کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6366342 1623100 2015 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Increased fermentation activity and persistent methanogenesis in a model aquifer system following source removal of an ethanol blend release
ترجمه فارسی عنوان
افزایش فعالیت تخمیری و متانوژنز ماندگار در یک سیستم آبخوان مدل پس از حذف منبع انتشار اتانول
کلمات کلیدی
آب های زیرزمینی، اتانول، حذف منبع، سمی بودن تخمیر متانوژنز،
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
چکیده انگلیسی


- Fermentation was stimulated after source removal of due to reduced ethanol toxicity.
- Methanogenesis outlasted ethanol, and was likely supported by soil-bound organic carbon.
- Monitoring of problematic metabolites after ethanol disappears should be considered.

The increased probability of groundwater contamination by ethanol-blended fuel calls for improved understanding of how remediation efforts affect the fate and transport of constituents of concern, including the generation and fate of fermentation byproducts. A pilot-scale (8 m3) model aquifer was used to investigate changes in the concentrations of ethanol and its metabolites (methane and volatile fatty acids) after removal of the contamination source. Following the shut-off of a continuous release of a dissolved ethanol blend (10% v:v ethanol, 50 mg/L benzene, and 50 mg/L toluene), fermentation activity was surprisingly stimulated and the concentrations of ethanol metabolites increased. A microcosm experiment showed that this result was due to a decrease in the dissolved ethanol concentration below its toxicity threshold (∼2000 mg/L for this system). Methane generation (>1.5 mg/L of dissolved methane) persisted for more than 100 days after the disappearance of ethanol, despite clean air-saturated water flowing continuously through the tank at a relative high seepage velocity (0.76 m/day). Quantitative real-time PCR showed that functional genes associated with methane metabolism (mcrA for methanogenesis and pmoA for methanotrophy) also persisted in the aquifer material. Persistent methanogenesis was apparently due to the anaerobic degradation of soil-bound organic carbon (e.g., biomass grown on ethanol and other substrates). Overall, this study reflects the complex plume dynamics following source removal, and suggests that monitoring for increases in the concentration of ethanol metabolites that impact groundwater quality should be considered.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Water Research - Volume 68, 1 January 2015, Pages 479-486
نویسندگان
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