Critical Evaluation of the 2D-CSIA Scheme for Distinguishing Fuel Oxygenate Degradation Reaction Mechanisms

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• 作者：M貌nica Rosell ; Rafael Gonzalez-Olmos ; Thore Rohwerder ; Klara Rusevova ; Anett Georgi ; Frank-Dieter Kopinke ; Hans H. Richnow
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2012
• 出版时间：May 1, 2012
• 年：2012
• 卷：46
• 期：9
• 页码：4757-4766
• 全文大小：326K
• 年卷期：v.46,no.9(May 1, 2012)
• ISSN：1520-5851

文摘

Although the uniform initial hydroxylation of methyl tert-butyl ether (MTBE) and other oxygenates during aerobic biodegradation has already been proven by molecular tools, variations in carbon and hydrogen enrichment factors (蔚_C and 蔚_H) have still been associated with different reaction mechanisms (McKelvie et al. Environ. Sci. Technol. 2009, 43, 2793鈥?799). Here, we present new laboratory-derived 蔚_C and 蔚_H data on the initial degradation mechanisms of MTBE, ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME) by chemical oxidation (permanganate, Fenton reagents), acid hydrolysis, and aerobic bacteria cultures (species of Aquincola, Methylibium, Gordonia, Mycobacterium, Pseudomonas, and Rhodococcus). Plotting of 螖未²H/ 螖未¹³C data from chemical oxidation and hydrolysis of ethers resulted in slopes (螞 values) of 22 卤 4 and between 6 and 12, respectively. With A. tertiaricarbonis L108, R. zopfii IFP 2005, and Gordonia sp. IFP 2009, 蔚_C was low (<|鈭?|鈥? and 蔚_H was insignificant. Fractionation obtained with P. putida GPo1 was similar to acid hydrolysis and M. austroafricanum JOB5 and R. ruber DSM 7511 displayed 螞 values previously only ascribed to anaerobic attack. The fractionation patterns rather correlate with the employment of different P450, AlkB, and other monooxygenases, likely catalyzing ether hydroxylation via different transition states. Our data questions the value of 2D-CSIA for a simple distinguishing of oxygenate biotransformation mechanisms, therefore caution and complementary tools are needed for proper interpretation of groundwater plumes at field sites.