Biodegradation of neutralized sarin : technology development toward a post sarin neutralization process /
Microbial degradation of sarin neutralization products, o-
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1997.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=739892141&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Microbial degradation of sarin neutralization products, o- isopropyl methylphosphonic acid (IMPA) and methylphosphonic acid (MPA), was studied under aerobic conditions. Both compounds were originally tested to be used as a carbon source, but neither was successful. With three alternative carbon sources provided in phosphorus limiting conditions, both compounds were biodegraded. The carbon sources were glucose, glycerol and sodium succinate. Both of the two pure cultures tested, Pseudomonas aeruginosa (ATCC 9027) and Enterobacter aerogenes IFO 12010 (ATCC 15038), were able to degrade MPA and form orthophosphate, but failed to degrade IMPA. Mixed carbon sources of glucose, glycerol and sodium succinate supported growth better than any single one of them. Consequently, mixed carbon sources in the medium increased the extent of MPA biodegradation range (<1,250 mg/1). The IMPA biodegradation rate (vmax) was 120.9 mg/l/day for the soil extract microorganisms, and 118.3 mg/l/day for the APG microorganisms. The specific growth rate was 1.9 day-1 for the soil extract microorganisms and 1.6 day-1 for the APG microorganisms. An initial IMPA concentration of 85 mg/l was degraded to an undetectable level within 80 hours by soil extract microorganisms. An initial IMPA concentration of 90 mg/l was degraded to an undetectable level within 60 hours by the APG microorganisms. Increasing IMPA concentrations increased the time for complete transformation. Encapsulation of acclimated cultures was evaluated for degradative performance relative to the same cultures suspended. Encapsulated cells degraded IMPA at a slower rate than the corresponding suspended cells. This was apparently caused by a diffusion limitation. Sarin neutralization also result in the release of fluoride ions. The existence of fluoride at anticipated treatment levels were found to affect the growth of the acclimated cultures and the rate of IMPA degradation. This research confirms the biodegradability of IMPA, and MPA. A conceptual process with combined chemical and biological treatment was proposed for a post sarin neutralization solution based on the experiment findings. |
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| Item Description: | Vita. "Major Subject: Civil Engineering". |
| Physical Description: | xii, 119 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 98-101. |