Titanium dioxide incorporated polyamide thin film composite membrane for bisphenol a separation and degradation

Abstract

Endocrine disrupting compounds (EDC) that exist in plastic waste is a real problem in wastewater management system nowadays since there is no exact way to treat it due to its low molecular weight. The estrogenic properties of bisphenol A (BPA), a ubiquitous synthetic monomer that can leach into the food and water supply, have prompted considerable research into exposure-associated health risks in humans. Photocatalytic process is one of the advanced oxidation processes that has been widely applied in wastewater treatment system due to its low cost and environmentally friendly. In addition, this process has huge ability to remove persistent pollutant like EDC in water. The main part of photocatalytic process is the photocatalyst itself and the immobilization of this photocatalyst in thin film membrane can make the resultant membrane acts as both photocatalytic site and selective layer for filtration. This approach also can reduce membrane fouling and avoid post treatment which is recovery of photocatalyst from treated water. Titanium dioxide (TiO2) was chosen as photocatalyst for degrades BPA particle due to its low in cost and high performance in degradation of pollutants. The main goal of this project is to fabricate and characterize a hybrid photocatalytic thin film composite membrane that consists of PSF support membrane and polyamide (PA)/TiO2 thin film layer for BPA removal. This hybrid membrane was fabricated through interfacial polymerization method using trimesoyl chloride (TMC) and m-phenylenediamine (MPD). Besides that, the effect of TiO2 loading (0-0.5%) on the photocatalytic membrane performances in term of photocatalytic degradation and BPA rejection were also studied. These hybrid membranes were analysed for several characterization using field emission scanning electron microscopy (FESEM), Fourier-transform Infrared spectroscopy (FTIR), energy-dispersive X-ray spextroscopy (EDX) and contact angle analyzer. A 100 ppm of BPA synthetic wastewater was prepared and used for membrane performance test. The performance of fabricated PA/TiO2 photocatalytic membrane in BPA degradation and rejection was tested using photocatalytic flat sheet membrane reactor. According to the results obtained this type of hybrid membranes show promising performance in BPA rejection but do not effective for BPA degradation. The fabrication of PA layer was contributed to higher rejection of BPA compare to PSF membrane. For PA/TiO2 TFC membrane, the highest rejection recorded is performed by 0.4 PA/TiO2 TFC membrane with 99.9 % BPA rejection while the lowest is given by 0.1 PA/TiO2 TFC membrane with 91.7% BPA rejection. Meanwhile, in terms of BPA degradation, the highest degradation achieve is 14% which performed by 0.4 PA/TiO2 TFC membrane and the lowest degradation is 4.5% which is performed by 0.1 PA/TiO2 TFC membrane. Based on the results obtained, PA/TiO2 TFC membrane is only suitable for BPA separation but not effective for its degradation.