Quaternized hydroxyethyl cellulose ethoxylate and membrane separation techniques for arsenic removal

Quaternized hydroxyethyl cellulose ethoxylate (QHECE) was combined with a regenerated cellulose membrane (10 kDa), and its potential for arsenic removal was investigated. The arsenic removal was evaluated by polymer-enhanced ultrafiltration (PEUF) using QHECE as a sorbent. The parameters studied during PEUF were pH, optimum concentration of polymer, effect of interfering ions and maximum retention capacity. Additionally, the electrochemical oxidation of As(III) to As(V) in the presence of QHECE was performed to remove total arsenic from solution. The PEUF results showed a retention of 63% for As(V) and null retention for As(III) at pH 9. This retention capacity was obtained using 100 mg of QHECE and 30 mg/L arsenic. Moreover, the As(V) retention did not decrease in the presence of interfering ions. The maximum retention capacity was 56 mg As/g polymer. The electrochemical oxidation of As(III) to As(V) was successfully performed using QHECE as the supporting electrolyte. After oxidation, the retention of arsenic by PEUF reached 90%. These results are promising and indicate new potential applications for these types of cationic polysaccharides.