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dc.contributor.authorQin, Chaoen_US
dc.date.accessioned2018-08-02T06:00:35Z
dc.date.available2018-08-02T06:00:35Z
dc.date.issued2017-02-07
dc.identifier.othervt_gsexam:9177en_US
dc.identifier.urihttp://hdl.handle.net/10919/84467
dc.description.abstractWith advantages of high cation exchange capacity, swelling-shrinking property and large specific surface area, monmtorillonite is chosen as a carrier and modified with Fe3+ saturation for estrogen decontamination. 17β-Estradiol (βE2) has highest estrogenic activity among estrogens and is selected as representative compound. Rapid βE2 transformation in the presence of Fe3+ - saturated montmorillonite in aqueous system was observed and βE2 oligomers were the major βE2 transformation products. About 98% of βE2 were transformed into oligomers which are >107 times less water-soluble than βE2 and therefore are much less bioavailable and mobile. Fe3+ -saturated montmorillonite catalysis achieved highest βE2 removal efficiency at neutral solution pH and higher temperature. Common cations did not have impact on the reaction efficiency. Dissolved organic matter slightly reduced βE2 removal efficiency. Regardless of wastewater source, ~40% βE2 removal efficiency was achieved for wastewater effluents when they were exposed to same dosage of Fe3+ -saturated montmorillonite as that for simple water systems which achieved ~83% removal efficiency. For real wastewater that contained higher organic matter, higher dosage of Fe3+ -saturated montmorillonite would be needed to create available reaction sites for βE2. This thesis also reports that Fe3+ -saturated montmorillonite effectively deactivate wastewater microorganisms. Microbial deactivation rate was 92±0.6% when secondary wastewater effluent was mixed with Fe3+ -saturated montmorillonite at 35 mg/mL for 30 min, and further increased to 97±0.6% after 4-h exposure. Freeze-drying Fe3+ -saturated montmorillonite iii after each usage resulted in 82±0.5% microbial deactivation efficiency even after fourth consecutive use. For convenient application, Fe3+ -saturated montmorillonite was further impregnated into filter paper through wet-end addition and formed uniformly impregnated paper. Scanning electron microscopy (SEM) imaging showed Fe3+ -saturated montmorillonite was evenly dispersed over cellulose fiber surface. When filtering 50 mL and 200 mL water spiked with live Escherichia coli (E. coli) cells at 3.67×108 CFU/mL, Fe3+ -saturated montmorillonite impregnated paper with 50% mineral weight loading deactivated E. coli with 99% and 77%, respectively. Dielectrophoresis and impedance analysis of filtrate confirmed that the deactivated E. coli passing through Fe3+ -saturated montmorillonite paper did not have trapping response due to higher membrane permeability and conductivity. The results demonstrate feasibility of using Fe3+ -saturated montmorillonite impregnated paper for convenient point-of-use drinking water disinfection.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.rightsThis item is protected by copyright and/or related rights. Some uses of this item may be deemed fair and permitted by law even without permission from the rights holder(s), or the rights holder(s) may have licensed the work for use under certain conditions. For other uses you need to obtain permission from the rights holder(s).en_US
dc.subjectFe3+-saturated montmorilloniteen_US
dc.subject17β-estradiolen_US
dc.subjectwastewateren_US
dc.subjectpolymerizationen_US
dc.subjectmicrobial deactivationen_US
dc.subjectpaper impregnationen_US
dc.titleMineral Surface Catalyzed Polymerization Of Estrogen And Microbial Deactivation By Fe3+-Saturated Montmorillonite: A Potentially Low Cost Material For Water Decontaminationen_US
dc.typeDissertationen_US
dc.contributor.departmentCrop and Soil Environmental Sciencesen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineCrop and Soil Environmental Sciencesen_US
dc.contributor.committeechairXia, Kangen_US
dc.contributor.committeememberEick, Matthew J.en_US
dc.contributor.committeememberTroya, Diegoen_US
dc.contributor.committeememberShang, Chaoen_US


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