Smart utilisation of reverse solute diffusion in forward osmosis for water treatment: A mini review

Xing Wu, Xiwang Zhang, Huanting Wang, Zongli Xie

Research output: Contribution to journalReview ArticleResearchpeer-review

23 Citations (Scopus)

Abstract

Forward osmosis (FO) has been widely studied as a promising technology in wastewater treatment, but undesirable reverse solute diffusion (RSD) is inevitable in the FO process. The RSD is generally regarded as a negative factor for the FO process, resulting in the loss of draw solutes and reduced FO efficiency. Conventional strategies to address RSD focus on reducing the amount of reverse draw solutes by fabricating high selective FO membranes and/or selecting the draw solute with low diffusion. However, since RSD is inevitable, doubts have been raised about the strategies to cope with the already occurring reverse draw solutes in the feed solution, and the feasibility to positively utilise the RSD phenomenon to improve the FO process. Herein, we review the state-of-the-art applications of RSD and their benefits such as improving selectivity and maintaining the stability of the feed solution for both independent FO processes and FO integrated processes. We also provide an outlook and discuss important considerations, including membrane fouling, membrane development and draw/feed solution properties, in RSD utilisation for water and wastewater treatment.

Original languageEnglish
Article number162430
Number of pages13
JournalScience of the Total Environment
Volume873
DOIs
Publication statusPublished - 15 May 2023

Keywords

  • Forward osmosis
  • Reverse solute diffusion
  • Wastewater treatment

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