(596b) Adsorptive Removal of Arsenic from Aqueous Solution By a Zirconium Ion Impregnated PVDF Membrane

Abstract:

Arsenic contamination in drinking water and groundwater has become an important environmental issue due to its acuteness and chronic toxicity. In this study, a novel zirconium ion impregnated PVDF membrane was developed for arsenic removal from aqueous solution. The zirconium ions were impregnated within the PVDF membrane by coordinated with ether and hydrogen bond which were produced by crosslinking of PVA (polyvinyl alcohol) and glutaraldehyde. The coating process was optimized by a Box-behnken experimental design approach. The kinetics study showed that the adsorption equilibrium was established within 24 h. The adsorption increased as the solution pH was decreased; the optimal pH for adsorption was 2.0. The experimental data were better described by Langmuir equation than Freundlich equation; the maximum adsorption capacity of 128 mg-As/g was achieved at pH of 2.0. The adsorption was not reduced in the presence of phosphate. The presence of humic acid, fluoride, carbonate and silicate had some negative effects on the adsorption. In the filtration study, 12.56 cm² membrane had 15.6 L arsenic solution to meet the maximum contaminate level of 10 ppb when treating a simulated arsenic contaminated water with an initial concentration of 97.6 ppb. The adsorption mechanism of adsorption was mainly associated with ion exchange between chloride and arsenic ions.

Key words: PVDF membrane, zirconium, PVA coating, arsenic, adsorption, filtration