Water treatment base exchange

Boiler water treatment Base exchange Dealkylization Demineralization Demin, water tank Demin, water pump Bulk acid and alkali storage Neutralizing... 

AVT Barg BD BDHR BF BOF BOOM BOP BS W BSI BTA Btu/lb BW BWR BX CA CANDUR CDI CFH CFR CHA CHF CHZ Cl CIP CMC CMC CMC COC All-Volatile treatment bar (pressure), gravity blowdown blowdown and heat recovery system blast furnace basic oxygen furnace boiler build, own, operate, maintain balance of plant basic sediment and water British Standards Institution benzotriazole British thermal unit(s) per pound boiler water boiling water reactor base-exchange water softener cellulose acetate Canadian deuterium reactor continuous deionization critical heat flux Code of Federal Regulations cyclohexylamine critical heat-flux carbohydrazide cast iron boiler clean-in-place carboxymethylcellulose (sodium) carboxy-methylcellulose critical miscelle concentration cycle of concentration... 

Where the feed contains a large proportion of treated water, softening is a minimum requirement and the raw water quality dictates whether a more sophisticated form of external treatment would be preferable. If the water has a high alkalinity it calls for de-alkalization and base exchange. De-ionization is the ideal water treatment, but is usually avoided if possible because of its cost and use of corrosive chemicals. Membrane processes giving partial de-ionization are not normally installed at present, but are certain to become important in the future. 

Finally, an estimate of the potential increase in the treatment-basin water-column base-cation concentration attributable to ion exchange was obtained by using the following information ... 

Since the mid-fifties sulfonated resins based on styrene/divinylbenzene copolymers, initially developed as ion exchangers mainly for water treatment, nave also been used as strongly acidic solid catalysts. Witn few exceptions, industrial application in continuous processes is limited to the manufacture of bulk chemicals, sucn as Disphenol A, (meth)acrylates, metnyl ethers of branched olefins (MTBE, TAME) and secondary alcohols (IPA, SBA). 

All cooling water treatment programs, whether designed in-house or via a water treatment service company, continue to focus on the minimization of hard water crystalline scales and sludges in the system as a major criteria for success. Program techniques employed are either pretreatment processes, such as lime-soda softening or ion exchange, the use of sulfuric acid or polymer-based chemicals that operate in an alkaline environment, or combinations of some or all of these processes. 

Water, soil, sediment, fly ash, fuel oil, sludge, still bottoms, fish, adipose Addition of 13C-labeled standards followed by solvent extraction (exact method depends on matrix), acid-base washing treatment, solvent exchange, and cleanup using alumina, silica gel, and activated carbon, addition of Relabeled internal standards. HRGC/HRMS (MIM) (EPA Method 8290) 10 ppq for water to 1 ppt for other matrices (depending on complexity) No data EPA 1994c... 

Ion-exchange resins and more advanced treatment processes based on membranes are increasingly used in drinking-water treatment. It is possible that chemicals can leach from the materials used in the manufacture of these systems therefore, these too should be managed by appropriate product and materials specifications. 

Polymeric macromoleculcs of types V-VII are needed for applications requiring enhanced molecular siite (see also Chap. III). Thus, linear polymers of type V are prepared by Mannich polymerization or from bis-Mannich bases by exchange reaction, for example, with bis-thiols, as in the case of poly(ketosulfide) 501, which is useful as a high-molecular-weight antioxidant in the processing of plastics.Macromolecules of type VI are generated by the functionalization of polymers, as shown by 502, which is obtained by aminomethylation of polyacrylamide and used as flocculant in water treatment." - ... 

Electrodialysis is a membrane-based process which can be used for separation, removal, or concentration of ionic species present in aqueous solutions. These operations are accomplished by the selective transport of ions through an ion exchange membrane under the influence of a direct current. One of the earliest applications of electrodialysis was the desalting of brackish water. However, since the 1970s, extensive studies have been performed on the application of electrodialysis for waste-water treatment, especially in the electroplating and metal-finishing industries. 

Figure 23 A scheme for water demineralization by treatment with weak-acid and weak-base exchangers.

Weak acids such as carbonic acid (H2CO3) and silicic acid (H2Si03) are not sufficiently dissociated (strong) to protonate the weakly basic amine grouping, and therefore are not sorbed by a weak base ion exchange resin. This property is manipulated to great effect in such applications as water treatment by ion exchange. 

Loading Free base form operation at a typical flowrate of 5-80 m m h . Unlike water treatment service cycles on strongly functional resins which are all film diffusion controlled the loading cycle on weakly basic anion exchange resins is often particle diffusion controlled and therefore rate sensitive. 

The first large scale application of ion exchange to effluent treatment was in the recovery of water, ammonia, and basic copper sulfate from the waste streams encountered in the cuprammonium rayon process. Originally a phenolic type condensation resin was employed, but more recently carboxylic acid acrylic-based exchangers have been introduced. A similar process exists for zinc recovery from the spinning acids of viscose rayon plants, except that in this operation a sulfonic acid resin is employed. 

Usually raw sugar processing gives rise to fairly viscous juices and syrups at temperatures between 70-90 °C. Therefore macroporous ion exchange resins are often selected for sugar extract treatments operated as deep beds at fairly low specific flows (m h ih r) because of the slower kinetics compared with water treatment. A most interesting application is afforded by the Quentin Process which is based upon the... 

Cans, at the turn of the 19lh century, synthesised aluminosilicate materials capable of water softening. He called them Permutits and for many years they were employed as domestic and industrial water softeners, as well as in the treatment of nuclear waste. This, together with the first identification of base exchange in soils (Way [2] and Thompson [3 J), led to the misunderstandings perpetuated in elementary texts that zeolites are responsible for the ion-exchange in soils, and that they are widely used as water softeners. In truth the clay minerals contribute mainly to the ability of soils to take up cations, such as ammonium, and Permutits were amorphous materials with low cation exchange capacities and limited chemical stability. 

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