Techniques for detecting and quantifying anaerobic transformations of benzene, toluene, ethylbenzene, and xylene (BTEX) are needed to assess the feasibility of using in situ bioremediation to treat BTEX-contaminated groundwater aquifers. Deuterated surrogates of toluene (toluene-d8) and xylene (o-xylene-d10) were injected into BTEX-contaminated aquifers during single-well push-pull tests to mon...

A novel strain of p-xylene-degrading sulfate reducer was isolated in pure culture. Strain PP31 was obtained from a p-xylene-degrading enrichment culture established from polluted marine sediment. Analyses of the 16S rRNA gene and two functional genes involved in sulfate respiration and anaerobic degradation of aromatic compounds revealed that the isolate was closely related to members of the ge...

A novel sulfate-reducing bacterium isolated from fuel-contaminated subsurface soil, strain PRTOL1, mineralizes toluene as the sole electron donor and carbon source under strictly anaerobic conditions. The mineralization of 80% of toluene carbon to CO2 was demonstrated in experiments with [ring-U-14C]toluene; 15% of toluene carbon was converted to biomass and nonvolatile metabolic by-products, p...

New compounds having two indolizine nuclei in a molecule were prepared in low to moderate yields from the reactions of potassium 2-indolizinethiolates with 1,omega-dihalides such as 1,2-diiodoethane, 1,3-dibromopropane, 1,4-dibromobutane, alpha,alpha'-dichloro-o-xylene, and alpha,alpha'-dichloro-p-xylene. Most of the products had the conformation in which the two indolizine rings in the molecul...

MFI zeolite membranes, especially b-oriented ones, show superb vapor permeation/separation performance for xylene isomer separation at low pressures. In industrial applications these membranes should be operated high pressures in the mode or with liquid feed pervaporation mode. This paper reports influence of activity on and membranes. High quality were synthesized an organic template modified ...

Ultraselective and sensitive detection of xylene and toluene with minimum interferences of other indoor air pollutants such as benzene, ethanol, and formaldehyde is achieved using NiO hierarchical nanostructures doped with Cr. Pure and 1.15-2.56 at% Cr-doped NiO flower-like hierarchical nanostructures assembled from nanosheets are prepared by a simple solvothermal reaction and their gas sensing...

The effect of H2 on isomerization pathways and on the acid site density on WOx-ZrO2 catalysts was explored using kinetic measurements of acid-catalyzed o-xylene isomerization reactions. Initial o-xylene isomerization rates on WOx-ZrO2 at 523 K are proportional to the H2 concentration even though H atoms are not involved directly in reaction turnovers, as shown by the low deuterium content in th...

Blood concentrations of 11 volatile organic compounds (VOCs) were measured up to four times over 2 years in a probability sample of more than 150 children from two poor, minority neighborhoods in Minneapolis, Minnesota. Blood levels of benzene, carbon tetrachloride, trichloroethene, and m-/p-xylene were comparable with those measured in selected adults from the Third National Health and Nutriti...

In the present work, the transformation of m-xylene was studied over fresh and pre-coked HZSM-5 catalyst in a riser simulator over the temperature range of 350-500C.Significant differences were observed in both the activity and product selectivity pattern for the two forms of the catalyst. While, the fresh catalyst generally gave higher m-xylene conversion, the pre-coked catalyst produced highe...

Molecular sieving MFI-type zeolite membranes were prepared by a secondary growth method without using an organic template. Silicalite membranes with intercrystalline pores minimized or eliminated were obtained by this synthesis method which avoids the template removal step. The silicalite membrane exhibits molecular sieving characteristics with pervaporation separation factor for p-xylene to o-...