Combining regenerable ion exchange and membrane technology for PFAS removal from industrial laundry wastewater

This proposal combines nanofiltration (NF) and regenerable ion exchange resin (IX) to optimize the removal of PFAS from wastewater. The need that this project addresses is to develop an economically viable method for the treatment of both long and short chain PFAS in wastewater that also contains elevated chloride concentrations. Regenerable ion exchange resin has already proven effective in removing PFAS in large scale treatment systems in the US and Australia, but is sensitive to the presence of chlorides and other anions. A treatment chain that 1) concentrates the PFAS and simultaneously removes anions using NF, followed by 2) regenerable IX to completely remove the PFAS from the water, has the potential to be more economically viable. This is especially true for Flanders (such as the Antwerp region), where several wastewater streams contain elevated chloride concentrations.

The project will focus on the wastewater produced by industrial laundries. This project is divided into three Work Packages (WP). In the first, the wastewater from multiple laundries will be fully characterized. Only laundries that already have a Membrane Bioreactor (MBR) and a Reverse Osmosis (RO) system will be investigated. This combination will allow us to leverage existing treatment technologies to increase our understanding of how the proposed treatment chain will be implemented most effectively. In WP 2, the water selected in WP 1 will be tested in the laboratory with three different NF membranes. Based on these tests, the best regenerable ion exchange resin will be selected to remove the PFAS from the NF-concentrate. Finally, the combination of the NF membrane with the best performing ion exchange resin will be tested on-site at the laundry on a pilot scale.

The added value of the project is to find a technical solution that effectively combines NF with regenerable IX. This is a technology combination that has never been tried before. This treatment chain has the potential to treat short-chain PFAS and even ultra-short-chain PFAS in a more performant and economical way than with the baseline technology of GAC.