Arsenic Treatment of Contaminated Water Using Surface-Functionalized Fabrics.

Arsenic is a widespread environmental contaminant that poses risks to human health throughout the world. Engineered systems for the removal of arsenic from fast-flowing water, such as contaminated streams or irrigation water channels, are currently unable to accommodate the dual needs of arsenic removal and water conveyance. This lack of technical capacity can lead to substantial release and exposure of hazardous quantities of arsenic, causing arsenic environmental health risks from settings as varied as Superfund sites in the US and rice-production fields in Asia. The overall goal of our proposed work is to develop and test novel fabric-based technologies, which, in concert with ecological engineering measures, may be utilized within contaminated flowing-water streams, as a practical means for removing arsenic from water. Cotton fibers have been chemically functionalized with a chitosan-copper polymer shown to selectively remove arsenic anions from solution even in the presence of competing anions, like phosphate. Functionalization of the fabric surface can increase the number of chemical reactive sites by up to 6,000 times over those found in traditional materials. Preliminary laboratory results have shown that ~100 mg of chitosan-copper-treated fabric can remove over 80% of As from 160 mL of a 50 μg/L As solution within 24 hours. Ongoing experiments are defining chemical and physical controls on the extent and kinetics of As binding to functionalized fabrics, and results will lead to potentially wide-ranging implications for treating chemically contaminated water, especially in low-resource agricultural settings.