نتایج جستجو برای: mtbe
تعداد نتایج: 571 فیلتر نتایج به سال:
To manage risk or to implement natural attenuation as a remedy, regulatory agencies must understand the processes that attenuate methyl-tert-butyl ether (MTBE) in ground water. Most case studies and laboratory studies in the literature indicate that natural biodegradation is not important; however, recent reports indicate that natural biodegradation of MTBE plays an important role under certain...
Methyl tert-butyl ether (MTBE) is a widespread groundwater contaminant that does not respond well to conventional treatment technologies. Growing evidence indicates that microbial communities indigenous to groundwater can degrade MTBE under aerobic and anaerobic conditions. Although pure cultures of microorganisms able to degrade or cometabolize MTBE have been reported, to date the specific org...
We have isolated a mixed bacterial culture (BC-1) which is capable of degrading the gasoline oxygenate methyl t-butyl ether (MTBE). BC-1 was developed from seed microorganisms present in a chemical plant biotreater sludge. This enrichment culture has been maintained in continuous culture treating high concentrations of MTBE (120 to 200 mg/liter) as the sole carbon source in a simple feed contai...
Methyl tert-butyl ether (MTBE) has been used in many countries as an octaneenhancing replacement for lead, primarily in midand high-grade gasoline. The prevalent use of MTBE has led to its introduction into environment. MTBE is poorly adsorbed, biologically and chemically stable, making it very persistent in the environment. MTBE has been classified as a possible human carcinogen. Many studies ...
The potential for aerobic methyl tert-butyl ether (MTBE) degradation was investigated with microcosms containing aquifer sediment and groundwater from four MTBE-contaminated sites characterized by oxygen-limited in situ conditions. MTBE depletion was observed for sediments from two sites (e.g., 4.5 mg/liter degraded in 15 days after a 4-day lag period), whereas no consumption of MTBE was observ...
Degradation of methyl tert-butyl ether (MTBE) vapors by cometabolism with pentane using a culture of pentane-oxidizing bacteria (Pseudomonas aeruginosa) was studied in a 2.4-L biofilter packed with vermiculite, an inert mineral support. Experimental pentane elimination capacity (EC) of approximately 12 g m(-3) h(-1) was obtained for an empty bed residence time (EBRT) of 1.1 h and inlet concentr...
This study investigated the aerobic biodegradation of methyl tertiary-butyl ether (MTBE) by a microbial consortium in a continuous up-flow packed-bed biofilm reactor using tezontle stone particles as a supporting material for the biofilm. Although MTBE is toxic for microbial communities, the microbial consortium used here was able to resist MTBE loading rates up to 128.3 mg L-1 h-1, with remova...
The kinetics and mechanism of the sonolytic degradation of methyl tert-butyl ether (MTBE) have been investigated at an ultrasonic frequency of 205 kHz and power of 200 W L-1. The observed first-order degradation rate constant for the loss of MTBE increased from 4.1 × 10-4 s-1 to 8.5 × 10-4 s-1 as the concentration of MTBE decreased from 1.0 to 0.01 mM. In the presence of O3, the sonolytic rate ...
Multidimensional compound-specific stable isotope analysis (CSIA) was applied in combination with RNA-based molecular tools to characterize methyl tertiary (tert-) butyl ether (MTBE) degradation mechanisms occurring in biofilms in an aerated treatment pond used for remediation of MTBE-contaminated groundwater. The main pathway for MTBE oxidation was elucidated by linking the low-level stable is...
Methyl-tert-butyl (MTBE) is widely used in gasoline to reduce ozone and carbon monoxide emissions. However, it is highly water-soluble and does not absorb well to sediments, making it move quickly through groundwater systems. In addition, MTBE resists biological degradation, compared to other gasoline components, probably because of the high energy required to cleave its ether bond. The contami...
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