A review of the design, applications, and mechanisms of electrically assisted reverse osmosis and nanofiltration processes

Abstract

Reverse osmosis (RO) and nanofiltration (NF) are the main membrane technologies used for water treatment applications. Despite their widespread use, these technologies face several limitations, including membrane fouling, limited selectivity towards certain ions or contaminants, and a lack of tunability in separation performance. The use of electricity, either by applying an external electric field or by integrating electrically conductive membranes, has shown potential to enhance membrane performance and expand process capabilities. Electrically assisted RO and NF processes have been investigated for nearly two decades, yet their development remains at an early stage due to several knowledge gaps. This paper provides a comprehensive review of studies on electrically assisted RO and NF systems, with a focus on membrane fabrication methods, system design considerations, mechanisms of action, and application areas. The aim is to highlight key limitations and research gaps to help guide future improvements of these processes. The future of electrically assisted NF and RO processes lies in the development of scalable fabrication strategies, evaluation of membrane stability, benchmarking against conventional systems, improved module design, and consideration of both energy and economic requirements.