Designing POU Water Treatment Systems for PFAS Removal

A point-of-use (POU) water treatment system treats water at the point where it is being used. It can be installed in front of each or all of a buildings taps, faucets and dedicated outlets from the original source line. 

When designing a POU system for removing perfluoroalkyl substances (PFAS), engineering teams can follow the following guidelines:

  • Assume a maximum flowrate of ½ gpm (2 LPM)
  • Assume a specific flowrate of 1.25 to 7.5 gpm/ft3 of resin (10 to 60 BV/h)
  • Use a minimum of 2 liters of Purolite® PFA694E for effective treatment
  • Install the resin in 2 x 1 liter cartridges that are installed in series
  • Install flow restrictors if flow is expected to exceed ½ gpm

Since the contact time is very short, a conservative capacity estimate is 1,000 gallons (about 4,000 liters) or 4 months operation, whichever comes first. Cartridges should be changed out regularly. Please note that performance will depend on the actual system design used by the OEM.*

*Note on Guidelines
These guidelines apply only to Purolite® PFA694E resin, which is designed specifically for simultaneous removal of multiple short- and long-chain PFAS compounds 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.