GEOC 193 |
| The chemistry of trace and toxic elements will be reviewed, noting important differences between sediment/wetland environments versus upland environments. One approach for evaluating mobility and biological availability is to consider the general forms of metals in these systems. Some forms such as soluble metals are especially mobile and biologically available. However, metals within the crystalline lattice structure of clay minerals are unavailable. Between these extremes, metals are found in potentially available forms where transformations between forms are affected by pH and oxidation conditions. These potentially available forms are associated with properties such as organic matter, sulfide, and iron oxide content, texture, and pH and oxidation conditions. Most metals, especially in contaminated systems, are found in these potentially available forms. Factors affecting transformations between these forms will be discussed. Selected case studies will demonstrate under some conditions, metal contaminants are effectively immobilized offering minimal environmental threat. In contrast, conditions or disturbance of other contaminated sites contribute to extensive release. |
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Speciation of Arsenic and Other Trace Elements in Soils and Sediments
8:35 AM-11:40 AM, Thursday, April 10, 2008 Morial Convention Center -- Rm. 211, Oral
Division of Geochemistry |