DOWEX Resins for Separation of Radium from Water

Radium - Ra Radium is a naturally occurring radioactive element that is found in some groundwater. The US Environmental Protection Agency set a maximum contaminant level for the combined isotopes at 5pCi/L. The uranium mining industry is also concerned about radium where it is a by-product of solution mining.

Applications

Potable Water: Radium exists as a divalent cation in groundwater, so processes that remove water hardness components like calcium and magnesium are effective. Radium can be non-selectively removed from groundwater via standard cation exchange resins such as DOWEX™ MARATHON™ C (Na) strong acid cation exchange resin and DOWEX MAC-3 weak acid cation exchange resin, using several different regeneration cycles. These processes change the composition of the water hardness components and produce radium containing wastes, which may not be desirable.

DOWEX RSC (Radium Selective Complexer): Dow produces a unique ion exchange product designated as DOWEX RSC resin that is extremely effective at removing radium and barium from drinking water. DOWEX RSC does not remove other water hardness ions. The resin is not regenerable and it concentrates the radium into a small volume for economical disposal.

DOWEX RSC can also be used to remove radium from waste brine from non-selective softening operations.

DOWEX RSC meets NSF / ANSI Standard 61 for contact with drinking water.   For more information see our regulatory information.

Mining: Radium is also of concern in mining applications. Radium can be non-selectively removed from groundwater via standard cation exchange resins such as DOWEX G-26 (H) strong acid cation exchange resin and DOWEX MAC-3 weak acid cation exchange resin, using several different regeneration cycles. These processes change the composition of the water hardness components and produce radium containing wastes, which may not be desirable. In uranium mining, radium is dealt with by direct barium precipitation techniques. These processes take up a lot of space and generate large quantities of sludge that must be further treated. Radium can also be selectively removed with DOWEX RSC.

DOWEX Ion Exchange Resins

Product	Description	Type	Matrix	Total Exchange Capacity* eq/l (kgr/ft3)	Available Forms
DOWEX RSC	Highly selective for removal of radium and barium from water.	Barium Doped	Styrene-DVB, Gel	.65 meq/mL	H+
DOWEX MARATHON C	A uniform particle size, high capacity cation exchange resin for industrial and residential softening and demineralization applications.	Strong Acid Cation	Styrene-DVB, Gel	2.0 (43.7) 1.8 (39.3)	Na+ and H+
DOWEX MAC-3	A macroporous weak acid cation exchange resin used for water softening, dealkalization, and demineralization applications.	Weak Acid Cation	Polyacrylic, Macroporous	3.8 (83.0)	H+
DOWEX G-26 (H)	Uniform particle size strong acid cation exchange resin for specialty demineralization and catalyst applications.	Strong Acid Cation	Styrene-DVB, Gel	2.0	H+