Filters: Tags: benzene (X)
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Methane and nitrous oxide are potent greenhouse gases whose atmospheric abundances have increased significantly in the past 200 years, together accounting for approximately half of the radiative forcing associated with increasing concentrations of carbon dioxide. In order to understand the factors causing increase of these gases globally, we need to determine their emission rates at regional to continental scales. We directly link atmospheric observations with surface emissions using a Lagrangian Particle Dispersion Model, and then determine emission rates by optimizing prior emissions estimates. We use measurements from NOAA's tall tower and aircraft program in 2004, The Stochastic Time-Inverted Lagrangian Transport...
Categories: Publication;
Types: Citation;
Tags: benzene,
evaluation,
health effects,
public health,
relevance
Field sampling and mathematical modeling are used to study the long-distance transport and attenuation of petroleum-derived benzene in the Uinta Basin, Utah. Benzene concentration was measured from oil and oil field formation waters of the Altamont-Bluebell and Pariette Bench oil fields in the basin. It was also measured from springs located in the regional groundwater discharge areas, hydraulically down-gradient from the oil fields sampled. The average benzene concentration in oils and co-produced waters is 1946 and 4.9 ppm at the Altamont-Bluebell field and 1533 and 0.6 ppm at the Pariette Bench field, respectively. Benzene concentration is below the detection limit in all springs sampled. Mathematical models...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Geofluids,
Uinta Basin,
benzene,
water washing
The time frame for natural attenuation of crude oil contamination in the subsurface has been studied for the last 27 years at a spill site located near Bemidji, Minnesota, USA. Data from the groundwater contaminant plume show that dissolved benzene concentrations adjacent to the oil decreased by 50% between 1993 and 2007. To assess how this decrease is related to benzene concentrations in the crude oil, samples of oil were bailed from floating oil in five wells and analysed for volatile components. Compared to reference oil collected from the pipeline in 1984, benzene concentrations in the well located farthest downgradient in the oil have decreased an average of 50%. Benzene and ethylbenzene depletion are linearly...
The fate of contaminants in the environment is controlled by both chemical reactions and transport phenomena in the subsurface. Our ability to understand the significance of these processes over time requires an accurate conceptual model that incorporates the various mechanisms of coupled chemical and physical processes. Adsorption, desorption, ion exchange, precipitation, dissolution, growth, solid solution, redox, microbial activity, and other processes are often incorporated into reactive transport models for the prediction of contaminant fate and transport. U.S. federal agencies use such models to evaluate contaminant transport and provide guidance to decision makers and regulators for treatment issues. We provide...
Categories: Publication;
Types: Citation;
Tags: ARS,
Agricultural Research Service,
BTEX,
CNWRA,
Center for Nuclear Waste Regulatory Analyse,
Groundwater samples were collected from domestic and public-supply wells in the Eagle Ford study area in 2015–16, in the Fayetteville study area in 2015, and in the Haynesville study area in 2014–15. One sample of produced water was collected from a gas well in the Haynesville Shale in Rusk County, Texas in 2010, and 5 samples of produced water were collected from oil and condensate wells in the Eagle Ford Shale in Gonzales and Lavaca Counties, Texas in 2015. Groundwater samples were analyzed for major ions, nutrients, and trace elements; methane, methane H and C isotopic compositions, and C1-C5 gas composition; H and O isotopic composition of water; noble gas concentrations and isotopic compositions; tritium,...
Methane and nitrous oxide are potent greenhouse gases whose atmospheric abundances have increased significantly in the past 200 years, together accounting for approximately half of the radiative forcing associated with increasing concentrations of carbon dioxide. In order to understand the factors causing increase of these gases globally, we need to determine their emission rates at regional to continental scales. We directly link atmospheric observations with surface emissions using a Lagrangian Particle Dispersion Model, and then determine emission rates by optimizing prior emissions estimates. We use measurements from NOAA's tall tower and aircraft program in 2004, The Stochastic Time-Inverted Lagrangian Transport...
The time frame for natural attenuation of crude oil contamination in the subsurface has been studied for the last 27 years at a spill site located near Bemidji, Minnesota, USA. Data from the groundwater contaminant plume show that dissolved benzene concentrations adjacent to the oil decreased by 50% between 1993 and 2007. To assess how this decrease is related to benzene concentrations in the crude oil, samples of oil were bailed from floating oil in five wells and analysed for volatile components. Compared to reference oil collected from the pipeline in 1984, benzene concentrations in the well located farthest downgradient in the oil have decreased an average of 50%. Benzene and ethylbenzene depletion are linearly...
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