Ozonation of Forward Osmosis Retentates for Quaternary Wastewater Treatment
Excited to share our latest work on the investigation of a potential approach for advanced urban wastewater treatment under increasingly strict EU regulations.
In collaboration with Vysoké učení technické v Brně, Liad Weisz et al. conducted a feasibility study exploring a hybrid process that combines Forward Osmosis (FO) for concentrating wastewater effluent with subsequent ozonation of the resulting retentate, focusing on the removal of organic micropollutants, bromate formation, and associated energy demand in comparison to standalone ozonation.
Key findings:

•  OMP removal: Using biomimetic Aquaporin FO membranes, we achieved rejection percentages between 85.9% and 100%.
• Process synergy: MgCl2 as a draw solution improved both FO performance and subsequent ozonation efficiency compared to NaCl.
• Oxidation by-product control: Higher volume reduction factors reduced bromate yield, helping minimize an important safety concern.
• Energy perspective: Modeling suggests lower overall energy demand than standalone ozonation, if draw solution regeneration is not considered (e.g., Fertilizer-Driven Forward Osmosis).

While draw solution regeneration remains a key challenge, the results indicate that quaternary wastewater treatment using FO and ozonation could be favorable under specific conditions, with volumetric reduction and draw solution salt selection as important factors.

Full paper: https://iwaponline.com/jwrd/article/doi/10.2166/wrd.2026.012/111777/Ozonation-of-forward-osmosis-retentates, opens an external URL in a new window