The Treatment of Endocrine-Disruptive Chemicals in Wastewater through Asymmetric Reverse Osmosis Membranes: A Review

Endocrine-disrupting chemicals (EDCs) present in aquatic environment have been regarded as detrimental organic pollutants that pose significant adverse impacts on human health and the aquatic ecosystem. The removal of EDCs is highly desired to mitigate their harmful effects. Physical treatment through membrane-based separation processes is an attractive approach, as it can effectively remove a wide range of recalcitrant organic and nonorganic EDCs. In particular, the reverse osmosis (RO) process has shown promise in removing EDCs of various concentrations and from different sources. Recently, the development of innovative asymmetric RO membranes has become the forefront in this field. Various membrane modification strategies have been commenced to address the limitations of commercial membranes. This review provides an overview of the recent advances in asymmetric RO membranes for EDC removal from water and wastewater system. The potential areas of improvement for RO processes and RO membranes are also highlighted. Based on the existing literature using RO for EDC removal from water, the most investigated EDCs are bisphenol A (BPA) and caffeine in the concentration range of 200 ppb to 100 ppm. Polyamide RO membranes have been shown to remove EDCs from water bodies with a removal efficiency of similar to 30 to 99%, largely depending on the type and concentration of the treated EDCs, as well as the properties of the RO membranes. It has been demonstrated that the performance can be further heightened by tailoring the properties of RO membranes and optimizing the operating conditions of the RO process.