THE STRONTIUM ISOTOPIC FINGERPRINT OF COAL COMBUSTION RESIDUALS FROM THE UNITED STATES: A DISTINCTION BETWEEN THE ISOTOPE RATIOS OF THE BULK AND WATER-SOLUBLE STRONTIUM

Abstract. Housing roughly 10 million head of cattle in the United States alone, open air cattle feedlots represent a significant but poorly constrained source of atmospheric particles. Here we present a comprehensive characterization of physical and chemical properties of particles emitted from a large representative cattle feedlot in the Southwest United States. In the summer of 2008, measurements and samplings were conducted at the upwind and downwind edges of the facility. A series of far-field measurements and samplings was also conducted 3.5 km north of the facility. Two instruments, a GRIMM Sequential Mobility Particle Sizer (SMPS) and a GRIMM Portable Aerosol Spectrometer (PAS), were used to measure particle size distributions over the range of 0.01 to 25 μm diameter. Raman microspectroscopy was used to determine the chemical composition of particles on a single particle basis. Volume size distributions of dust were dominated by coarse mode particles. Twenty-four hour averaged concentrations of PM10 (particulate matter with a diameter of 10 μm or less) were as high as 1200 μg m−3 during the campaign. The primary constituents of the particulate matter were carbonaceous materials, such as humic acid, water soluble organics, and less soluble fatty acids, including stearic acid and tristearin. A significant fraction of the organic particles was present in internal mixtures with salts. Basic characteristics such as size distribution and composition of agricultural aerosols were found to be different than the properties of those found in urban and semi-urban aerosols. Failing to account for such differences may lead to errors in estimates of aerosol effects on local air quality, visibility, and public health.

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The Development and Use of Isoscapes to Determine the Geographical Origin of Quercus spp. in the United States

Forests ◽

10.3390/f11080862 ◽

2020 ◽

Vol 11 (8) ◽

pp. 862 ◽

Cited By ~ 1

Author(s):

Charles J. Watkinson ◽

Peter Gasson ◽

Gareth O. Rees ◽

Markus Boner

Keyword(s):

United States ◽

Stable Isotope ◽

Oxygen Isotope ◽

Hydrogen Isotope ◽

Isotope Ratios ◽

The United States ◽

Stable Isotope Ratios ◽

Carbon Isotope Ratios ◽

Oxygen Isotope Ratios ◽

Hydrogen Isotope Ratios

The stable isotope ratios of oxygen, hydrogen, carbon and sulfur from extracted wood of 87 samples of oaks from the United States were analysed. Relationships with climate variables and the stable isotope ratios of the 69 training dataset samples were investigated to a monthly resolution using long-term monthly mean climate data from NASA and the University of East Anglia’s Climate Research Unit, in conjunction with forecast data for hydrogen and oxygen isotope ratios in precipitation. These relationships were used to construct model isoscapes for oxygen, hydrogen, carbon and sulfur for US oak with the aim of using them to forecast isotopic patterns in areas that were not sampled and predict values in samples not used to construct the models. The leading predictors for isoscape generation were oxygen isotope ratios in January precipitation for oak oxygen isotope ratios, hydrogen isotope ratios in July precipitation for oak hydrogen isotope ratios, water vapour in April for carbon isotope ratios, and reflected shortwave radiation in March in combination with sulfate concentration in May for oak sulfur isotopes. The generated isoscapes can be used to show regions an unknown sample may have originated from with a resolution dependent on the rarity of the stable isotope signature within the United States. The models were assessed using the data of 18 samples of georeferenced oak. The assessment found that 100% of oxygen, 94% of hydrogen, 78% of carbon, and 94% of sulfur isotope ratios in the 18 test dataset samples fell within two standard deviations of the isoscape models. Using the results of the isoscapes in combination found that there were 4/18 test samples which did not fall within two standard deviations of the four models, this is largely attributed to the lower predictive power of the carbon isoscape model in conjunction with high local variability in carbon isotope ratios in both the test and training data. The method by which this geographic origin method has been developed will be useful to combat illegal logging and to validate legal supply chains for the purpose of good practice due diligence.

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Efficacy of soluble sodium tripolyphosphate amendments for the in-situ immobilisation of uranium

Environmental Chemistry ◽

10.1071/en07030 ◽

2007 ◽

Vol 4 (5) ◽

pp. 293 ◽

Cited By ~ 9

Author(s):

Dawn M. Wellman ◽

Eric M. Pierce ◽

Michelle M. Valenta

Keyword(s):

United States ◽

Drinking Water ◽

Sodium Tripolyphosphate ◽

The United States ◽

Water Soluble ◽

Column Experiments ◽

Site Specific ◽

Water Saturated ◽

Phosphate Compounds

Environmental context. Contamination of groundwater and sediments by heavy metals and radioactive metals is a significant problem within the United States Department of Energy complex as a result of past nuclear operations. One way to remediate these metals is through reaction with phosphate compounds, which can immobilise the metals by forming highly stable metal phosphate compounds. Long-chain, water-soluble phosphate compounds provide a means to inject phosphate into subsurface contaminant plumes, to precipitate metal ions from solution. Results presented here illustrate that application of a soluble sodium tripolyphosphate to sediment contaminated with uranium will rapidly reduce the concentration of uranium in the pore water to concentrations near or below drinking water limits under water-saturated and unsaturated conditions. Abstract. A series of conventional water-saturated and pressurised unsaturated flow column experiments were conducted to evaluate the effects of using soluble polyphosphate amendments for in-situ, subsurface remediation of uranium. Experiments were conducted under mildly alkaline, calcareous conditions, representative of conditions commonly encountered at sites across the arid western United States. Results presented here illustrate that application of a soluble polyphosphate amendment to sediment contaminated with uranium will rapidly reduce the concentration of uranium released to the porewater to near or below drinking water limits under water-saturated and -unsaturated conditions. Column experiments conducted in the absence of polyphosphate illustrate sustained release of aqueous uranium at concentrations well above drinking water standards in excess of over 25 pore volumes under water-saturated conditions and over 50 pore volumes under unsaturated conditions. In the presence of tripolyphosphate, the concentration of aqueous uranium released from the sediment was below drinking water limits within 10 to 35 pore volumes under water-saturated and unsaturated conditions, respectively. Moreover, results indicate the necessity of conducting site-specific dynamic tests to tailor phosphate-based remediation technology to site specific geochemical and hydrological conditions.

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Links between Purchase Location and Stable Isotope Ratios of Bottled Water, Soda, and Beer in the United States

Journal of Agricultural and Food Chemistry ◽

10.1021/jf1003539 ◽

2010 ◽

Vol 58 (12) ◽

pp. 7311-7316 ◽

Cited By ~ 29

Author(s):

Lesley A. Chesson ◽

Luciano O. Valenzuela ◽

Shannon P. O’Grady ◽

Thure E. Cerling ◽

James R. Ehleringer

Keyword(s):

United States ◽

Stable Isotope ◽

Isotope Ratios ◽

The United States ◽

Bottled Water ◽

Stable Isotope Ratios

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Hydrogen and Oxygen Stable Isotope Ratios of Milk in the United States

Journal of Agricultural and Food Chemistry ◽

10.1021/jf904151c ◽

2010 ◽

Vol 58 (4) ◽

pp. 2358-2363 ◽

Cited By ~ 51

Author(s):

Lesley A. Chesson ◽

Luciano O. Valenzuela ◽

Shannon P. O’Grady ◽

Thure E. Cerling ◽

James R. Ehleringer

Keyword(s):

United States ◽

Stable Isotope ◽

Isotope Ratios ◽

The United States ◽

Stable Isotope Ratios ◽

Oxygen Stable Isotope

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Comparative Analysis of Soluble Phosphate Amendments for the Remediation of Heavy Metal Contaminants: Effect on Sediment Hydraulic Conductivity

Environmental Chemistry ◽

10.1071/en05023 ◽

2006 ◽

Vol 3 (3) ◽

pp. 219 ◽

Cited By ~ 25

Author(s):

Dawn M. Wellman ◽

Jonathan P. Icenhower ◽

Antoinette T. Owen

Keyword(s):

United States ◽

Hydraulic Conductivity ◽

Pore Structure ◽

Pore Space ◽

The United States ◽

Water Soluble ◽

Department Of Energy ◽

United States Department ◽

Soluble Phosphate ◽

Long Chain

Environmental Context. The contamination of surface and subsurface geologic media by heavy metals and radionuclides is a significant problem within the United States Department of Energy complex as a result of past nuclear operations. Water-soluble phosphate compounds provide a means to inject phosphorus into subsurface contaminant plumes, to precipitate metal ions from solution. However, phosphate phases can form within the sedimentary pore structure to block a fraction of the pore space and inhibit further remediation of the contaminant plume. A series of tests have been conducted to evaluate changes in sedimentary pore structure during the application of several proposed phosphate remediation amendments. Abstract. A series of conventional, saturated column experiments have been conducted to evaluate the effect of utilizing in situ, soluble, phosphate amendments for subsurface metal remediation on sediment hydraulic conductivity. Experiments have been conducted under mildly alkaline and calcareous conditions representative of conditions commonly encountered at sites across the arid western United States, which have been used in weapons and fuel production and display significant subsurface contamination. Results indicate that the displacement of a single pore volume of either sodium monophosphate or phytic acid amendments causes approximately a 30% decrease in the hydraulic conductivity of the sediment. Long-chain polyphosphate amendments afford no measurable reduction in hydraulic conductivity. These results demonstrate (1) the efficacy of long-chain polyphosphate amendments for subsurface metal sequestration; and (2) the necessity of conducting dynamic experiments to evaluate the effects of subsurface remediation.

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Coal

The Changing Energy Mix ◽

10.1093/oso/9780190098391.003.0004 ◽

2020 ◽

pp. 81-119

Author(s):

Paul F. Meier

Keyword(s):

United States ◽

Coal Combustion ◽

Electricity Generation ◽

Ground Level ◽

The United States ◽

Pulverized Coal ◽

Ground Level Ozone ◽

Energy Applications ◽

Residential Heating ◽

Coal Technology

Coal has two main energy applications, with about 90% used for electricity generation and 10% used for commercial and residential heating. In terms of electricity generation in the United States, coal is responsible for about 28%, a significant decrease from 53% twenty years earlier when it was the leading energy for producing electricity. There are two primary commercial methods for generating electricity from coal including pulverized coal combustion and fluidized bed coal combustion. To safely burn coal, sulfur, nitrogen, and heavy metals are removed at the electric plant. The sequestering of sulfur and nitrogen are important steps for limiting acid rain and ground level ozone. To generate electricity, the United States has about 360 coal plants with about 790 generators, of which greater than 90% use pulverized coal technology. Most coal is transported by rail.

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