Absorptive and sacrificial medias are used to remove select contaminants. Treatment processes are based upon Empty Bed Contact Time and treatment systems are often designed in series (lead-lag), with a primary vessel to contain the bulk of the contaminants and a secondary vessel (in series) to refine or polish the treated water. These medias are not regenerable hence they are removed and replaced when they reach saturation. Some of the notable media products include:
- Granular Activated Carbon – a naturally occurring coal which is used to remove a wide diversity of contaminants such as PFOA’s, sulfides, etc.
- Activated Alumina – a highly porous form of aluminum oxide is used to remove arsenic, fluoride and other contaminants.
- Sacrificial Ion Exchange Resin – polystyrene based media products used to remove various contaminates. Some resins are “ion selective” meaning they have a higher affinity for one contaminant over another. Sacrificial resins are non-regenerable.