DOWEX Ion Exchange Resins WATER CONDITIONING MANUAL

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Demineralization (Deionization) Process A B C D E F G MARATHON C MARATHON C-10 or MARATHON MSC MARATHON C MARATHON C-10 or MARATHON MSC MARATHON C MARATHON C-10 or MARATHON MSC MARATHON C MARATHON C-10 or MARATHON MSC MARATHON C MARATHON C-10 or MARATHON MSC MARATHON C MARATHON C-10 or MARATHON MSC MAC-3 2 BED 2 BED Table 11. Basic types of demineralizers with DOWEX resin used. ——————————Constituents Removed—————————— Cations Strong Acids Weak Acids Diagram (Ca, Mg, Na) (SO4, Cl, NO3) CO2 a MARATHON WBA or MARATHON WBA-2 MARATHON A MARATHON 11 or MARATHON MSA MARATHON WBA or MARATHON WBA-2 MARATHON WBA or MARATHON WBA-2 3 BED 4 BED Degasifier MARATHON C MARATHON C-10 or MARATHON MSC 2 BED WITH DEGASIFIER Degasifier MARATHON WBA or MARATHON WBA-2 3 BED WITH DEGASIFIER MARATHON C MARATHON C-10 or MARATHON MSC MARATHON C MARATHON C-10 or MARATHON MSC MARATHON A MARATHON 11 or MARATHON MSA MIXED BED MARATHON A MARATHON 11 or MARATHON MSA MARATHON A2 MARATHON A MARATHON 11 or MARATHON MSA MARATHON A MARATHON 11 or MARATHON MSA ANION SYSTEM AS IN A–F ABOVE MARATHON C MARATHON C-10 or MARATHON MSC MARATHON C MARATHON C-10 or MARATHON MSC MARATHON C MARATHON C-10 or MARATHON MSC MARATHON C MARATHON C-10 or MARATHON MSC MARATHON C MARATHON C-10 or MARATHON MSC MARATHON C MARATHON C-10 or MARATHON MSC MAC-3 MARATHON C MARATHON C-10 or MARATHON MSC MARATHON WBA or MARATHON WBA-2 MARATHON A MARATHON 11 or MARATHON MSA MARATHON WBA or MARATHON WBA-2 MARATHON WBA or MARATHON WBA-2 MARATHON A2 MARATHON WBA or MARATHON WBA-2 DOWEX Ion Exchange Resins 38 Water Conditioning Manual SiO2 — — MARATHON A MARATHON 11 or MARATHON MSA MARATHON A MARATHON 11 or MARATHON MSA MARATHON A MARATHON 11 or MARATHON MSA Degasifier + MARATHON A2 Degasifier + MARATHON A MARATHON 11 or MARATHON MSA MARATHON A MARATHON 11 or MARATHON MSA MARATHON A MARATHON 11 or MARATHON MSA MARATHON A MARATHON 11 or MARATHON MSA MARATHON A2 MARATHON A MARATHON 11 or MARATHON MSA As with appropriate anion system shown in A–F above. a CO2 results from alkalinity converted by DOWEX MARATHON C, MARATHON C-10, OR MARATHON MSC resin.
Demineralization (Deionization) Process 7.3.1 Equipment Sizing See Section 11.7. Note: CADIX can also be used to perform these calculations. 7.4 Product Water Quality If it is a process water, it is likely that complete removal of carbon dioxide and silica is unnecessary. If so, a weak base anion resin is used. If removal of carbon dioxide and silica is required, a strong base anion resin is chosen. Demineralizers can produce waters with varied quality, depending on the type of system and the water supply. They usually produce water free of suspended solids. Determination of dissolved solids by evaporation will include any organic matter that may be present in the deionized water. Water quality is often measured in terms of the amount of suspended solids, dissolved solids concentration, and conductivity (µS/cm) or resistivity (MΩ.cm). Since conductivity is the reciprocal of resistivity, 1 µS/cm is equivalent to 1 MΩ.cm and represents approximately 0.5 ppm. A mixed bed unit is required if water purity in excess of 5 MΩ.cm is needed. The mixed bed may be the primary unit or a polishing unit following a multiple bed system. 7.5 Product Water Quantity Usually, if the water demand is less than approximately 50 gpm (11.4 m 3 /h), the plant will benefit from the simplest piece of equipment at the expense of a higher chemical operating cost. For that reason, it is common to find mixed bed demineralizers widely used for small plant requirements because both the anion and cation resin can be contained in one unit and no degasifier is used. On the other hand, when plant demands exceed 200 gpm, it is almost certain that several units will be built into the demineralizer and one will probably be a degasifier. 7.6 Other Demineralization Techniques The various ion exchange resin combinations indicated in the flow diagrams in Table 11 represent the majority of system designs employed today. Variations from these standard designs, however, are being increasingly utilized, especially those techniques that demonstrate significant chemical regenerant utilization improvements. Two of these techniques are outlined here. 7.6.1 Counter-current Operation This term refers to the relative flow directions of the service and regeneration cycles. As opposed to the typical downflow service and regeneration of many systems, counter-current operation is typically downflow service and upflow regeneration. The primary advantage of counter-current operation is that very low leakage can be obtained at moderate regeneration levels, thus minimizing operating and waste disposal costs. Counter-current operation is also advantageous in softening. 7.6.2 Layered Beds A layered bed of ion exchange resin involves the use of two cation resins or two anion resins in a single unit. A cation layered bed is composed of a weak acid resin upper layer and a strong acid resin lower layer, while an anion layered bed uses either a weak base resin upper layer with a strong base resin lower layer or a strong base resin upper layer and weak base resin lower layer depending on the density of the resins. In general, the use of layered beds allows some of the advantages of weak acid and weak base resins to be realized in the operation of a single cation or anion bed. Improved regenerant efficiencies and, in some cases, improved operating capacities over the corresponding strong acid or strong base units alone are attained. The layered bed concept is made possible by the density and particle size differences between the resins used. Upon exhaustion, the backwashing operation separates the resin layers that may have become partially mixed during service. In order for the full advantages of the weak acid and weak base resins to be realized, good resin separation is important. DOWEX Ion Exchange Resins 39 Water Conditioning Manual
Page 1 and 2: Dow Liquid Separations DOWEX Ion Ex
Page 3 and 4: TABLE OF CONTENTS 1 Introduction to
Page 5 and 6: TABLE OF TABLES Table 1. Terms comm
Page 7 and 8: Introduction to Ion Exchange 1 INTR
Page 9 and 10: Terms, Acronyms, And Abbreviations
Page 19 and 20: Sodium Cycle Ion Exchange Process (
Page 27 and 28: Brackish Water Softening Using H2SO
Page 29 and 30: Brackish Water Softening Resin oper
Page 31 and 32: Dealkalization: Salt Splitting Proc
Page 33 and 34: Dealkalization: Weak Acid Cation Re
Page 35 and 36: Dealkalization: Weak Acid Cation Re
Page 37: Demineralization (Deionization) Pro
Page 41 and 42: The UPCORE Counter-Current Regenera
Page 47 and 48: Ion Exchange Resin Operational Info
Page 57 and 58: Ion Exchange Cleaning Procedures 10
Page 59 and 60: Ion Exchange Cleaning Procedures Re
Page 61 and 62: Ion Exchange Cleaning Procedures 10
Page 63 and 64: Ion Exchange Cleaning Procedures Ta
Page 65 and 66: Designing an Ion Exchange system fr
Page 67 and 68: Designing an Ion Exchange system As
Page 69 and 70: Designing an Ion Exchange system 11
Page 71 and 72: Useful Graphs, Tables, and Other In
Page 89 and 90:
Useful Graphs, Tables, and Other In
Page 91 and 92:
Index 14 INDEX A Abbreviations · 9
Page 93:
Dow Liquid Separations Offices. For
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