TREATMENT AND CONTAINMENT OF CONTAMINATED SEDIMENTS

摘要

Several approaches to the containment and treatment of contaminated sediment were evaluated, including the efficacy of adding activated carbon to sediment as an in-situ stabilization method and the use of conventional and innovative treatment caps. The applicability of phytoremediation for dredged sediments and sediments in shallow water or wetlands was also explored. The effectiveness of any treatment relies on successful application in the field and the emphasis herein is on evaluation of these approaches in the field. A demonstration at Hunters Point, San Francisco Bay, California strives to prove the efficacy of activated carbon treatment, and stands as an example for applications elsewhere. Simultaneous containment and treatment of sediment contaminants is being demonstrated in the Anacostia River, Washington, DC using both organic and metal sequestering agents incorporated into a cap. Both conventional placement and placement in a laminated mat were demonstrated to provide an array of placement approaches. The laminated mat allowed placement of thin layers of high value material at specific location, enabling the use of high value "active" capping materials such as activated carbon and microscale iron. Phyto- and rhizoremediation using plants and related bacteria is a promising approach for treatment of contaminated sediments, but has its inborn limitations. To overcome the slow performance of the process, transgenic plants were evaluated that express the bacterial gene responsible for cleaving PCBs, or metal binding proteins to provide additional metal binding capacity. Continued development of cap and sediment treatments, and approaches to assess effectiveness and long-term reliability are encouraged.