Field evidence for co-metabolism of trichloroethene stimulated by addition of electron donor to groundwater.

For more than 10 years, electron donor has been injected into the Snake River aquifer beneath the Test Area North site of the Idaho National Laboratory for the purpose of stimulating microbial reductive dechlorination of trichloroethene (TCE) in groundwater. This has resulted in significant TCE removal from the source area of the contaminant plume and elevated dissolved CH(4) in the groundwater extending 250 m from the injection well. The delta(13)C of the CH(4) increases from -56 per thousand in the source area to -13 per thousand with distance from the injection well, whereas the delta(13)C of dissolved inorganic carbon decreases from 8 per thousand to -13 per thousand, indicating a shift from methanogenesis to methane oxidation.

Assessment of xylanase activity in dry storage as a potential method of reducing feedstock cost.

Enzymatic preprocessing of lignocellulosic biomass in dry storage systems has the potential to improve feedstock characteristics and lower ethanol production costs. To assess the potential for endoxylanase activity at low water contents, endoxylanase activity was tested using a refined wheat arabinoxylan substrate and three commercial endoxylanases over the water activity range 0.21-1.

The effect of drying temperature on the composition of biomass.

The compositional quality of different lignocellulosic feedstocks influences their performance and potential demand at a biorefinery. Many analytical protocols for determining the composition or performance characteristics of biomass involve a drying step, where the drying temperature can vary depending on the specific protocol. To get reliable data, it is important to determine the correct drying temperature to vaporize the water without negatively impacting the compositional quality of the biomass.

Vapor-phase analysis of isobutyl acetate, isopropyl acetate, n-propyl acetate and their respective alcohols using solid-phase microextraction-gas chromatography with a mass selective detector.

A solid-phase microextraction (SPME)-GC-MS method for three esters and the corresponding alcohols was tested for responses in accuracy, within-run precision (repeatability), and between-run precision (reproducibility) due to individual operators, individual analysis days, and differing analyte concentrations. At 5 ppm (v/v) [ppmv], three of the six analytes showed significant (p < 0.05) operator effects, while five of six analytes gave a significant effect due to the days of analysis.

Effects of particulate explosives on estimating contamination at a historical explosives testing area.

A historical explosives testing area harbored contamination as unevenly distributed solid particles within a contaminant-stained soil matrix. Particles larger than 3 mm diameter accounted for 96.4% of the explosives contamination.