Petroleum Refinery Wastewater Treatment using Three Steps Modified Nanohybrid Membrane Coupled with Ozonation as Integrated Pre-treatment

Polyethersulfone as membrane material possesses superior characteristics; however, it is limited by its semihydrophobic nature, which renders it prone to fouling and restricts the practical applications. Three-steps modifications of PES membranes consist of ZnO nanoparticle incorporation, UV irradiation, and cross-linked PVA coating were carried out to improve membrane performance and stability. The membranes were fabricated using the dry/wet phase inversion technique. The results revealed that the modifications significantly improved membrane structural characteristics. Three-steps combination treatments enhanced the membrane surface hydrophilicity by lowering the contact angle from 70 degrees to 61.4 degrees. A three-step modification including ZnO loading, UV irradiation, and PVA coating on PES membranes can increase the rejection of organic matter from 16% to 54% despite sacrificing permeate flux. Crosslinked PVA coating at a concentration of 3 wt-% increased the water permeability from 4.6 to 8.6 L.m(-2). h(-1) while maintaining the rejection rate. Ozonation for 3 hours as pretreatment enhanced the total dissolved solids, chemical oxygen demand, and Ammonia rejections up to 18.6%, 16.7%, and NH3 87.1%, respectively. Quantitative fouling evaluation revealed that three-steps modification on PES membrane significantly improved the anti-fouling property of the membrane.