Dow Water & Process Solutions

DOWEX Ion Exchange Resins for Separation of Boron from Liquid Media

Boron - B Boron occurs in nature in its oxidized forms as boric acid and its salts. Boric acid is a very weak acid and acts much like silicate so it is difficult to remove from water. It has a very low selectivity for an anion exchange resin so resin capacity will be limited by the presence of other anions.

Applications

Potable Water: Borate is a very "weakly held" anion so non-selective methods must remove all other anions before they will remove the borate.  The more economical option is to selectively remove borate with DOWEX™ BSR-1.  In addition, boron selective resin is playing an ever increasing role in seawater desalination processes.(1)

DOWEX BSR-1 meets NSF/ANSI Standard 61 for contact with drinking water.   For more information see our regulatory information.

Waste Water: When borate is present as an acid, it can be removed from solutions with DOWEX™ M-43 anion exchange resin, an acid absorber. Borate salts are more typically present, requiring a strong base resin like DOWEX 21K XLT resin for control. Here the resin will remove all of the anions along with other common anions like chloride or sulfate. For streams that have a high organic content and are prone to surface fouling, DOWEX MARATHON™ MSA resin is recommended.

Ultrapure Water: Selective borate removal can be achieved using DOWEX BSR-1  resin. DOWEX BSR-1 has been applied to ultrapure water and chemical production where parts per billion removal efficiency is required.

Chemical Processing: Borohydride is a commonly used reducing agent that becomes oxidized to borate.  It can be non-selectively removed as an anion with an anion exchange resin or selectively with with DOWEX BSR-1.  For more on the use of ion exchange resins in chemical processing see the chemical processing application page.

DOWEX Ion Exchange Resins

Product	Description	Type	Matrix	Total Exchange Capacity* eq/l (kgr/ft3)	Available Forms
DOWEX 21K XLT	Uniform particle size, high capacity, strong base anion exchange resin for mineral processing applications.	Type I Strong Base Anion	Styrene-DVB, Gel	1.4	Cl-
DOWEX MARATHON MSA	Uniform particle size, high capacity, macroporous strong base anion exchange resin for water demineralization applications.	Type I Strong Base Anion	Styrene-DVB, Macroporous	1.1 (24.0)	Cl-
DOWEX M-43	Corrosion control with DOWEX M-43 ion exchange resin.	Weak Base Anion	Styrene-DVB, Macroporous	1.55	FB (Free Base) form
DOWEX BSR-1	A uniform particle size weak base anion exchange resin for selective boron removal.	Weak Base Anion	Styrene-DVB, Macroporous	0.7

References (1) Marston, Busch, Prabhakaran: Boron Selective Resin for Seawater Desalination, May 24, 2005, European Desalination Society Conference, LaSpazia, Italy.