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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Towards a novel methodology for the environmental remediation of oil-polluted aqueous systems

Lawson, Jeffrey January 2010 (has links)
Aromatic hydrocarbons are a prevalent constituent of crude oil. The refined products of crude oil such as petroleum and diesel can find their way into groundwater though oil-spillages and are also present in the oil and gas industry’s produced water. These aromatics are biorecalcitrant, however upon ingestion with water, may be metabolised to toxic intermediates that are carcinogenic or mutagenic in nature. Although some treatment technologies are available most of these are under development and are yet to be proven in the field. This illustrates the need for novel, economical and environmentally friendly technologies to be developed with a view to remediating aqueous systems that have been polluted with aromatics hydrocarbons. The supramolecular cyclodextrin molecule, with its hydrophobic interior and hydrophobic exterior seems to be an excellent molecule for the trapping of the pollutant molecules, however the inclusion complexes with this cyclic sugar are water-soluble therefore there is a need for the cyclodextrin to be rendered waterinsoluble. A study of the aqueous solubilities of some aromatic hydrocarbons that may be present in crude oil has been carried out and shows that the majority of these molecules have a degree of water solubility that may increase upon environmental weathering. The successful reaction between a solid-phase resin and the β-cyclodextrin molecule has been achieved, with the total dryness of the system being required including Soxhlet extraction of the resin with anhydrous acetone before the reaction. The reaction between β-cyclodextrin and a range of isocyanates proved unsuccessful, but a range of symmetrical aryl ureas were synthesised from their isocyanates with the influence that different activating or deactivating groups on the ring have on the propensity to form the ureas being shown. The successful alkylation between β-cyclodextrin and a series of haloalkanes has shown the effect of increasing chain length on the degree of alkylation. This reaction involved the deprotonation of the cyclodextrin by sodium hydride in anhydrous dimethyl sulphoxide followed by reaction with the alkyl iodide. Increasing the equivalents of hydride or iodide, or the reaction time did not have a noticeable effect on the degree of reaction indicating that steric constraints were limiting the degree of reaction. Testing several of these alkyl iodides gave an indication as to their tendency to uptake and remove several model pollutants that had been dissolved in water with the propylated β-cyclodextrin displaying potential for the remediation of aqueous systems that had been polluted. Several of these results were very promising leading to the conclusion that further derivatives of these alkylated sugars may be even more suitable for future research into the remediation of organically polluted aqueous systems.
12

An evaluation of an ion-exchange method for the removal of technetium-99 from groundwater

Elliott, Wanda Sue, January 2007 (has links) (PDF)
Thesis (M.S. in environmental Science)--Washington State University, December 2007. / Includes bibliographical references (p. 27).
13

A physiologically based toxicokinetic (PBTK) model for inhalation exposureto benzene and its engineering applications

Kulkarni, Tara Aniket. Dzurik, Andrew Albert, January 2004 (has links)
Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Andrew Dzurik, Florida State University, College of Engineering, Dept. of Civil and Environmental Engineering. Title and description from dissertation home page (June 18, 2004). Includes bibliographical references.
14

Virtual and augmented reality simulation of Chattanooga Creek

Vadlamudi, Sirisha. January 2003 (has links) (PDF)
Thesis (M.S.)--University of Tennessee, Knoxville, 2003. / Title from title page screen (viewed Mar. 25,2004). Thesis advisor: Daniel B. Koch. Document formatted into pages (viii, 113 p. : ill.). Vita. Includes bibliographical references (p. 58-61).
15

MINESCAPE: RE-ENVISIONING THE POST-MINE LANDSCAPE OF YELLOWKNIFE, NWT

Stone, David 09 July 2012 (has links)
This thesis explores the process of remediation and renewal in the context of decommissioned gold mining operations in Yellowknife, Northwest Territories, Canada. The work aims to demonstrate that architecture can facilitate understanding and bring awareness to the processes involved in reclaiming industrial sites by creating places for observation, interaction and refl ection. Existing mine infrastructure will be adapted and augmented to support phytoremediation processes, clean energy generation and municipal waste treatment for adjacent Yellowknife residents. These interventions are based on a series of studies involving mineral extraction processes, historic mine development and geological formations. The architectural interventions are phased and are intended to be prototypical strategies for decommissioned mine sites in general, but are specifi cally relevant to those located in sub-arctic climates.
16

Immobilization of mercury using iron sulfide minerals

Bower, Julia Michelle. January 2007 (has links) (PDF)
Thesis (M.S.)--Auburn University, 2007. / Abstract. Includes bibliographic references (ℓ. 70-76)
17

13C and 37Cl characterization of PCE and application to contamination of the Harrison Landfill: Tucson, Arizona

Rosengreen, Sven Albert. January 2000 (has links) (PDF)
Thesis (Ph. D. - Hydrology and Water Resources) - University of Arizona. / Includes bibliographical references (leaves 95-99).
18

The recovery of sulphur from waste gypsum

Nengovhela, Ryneth Nkhangweleni January 2008 (has links)
Thesis (PhD.(Chemistry)--University of Pretoria, 2008. / On title page: Submitted in partial fulfilment of the requirements for the degree Philosophiae Doctor in Chemistry in the faculty of Natural and Agricultural Sciences of the University of Pretoria. Includes bibliographical references.
19

Characterization of metal-reducing microbial communities from acidic subsurface sediments contaminated with uranium(VI)

Edwards, Ellen McLain. Kostka, Joel E. January 2005 (has links)
Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. Joel E. Kostka, Florida State University, College of Arts and Sciences, Dept. of Oceanography. Title and description from dissertation home page (viewed June 22, 2005). Document formatted into pages; contains xii, 94 pages. Includes bibliographical references.
20

Optimization of natural attenuation with active remediation under uncertainty using a multi-objective genetic algorithm

Iyer, Satyajeet Krishnamurthy. Hilton, Amy B. Chan. January 2004 (has links)
Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr Amy B. Chan Hilton, Florida State University, College of Engineering, Dept. of Civil and Environmental Engineering. Title and description from dissertation home page (viewed June 18, 2004). Includes bibliographical references.

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