68 research outputs found
Critical evaluation of the 2D-CSIA scheme for distinguishing fuel oxygenate degradation reaction mechanisms
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 (εC and εH) have still been associated with different reaction mechanisms (McKelvie et al. Environ. Sci. Technol. 2009, 43, 2793-2799). Here, we present new laboratory-derived εC and εH 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 Δδ2H/ Δδ13C data from chemical oxidation and hydrolysis of ethers resulted in slopes (Λ values) of 22 ± 4 and between 6 and 12, respectively. With A. tertiaricarbonis L108, R. zopfii IFP 2005 and Gordonia sp. IFP 2009, εC was low (<|-1|¿) and εH insignificant. Fractionation obtained with P. putida GPo1 was similar to acid hydrolysis and M. austroafricanum JOB5 and R. ruber DSM 7511 displayed Λ 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
Contrasting hydrogen peroxide- and persulfate-driven oxidation systems: Impact of radical scavenging on treatment efficiency and cost
Treatment of Methylene Blue water solution by submerged pulse arc in multi-electrode reactor
Structural effects on the catalytic activity of carbon-supported magnetite nanocomposites in heterogeneous Fenton-like reactions
Promoted discoloration of methyl orange in H2O2/Fe(III) Fenton system: Effects of gallic acid on iron cycling
Advanced treatment of dye wastewater using a novel integrative Fenton-like/MnO2-filled upward flow biological filter bed system equipped with modified ceramsite
Photocatalytic degradation of phenol by LaFeO3 nanocrystalline synthesized by gel combustion method via citric acid route
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