Andrew C. Garrabrants

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A framework for the evaluation of inorganic constituent leaching from wastes and secondary materials is presented. The framework is based on the measurement of intrinsic leaching properties of the material in conjunction with mathematical modeling to estimate release under field management scenarios. Site specific and default scenarios are considered, which(More)
Two equilibrium-based characterization protocols were applied to ground samples of a cement-based material containing metal oxide powders in both noncarbonated and carbonated states. The effects of carbonation were shown through comparison of (i) material buffering capacity, (ii) constituent equilibrium as a function of leachate pH, and (iii) constituent(More)
Changes in emissions control at U.S. coal-fired power plants will shift metals content from the flue gas to the air pollution control (APC) residues. To determine the potential fate of metals that are captured through use of enhanced APC practices, the leaching behavior of 73 APC residues was characterized following the approach of the Leaching(More)
Current concerns about the environmental safety of coal combustion fly ash have motivated this evaluation of the impact of fly ash use as a cement replacement in concrete materials on the leaching of constituents of potential concern. The chemical effects of fly ash on leaching were determined through characterization of liquid-solid partitioning using EPA(More)
Monolithic waste materials (e.g. Portland cement treated wastes) in many field scenarios do not remain continuously saturated, but experience intermittent wetting interspersed with periods of storage in an unsaturated environment. During storage, the matrix may loss moisture to the environment, promoting precipitation or redistribution of species. In(More)
The use of equilibrium-based and mass transfer-based leaching tests has been proposed to provide an integrated assessment of leaching processes from solid wastes. The objectives of the research presented here are to (i) validate this assessment approach for contaminated soils and cement-based matrices, (ii) evaluate the use of diffusion and coupled(More)
Concerns about the environmental safety of coal combustion fly ash use as a supplemental cementitious material have necessitated comprehensive evaluation of the potential for leaching concrete materials containing fly ash used as a cement replacement. Using concrete formulations representative of US residential and commercial applications, test monoliths(More)
Constituent availability, or the potentially mobile fraction of the total content, is an important characterization parameter for waste materials and soils. The availability of inorganic species is often evaluated from the results of a sequential extraction procedure at a high liquid-to-solid (LS) ratio using pH control. Several tests maintain pH at 4 and 7(More)
Column leaching testing can be considered a better basis for assessing field impact data than any other available batch test method and thus provides a fundamental basis from which to estimate constituent release under a variety of field conditions. However, column testing is time-intensive compared to the more simplified batch testing, and may not always(More)
In situ stabilization and solidification (ISS) is a remediation technique used at former manufactured gas plant (MGP) sites to reduce the rate and extent of contaminant release to groundwater. Assessment of the effectiveness of this treatment method with regard to containment of polycyclic aromatic hydrocarbons (PAHs) poses significant challenges due to the(More)
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