Adsorption performance of silver ion on acrylic grafted carboxymethyl chitosan/dialdehyde starch.

In the present study, the novel environmental-friendly adsorbent (PAA-g-CMCDAS) obtained from carboxymethyl chitosan (CMC), dialdehyde starch (DAS) and polyacrylic acid (PAA) is used for removing silver ion. The adsorbent characterized by XRD, SEM, TGA, BET and FTIR, was evaluated for removal of silver ion from aqueous solution. The adsorption process of silver ions conformed to Langmuir isotherm and the second-order kinetic mode. The maximum adsorption capacity for silver ions was 404.77 mg·g−1, and the maximum removal efficiency was 95.05%. Also, the reusability and selectivity of PAA-g-CMCDAS was investigated, and the adsorption amount was still 388.77 mg·g−1 and the removal efficiency was up to 91.29% after five times recycle; the removal efficiency of silver ions in mixed metal ions solution was 24.24% with the total removal efficiency of mixed metal ions 58%. Therefore, PAA-g-CMCDAS was an excellent silver ion adsorbent with good reusability. [ABSTRACT FROM AUTHOR]