Fibrous ion exchangers

In the present paper are presented the results of the investigation of their physico-chemical and mechanical properties, chemical stability, as well as the data on water and sulphur dioxide sorption as a function of their concentration in the gas phase. Influence of different parameters on the efficiency of absorption of SO2 from air by COg and HCOj foimofthe fibres has been tested. These parameters are gas flow rate, concentration, and air humidity. The optimal condition for regeneration has been established. It has been shown that the fibrous ion-exchange materials made of strong-base fibres are highly efficient means for removal of SO2 from air. 

Specificity of large-volume purification of gases from harmful impurities, including SO2, defined a most acceptable physical form of the ion exdiange materials applied fibrous ion exchangers in the form of non-woven cloths. 

A gas mixture of SO.j (1 wt.%) and N2 was throttled from vessel 1 through pressure reducer 2, precise control valve 3, and from rate meter 4 into mixer 5 where it was mixed with the main air flow injected by compressor 6. A portion of air flow preliminarily passed through moistener 10 which made it possible to prepare a gas/air mixture of different moisture content. The prepared gas/air mixture entered absorption cell 13 with a fibrous ion exchanger. At the cell... 

V. S. Soldatov, New Fibrous Ion Exchangers for Purification of Liquids and Gases. Chemistry for Protection of the Environment, Elsevier, 1984, pp. 353—364. 

Interest is currently being shown in woven fibrous ion exchange materials which as well as having potential use in analytical separations may also offer process benefits in such areas as effluent treatment and hydrometallurgy. 

DesaHnation of very diluted solutions is done in an electrodeionization apparatus (please refer to Section 6.3.2). The desalination compartment of an electrodeionization stack is filled with bead-type or fibrous ion-exchange material. Such packing not only lowers the electrical resistance of desalination chambers, but... 

Spec determination of the lanthanum complexation with reagents of the arsenazo III group on the solid phase of fibrous ion exchangers Spec A = 540 nm of the binary complex... 

General stmcture (fibrous or beaded form), particle size and variation, pore structures and dimensions, surface chemistry (hydrophilic or hydrophobic), swelling characteristics of matrix are important factors which effect chromatographic resolution [11,18]. Porosity of ion exchange... 

While gravity-fed columns including adsorption or ion exchange are recommended when extensive sample cleanup is required, the analyst should be cautious about contamination and adsorptive effects contributing to sample loss. Liquid-liquid partitioning is the preferred technique. When concentrating solvents, care should be taken to insure against loss of volatile extracts. Plastic equipment or fibrous filters should be avoided. 

One of the key problems with many ion-exchange materials, including the polyamidoxime sorbents used for uranium extraction is encountered in the desorption (elution) stage. With the polyaminodimer, the HCl elution of uranium is usually carried out in two steps. The removal of calcium and magnesium with dilute HCl solution ( 0.01 M) is followed by uranium elution with 0.3-1.0 M HCl [212, 213]. The concentrated efSuent contains tens to hundreds of milligrams of uranium per liter and the removal of uranium reaches 93%. However, the elution with HCl seriously reduces the sorbent capacity [198, p. 213 163, 207, 208], e.g., a six-day treatment of the fibrous amidoxime sorbents with 1 M HCl... 

Strong-base ion-exchange fibrous materials (SBF) were tested as sorbents for purification of air from acid impurities exemplified by S02- The SBF exchangers were prepared by amination with the trimethylamine of chloromethylated polystyrene grafted on polypropylene fibres. 

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