Title

Development of an innovative remediation methodology for contaminated soils and sediments using high-energy radiation

Date of Award

1997

Availability

Article

Degree Name

Doctor of Philosophy (Ph.D.)

First Committee Member

Thomas D. Waite, Committee Chair

Abstract

The research objectives were to develop and demonstrate a remediation methodology for contaminated soils and sediments using high energy radiation, and develop predictive tools for process simulation. Proposed treatment involves irradiating and dewatering slurries, recycling wash water, and returning clean soil to original location. Extensive literature review of contaminated soils in environment was conducted. Processes affecting removal of contaminants were studied and available treatment technologies were evaluated. An extensive bench scale study was developed incorporating the use of $\sp{60}$Co gamma facility at University of Miami Medical School. Experimental design was developed to investigate feasibility of radiolytic degradation of contaminants in soils. Soil type, wash water type, and initial contaminant concentrations were chosen as experimental parameters. Three soils namely, Ottawa sand and Catlin soil (silty-clay) from Illinois, and Nursery soil (predominantly silty soil) from Miami were selected. Tap water and deionized water were chosen as wash waters, and three initial contaminant concentrations were chosen. BTEXs and 3-Chlorobiphenyl were chosen as representative contaminant groups. Descriptive and comparative statistical analyses of experimental results were conducted. The descriptive analysis showed soil type as a significant factor. Sand was the easiest matrix to clean followed by Nursery and Catlin soils. 3-Chlorobiphenyl was bound in an emulsion phase in Catlin soil, and could not be extracted with analytical procedures employed in this research. Wash water had no effect on contaminant removal and lower contaminant concentrations were removed more effectively than higher concentrations. Statistical comparisons generally confirmed the findings of descriptive analysis. No radiation byproducts with similar chromatographic characteristics as parent contaminants were identified for BTEXs and 3-Chlorobiphenyl. No EPA Method 8270 toxic byproducts were detected in GC/MS analysis of 3-Chlorobiphenyl samples. Empirical dose-destruction relationships were developed to provide predictive capabilities for radiolytic destruction. A methodology using chemical kinetics model MACKSIMA was developed to simulate radiolytic destruction of contaminants. Empirical rate constants were developed for soil organic matter and sand. Radiolytic destruction of contaminants from experiments, empirical equations, and MACKSIMA simulations showed good agreement. Treatment cost estimates indicated that electron beam technology could be developed as a competitive technology for remediating contaminated soils and sediments.

Keywords

Engineering, Civil; Environmental Sciences; Engineering, Environmental

Link to Full Text

http://access.library.miami.edu/login?url=http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:9824535