Electrochemically Enhanced Forward Osmosis Processes Unlocking Efficiency and Versatility

Abstract

The growing interest in forward osmosis (FO) for water reclamation and desalination over the past two decades stems from its potential for lower energy consumption. Despite its promise, FO faces significant challenges, such as the lack of an appropriate draw solute, concentration polarization, membrane fouling, and reverse solute flux (RSF). Recent trends in research have focused on combining various technologies with FO to address these challenges. Notably, the integration of electrochemical technologies with FO offers new possibilities. This review covers FO combined with electrochemical cells (FO-ECs), categorizing them based on their working principles and applications in improving FO. The review discusses different FO-EC configurations, including (1) electrodialysis-combined FO for RSF, (2) electro-FO for water flux enhancement, and (3) electrochemical oxidation-combined FO and FO with electro-conductive membranes for self-cleaning and fouling mitigation. Additionally, it covers (4) reusable electro-responsive draw solutes, (5) electrochemical osmosis systems for metal removal and energy production, and (6) osmotic microbial fuel cells for energy recovery and other benefits. The review also assesses the practical applicability and potential for achieving carbon neutrality of the FO-ECs. It concludes with a forward-looking perspective, outlining future research directions to optimize and expand the use of electrochemical-enhanced FO technologies. © 2024 The Authors. ChemElectroChem published by Wiley-VCH GmbH.