REDUCTIVE DEHALOGENATION OF HALOACETIC ACID CATALYZED BY Ag⁰ NANOPARTICLES INCORPORATED IN SOL-GEL MATRICES

Halogenated disinfection by products (DBPs) are halo-organic compounds formed upon the addition of chlorine to water for disinfection purposes and by the use of C2-chlorocarbon and chlorofluorocarbon (CFC) replacements in industrial processes. US EPA, WHO and the EU Commission consider them as hazardous carcinogens. One class of the pollutants is 5-Halo Acetic Acids-HAA5. HAA5 monitored limit set to be 20-80 µg/L in drinking water. HAA5 come from food processing and disinfection of water. Furthermore Chlorinated acetic acids can be found in water, poultry, vegetables and even in beer^[1],[2].

Various approaches for degradation of HAAs have been studied including bioremediation^[3], chemical methods based on zero valent iron^[4] and bimetallic particles and electro-catalysis. In this study Ag⁰ nanoparticles incorporated in SiO₂ matrices via the sol-gel synthesis route have been successfully applied as a heterogeneous catalyst for the reductive dehalogenation of bromoacetic acid and trichloroacetic acid by NaBH₄ at a variety of conditions.

[1] WHO/SDE/WSH/03.04/85

[2] WHO/SDE/WSH/03.04/79

[3] JASON E. MCGRATH, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Aug. 1997, p. 3333–3335

[4] LI ZHANNG, Environ. Sci. Technol. 2004, 38, 6881-6889