Abstract
The sorption of borate, arsenite and tellurate ions on a strongly basic anion-exchanger in the chloride form was investigated by means of a series of equilibrium experiments. Prom the results obtained, an attempt was made to determine the state of condensation of these anions under various conditions of concentration and pH. The concentration ranges of boric, arsenious and telluric acid studied were 0. 02. -0. 66M, 0. 1-0. 18M and 0. 14-0. 5M respectively, the pH value of these solutions being altered (in the approximate range 5-11) by addition of sodium hydroxide. The results have been interpreted in terms of sorption by the resin of the following ions: (a) B5O8- , B4O7-- (or HB5O9-- ) and H2BO3 from borate solutions. (b) As3O5- , As2O4-- , H2AsO3- , HAsO3-- and AsO3 --- from arsenite solutions. (c) Te4O13-- , Te3O10-- , H5TeO6- and H4TeO6- from tellurate solutions. the actual ion sorbed depending on the pH and concentration of the solution. It appears that a decondensation of the polyanions can be brought about by dilution or by raising the pH of solution. The ultra-violet absorption spectra of arsenite and tellurate solutions were also studied, and evidence has been obtained that a correlation exists between the ions sorbed on the resin and the ionic state of the solution when the resin Is absent.