Influence of chitosan physiochemical properties on its adsorption of arsenate

CARB 91

Hong Zhang, fthz1@uaf.edu, civil and environmental engineering, university of alaska fairbanks, p.o.box751023, fairbanks, AK 99775 and Silke Schiewer, ffsos@uaf.edu, Department of Civil and Environmental Engineering, University of Alaska Fairbanks, Fairbanks, AK 99775.
Arsenic contamination has emerged as a major health problem all over the world. The new drinking water limit (10 ppb) has made it a challenge to find cost effective methods to remove it. Biosorption, using biological waste products as sorbents, may provide a cost effective treatment strategy. The current study investigated chitosan, generated from waste crab shells, as bio-sorbent to remove arsenate in a batch reaction system. Experimental results indicate that electrostatic attraction between positively charged amino groups on chitosan and arsenate anions is likely the primary binding mechanism The isotherm studies results suggested that the maximum uptake amount was 90mg of arsenate per gram chitosan. Further adsorption studies with chitsan having varying amount of amino groups and crystallinity suggested that the only the amino groups distributing on the surface contributed to the bonding. Overall, the results indicate that biosorption using chitosan can be a promising technique for arsenate removal.