Progress in the modification of polyvinyl chloride (PVC) membranes: A performance review for wastewater treatment

Various industries generate a considerable volume of wastewater containing toxic contaminants, arsenic, dyes, heavy metals, perchlorate, oil from multiple sectors. Among several polymeric materials, low-cost polyvinyl chloride (PVC) has attracted significant consideration as a membrane material due to its excellent properties such as good thermal stability, good stiffness, high mechanical strength, high resistance to chlorine, bases, and acids compared to other polymers. However, fouling of hydrophobic PVC-based membranes due to adsorption or deposition of particles, macromolecules, and biomolecules (e.g., polysaccharides proteins), salts, colloids on the surface and pores of the membrane is a major hindrance. Thus, to advance the performance of hydrophobic PVC-based membranes, the hydrophilicity (i.e., wettability) and fouling resistance properties of the membranes should be improved. Despite current trends, it remains challenging to fabricate membranes with high flux and fouling resistance properties, high mechanical strength with longer membrane life when subjected to wastewater treatments. This review provides an overview of the current trends, research, and developments in PVC membranes and the potential outlook for improvements in performance for wastewater separation. In this review, properties of PVC polymer (e.g., thermal stability, crystalline properties, and chemical resistance) are discussed first, followed by the fabrication techniques of PVC-based membrane. We also highlight the parametric effects on PVC-based membrane performance. Following that, various approaches for enhancing the anti-fouling properties of PVC membranes via hydrophilic modification were reviewed, including surface modification and blending modification. Lastly, PVC membrane manufacturing and modification prospects were discussed, owing to its anticipated role as a superior membrane material.