The goal of this research is to provide a new affordable technology too coastal decision-makers for disposal and containment of heavy metal contaminated sediments. This project is examining the use of orthophosphate as a multi-metals chemical stabilization technology for treating contaminated sediments. In the environment metal phosphate minerals are considered extremely stable insoluble minerals even over a wide range of pH conditions. Phosphate has been used for decades to stabilize heavy metal contaminated wastes in the terrestrial environment, but the application of this technology to contaminated sediments is relatively new. Chemical stabilization treatability studies are being used to identify phosphate sources, doses, optimum reaction conditions, and stabilization mechanisms for contaminated sediments from three NERR watersheds.
Preliminary results are very promising.
Laboratory based batch treatments have successfully reduced the solubility of zinc, copper, cadmium, and chromium. Further optimization of the treatment procedures during the course of this research may result in lead stabilization as well. Preliminary diffusion experiments have shown that naturally occurring phosphate minerals will successfully inhibit the migration of heavy metals from contaminated sediments, when they are placed next to them as a barrier material. This project would consist of a series of tank studies involving both chemical and biological monitoring of the systems. The research is being conducted by the University of New Hampshire and Louisiana State University.