The effect of UV irradiation on PSf/TiO2 mixed matrix membrane for chromium rejection

Abstract

The study investigated a novel approach for surface modification of membranes and sustainable water recovery from chromium contaminated water by employing a lab scale dead-end cell filtration unit. Various PSf/TiO2 composite membranes prepared with different concentrations of TiO2 nanoparticles were exposed to UV radiations for surface modification. On exposure to UV light, TiO2 nanoparticles emit electrons and create a surface roughness with a charge on the membranes which resulted in enhanced chromium rejection as well as flux. The surface modification has been analyzed by AFM and SEM (surface and cross sectional) images. The structural modification was investigated by ATR-IR and UV–Visible spectroscopy. The expected enhancement in hydrophilicity was studied by water uptake and contact angle measurements. The analysis of water flux and chromium rejection performed in a dead end filtration unit revealed a high water flux and 100% chromium rejection with 2 wt.% of TiO2 composite membrane in acidic pH. The pH of feed plays an important role in chromium rejection. The rejection of chromium decreases with an increase in feed concentration due to the variation in ion distribution. The effect of interference of other metals in chromium rejection is investigated. The overall work not only demonstrates the positive effects of surface modification, but also effective removal of hazardous chromium.