An innovative approach to the detection of water-solvated chlorophenols and the subsequent dechlorination of water-solvated pentachlorophenol /
in most aquatic environments. Direct consumption and
| Main Author: | |
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1995.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=739663381&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | in most aquatic environments. Direct consumption and bioaccumulation from potable water are two pathways that can expose humans to these toidns which have been labeled as both systemic toxins and as potential carcinogens. Their toxicity and lipophilicity are a result of their degree of chlorination; thus dechlorination leads to detoxification. Current detection of these compounds is based on complicated instrumentation that is both expensive and requires technical expertise. Detoxification has been accomplished using certain biological organisms and chemical techniques. There is a need for a simple field-practical assay for water solvated chlorophenols that offers both sensitivity and selectivity. If water-solvated chlorophenols are detected, there is the need to dechlorinate, and thus detoxification, the more toxic chlorophenols, especially pentachlorophenol. A simple, field-practical assay for water-solvated chlorophenols based on fluorescent derivatization was developed. The water-solvated chlorophenols were derivatized and the derivatized complex was extracted from other impurities found in potable water. The fluorescent complex was bound on a reactive interface housed in a glass minicolumn and fluorescence was induced by ultraviolet radiation. This assay offered great sensitivity (O. Igg) and selectivity. All detection error was positive error which would minimize exposure to an unknown risk. Dechlorination of water-solvated pentachlorophenol was accomplished using three morphologically different ammonium- exchanged calcium montmorillonites. Ammonium-exchanged Nevalite montmorillonite (AENM) demonstrated the ability to dechlorinate water-solvated pentachlorophenol by 23% in 60 hours. A second, better-characterized exchanged calcium montmorinonite, ammonium-exchanged calcium montmorillonite (AECM) demonstrated similar ability to dechlorinate pentachlorophenol in aqueous solution by 18.2% in 60 hours. Calcium montmorillonite was then propped with hydroxy aluminum, greatly increasing the interlaminar area. Ammonium-exchange of this propped clay greatly increased its dechlorination ability to 26.6%. Hydra attenuate, small fresh-water coelenterates which are sensitive to halogenated compounds such as pentachlorophenol, were used as a bioassay to evaluate if absorption and dechlorination of pentachlorophenol resulted in decreased toxicity. This bioassay demonstrated that two of the three clays were able to afford protection. in potable water. The fluorescent complex was bound on a reactive interface housed in a glass radiation. This assay offered great sensitivity (O. ltlg) to afford protection. |
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| Item Description: | Vita. "Major Subject: Toxicology". |
| Physical Description: | xv, 163 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 149-162. |