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PD/MG BIMETALLIC CORROSION SYSTEMS FOR DECHLORINATION OF PCB CONTAMINATED MATRICES
Citation:
AGARWAL, S., S. R. AL-ABED, AND D. D. DIONYSIOU. PD/MG BIMETALLIC CORROSION SYSTEMS FOR DECHLORINATION OF PCB CONTAMINATED MATRICES. Presented at University of Cincinnati Poster Forum, Chicago, IL, March 02, 2007.
Impact/Purpose:
to present information
Description:
Polychlorinated biphenyls (PCBs), a family of 209 compounds manufactured till mid70's, are toxic pollutants that persist in the environment. Enhanced corrosion of an active metal combined with catalytic hydrogenation properties of Pd in bimetallic cells can effectively reduce PCBs. Bimetallic systems like Pd/Fe have been widely tested. for degrading them. However, Mg has higher reduction potential than Fe and does not require anaerobic experimental conditions. Superiority of Mg in these critical aspects, coupled with its natural abundance, low cost and environmentally friendly nature, has led to growing interest in Pd/Mg systems. The primary objective of the study was to evaluate Mg as an alternative to widely used Fe in Pd-doped bimetallic systems. A new wet chemistry procedure was developed to synthesize Pd/Mg particles with 0.11 % to 1.62% Pd content and nano-scale Pd-islands as determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Aqueous 2-ClBP matrices were effectively degraded using these particles, the dechlorination kinetics showing linear dependence on the total Pd content. A carbon mole balance showed 85-105% recoveries. Performance of the Pd/Mg particles in PCB spiked clays and sediment suggests that they may work well in such systems. Finally, a mechanism for PCB dechlorination in Pd/Mg systems was proposed.