amine) concentrations of 6.21 mM, 2 M, 3 M and 4 M, respectively, PVAc/rGO/Fe₂O₃ achieved 99.9% Pb²⁺ removal from both water samples. The removal of Pb²⁺ was confirmed by textural analyses (SEM, EDX, FTIR, and AFM) of the post-experimental membranes. Under optimal process parameters, PVAc/rGO/Fe₂O₃ achieved intriguingly high water permeate fluxes of 1.84 × 10⁻² g m⁻² s⁻¹ and 2.30 × 10⁻² g m⁻² s⁻¹ for model aqueous Pb²⁺ solutions and anticorrosive paint industrial wastewater, respectively, and thus easily outclassed many advanced membranes reported for the remediation of Pb²⁺ in the literature. Thanks to its highly cost-effective and environmentally friendly nature, ease of synthesis and intriguing performance, the newly designed PVAc/rGO/Fe₂O₃ MMM can be deemed of great promise for the practical remediation of Pb²⁺ and other pollutants from industrial wastewater on a large scale.