Batch test studies of stabilization and solidification of hydrophobic organic contaminants.

摘要

A review of the literature suggests that there is a lack of information regarding why cement-based solidification and stabilization (S/S) treatment technology has been shown to be effective in the treatment of organic contaminants for various field projects. Furthermore, although cement and coal fly ash have been used together as fly ash concrete as early as the late 1940s, there appears to be a lack of research on the role of coal-based fly ash in cement-based S/S treatments in terms of sorption of organic compounds. To address these concerns, the overall objective of this thesis is to examine the sorption levels of common organic contaminants to specific materials that are to act as surrogates for the materials used in cement-based S/S remediation systems as well as use of coal fly ash as additive in such systems.;To fulfill the objectives of this research, a series of batch testing experiments were performed to evaluate the sorption levels of benzene, ethylbenzene, naphthalene, and trichloroethylene (TCE) to soil-cement materials using gas chromatography.;It was generally found that the level of sorption was proportionate to the amount of organic carbon (i.e. in humic acid simulating soil organic matter) present in the sample. Furthermore, fly ash was found to be a good sorbent for the contaminants examined in this study, possibly due to the presence of organic carbon and surface characteristics. It was also found that pre-hydration of the cement with the fly ash tended to decrease the level of sorption obtained.;Sorption values observed in batch tests for benzene, ethylbenzene, naphthalene, and TCE were used to show potential implications of the work in the context of contaminant migration from cement-based S/S treatments. Modeling showed that within 100 years only 3%, if not less, of a continuous source contamination will reach property boundary compared to more than 90% in the absence of any barrier system.