Biosorption of uranium(VI) from aqueous solution using microsphere adsorbents of carboxymethyl cellulose loaded with aluminum(III)

The carboxymethyl cellulose microsphere loaded with Al(III) (CMC-Al) has been explored for removal of uranium(VI) from U-containing water. Various factors, including pH, adsorbent dosage and uranium(VI) concentration, were tested. Langmuir and Freundlich isotherms were applied to the adsorption data. The thermodynamic parameters such as ΔH°, ΔS° and ΔG° were also evaluated. The mechanism of modification and adsorption on CMC-Al were analyzed by SEM, EDX and XPS. Results show Al (III) was loaded on CMC through ion exchange of sodium ion of CMC. The coordination reaction happened during the adsorption process between CMC-Al and uranium(VI). (author)