COMPARISON OF CHITOSAN SULFATATION METHODS FOR CU²⁺ ADSORPTION

Abstract

Chitosan is a polysaccharide that has free amine and hydroxyl groups, which is considered a good adsorbent material for heavy metals in contaminated water. In order to improve this property, some necessary modifications have been proposed in order to increase the adsorptive capacity of this polysaccharide. The objective of this work was to modify the structure of chitosan and carboxymethyl chitosan by sulfation, to characterize the materials synthesized through yield, by FT-IR and to analyze elementary and evaluate an adsorbent capacity of the materials against copper ions. The results attenuated that the reaction yield of the materials varied from 58% to 91%, and it was possible to identify through FT-IR the required groups C-O-S and S = O regarding the insertion of the sultate groups, identifying the presence of the sulfate groups in the structure. In adsorption tests, as sulphates sulphated over a percentage of adsorption above 90% copper, a performance superior to pure chitosan (%). The adsorptive capacity of 63 mg / g, in relation to the results found in the literature. Thus, it was observed that sulfation is a viable  modification route for adsorption of metals.