Master of Engineering Science
Chemical and Biochemical Engineering
Field practice suggests that a combination of biotic and abiotic technologies to treat soil impacted by chlorinated solvents positively influences a remediation project’s success rate. Two large remediation programs have used a material containing both zero-valent iron (ZVI) and a dry organic substrate to abiotically reduce contaminants and increase anaerobic bioremediation in soil contaminated with tetrachloroethylene and 1,2-dichloroethylene using ex-situ mixing techniques. This research assesses the contributions made by the dry organic substrate and ZVI to the observed changes in chlorinated solvent concentrations by analyzing field samples collected from the sites previously remediated, as well as conducting bench-scale batch reactor experiments designed to test the individual contributions of the ZVI and the organic substrate to dechlorination processes. Laboratory experiments suggest the mixture of ZVI and organic substrate does not lead to the concentration decreases observed in the full-scale remediation projects, and that volatilization may be the most prominent contributing process for contaminant removal from soil. Field samples analyzed for microorganisms show a community shift in the area remediated as well as a decrease in Dehalococcoides population size, indicating soil mixing is detrimental to microbial dechlorination activity.
Stevenson, Alexander, "Role of Zero Valent Iron and Organic Substrates in Chlorinated Solvent Degradation: An Ex-Situ Remediation Case Study" (2018). Electronic Thesis and Dissertation Repository. 5382.