Advancements in polymeric membranes for challenging water filtration environments: A comprehensive review

Abstract

Polymeric membranes were initially introduced for commercial water treatment applications in the 1960 s. Over the years, membrane manufacturers and scientists have made significant strides in enhancing these membranes, focusing on improving water permeance (while maintaining solute rejection) and increasing resistance to both organic and inorganic fouling. These advancements have produced more efficient membranes with reduced system footprints for water treatment processes. However, the demands of harsh filtration environments, including extreme pH conditions, elevated temperatures, high operating pressures and the presence of oxidative agents, have necessitated further improvements in membrane technology. In this paper, we embark on a comprehensive review of the advancements achieved in various types of polymeric membranes customized for use in these demanding environments. Our exploration of research efforts aimed at enhancing membrane properties for water filtration in challenging conditions can be broadly categorized into four primary areas, i.e., chlorine/oxidative resistance, acid/alkali stability, thermal resistance and compaction resistance. To facilitate a comprehensive understanding of these advancements, we categorize the strategies employed by researchers into several methods, i.e., surface modification of asymmetric membranes, bulk modification of asymmetric membranes (a.k.a. mixed matrix membrane) and surface modification of polyimide thin film composite membranes. By thoroughly reviewing the progress and strategies in these areas, this article aims to offer valuable insights into developing polymeric membranes with enhanced properties for challenging environments in water filtration applications.