Biofouling mitigation of bilayer polysulfone membrane assisted by zinc oxide-polyrhodanine couple nanoparticle

Abstract

Biofouling is known as a serious problem for membrane applications. There are several techniques to improve membrane biofouling resistance. In this work, polysulfone (PSf) membrane was modified using polyvinyl alcohol (PVA) layer and zinc oxide-polyrhodanine (ZnO-PRh) couple nanoparticles. The ZnO-PRh couple nanoparticles as a new antibacterial agent were immobilized upon the surface using a dip coating method. Also, the PVA layer was used in order to improve the hydrophilicity and binding of nanoparticles on the membrane surface. Fourier transform infrared (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle analysis were utilized for characterization of the samples. The effects of the ZnO-PRh nanoparticles and cross-linker concentration on the membrane performance were investigated. The highest flux of treated membranes was obtained for the combination of 5% and 0.75% for Glutaraldehyde (GA) and nanoparticle, respectively. It was observed that by adding ZnO-PRh/PVA to the membrane, surface hydrophilicity (from 111.8 to 59.0˚ of water contact angle), permeate flux (from 24.458 to 46.653 kg. m−2. h-1 for the PVA and ZnO-PRh/PVA membranes, respectively), the rejection (from 81.521 to 97.52 and 83.77 to 98.97 for citrate and total phosphate samples), fouling resistance, and antibacterial property increased.