Groundwater chlorinated phenol-contaminated

In addition to transformation by corrodable metals (such as Fe° and Zn°), bimetallic combinations of a catalytic metal with a corrodable metal (such as Pd/Fe or Ni/Fe) have also been shown to transform a variety of contaminants. In most cases, rates of transformation by bimetallic combinations have been significantly faster than those observed for iron metal alone [26,96,135-139]. Not only have faster transformation rates been observed with bimetallic combinations, but, in some cases, transformation of highly recalcitrant compounds, such as polychlorinated biphenyls (PCBs), chlorinated phenols, and DDT has been achieved [24,140,141]. The mechanism responsible for the enhanced reactivity with bimetallic combinations is still unclear however, it has been suggested that electrochemical effects, catalytic hydrogenation, or intercalation of H2 may be responsible. A likely limitation to the full-scale application of bimetallic combinations to groundwater remediation is deactivation of the catalytic surface either by poisoning (e.g., by sulfide) or by formation of thick oxide films [136,142,143]. 

---