DOWEX™ - Lenntech

1 Dow Lenntech Tel. +31-152-610-900. Water Solutions Fax. +31-152-616-289. DOWEX . Ion Exchange Resins WATER CONDITIONING MANUAL. WATER. CONDITIONING. MANUAL. A Practical Handbook for Engineers and Chemists Products Design Applications Equipment Operation Engineering Information What this handbook is about . This is a handbook for people responsible for water supplies, but who are not necessarily water chemists. Here are basic data on ways of conditioning water with DOWEX ion exchange resins and straightforward explanations of how you can determine costs and results using the various methods on your own water.

2 Better Water = Better Operation Because water is one of the most important raw materials brought into any plant, it follows that better water will cut overall costs and improve plant operating efficiency. These improvements can range from elimination of scale and corrosion in water- and steam-carrying equipment through reduced maintenance and outage time to better finished products. Ion Exchange Versatility DOWEX cation and anion exchange resins, used separately or in combination, with or without other water-treating materials, do an amazing variety of water-conditioning jobs; from simple softening of hard water supplies to removal of dissolved solids down to a part per billion!

3 The following trademarks are used in this handbook: DOWEX ion exchange resins DOWEX MAC-3 ion exchange resin DOWEX MARATHON ion exchange resins DOWEX MONOSPHERE ion exchange resins DOWEX UPCORE Mono ion exchange resins FILMTEC reverse osmosis membranes UPCORE system TABLE OF CONTENTS. 1 Introduction to Ion Exchange .. 7. What is Ion Exchange? .. 7. Selecting DOWEX Resins .. 8. 2 Terms, Acronyms, And Abbreviations .. 9. 3 Sodium Cycle Ion Exchange Process (Water Softening) .. 19. Ion Exchange Resins Specified .. 19. Typical Reaction and Chemicals Used .. 19.

4 Equipment Required .. 20. Softener Design for Co-current and Counter-current Operation .. 20. Precautions .. 25. 4 Brackish Water Softening .. 26. Ion Exchange Resin Specified .. 26. Typical Reactions and Chemicals Used .. 26. Equipment Required .. 27. 5 Dealkalization: Salt Splitting Process .. 30. Ion Exchange Resin Specified .. 30. Typical Reactions and Chemicals Used .. 30. Equipment Required .. 30. General Advantages .. 32. Precautions .. 32. Reference Documents .. 32. 6 Dealkalization: Weak Acid Cation Resin Process .. 33. Ion Exchange Resin Specified.

5 33. Typical Reactions and Chemicals Used .. 33. Equipment Required .. 33. General Advantages .. 34. Reference Documents .. 35. 7 Demineralization (Deionization) Process .. 36. Ion Exchange Resins Specified .. 36. Typical Reactions and Chemicals Used .. 36. Equipment Required .. 37. Product Water Quality .. 39. Product Water Quantity .. 39. Other Demineralization 39. Reference Documents .. 40. 8 The UPCORE Counter-Current Regeneration System .. 41. Process Description .. 41. Self-Cleaning Ability .. 42. Regeneration Cycle .. 42. UPCORE and the Layered Bed Anion Option.

6 43. Comparison with other Regeneration Systems .. 43. Reference Documents .. 45. DOWEX Ion Exchange Resins 3 Water Conditioning Manual 9 Ion Exchange Resin Operational Information .. 46. Storage and Handling of Ion Exchange Resins .. 46. Loading/Unloading Resins .. 47. Resin Sampling .. 48. Analytical Testing of Ion Exchange Resins .. 50. Backwash of an Ion Exchange Resin Bed .. 50. Resin Stability and Factors .. 52. Useful Life Remaining on Ion Exchange Resin .. 55. 10 Ion Exchange Cleaning Procedures .. 57. Ion Exchange Troubleshooting .. 61. 11 Designing an Ion Exchange system.

7 64. Product Water Requirements .. 64. Feed Water Composition and Contaminants .. 64. Selection of Layout and Resin Types (Configuration) .. 64. Chemical Efficiencies for Different Resin Configurations .. 65. Atmospheric Degasifier .. 66. Resin Operating Capacities and Regenerant Levels .. 66. Vessel Sizing .. 67. Number of Lines .. 69. Mixed Bed Design Considerations .. 69. 12 Useful Graphs, Tables, and Other Information .. 70. Particle Size Distribution .. 70. Conversion of and Units .. 72. Conversion of Concentration Units of lonic Species .. 73. Calcium Carbonate (CaCO 3) Equivalent of Common Substances.

8 75. Conversion of Temperature Units .. 76. Conductance vs. Total Dissolved Solids .. 77. Handling Regenerant Chemicals .. 78. Concentration and Density of Regenerant Solutions .. 80. Solubility of CaSO 4 .. 85. Removal of Oxygen .. 86. Removal of Chlorine .. 87. Tank Dimensions and Capacities .. 88. Other Information .. 89. 13 Bibliography .. 90. 14 Index .. 91. DOWEX Ion Exchange Resins 4 Water Conditioning Manual TABLE OF TABLES. Table 1. Terms common to ion exchange.. 9. Table 2. Acronyms and abbreviations common to ion exchange.. 17. Table 3. Recommended concentrations and flow rates for H 2SO4 27.

9 Table 4. TDS range for weak acid cation softening.. 28. Table 5. Results of high TDS water softening using weak acid resin.. 28. Table 6. Results of dealkalization by the salt splitting process.. 30. Table 7. Regenerant concentration and flow rate .. 32. Table 8. Results of dealkalization by the weak acid cation resin process.. 34. Table 9. Regenerant concentration and flow rate .. 34. Table 10. Results of treatment by the demineralization process.. 37. Table 11. Basic types of demineralizers with DOWEX resin used.. 38. Table 12. Characteristics of co-current regeneration system.

10 43. Table 13. Characteristics of blocked counter-current regeneration systems.. 44. Table 14. Characteristics of upflow counter-current regeneration systems.. 44. Table 15. Analyses available from Dow Water Solutions.. 50. Table 16. Guidelines for strong acid cation resins.. 52. Table 17. Guidelines for strong base anion resins.. 52. Table 18. Guidelines for weak functionality resins.. 52. Table 19. Recommended maximum free chlorine levels (ppm as CI 2).. 54. Table 20. System loss of throughput capacity.. 61. Table 21. Failure to produce specified water quality.