You are here:
IN-SITU STRATEGIES FOR THE SEQUESTRATION OF ZINC IN CONTAMINATED SEDIMENTS
Citation:
WILLIAMS, A., K. G. SCHECKEL, AND JAMES A. RYAN. IN-SITU STRATEGIES FOR THE SEQUESTRATION OF ZINC IN CONTAMINATED SEDIMENTS. Presented at 15th Annual West Coast Conference on Soils, Sediments and Water, San Diego, CA, March 14 - 17, 2005.
Impact/Purpose:
to present information
Description:
The application of in-situ remediation strategies for the sequestration of zinc is being studied as an alternative to the traditional method of excavation and containment. The site of study is the Indian Head Naval Warfare Center (IHNWC) located adjacent to Mattawoman Creek in Charles County, Maryland. IHNWC has been an active military site for over 100 years. During World War I the site contained a zinc recovery furnace as part of the Navy metal recycling program. The current site of the recovery furnace is characterized by high levels of zinc in both the groundwater and surface soil, which has limited growth of vegetation and caused subsequent erosion on the surface. This has allowed for the transport of zinc contaminated sediments to Mattawoman Creek. Zinc levels at the shore of Mattawoman range from 4.5 to 10.7 g zinc/kg sediment. The high levels of zinc in the sediments offshore of Mattawoman creek have created a potential pathway for the introduction of the zinc in to the food chain. Due to this concern, the primary goal of this research is to evaluate various amendments to remove zinc from a mobile and bioavailable phase. Currently, the IHNWC site is being treated with various amounts of natural apatite (calcium phosphate) and iron-rich biosolids. Bench-scale experiments have examined the effectiveness of apatite and biosolids on zinc retention, with biosolids acting as the best agent for the immobilization of zinc. In addition, a combination of both traditional aqueous extraction methods and advanced spectroscopic techniques are being applied to obtain a detailed, molecular-level understanding of how the zinc is released and sequestered in the IHSWC sediments.