Masters Theses

Abstract

"Pesticides and pesticide degradates found in drinking water sources are of particular concern to human health. When treated and disinfected at a drinking water plant, pesticides etridiazole, metribuzin, and diazinon undergo many treatment processes including lime softening, where the water pH is raised to 10 for calcium removal or 11 for magnesium removal. This thesis focuses on modeling the kinetics of hydrolysis of three pesticides that have the potential to undergo hydrolysis in drinking water plants. Linearly and non-linearly regressed first order and non-linearly regressed second order models were applied to the experimental data and compared to limited literature values. These three compounds were chosen because they were determined to be highly hydrolysable and are currently used in the field and thus a potential drinking water contamination concern. Additionally, these compounds were compatible in a mixture and analyzed by gas-chromatography with electron capture detection (GC-ECD).

Of the three pesticides included in this study, diazinon was most susceptible to hydrolysis and at the widest range of pH values. Etridiazole experienced only base-catalyzed hydrolysis, while metribuzin and diazinon experienced both acid- and basecatalyzed hydrolysis at the extreme pH levels. Non-linear and linear regression models were created and fit etridiazole and diazinon reasonably well. Only diazinon exhibited a moderate hydrolysis rate (k' = 0.01 h⁻¹) at a pH relevant to lime softening at pH 11, and must be studied further. In general, diazinon's rate constants were compatible with the published literature values. Validation of models in surface and ground water is warranted"--Abstract, page iii.

Advisor(s)

Adams, C. D. (Craig D.)

Committee Member(s)

Burken, Joel G. (Joel Gerard)
Ludlow, Douglas K.

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

M.S. in Environmental Engineering

Sponsor(s)

Missouri. Public Drinking Water Program

Publisher

Missouri University of Science and Technology

Publication Date

2008

Pagination

x, 104 pages

Note about bibliography

Includes bibliographical references (pages 97-103).

Rights

© 2008 Michelle Kim Marincel, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Water -- Purification -- Mathematical models
Hydrolysis -- Mathematical models
Water -- Pesticide content
Pesticides -- Environmental aspects

Thesis Number

T 10278

Print OCLC #

870999146

Electronic OCLC #

905978620

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