SREL Reprint #2476

Remediation of metal- and radionuclides-contaminated soils by in situ stabilization techniques

A. S. Knox, J. C. Seaman, M. J. Mench, and J. Vangronsveld

Introduction: The extent of metal and radionuclide contamination in the world is immense. In the soil environment, metals and radionuclides can be dissolved in solution, held on inorganic soil constituents through various sorption or ion exchange reactions, complexed with soil organics, or precipitated as pure or mixed solids. Soluble contaminants are subject to migration with soil water, uptake by plants or aquatic organisms, or loss due to volatilization (Smith et al., 1995). Lead (Pb), chromium (Cr), zinc (Zn), arsenic (As), and cadmium (Cd) are the most frequently identified inorganic contaminants in soil and groundwater in the order of their relative occurrence (National Research Council, 1994; Knox et al., 1999). Unlike degradable organic contaminants and even short-lived radionuclides that can become less toxic over time, metals can be considered conservative because they are not decomposed in the environment. However, many metals, especially redox-sensitive elements such as As and Cr, can undergo transformations or sorption reactions that alter both mobility and relative toxicity.
Soil contamination can have dire consequences, such as loss of ecosystem and agricultural productivity, diminished food chain quality, tainted water resources, economic loss, and human and animal illness. Public attention generally focuses on dramatic examples of contamination such as the nuclear accident in Chernobyl, Ukraine, where significant releases of radioactivity occurred (Adriano et al., 1997). The most dramatic ecological effects, however, were confined to a 30-km radius from the reactor. In contrast, extensive areas of eastern and central Europe suffer from diseases associated with elevated levels of Pb in the air, Co in the soil, and a food chain that is contaminated by metals related to heavy industry (Tikhonov, 1996). At present, there is a critical need for the development of cost-effective remediation technologies that reduce such risks. . . .

SREL Reprint #2476

Knox, A. S., J. C. Seaman, M. J. Mench, and J. Vangronsveld. 2000. Remediation of metal- and radionuclides-contaminated soils by in situ stabilization techniques. pp. 21-61 In: I. K. Iskandar (Ed.). Environmental Restoration of Metals-Contaminated Soil. Lewis Publishers, Boca Raton, FL.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).