Recycled PET/metal oxides nanocomposite membrane for treatment of real industrial effluents: Membrane fabrication, stability, antifouling behavior, and process modeling and optimization

Abstract

An environmentally friendly nanofiltration membrane from recycled PET (Polyethylene terephthalate) was fabricated for rejection of Pb (II) and Cr (VI) from synthetic and real industrial effluents. Various ZnO/y-FeOOH NPs concentrations from 0.5 to 1 wt% were investigated as a hydrophilic agent. The membranes were characterized by FE-SEM, XRD, WCA, AFM, and FTIR analysis. Membrane stability in acid/alkaline/boiling water was also studied. The Box–Behnken design (BBD) was used for the optimization of the metals rejection. The influence of the pH, transmembrane pressure (TMP), and heavy metal ion concentrations on the rejection were investigated. The optimal conditions were achieved as; 3.59, 0.5 bar, and 11 mg/L for Pb (II) and 3.9, 0.5 bar, and 10 mg/L for Cr (VI) rejection. The pure water flux (PWF) was 169.39 kg/m2·h, and the rejection rate of Pb (II) and Cr (VI) were 94.7 %, and 63.4 %, respectively. The antifouling behavior of the membranes was also studied by the filtration of milk solution. The rPET/ZnO/y-FeOOH membrane with 0.5 wt% of NPs had a high antifouling capability (FRR 96.2 %, Rr 90.21 %, and Rir 3.001 %). This study confirmed that the fabricated rPET/ZnO/y-FeOOH membrane is a promising filter for the removal of heavy metals from industrial effluents.