Development and assessment of nanoscale zerovalent Fe and Ni/Fe particles for the reductive dechlorination of Polychlorinated Biphenyls

In this study, the possibility to use zerovalent Fe and Ni/Fe nanoparticles in the reductive dechlorination of polychlorinated biphenyls (PCBs) was investigated. Only zerovalent Ni/Fe nanoparticles were able to promote the chemical dechlorination of the coplanar PCB congener 2,3,4,5-tetrachlorobiphenyl in batch reactors at ambient temperature, particularly when methanol was used as a cosolvent. The addition of zerovalent Fe nanoparticles to a marine contaminated sediment of the Venice lagoon (Italy), which was incubated under biogeochemical laboratory conditions close to those occurring in situ in the presence of the PCB mixture Aroclor 1254, increased 4 times the rate of the microbial PCB reductive dechlorination process. Thus, they are promising agents for the biologic decontamination of PCB polluted marine sediments.