Evaluation of Treating PCB-Contaminated Sediment with Zero-Valent Iron

PCBs, DDT, dioxins, and other halogenated organic compounds have been detected in many of the nation's waterways at significantly elevated concentrations. It has been shown that the concentrations of PCBs in sediments have declined since their use has been discontinued; however, in recent years, the concentrations have remained essentially constant (above risk-based levels). Therefore, although use of many of these compounds has been discontinued, they are very persistent in the aquatic environment, and they are still present in the nation's sediments at concentrations that pose significant risk to the environment and to humans. These chemicals have a strong potential to bioaccumulate in aquatic organisms and to predatory species (including humans) who consume the aquatic organisms.