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is controlled by the chemical adsorption of Eu3+ on the functional groups of the polysaccharide.
In the second phase of this study, the release of adsorbed Eu3+ ions by means of different substances was investigated for I beads with concentrations of 1 wt/v% and 2 wt/v%. All the tested substances proved effective for removing Eu3+ ions, while the salts demonstrated higher desorption yields than their corresponding acids. The salt concentrations increased during the desorption step, from 0.5 M to 1 M, generally improving the desorption yields )though this effect was not always significant(. Varying the pH of the solution during the removal of the Eu3+ ions, using a NaNO3 salt, did not significantly affect the adsorption or desorption yields.
Analysis of I beads with concentrations of 1 wt/v% and 2 wt/v%, prepared in CaCl2 solution, revealed a denser network structure after adsorption, with smaller pores compared to those found after the removal of the Eu3+ ions. Various analyses after the first and third removals showed that Eu3+ ions attached to the polysaccharide were released; it is likely that Eu3+ ions replaced the Ca2+ ions, participating in cross-linking. Finally, the hydrogels prepared in this study were identified as effective adsorbents for five additional lanthanide ions: Ce3+, Nd3+, Sm3+, Gd3+, and Dy3+—exhibiting adsorption yields comparable to those obtained for the Eu3+ ions.
Keywords: Europium, Hydrogels, Polysaccharides, Sorption, Wastewaters.
Book Of Abstracts | Class 2023
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