SREL Reprint #2464

Chemophytostabilization of metals in contaminated soils

Anna Sophia Knox1, John Seaman1, Domy C. Adriano1, and Gary Pierzynski2

1The University of Georgia, Aiken, South Carolina
2Kansas State University, Manhattan, Kansas

Introduction: Contamination of soils from industry-derived metals and organic chemicals has become a major concern because of the critical role such resources play in promoting sustainable social and economic development. Soil contaminants may not only adversely affect agricultural production but may also jeopardize the food chain, underlying groundwater resources, and general ecosystem health. Contaminant metals are somewhat unique in that they do not undergo either chemically or biologically induced degradation that can alter or reduce their toxicity over time. However, metals may undergo transformations that alter their chemical speciation and solid-phase associations that impact mobility and toxicity in the environment. Metals such as lead (Pb), arsenic (As), and cadmium (Cd) are among the most commonly identified constituents of regulatory concern at contaminated sites throughout the United States [1].
Remediation strategies have rapidly evolved from gross contaminant removal including excavation and disposal or conventional pump-and-treat, followed by enhanced extraction techniques (i.e., chelation, surfactants, etc.) targeted at the specific contaminant of interest, to risk-based remediation often based on an understanding of natural attenuation processes [2], i.e., containment or in situ immobilization. In situ remediation techniques manipulate and enhance the chemical and biological processes controlling the natural attenuation of a contaminant based on fundamental geochemical principles. In cases where the "natural" accumulation of the metal contaminant is rare, in situ methods are often based on the fate of a natural chemical analog, e.g., K+ as a surrogate for 137Cs+. In situ stabilization methods are generally less expensive and disruptive to a distressed (i.e., contaminated) ecosystem and result in limited worker exposure compared to conventional excavation, treatment, and disposal methods. However, the contaminant remains in place and may become a health or regulatory concern at a later date due to various unforeseen chemical and biological transformations or changes in government regulations or public perception. . . .

SREL Reprint #2464

Knox, A. S., J. Seaman, D. C. Adriano, and G. Pierzynski. 2000. Chemophytostabilization of metals in contaminated soils. pp. 811-836. In: D. L. Wise, D. J. Trantolo, E. J. Cichon, H. I. Inyang and U. Stottmeister (Eds.). Bioremediation of Contaminated Soils. Marcel Dekker, Inc. New York.

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