Overview of PSAS treatment technologies

A major goal of the Borough's recently commissioned PFAS study is to determine which treatment options would work best for the Borough's water system.

Granular Activated Carbon (GAC)

  • A porous adsorption media typically made from wood, coconut shells, coal, or peat, and used for water purification.
  • Adsorption is a process of concentrating a substance located in a gas or liquid at the surface of a solid. The substance adsorbed is held to the solid by chemical forces.
  • GAC is a proven technology with high removal efficiencies (up to 99.9%). Regenerative carbon beds allow for easy recovery of adsorption media.
  • Carbon media is cheaper than ion exchange resin but doesn't last as long.
  • Similar footprint, installation cost, and operating cost as ion exchange.

Ion Exchange (IX)

  • Ion exchange is a treatment process where water passes through a bed of synthetic resin. Negatively charged contaminants in the water are exchanged with more innocuous negatively charged ions, typically chloride, on resins surface.
  • Proven to provide great than > 99% removal.
  • Resins can be regenerated to restore it to its initial condition. The regeneration process uses sodium chloride (known as brine).
  • The sent brine is a concentrated solution of removed contaminants and must be disposed of properly.
  • Ion exchange treatment can lower the pH of treat water.

Reverse Osmosis (RO)

  • Reverse Osmosis (aka nanofilitration) is a membrane-separation technique in which a semi-permeable membrane allows water to pass through while preventing the passage of organic and inorganic dissolved, colloidal, and particulate matter.
  • Will provide > 99% removal of PFOA & PFOS.
  • Useful in removing a wide range of contaminants, including inorganics, dissolved solids, and synthetic organic chemicals.
GAC System

Example of a GAC or IX system

Reverse Osmosis System

Example of RO System