BTEX

BTEX. See Benzene-toluene-ethyl benzene-xylenes. 

BTEX Benzene, toluene, xylene PCB Polychlorinated biphenyl... 

CAf-PUFF PTPLU BTEX RANDWALK CEQUALW2 RESTMF Other models... 

G. S. Frysinger, R. B. Gaines and E. B. Ledford-Jr, Quantitative determination of BTEX and total aromatic compounds in gasoline by comprehensive two-dimensional gas chromatography (GC X GC) , 7. High Resolut. Chromatogr. 22 195-200 (1999). 

Phillips and Xu have presented two-dimensional (2D) chromatograms of kerosines, separated with different stationary phase combinations, in many thousands of components (37). Frysinger et al. have separate benzene-toluene-ethyl benzene-xylenes (BTEX) and total aromatics in gasolines by using GC X GC... 

They reported that most of bacteria for removing benzene, toluene, ethylbenzene, and xylene (BTEX) may have a high biological activity in a weak basic environment. 

Seller HR (2002) Analysis of benzylsuccinates in groundwater by liquid chromatography/tandem mass spectrometry and its use for monitoring in situ BTEX biodegradation. Environ Sci Technol 36 2724-2728. 

The fate of toluene and o-xylene in an aquifer contaminated with BTEX was examined by injecting toluene-dj and o-xylene-djo followed by quantification of the label in benzyl succinate and 2-methylbenzene succinate (Reusser et al. 2002) that are established metabolites on the anaerobic pathway for the degradation of toluene and o-xylene. 

Fischer A, J Bauer, RU Meckenstock, W Stickler, C Griebler, P Maloszewski, M Kastner, HH Richnow (2006) A multitracer test proving the reliability of Rayleigh equation-based approach for assessing hiodegra-datyion in a BTEX contaminated aquifer. Environ Sci Technol 40 4245-4252. 

Reusser DE, JD Istok, HR Beller, JA Field (2002) In situ transformation of deuterated toluene and xylene to benzylsuccinic acid analogues in BTEX-contaminated aquifers. Environ Sci Technol 36 4127-4134. 

Benzene is one of a group of related aromatic monocyclic hydrocarbons (BTEX—benzene, toluene, ethylbenzene, and xylene), and since these are water soluble, there has been concern for their dissipation and persistence in groundwater under both aerobic and anaerobic conditions. Although aerobic growth at the expense of benzene was established many years ago, the pathway for its degradation was established only much later. The aerobic degradation of benzene by bacteria is... 

The degradation of BTEX both individually or in admixture has been shown in a lignindegrading white-rot fungus under nonlignolytic conditions, and was confirmed with ring-labeled toluene (Yadav and Reddy 1993). Interest in fungal transformation of PAHs is noted in the next part of this chapter, and illustrative examples of the hydroxylation of monocyclic arenes include the following (Smith and Rosazza 1983) ... 

Yadav JS, CA Reddy (1993) Degradation of benzene, toluene, ethylbenzene, and xylenes (BTEX) by the lignin-degrading basidiomycete Phanerochaete chrysosporium. Appl Environ Microbiol 59 756-762. 

A sulfate enrichment culture prepared from a contaminated site gave enrichment factors (e) of-1.1 for naphthalene and -0.9 for 2-methylnaphthalene (Griebler et al. 2004). These values combined with literature values from analogous laboratory experiments were used to quantify degradation of toluene, xylenes, and naphthalene at the site. Additional evidence for degradation of BTEX was derived from analyses of established metabolites produced by anaerobic degradation. 

Consistent with this, it was observed that, during the metabolism of C-labeled BTEX although the substrates were mineralized to ca. 70%, ca. 20% of the label in toluene and ca. 30% in o-xylene were found in humus. It was suggested that the alkylated catechol metabolites might plausibly be responsible for this association (Tsao et al. 1998). 

In many situations, such as in deep groundwater, oxygen concentration may be severely limiting due to its consumption by surflcial aerobic organisms, or its low rate of transport into the system. Therefore, there has been great interest in the anaerobic degradation of BTEX. Although this has been... 

In a simulated spill, groundwater was spiked with BTEX, MTBE, and chloride as marker, and injected into a sandy aquifer (Schirmer and Barker 1998). Whereas the level of BTEX fell, loss of MTBE was much slower, and only ca. 3% remained after 8 years, although the mechanism of its loss was not resolved. 

Barbaro JR, JF Barker, LA Lemon, Cl Mayfield (1992) Biotransformation of BTEX nnder anaerobic, denitrifying conditions field and laboratory observations. J Contam Hydrol 11 245-272. 

Borden RC, RA Daniel, LE LeBrun, CW Davis (1997) Intrinsic biodegradation of MTBE and BTEX in a gasoline-contaminated aquifer. Water Resour Res 33 1105-1115. 

Bowlen GF, DS Kosson (1995) In situ processes for bioremediation of BTEX and petroleum fuel products. In Microbial transformation and Degradation of Toxic Organic Chemicals (Eds LY Young, CE Cerni-glia), pp. 515-545. Wiley-Liss, New York. 

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