REACTIVE Fe/Pd BIMETALLIC SYSTEMS-IMPREGNATED ADSORPTIVE ACTIVATED CARBON FOR THE ENVIRONMENTAL RISK MANAGEMENT OF CONTAMINATED SITES

摘要

Remediation of sediments contaminated with hydrophobic organics such as polychlorinated biphenyls (PCBs) remains a scientific and technical challenge. Recently, the use of reactive zero-valent metals (such as Fe and Mg) coupled with noble metals (such as Pd, Pt, Ni and Ag) has been well documented to work efficiently for the reductive dechlorination reaction of PCBs and other chlorinated compounds. Dechlorination of PCBs using zero-valent iron/Pd (ZVI/Pd) systems can be further improved by introducing nanoscale ZVI particles and Pd nano-is|ands on the ZVI. Although the high reactivity of the nanoscale ZVI/Pd system seems promising in case of liquid phase treatment, some technical challenges should be addressed for in situ remediation of contaminated sediments: i) the availability of PCBs for adsorption onto the surface of Fe/Pd particles is very limited and ii) the injection and dispersion of colloidal and particulate Fe/Pd is a critical hurdle.