Applications of Ion Exchange

Examples of major ion-exchange applications are listed in Table 13.2-1. The fidds of water treatment, effluent treatment, and pollution control are predominant and there have been many recent advances. For example, the partial demineralization of brackish water using the Sirotherm process has been developed in Australia and this is probably one of the most innovative developments in recent years. Important apfrii-cations in the fields of medicine, pharmacology, chemical processing, catalysis, and analytic techniques are also mentioned. The remainder of this section describes some impoitam applications in detail. 

Michael Streat and Francis Louis Dirk Cloete 

Uranium Thorium Rare earths Transition metals Transuranic elements Gold, silver, platinum Chromium 

Sodium reduction Taste masking Sustained release Diagnostic Tablet disintegration pH control Potassium removal Skin treatment Toxin removal 

Ion-exchange is used widely in condensate polishing, and the application of mixed-bed ion-exchange columns in high-pressure boilers (conventional and nuclear) is now widespread. Sorption of impurities at concentrations of 50 ppb and less is customary and this can be achieved with considerable elegance. The 

The principal applications of ion exchange in the purification and treatment of sugar solutions, juices, and syrups me as follows  

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The student who is interested in details of the physical principles involved and of further applications of ion exchange should consult Ion Exchanges in Organic and Biochemistry by Calvin Calmon and T. R. E. Kressman. (Inter- cience Publication Inc., New York.)... 

Ion exchange resins are, in general, not suitable for macro-work owing to the limited number of exchange groups. Among the more important applications of ion exchangers are ... 

Examples of the application of ion-exchange chromatography to the analysis of (a) inorganic anions, (b) inorganic cations, (c) antifreeze, and (d) vitamins. (Chromatograms courtesy of Alltech Associates, Inc. Deerfield, IL). 

If the solution were removed from Tank 1 and added to Tank 2, which also contained 1 eq of resin in the X ion form, the solution and resin phase would both contain 0.25 eq of Y ion and 0,75 eq of X ion. Repeating the procedure in a third and fourth tank would reduce the solution content of Y ions to 0.125 and 0.0625 eq. respectively. Despite an unfavorable resin preference. using a sufficient number of stages could reduce the concentration of Y ions in solution to any level desired. This analysis simplifies the column technique, but it does provide insights into the process dynamics. Separations are possible despite poor selectivity for the ion being removed. Most industrial applications of ion exchange use fixed-bed column... 

Application of Ion Exchange to Materials Recovery - A compilation of links to internet recycling resources provided by Allan Barton of Murdoch University, author of Resources Recycling and Recovery. Visit this at the following URL... http //wwwscience.murdoch.edu.au/teachin. 

In recent years, the rate of information available on the use of ion-exchange resins as reaction catalysts has increased, and the practical application of ion-exchanger catalysis in the field of chemistry has been widely developed. Ion-exchangers are already used in more than twenty types of different chemical reactions. Some of the significant examples of the applications of ion-exchange catalysis are in hydration [1,2], dehydration [3,4], esterification [5,6], alkylation [7], condensation [8-11], and polymerization, and isomerization reactions [12-14]. Cationic resins in form, also used as catalysts in the hydrolysis reactions, and the literature on hydrolysis itself is quite extensive [15-28], Several types of ion exchange catalysts have been used in the hydrolysis of different compounds. Some of these are given in Table 1. 

There are many applications of ion-exchange resins in analytical chemistry in both quantitative and qualitative... 

As a result of the high activity in the biotechnology field, one of the most popular and important applications of ion exchange... 

The chromatographic pumps and flow path used in IEC must be resistant to corrosion. For this reason, polymers such as poly(etheretherketone) (PEEK , ICI Americas Wilmington, DE) have entered into widespread usage in ion chromatography. Electrochemical detectors may also be subject to corrosion by certain ions. This chapter will review the chromatographic materials, detectors, and applications of ion exchange chromatography. For some classes of compounds, where reversed phase or normal phase alternatives may have been developed, alternative separation techniques will be presented. 

The search for models of biological membranes led to the formation of a separate branch of electrochemistry, i.e. membrane electrochemistry. The most important results obtained in this field include the theory and application of ion-exchanger membranes and the discovery of ion-selective electrodes (including glass electrodes) and bilayer lipid membranes. 

The applications of ion-exchange chromatography are exemplified by the selection shown in Table 4.18. Among the most notable are the separation of lanthanides and actinides using a citrate, lactate or EDTA eluting agent ... 

Lantagne and Velin [267] have reviewed the application of dialysis, electrodialysis and membrane cell electrolysis for the recovery of waste acids. Because of the new trends governed by environmental pressures, conventional treatment methods based on neutralization and disposal are being questioned. Membrane and electromembrane technologies are considered to be potential energy-efficient substitutes for conventional approaches. Paper mills will focus on the application of ion-exchange membranes namely dialysis, electrodialysis and membrane cell electrolysis for recovery of waste acids. 

Qian P, Schoenau JJ. Practical applications of ion exchange resins in agricultural and environmental soil research. Can. J. Soil Sci. 2002 82 9-21. 

IV. Application of Ion Exchange Refining to the Commercial Manufacture of Crystalline Dextrose... 

Application of ion exchange to the manufacture of dextrose has been in the process of development for several years. Numerous problems, not present in the application of ion exchange to water purification, were met which required solution. Although some problems remain,... 

The application of ion exchangers to dextrose process liquors involved considerable experimental work because of a number of factors which do not enter into their application to water purification. The accumulation of fats and proteins on the resin surfaces must be guarded against by proper clarification of the liquors to be treated. Such accumulation may result from precipitation as the neutralization progresses, and may soon destroy the effective acid-removing capacity of the anion exchange resin. This difficulty can effectively be eliminated by prior precipitation of thfe refinery residue from the acid liquor by bentonite, a colloidal clay of opposite electrical charge to the colloids,21 followed by filtration. 

The application of ion exchange refining to the dextrose manufacturing process affords a number of advantages, some of which are briefly discussed below.22... 

Application of ion exchange refining to the process for the manufacture of dextrose may be understood from the following description of such a process. Triple-washed starch is diluted with ion-free water to the desired concentration and is acidified with a definite quantity of mineral acid such as hydrochloric or sulfuric. It is desirable that the acidified starch slurry be held for at least thirty minutes in order to permit an effective equilibrium acidity to be reached. The starch slurry may contain a quantity of soft water salts which consume acid, and since this consumption is variable, the acidity is checked and adjusted to the desired level following the holding period. The conversion is then carried out at elevated temperature and under pressure for a period sufficient to yield maximum dextrose. The conversion may be carried out batchwise in an autoclave, or continuously. 

Kirk-Othmer Encyclopedia of Chemical Technology Volume 13. Ion Exchange (Wiley, New York, 1981). Libirti, L. and Millar, J. R. (ed.) Fundamentals and applications of Ion Exchange (NATO Asi Series Series E Applied Sciences No. 98) 1985. 

An additional interesting application of ion-exchange membranes for the treatment of electroorganic product solutions is the electrodialysis (e.g. [70, 72]). It... 

J. Inczedy. Analytical Applications of Ion Exchangers, Pergamon Press, Oxford, NY, M. Williams, English translation ed., 1966. 

So far we have focused on the accumulation and the adsorption of the electrolyte counterion to the charged surface. Next, we will derive the retention factor of the analyte ion as a function of the bulk concentration of We assume here that the concentration of c, is so small in comparison to Cg, that it does not influence the distribution B in the system. This condition is usually met in analytical applications of ion exchange chromatography. 

Some specific applications of ion exchange water softening milk softening (substitution... 

The chief advantage of an ion exchange technique lies in simplicity and rapidity with which various separations or concentrations may be achieved. The application of ion exchange technique in analytical chemistry... 

Table 2. Selected examples of the application of ion-exchange chromatography... 

After soil and clays, natural and synthetic aluminum silicates and synthetic zeolites were tested as ion-exchange materials by other scientists. However, the first practical applications of ion exchange took place hi the early 20th century. 

O. Folin, R. Bell The first analytical application of ion exchange. 1917... 

G. E. Boyd J. Schubert A.W. Adamson Demonstration of the applicability of ion exchange for adsorption of fission products in trace amounts (lanthanides). 1942... 

IAEA, Application of Ion Exchange Processes for the Treatment of Radioactive Waste and Management of Spent Ion Exchangers, Technical Reports Series No. 408, International Atomic Energy Agency (IAEA), Vienna (2002)... 

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