Photocatalytic filtration reactors equipped with bi-plasmonic nanocomposite/poly acrylic acid-modified polyamide membranes for industrial wastewater treatment

In this study, two new composite membranes with antifouling and anti-biofouling properties were prepared through the modification of commercial polyamide (PA) discs using combination of in-situ polymerization of polyacrylic acid (PAA) and grafting of two synthesized bi-plasmonic Au-Ag and Ag-Au photocatalysts. The synthesis and characterization of the photocatalysts in batch mode were discussed in details as primary studies. Two intense 405-nm and 532-nm lasers for Ag-Au and Au-Ag photocatalysts, respectively and a solar-simulated xenon lamp for both photocatalysts were applied for photodegradation studies and the results were compared. In addition, the effect of other parameters such as type and amount of photocatalysts, and initial concentration of pollutants on the degradation efficiency of ofloxacin (OFX) and methylene blue (MB) as the model pollutant drug and dye were comprehensively investigated and the Langmuir-Hinshelwood adsorption model was used for evaluation of kinetics, degradation rate and half-life time of the reactions. After selection of xenon lamp as the optimum light source, the photodegradation of OFX and MB was evaluated in a dead-end membrane reactor (MR) and flux performance, antifouling property and pollutant removal of the membranes were evaluated using pharmaceutical and textile wastewater samples. In addition, the antibacterial activity of the prepared membranes was evaluated using Gram-negative E. coli bacteria as the model microorganism using thin film assay and Kirby-Bauer disk diffusion methods to examine the anti-biofouling potential of the constructed reactors. It was demonstrated that the prepared MR is able to produce cleaner water with more stable flux performance and good membrane fouling/biofouling properties in energy saving manner with respect to the unmodified ones.