Anaerobic sulfate-reducing bacteria were enriched from contaminated aquifer samples with naphthalene, o-, and m-xylene as sole carbon and energy source in the presence of Amberlite-XAD7, a solid adsorber resin. XAD7 served as a substrate reservoir maintaining a constantly low substrate concentration in the culture medium. In equilibration experiments with XAD7, the aromatic hydrocarbons needed ...

Characteristic speciation of airborne volatile organics in Kaohsiung, the largest industrial city in Taiwan, is present in this paper. Hourly concentration of airborne volatile organic compounds (VOCs) was monitored by on-line GC/FID and 3 hours-averaged sample was parallel conducted by canister during rush hour. Field sampling works were conducted at a traffic station (Qian-Jin) and an industr...

Various alkylbenzenes were depleted during growth of an anaerobic, sulfate-reducing enrichment culture with crude oil as the only source of organic substrates. From this culture, two new types of mesophilic, rod-shaped sulfate-reducing bacteria, strains oXyS1 and mXyS1, were isolated with o-xylene and m-xylene, respectively, as organic substrates. Sequence analyses of 16S rRNA genes revealed th...

Equilibrated Vapor Concentrations for Bicomponent Organic Solvents: Hajime HORI, et al. Department of Environmental Management I, School of Health Sciences, University of Occupational and Environmental Health, Japan— The equilibrated vapor concentrations for bicomponent organic solvents of toluene–o-xylene, methanol– toluene and methanol–o-xylene mixtures were measured at various compositions. ...

Toluene-o-xylene monooxygenase is an enzymatic complex, encoded by the touABCDEF genes, responsible for the early stages of toluene and o-xylene degradation in Pseudomonas stutzeri OX1. In order to identify the loci involved in the transcriptional regulation of the tou gene cluster, deletion analysis and complementation studies were carried out with Pseudomonas putida PaW340 as a heterologous h...

Separation of hydrocarbon molecules, such as benzene/cyclohexane and o-xylene/m-xylene/p-xylene, is relevant due to their widespread application chemical feedstock but challenging because similar boiling points close molecular sizes. Physisorption separation could offer an energy-efficient solution this problem, the design synthesis sorbents that exhibit high selectivity for one hydrocarbons re...

m-Xylene transformation has been studied on as-prepared H-Y and a series of dealuminated Y zeolite catalysts. The conversion of m-xylene was found to increase initially with acidity, however, decreases subsequently. It has been proposed that the high concentration of acid sites in the H-Y catalyst increases paring reaction, in addition to the well-known isomerization and disproportionation path...

The objective of this study was to assess the occupational exposure of jeepney drivers to selected volatile organic compounds (VOCs) in Manila, Philippines. Personal sampling was conducted on 15 jeepney drivers. Area sampling was conducted to determine the background VOC concentration in Manila as compared to that in a rural area. Both personal and area samples were collected for 5 working days...

Rhodococcus sp. strain DK17 was isolated from soil and analyzed for the ability to grow on o-xylene as the sole carbon and energy source. Although DK17 cannot grow on m- and p-xylene, it is capable of growth on benzene, phenol, toluene, ethylbenzene, isopropylbenzene, and other alkylbenzene isomers. One UV-generated mutant strain, DK176, simultaneously lost the ability to grow on o-xylene, ethy...

Xylenes transformations have been investigated over ZSM-5 zeolite in a riser simulator that mimics closely the operation of commercial fluidized-bed reactors. P-xylene was found to be more reactive than the other isomers followed by o-xylene and m-xylene was found to be least reactive. The order of reactivity is consistent with the order of diffusivity. At low temperature (400°C), isomerization...