کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6368229 | 1316945 | 2010 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Dechlorination kinetics of TCE at toxic TCE concentrations: Assessment of different models Dechlorination kinetics of TCE at toxic TCE concentrations: Assessment of different models](/preview/png/6368229.png)
The reductive dechlorination of trichloroethene (TCE) in a TCE source zone can be self-inhibited by TCE toxicity. A study was set up to examine the toxicity of TCE in terms of species specific degradation kinetics and microbial growth and to evaluate models that describe this self-inhibition. A batch experiment was performed using the TCE dechlorinating KB-1 culture at initial TCE concentrations ranging from 0.04Â mM to saturation (8.4Â mM). Biodegradation activity was highest at 0.3Â mM TCE and no activity was found at concentrations from 4 to 8Â mM. Species specific TCE and cis-DCE (cis-dichloroethene) degradation rates and Dehalococcoides numbers were modeled with Monod kinetics combined with either Haldane inhibition or a log-logistic dose-response inhibition on these rates. The log-logistic toxicity model appeared the most appropriate model and predicts that the species specific degradation activities are reduced by a factor 2 at about 1Â mM TCE, respectively cis-DCE. However, the model showed that the inhibitive effects on the time for TCE to ethene degradation are a complex function of degradation kinetics and the initial cell densities of the dechlorinating species. Our analysis suggests that the self-inhibition on biodegradation cannot be predicted by a single concentration threshold without information on the cell densities.
Journal: Water Research - Volume 44, Issue 1, January 2010, Pages 331-339