Vinyl Chloride and cis-Dichloroethene Dechlorination Kinetics and Microorganism Growth under Substrate Limiting Conditions
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- 作者：Alison M. Cupples ; Alfred M. Spormann ; and Perry L. McCarty
- 刊名：Environmental Science & Technology
- 出版年：2004
- 出版时间：February 15, 2004
- 年：2004
- 卷：38
- 期：4
- 页码：1102 - 1107
- 全文大小：128K
- 年卷期：v.38,no.4(February 15, 2004)
- ISSN：1520-5851
文摘
The reductive dechlorination of tetrachloroethene (PCE)and trichloroethene (TCE) at contaminated sites often resultsin the accumulation of cis-1,2-dichloroethene (DCE) andvinyl chloride (VC), rather than the nonhazardous end productethene. This accumulation may be caused by the absenceof appropriate microorganisms, insufficient supply ofdonor substrate, or reaction kinetic limitations. Here, weaddress the issue of reaction kinetic limitations by investigatingthe effect of limiting substrate concentrations (electrondonor and acceptor) on DCE and VC dechlorination kineticsand microorganism growth by bacterium VS. For this, amodel based on Monod kinetics, but also accounting forcompetition between electron acceptors and the effect oflow electron donor and acceptor concentrations (dual-substrate kinetics), was examined. Competitive coefficientsfor VC (7.8 ± 1.5 
M) and DCE (3.6 ± 1.1 M) wereobtained and included in the model. The half velocitycoefficient for hydrogen, the electron donor, wasexperimentally determined (7 ± 2 nM) through investigatingdechlorination over different substrate concentrations.This complete model was then used, along with experimentaldata, to determine substrate concentrations at which thedechlorinating microorganisms would be in net decay. Notably,the model indicates net decay will result if the totalelectron acceptor concentration (DCE plus VC) is below0.7 M, regardless of electron donor levels. The ability toachieve sustainable bioremediation to acceptable levelscan be greatly influenced by this threshold level.
M) and DCE (3.6 ± 1.1 M) wereobtained and included in the model. The half velocitycoefficient for hydrogen, the electron donor, wasexperimentally determined (7 ± 2 nM) through investigatingdechlorination over different substrate concentrations.This complete model was then used, along with experimentaldata, to determine substrate concentrations at which thedechlorinating microorganisms would be in net decay. Notably,the model indicates net decay will result if the totalelectron acceptor concentration (DCE plus VC) is below0.7 M, regardless of electron donor levels. The ability toachieve sustainable bioremediation to acceptable levelscan be greatly influenced by this threshold level.