Designing POU and POE systems for Industrial PFAS Removal with Selective Resin

Commercial installation of Purolite's selective Purofine® PFA694E ion exchange resin shows that it is excellent for reducing PFASs or PFCs such as PFOA and PFOS to either the EPA guideline of 70 ppt or to non-detect levels (usually 1 to 5 ppt, depending on the accuracy of the lab used for testing). In such systems, the resin works effectively with very limited contact time, generally 1.5 – 3 minutes vs. 10 – 20 minutes that are needed for GAC.

Short contact time makes this resin ideal for the stop-start operation typical in Point-Of-Entry (POE) and Point-of-Use (POU) devices. Standard ion exchange resins can remove PFASs, but can vary significantly in their ability to effectively reduce PFASs to non-detect levels—and are not recommended for such demanding applications.

Only resins that are specially designed to target short- and long-chain PFASs will be most effective at treating these contaminants.

Currently, there are no NSF/ANSI standards existing for certification of ion exchange-based POE or POU devices. In some countries like Italy, manufacturers are starting to offer do-it-yourself POU kits that are certified to local standards. It is anticipatied that similar certification under NSF/ANSI standards will eventually occur.

Until that time, Purolite offers some guidelines to OEMs for developing POU and POE systems. Please note that performance will depend on the actual system design used by the OEM.*

*Note on Guidelines
These guidelines apply only to Purofine® PFA694E resin, which is designed specifically for PFAS (or PFC) removal with short contact times. These guidelines do not apply for standard ion exchange resins. Purolite reserves the right to revise these guidelines if the water to be treated is atypical. Please consults your local Purolite office for more guidance before design. No performance guarantee can be given as the performance of the treatment system depends on the design of the entire treatment system over which Purolite has no control.