Chemical Attenuation Rates, Coefficients, and Constants in Leachate Migration. Volume 1. A Critical Review. Final Report

摘要

Data from existing literature on chemical (precipitation/dissolution and adsorption/desorption) and biological (methylation and alkylation) attenuation mechanisms that affect aqueous concentrations of elements and thus their geochemical behavior in the subsurface environment was compiled and evaluated. Elements considered for chemical mechanisms were Al, Sb, As, Ba, Be, B, Cd, Cr, Cu, F, Fe, Pb, Mn, Hg, Mo, Ni, Se, Na, S, V and Zn. The review of biological mechanisms focused on microbiological alkylation of As, Hg, and Se. The information discussed for each elements includes: (1) thermodynamic predictions of stable solid and solution species which may be present in the utility waste environment; (2) observed solubility-controlling solids; and (3) a summary of the effect of different geochemical factors that control adsorption/desorption. The definitions of constants and examples of their use in calculating attenuation along with extensive tables for thermodynamic equilibrium constants and adsorption/desorption constants for each element are an important aspect of this report. Because quantitative information on alkylation is not available, calculations were made under assumed environmental conditions to display and assess the importance of subsurface alkylation reactions. 372 references, 47 figures, 38 tables. (ERA citation 09:023561)