کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4547518 1627119 2007 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Quantifying MTBE biodegradation in the Vandenberg Air Force Base ethanol release study using stable carbon isotopes
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Quantifying MTBE biodegradation in the Vandenberg Air Force Base ethanol release study using stable carbon isotopes
چکیده انگلیسی

Compound-specific isotope analysis (CSIA) was used to assess biodegradation of MTBE and TBA during an ethanol release study at Vandenberg Air Force Base. Two continuous side-by-side field releases were conducted within a preexisting MTBE plume to form two lanes. The first involved the continuous injection of site groundwater amended with benzene, toluene and o-xylene (“No ethanol lane”), while the other involved the continuous injection of site groundwater amended with benzene, toluene and o-xylene and ethanol (“With ethanol lane”). The δ13C of MTBE for all wells in the “No ethanol lane” remained constant during the experiment with a mean value of − 31.3 ± 0.5‰ (n = 40), suggesting the absence of any substantial MTBE biodegradation in this lane. In contrast, substantial enrichment in 13C of MTBE by 40.6‰, was measured in the “With ethanol lane”, consistent with the effects of biodegradation. A substantial amount of TBA (up to 1200 μg/L) was produced by the biodegradation of MTBE in the “With ethanol lane”. The mean value of δ13C for TBA in groundwater samples in the “With ethanol lane” was − 26.0 ± 1.0‰ (n = 32). Uniform δ13C TBA values through space and time in this lane suggest that substantial anaerobic biodegradation of TBA did not occur during the experiment. Using the reported range in isotopic enrichment factors for MTBE of − 9.2‰ to − 15.6‰, and values of δ13C of MTBE in groundwater samples, MTBE first-order biodegradation rates in the “With ethanol lane” were 12.0 to 20.3 year− 1 (n = 18). The isotope-derived rate constants are in good agreement with the previously published rate constant of 16.8 year− 1 calculated using contaminant mass-discharge for the “With ethanol lane”.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Contaminant Hydrology - Volume 94, Issues 3–4, 7 December 2007, Pages 157–165
نویسندگان
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