Superior photocatalytic and self-cleaning performance of PVDF-TiO₂@NH₂-MIL-125(Ti)/PVA membranes for efficient produced water treatment

This study addresses the growing need for effective water treatment technologies in response to increasing global water production. The Water Quality Index (WQI) calculations indicated poor water quality in the sample, with a value of 92.01. Membrane technology has shown potential for improving water treatment. However, issues such as fouling and selectivity often hinder its practical application. This research explores the integration of polyvinyl alcohol (PVA) and metal-organic framework TiO₂@NH₂-MIL-125(Ti) into polyvinylidene fluoride (PVDF) membranes to enhance their performance in treating produced water. The incorporation of TiO₂@NH₂-MIL-125(Ti)/PVA significantly improved the membrane's key performance indicators, including flux, rejection rates, and photocatalytic activity. The PM-04 membrane, containing 2 wt% PVA, demonstrated the highest flux rates of 143.93 L·m−2·h−1 under dark conditions and 160.66 L·m−2·h−1 under visible light. Under visible light irradiation, it achieved impressive removal efficiencies of 90.56 % for COD, 75.23 % for TDS, and 82.27 % for NH₃-N. The kinetics of COD removal followed a zero-order model, highlighting the membrane's efficient photocatalytic degradation capabilities. Additionally, the membrane's resistance to fouling was confirmed through self-cleaning and reusability tests, reducing maintenance requirements and extending its operational lifespan. With a significant processing capacity of 2,190,000 m3 per year and a competitive specific processing cost (SPC) of $0.019 per cubic meter, the PM-04 membrane offers a promising, cost-effective alternative to conventional water treatment technologies.