Comparison of NLDH and g-C3N4 nanoplates and formative Ag3PO4 nanoparticles in PES microfiltration membrane fouling: Applications in MBR

Abstract

Development of antifouling membranes for wastewater treatment technology can serve as an economic and efficient approach urgently demanded. Attempts have been made to develop cost-effective blended microfiltration membranes containing ZnAlCu nanolayered double hydroxide (NLDH) or g-C3N4 nanosheets, and Ag3PO4 and NH2-Ag3PO4 nanoparticles with the view of finding the effect of their chemical and structural properties on the membranes performance. The obtained ZnAlCu-NLDH/polyethersulfone (PES) and g-C3N4/PES nanocomposite membranes exhibited the significant flux recovery ratio (FRR), as an antifouling index, of 75.8 and 70.7%, respectively, as compared with the pristine PES membrane having 50.9% of FRR. Inclusion of Ag3PO4 and NH2–Ag3PO4 nanoparticles remarkably increased the permeate flux of the membranes, so that the pure water flux of nanoparticles blended membranes at the pressure of 0.5bar was found to be 292.6 and 319.5Lm−2h-1, respectively, as compared with 229.2Lm−2h-1 for the pristine PES microfiltration membrane. Moreover, the fabricated membrane containing Ag3PO4/NLDH and NH2–Ag3PO4/g–C3N4 nanofillers showed a high flux, wettability and antifouling properties, with regard to the prevention of the interaction of the organic foulant and the hydrophilic membranes. Consequently, the self-cleaning property of nanocomposite blended membranes and the low leaching of nanocomposites could lead to the fabrication of a promising mixed matrix membrane for practical wastewater treatment in membrane bioreactors (MBRs). The increase in the critical flux (CF) also showed the desirable application of the nanocomposite microfiltration (MF) in MBR.