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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.
31

Terrestrial controls on the biogeochemistry of dissolved organic matter and inorganic nitrogen in streams of the central Amazon Basin, Brazil /

McClain, Michael Eugene. January 1996 (has links)
Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [122]-141).
32

COMPETITIVE ADSORPTION OF VOLATILE ORGANIC COMPOUNDS ONTO NATURAL AND SYNTHETIC ADSORBENTS (TRICHLOROETHYLENE, 1,4-DICHLOROBENZENE, TETRACHLOROETHYLENE, CARBON TETRACHLORIDE, PREDICTIVE MODELS).

Odem, Wilbert Irwin. January 1985 (has links)
No description available.
33

Catalytic advanced oxidation processes for degradation of environmental emerging contaminants

Law, Cheuk Fung Japhet 21 January 2019 (has links)
In recent years, the increasing release of trace organic chemicals to the aquatic environment have been problematic to both the ecosystem and the human society. These trace organic chemicals, regarded as emerging contaminants, include different categories of chemicals, which are either deemed to be safe for human consumption or they are naturally occurring compounds. As a newly recognized class of emerging contaminant, artificial sweeteners are proven to be one of the most ubiquitous classes of emerging contaminants in environmental waters. Its transformation to different suite of TPs during water treatment processes generated more toxic influence than the parent compound is problematic. The realization of the widespread of emerging contaminants, together with their ambiguous fate and impact to the environment have led to the development of advanced oxidation processes that can effectively attenuate this wide range of contaminants. In this work, several catalytic advanced oxidation processes were studied. On one hand, it aimed to evaluate their effectiveness on the removal of the artificial sweetener - acesulfame; and on the other hand, to shed lights on the future development of catalytic advanced oxidation processes. In the first part of this thesis, the photo-Fenton treatment was evaluated on its potential to effectively remove acesulfame together with the produced transformation products, and the post-treatment toxicity screening. The photo-Fenton treatment was found to be effective in removing both the parent compound and the transformation products, without leading to an increase in toxicity, which is largely related to the effective removal of the transformation products. In attempt to reduce the reliance on UV irradiation, newly synthesized carbon and nitrogen co-doped TiO2-based photocatalyst was applied to capture the simulated sunlight for the degradation of acesulfame. The heterogenous photocatalytic treatment was found to involve several different oxidative reactive species for both degradation and transformation by using several scavengers to alter the degradation profile. Unexpected transformation product was also formed upon treatment in actual water matrix, suggesting the impact of water constituents to the transformation of emerging contaminants. Toxicity results indicated the inability to achieve detoxification, suggesting that a more effective degradation process was needed. To accelerate the degradation process, and enhance the performance at neutral pH, the use of redox mediators for Fenton/Fenton-like system was evaluated. Developed novel Fenton-like system involving copper(II) as transition metal ion, persulfate as oxidant and mercaptosuccinic acid as redox mediator led to effective removal of different contaminants. Elucidation of the proposed oxidation mechanism suggested the role of each components of the system, and the generation of different reactive species for degradation as indicated by the different acesulfame transformation profile obtained. The implementation of redox mediators to Fenton/Fenton-like system was beneficial and an effective approach. In short, this work presents several kinds of catalytic advanced oxidation process and shed lights on improving the degradation performance with directions for the future development of better and more effective water treatment processes.
34

Effects of nitrogen deposition and flow permanence on stream organic matter dynamics /

Chadwick, Michael Andrew Joseph, January 2003 (has links) (PDF)
Thesis (Ph. D.) in Ecology and Environmental Science--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 137-163).
35

The use of some physico-chemical properties to predict algal uptake of ogranic compounds /

Mailhot, Hélène. January 1986 (has links)
No description available.
36

Characterization and surfactant enhanced remediation of organic contaminants in saturated porous media

Taylor, Tammy Palmer 08 1900 (has links)
No description available.
37

"Characterization and removal of NOM from raw waters in coastal environments"

Check, Jason Kenneth. January 2005 (has links) (PDF)
Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2005. / Michael Saunders, Committee Chair ; Paul Work, Committee Member ; Jaehong Kim, Committee Member. Includes bibliographical references.
38

Organic matter processing and opportunities for stream mitigation in an intensively mined West Virginia watershed

Minter, Megan Stephanie. January 2009 (has links)
Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains ix, 117 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references.
39

An atomic force microscopy study of bacterial adhesion to natural organic matter-coated surfaces in the environment

Abu-Lail, Laila I. January 2006 (has links)
Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: AFM, Bacterial Adhesion. Includes bibliographical references (p.130-143).
40

Adsorption of phosphates and organic acids on aluminum hydroxide in aquatic environment : mechanisms and interactions /

Guan, Xiaohong. January 2005 (has links)
Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references (leaves 200-223). Also available in electronic version.

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