Oxidative remediation of methylated arsonates: A mechanistic study

ENVR 41

Tielian Xu, txu001@fiu.edu1, Prashant V. Kamat, pkamat@nd.edu2, and Kevin O'Shea, osheak@fiu.edu1. (1) Department of Chemistry and Biochemistry, Florida International University, University Park, Miami, FL 33199, (2) Department of Chemistry and Biochemistry, University of Notre Dame, Radiation Laboratory, Notre Dame, IN 46556
Arsenicals, used extensively in agriculture as insecticides and herbicides, are problematic environmental contaminants. Methylated arsenic compounds, monomethylarsonate (MMA) and dimethylarsenate (DMA), are the normal metabolites of inorganic forms of arsenic. We report herein the reactions of MMA and DMA with different oxidative radicals, hydroxyl radicals/oxide radical anions, azide radicals and sulfate radicals. The oxidative radicals were selectively generated using pulse radiolysis. Transient spectroscopy was used to study the mechanistic and kinetic species of the oxidation reactions of methylated arsenic. Our results provide a better understanding of radical-mediated advance oxidation processes (AOP) of arsenicals as potential remediation processes. Specific AOPs, gamma radiolysis and TiO2 catalyzed photodegradation were studied and show considerable promise for the decomposition of MMA and DMA.
 

Occurrence, Chemistry, Toxicity and Remediation of Arsenic
8:00 AM-11:20 AM, Monday, 27 March 2006 Georgia World Congress Center -- B218, Oral

Division of Environmental Chemistry

The 231st ACS National Meeting, Atlanta, GA, March 26-30, 2006