An ultrafine nanoparticle made from iron is turning out to be a remarkably effective tool for cleaning up contaminated soil and groundwater–a trillion-dollar problem that encompasses more than 1000 still-untreated Superfund sites in the United States, some 150,000 underground storage tank releases, and a staggering number of landfills, abandoned mines, and industrial sites.

When metallic iron oxidizes in the presence of contaminants such as trichloroethene, carbon tetrachloride, dioxins, or PCBs, these organic molecules get caught up in the reactions and broken down into simple carbon compounds that are far less toxic. Likewise with dangerous heavy metals such as lead, nickel, mercury, or even uranium.

NSF press release