Ion-Exchange Resins for Industrial Water Purification

1. Ion-Exchange Resins for Industrial Water Purification EMAC 276 - April 22nd, 2009 Bradley Greenman Jerry Lin Tim Sykes Jamie Vaughn Ion exchange resin beads

2. History & Application • 1850 – Thompson & Way observe Zeolites • 1930’s – Phenol & Formaldehyde monomers Bakelite Resins competed with Sulfonated Carbon • 1970’s - Modern Resins: Mostly Polystyrene (PS) or Polyacrylic with Divinyl Benzene (DVB) copolymers • Exchange Behavior:

3. Applications • Watersoftening (Ca++, Mg++ Na+, H+) • Demineralization (i.e. CaCO3) • Heavy Metal Ion Removal (Pb, Cu, Ni, Zn, Cd..) • Sometimes called Hydrometallurgy • Radioactive Ion removal • Ultrapure Water (up to 18.2 MΩ)

4. Classes of Functional Groups

5. The Polymers • Free Radical Polymerization w/ PS and 0.5-25% DVB yields PS-DVB copolymer • Benzoyl Peroxide Catalyst • Occurs in solution resulting in spherical precipitates which are collected for use • Size of precipitate beads is controlled by manipulating suspension stabilizers • Functional Group added with post-polymerization acid/solution treatment

6. The Polymers (continued) • Similar Free Radical Polymerization process but w/ methacrylic acid and DVB for cross-linked polyacrylic-DVB copolymer with carboxylic functional groups • Varied treatments yield various functional groups: SBA: Trimethylamine, Dimethylethanolamine WBA: methylamine, dimethylamine

7. Material Properties • Cross-linked insoluble polymer matrix w/ fixed hydrophilic functional groups w/ mobile counter ions (i.e. the H+ or Na+) • Degree of Cross-linking %DVB • Chemical/Thermal/Physical Stability %DVB • Pore Size • Ion exchange rate • Ion exchange capacity • In milliequivalents/gram: 0.01-9 meq/g, commonly between 2–5 • Particle Size ranges from 1-2 mm to 100’s of μm

8. Applications: Sybron-Bayer Left: Detail of Ion-Exchange Vessel and plumbing Below: Schematic of multi-stage ion-exchange vessel system Ion-exchange step Regeneration Step Other leading producers include Dow Chemical Inc. and Purolite Inc.

9. Polymer Cost Zeolites cost approximately: $74-110/ft3 [Meindersma] They can also be used at higher temperatures Disadvantages: -Complicated Regeneration -Large scale Mining -Brittle Ceramic Cost range: $45-175/ft3[Harland] Breakdown by Class: SAC: $70-120/ft3 WAC: $150-200/ft3 SBA: $180-250/ft3 WBA: $180-200/ft3 [RemCo]

10. Ion-Exchange Resin Trends • Competition: Some Zeolites are still used, Activated Carbons, Reverse Osmosis • Environmental: Regeneration effluent disposal • Problems: Cannot remove particulate or microbes, Inefficient at removing Cl- or F- • Can couple with activated carbon bed for these • Degradation modes: Thermal and physical • Future Development: Trying to fabricate smaller beads/powders, membranes, Pharmaceuticals, Space station use

11. References Bolto, B.A., and L. Pawlowski. Wastewater Treatment by Ion Ex Zagorodni, Andrei A., Ion Exchange Materials: Properties and Applications. Elsevier: 2006, ISBN: 0-08-044552-7. Harland, Clive E., Ion Exchange: Theory and Practice, 2nd ed. RSC Publishing: 1994. ISBN: 0-85-186484-8 Sybron Chemicals Inc. Technical Document: Introduction to Industrial Ion Exchange. Birmingham, New Jersey Res-Kem Corporation. http://www.reskem.com/pages/resin.php. April 2009. Helfferich, Friedrich G. Ion Exchange. Dover Publications: 1962. ISBN 0-48-668784-8. APEC Water Systems, www.freedrinkingwater.com/water-education/quality-water-filtration-method.htm. April 2009. Remco Engineering Water and Control Systems. http://www.remco.com/ix.htm. April 2009. change. 1st ed. New York: E. & F. Spon, 1987. Meindersma, Haan. Economical feasibility of zeolitemembranes for industrial scale separations of aromatic hydrocarbons. Desalination (2002) pp. 29-34.