Dow Water & Process Solutions

DOWEX Resins for Perchlorate

Applications

Perchlorate Removal from Potable Water:
Perchlorates are man made chemicals used in munitions and rocket propellants. They are highly soluble in water so they can be widely found in ground water due to their high mobility.

Dow offers four resin types that can be applied to ClO₄^- retention and removal even at low, ppb treat-to levels. These include the DOWEX™ 1, a gel type I, strong base anion resin, the DOWEX NSR-1, a typical Nitrate Selective Resin, the DOWEX PSR-2, a gel type strong base tri-n-butyl amine resin and DOWEX PSR-3, a macroporous type strong base tri-n-butyl amine resin.  

Resin selection will depend on the concentration of ClO₄^- present and other competing ions like nitrate (NO₃^-) or sulfate (SO₄⁼), as well as other minerals, metals or trace organics. Since large quantities of water are pumped though such resins, the build-up and retention of the non-perchlorate portion of the feed stream, such as NO₃^-, SO₄⁼ or organic foulants, can greatly influence the success of one resin type over another.

For a listing of NSF / ANSI Standard 61 products see our regulatory information.

DOWEX Ion Exchange Resins

Product	Description	Type	Matrix	Total Exchange Capacity* eq/l (kgr/ft3)	Available Forms
DOWEX 1	High capacity strong base anion exchange resin.	Type I Strong Base Anion	Styrene-DVB, Gel	1.4 (30.6)	Cl-
DOWEX NSR-1	A strong base, nitrate selective, anion exchange resin.	Triethylamine Strong Base Anion	Styrene-DVB, Macroporous	0.9 (19.7)	Cl-
DOWEX PSR-2	A strong base anion exchange resin designed for the selective removal of trace contaminants from potable water.	Tri-n-butyl Amine	Styrene-DVB, Gel	0.65 (14.2)	Cl-
DOWEX PSR-3	A strong base anion exchange resin designed for the selective removal of trace contaminants from potable water.	Tri-n-butyl Amine	Styrene-DVB, Macroporous	0.6 (13.1)	Cl-

In realtive terms however, each resin type can offer varied levels of water treatment: Resin Type Typical Treatment Volumes* (gallons per cubic foot) Comments DOWEX 1 Resin 50,000 to 100,000 Excellent choice for high perchlorate, low sulfate/nitrate DOWEX NSR-1 Resin 100,000 to 175,000 Offers improved selectivity when sulfate present DOWEX PSR-2 Resin 300,000 to 1,250,000 Has higher perchlorate selectivity for greater loading capacity DOWEX PSR-3 Resin 300,000 to 1,250,000 Offers the highest perchlorate selectivity, with greater flexibility in operation *Typical treatment volumes vary greatly, based on feedwater concentrations, flow rate, end point selected for perchlorate exhaustion and system configuration. References 1."Anion Exchange Resins Remove Perchlorate from Groundwater." D. Gisch, Water and Wastewater International, May 2003, 10. 2."Regeneration of Perchlorate (ClO4¯) - Loaded Anion Exchange Resins by a Novel Tetrachloroferrate (FeCl4¯) Displacement Technique." Gu, Boaher, et. al, Environ. Sci. Technol. 2001, 35, 3363-3368.