Production of cooling water by Ti3C2Tx MXene interlayered forward osmosis membranes for post-combustion CO2 capture system

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

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.

Recent advances in thin film nanocomposite membranes containing an interlayer (TFNi): fabrication, applications, characterization and perspectives

Polyamide (PA) reverse osmosis and nanofiltration membranes have been applied widely for desalination and wastewater reuse in the last 5-10 years. A novel thin-film nanocomposite (TFN) membrane featuring a nanomaterial interlayer (TFNi) has emerged in recent years and attracted the attention of researchers. The novel TFNi membranes are prepared from different nanomaterials and with different loading methods. The choices of intercalated nanomaterials, substrate layers and loading methods are based on the object to be treated. The introduction of nanostructured interlayers improves the formation of the PA separation layer and provides ultrafast water molecule transport channels. In this manner, the TFNi membrane mitigates the trade-off between permeability and selectivity reported for polyamide composite membranes. In addition, TFNi membranes enhance the removal of metal ions and organics and the recovery of organic solvents during nanofiltration and reverse osmosis, which is critical for environmental ecology and industrial applications. This review provides statistics and analyzes the developments in TFNi membranes over the last 5-10 years. The latest research results are reviewed, including the selection of the substrate and interlayer materials, preparation methods, specific application areas and more advanced characterization methods. Mechanistic aspects are analyzed to encourage future research, and potential mechanisms for industrialization are discussed.