Date of Award

Spring 1995

Document Type

Thesis

Degree Name

Master of Science in Environmental Science - (M.S.)

Department

Chemical Engineering, Chemistry and Environmental Science

First Advisor

Samir S. Sofer

Second Advisor

Richard B. Trattner

Third Advisor

Dana E. Knox

Abstract

The purpose of this work is to show the effects of bio-oxidation of a pesticide through a spiral wound bioreactor using immobilized mixed culture bacteria. The pesticide used for this study is Isotox® and its active ingredients are acephate or O,S-dimethyl acetylphosphoramidothioate and vendex or hexakis (2-methyl-2-phenylpropyI)- distannoxane. Qualitative analysis of the product indicated presence of sulfate.

A consistent and unique DO pattern for Isotox® showed at least 4 minima, whereas phenol has only one minimum. The consistency of the DO pattern for Isotox® has been observed for over 30 injections into the bioreactor system. For both an acclimated and an unacclimated system, the basic DO pattern was consistent.

The analysis of bio-oxidized reservoir water showed concentrations in the ranges of parts per billion (ppb). About 90% of the vendex injected was adsorbed by the bacteria as indicated by tin analysis of the product water. A single batch of 16.4784 g dry biomass immobilized on a spiral bioreactor was able to effectively remove 2338 ml of the pesticide containing over 1000 ppm tin. Adsorption is on the order of 0.086 g tin per gram dry bacteria.

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