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Results of mobile ground-based atmospheric measurements conducted during the Barnett Shale Coordinated Campaign in spring and fall of 2013 are presented. Methane and ethane are continuously measured downwind of facilities such as natural gas processing plants, compressor stations, and production well pads. Gaussian dispersion simulations of these methane plumes, using an iterative forward plume dispersion algorithm, are used to estimate both the source location and the emission magnitude. The distribution of emitters is peaked in the 0-5 kg/h range, with a significant tail. The ethane/methane molar enhancement ratio for this same distribution is investigated, showing a peak at ∼1.5% and a broad distribution between ∼4% and ∼17%. The regional distributions of source emissions and ethane/methane enhancement ratios are examined: the largest methane emissions appear between Fort Worth and Dallas, while the highest ethane/methane enhancement ratios occur for plumes observed in the northwestern potion of the region. Individual facilities, focusing on large emitters, are further analyzed by constraining the source location.
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http://dx.doi.org/10.1021/es506352j | DOI Listing |
Waste Manag
September 2025
Department of Earth and Environment Sciences, St. Francis Xavier University, Antigonish, Canada.
We measured emissions from ten landfills using mobile surveys and Surface Emission Monitoring (SEM) to determine what fraction of emissions can be identified by SEM surveys. SEM is commonly used for regulatory compliance and leak detection at specific locations. However, evolving regulations emphasize the need to manage methane emissions from the entire landfill site, and the suitability of SEM for this objective remains unclear.
View Article and Find Full Text PDFSci Total Environ
September 2025
Department of Animal Sciences and Aquatic Ecology, Ghent University, Gent, Belgium.
Wetlands play a crucial role in global greenhouse gas (GHG) dynamics, yet their response to climate change is not yet fully understood. Here, we investigate how increasing temperature and oxygen availability interact to regulate wetland GHG emissions through combined analysis of biogeochemical and functional gene measurements. We found distinct temperature-dependent shifts in carbon emission pathways, with CO emissions unexpectedly declining as temperature rose from 15 to 25 °C, while increasing consistently at higher temperatures (25-35 °C), reflecting a transition to more thermally-driven processes.
View Article and Find Full Text PDFJ Dairy Sci
September 2025
Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI 53706. Electronic address:
The objective of this experiment was to evaluate the effects of dietary starch concentration by replacing high-moisture corn with soy hulls and a direct-fed microbial (DFM) containing Bacillus subtilis 810 and Bacillus licheniformis 809 on the lactation performance, feeding behavior, total-tract nutrient digestibility, and enteric CH emissions of dairy cows. Sixty-four multiparous Holstein cows (67 ± 24 DIM and 729 ± 60 kg of BW at the beginning of the covariate period) were randomly assigned to 1 of 4 treatments with a 2 × 2 factorial arrangement for a 12-wk treatment period, after a 1-wk acclimation period and 2-wk covariate period. Treatments consisted of diets with 21% starch and no DFM (RS-CON), 21% starch and DFM (RS-DFM), 27% starch and no DFM (NS-CON), and 27% starch and DFM (NS-DFM).
View Article and Find Full Text PDFJ Dairy Sci
September 2025
Animal Nutrition, Production Systems, Natural Resources Institute Finland (Luke), 31600 Jokioinen, Finland.
The aim of this study was to evaluate the precision and accuracy of GreenFeed (GF) Emission Monitoring system in measuring O, CO, and CH exchanges, and heat production (HP) when compared with respiration chambers (RC). Thirty-two lactating Nordic Red cows (634 ± 60.4 kg BW, 145 ± 63.
View Article and Find Full Text PDFWaste Manag
September 2025
Technical University of Denmark, Department of Environment and Resource Engineering, Bygningstorvet, Building 115, 2800 Kongens Lyngby, Denmark. Electronic address:
During the storage of livestock manure in tanks, anaerobic degradation of organic material results in the production and emission of CH. This study tested a biofilter designed for CH oxidation as a potential technology for mitigating CH emissions from covered manure storage tanks. A full-scale biofilter (400 m) was built next to a pig manure tank (4.
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