Evaluation of antifouling/biofouling ability of a novel MIL101(Cr)/PES composite membrane for acetate wastewater treatment in MBR application

Membrane bioreactors (MBRs) as biotechnology-based wastewater treatment processes have recently attracted lots of attentions. However, membrane fouling/biofouling as a significant obstacle has prevented MBRs from being widely used. The phase inversion method was used to fabricate a novel MIL-101(Cr) (MCPs)/polyethersulfone (PES) composite membrane. Adding MCPs up to 0.4 wt% significantly improved the membrane surface hydrophilicity and increased the membrane porosity, pore size, and fouling/biofouling formation resistance. Pure water flux of the optimal composite membrane increased by about 198.61% compared to the neat one. It also showed the lowest total fouling ratio (Rt: 48.79%) and irreversible fouling ratio (Rir: 10.43%), and the highest flux recovery ratio (FRR: 89.54%) and protein rejection (99%). Its COD removal efficiency for acetate as synthesis wastewater was about 75%. Performance of the optimal composite membrane was also evaluated at varied mixed liquor suspended solids (MLSS) concentrations of 8000, 10,000, and 12,000 mg/L. Increasing MLSS concentration decreased permeation flux due to rising sludge viscosity and fouling/biofouling formation. The results gave useful insights into preparation of hydrophilic composite membranes through blending of MCPs and PES to treat organic wastewaters using the MBR applications.