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|Title:||Persistence and Effectiveness of Hydroxypropyl-β-Cyclodextrin during Soil Remediation|
|Advisor:||Smith, James E.|
|Keywords:||Earth Sciences;Earth Sciences|
|Abstract:||<p>Hydroxypropyl-β-cyclodextrin (HBβCD) is receiving increasing interest as an enhancing remediation agent used for soils contaminated with hydrophobic contaminants. While being used in remediation experiments, no previous study has investigated the fate of HBβCD under non-enhanced uncontrolled conditions in field soils. This study assesses the removal efficiency of DDT using 10%-HBβCD solutions within laboratory soil columns, and examines the persistence of HBβCD within uncontrolled un-enhanced field soil conditions. The bench scale soil column study was found to remove 19% and 20% of the initial DDT and DDE masses respectively after ten treatments of 10%- HBβCD solutions applied twice per day for one week. This definitively shows HBβCD does vertically mobilize DDT in the soil profile. Stable carbon isotopic measurements of technical grade HBβCD resulted in an expected 0 l3C value of -16%0. The expected stable carbon isotopic value (δl3C) of the initial untreated soils was -24.5%0. The soils treated with 10%-and 20%-HBβCD solutions both indicated an increase in carbon isotopic values during and after the experiment, indicating retention of HBβCD within the soil. Measurements of HBβCD in soils using liquid chromatograph mass spectrometry (LCMS) indicated a smaller persistence of HBβCD within the soils during and shortly after HBβCD applications. The carbon isotopic measurements and LCMS concentration of HBβCD reflected similar short and long-term trends for both increasing and decreasing concentrations. Evidence from both stable carbon isotope analysis and LCMS analysis indicated that HBβCD persisted in the soils six weeks after applications; however, there was no evidence of HBβCD in soils eleven months after the treatments ceased.</p>|
|Appears in Collections:||Open Access Dissertations and Theses|
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