PFAS removal by reverse osmosis

Reverse osmosis (RO) is a very effective technology for PFAS removal. It is capable of removing more than 90% PFAS in the feedwater, including both long-chain and short-chain PFAS.

As a special design of RO system, closed circuit reverse osmosis (CCRO) (connect to was piloted for PFAS rejection. The test results were quite promising: permeate concentrations of six common PFAS (including PFOA, PFOS and short chain perfluorobutanesulfonic acid PFBS) decreased to 2 ppt, the lowest detectable level [1]. Apart from the high PFAS rejection, another advantage of CCRO is the high system recovery (up to 98%), meaning that a significant less amount of PFAS-containing concentrate needs to be disposed than conventional RO system.

Nonetheless, RO is often viewed as a desalination technology, its application in full-scale drinking water production is not widespread. However, it is gaining more interests due to high effectiveness in emerging micropollutant removal. Because RO membrane is susceptible to fouling caused by e.g. particles, organics, and hardness substances, relevant pre-treatments are necessary to protect RO membrane from frequent cleaning/replacement. Additional post-treatments, e.g. re-mineralization and pH correction, might also be carried out in the RO permeate for water utilities to avoid pipeline corrosion and to makeup the hardness human body needs.

In comparison to granular activated carbon and ion exchange resin, which possess fixed accessible adsorption and exchangeable sites, RO is based on physical rejection and does not necessarily require a high surface area for a high PFAS load. Considering its relatively large capital cost, RO would be suitable for high flowrates or high-concentrated PFAS waters, e.g. in a military location or industries which produce PFAS-containing streams. 

For more information or quotation, please contact us: Feedback Form or call us on +31 152 610 900

References:

[1] Growing regulatory scrutiny stirs PFAS treatment and monitoring markets, GWI, Sep, 2019.