Environmentally persistent free radicals (EPFRs) are formed on the surfaces of transition metal-containing particles by chemisorption of a molecular precursor and electron transfer from the organic to the metal, resulting in reduction of the metal and formation of the EPFR. Association of some radicals with the metal increases their stability and reduces their rate of reaction with oxygen such that they can persist for several days in the environment. EPFRs have been found associated with soot and fly-ash produced from the combustion of hazardous wastes and Superfund soils from a former wood-treatment facility contaminated with pentachlorophenol. EPFRs are formed in high concentrations in the thermal and cool-zones of incinerators and other thermal treatment devices for remediation of Superfund sites, where they can also react, primarily by radical-radical recombination, to form polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs).
This project, by Dr. Barry Dellinger, explores the origin and fate of EPFRs in thermal treatment devices through four Specific Aims. Go to this link to learn more: Formation and Reactions of Environmentally Persistent Free Radicals in Thermal Processing of Superfund Wastes.