Sorption Of Ni (ii) And Co (ii) Ions From Water Solution By Strong-acid Cationite Cu-2-8n
SORPTION OF Ni (II) AND Co (II) IONS FROM WATER SOLUTION BY STRONG-ACID CATIONITE Cu-2-8n
A. Kryvoruchko, L. Yurlova, I. Atamanenko, B. Kornilovich
Institute of Colloid Chemistry and Chemistry of Water, Ukrainian National Academy of Sciences, Vernadsky avenue 42, 03680 Kiev-142, Ukraine
Ionic impurities in water lead to arising of several problems in the cooling and heating systems, in the steam generators and in the industrial consumption of water. Ion exchange had got a good acceptance to remove the ionic admixtures due to a number of reasons. So, the ion-exchange resins possess by a high exchange capacity, are capable to recover easily, are safe and handy in use.
It looks as promising to use ion exchange to control contamination of aquatic systems by the heavy metal ions. The ion-exchange resigns supplied by industry are available in the two structural states: gel-like and macroporous ones. In the gel-like ion-exchange resins, the functional groups are distributed over all their grain. The KU-2-8n cation exchanger produced by the Pridneprovsky chemical plant belongs to these ion exchangers. In this paper, the values of both static and dynamic capacities of an ion exchanger have been established. It looked also interesting to study the extraction kinetics of the heavy metal ions from aqueous solutions through its use. The ion exchanger under study has been pretreated according to the GOST 10896-78 and was in both the Na- and H-forms.
In order to study the absorption of nickel and cobalt ions, 1 g of air-dry ion exchanger has been soaked by the solution (100 ml) containing 25 ppm of the metal under study. Sulfuric acid has been added to correct the pH of the feed solutions. Its value for the nickel and cobalt solutions was 4.5 and 4.4, respectively. The flasks were shaken for 5–120 min. Then, after filtration of the ion exchanger, it was measured pH of the solutions reached and their concentration of metal ions. The complexing titration and photometry method made use accordingly to determine the content of nickel and cobalt ions in their solutions. Moisture content of the ion-exchange resins is known to vary
depending on the product’s lot. For this reason, the mass parts of moisture for each form of the resin under study have been specified in order to find out the exchange capacity and the moisture degree of an absorbent.
The value of the exchange capacity, E, represented in the paper pertains to the weight unit of the dry absorbent.
The maximum degree in extracting nickel ions from its solutions (viz. 0.7 and 0.67) is reached when the CU-2-8n cation exchanger in the H-form and Na-form is put to use. At the same time, in the case of cobalt ions, the extraction degree does not differ for the both forms of the ion exchanger, and it is equal to 0.66 and 0.65, respectively.
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