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1.
Selenomethionine (SeM) is an organic toxicant that is present in seleniferous environments. No kinetic data is yet available
regarding SeM reactions in coal mine environments, where selenium (Se) toxicity is a potential concern. A kinetic study was
conducted on two reclaimed coal mine soils (Typic Torriorthents) from Wyoming having sandy and clayey textures. Four levels
of SeM treatments (0, 50, 100 μM, and plant amendment from the mine vegetation) were reacted with the soils for 4, 7, 14,
28, 42, 56, and 84 days to characterize the kinetic behavior of overall SeM disappearance from soil solutions. Detection of
SeM in soil solutions at the control level (0 μM SeM) indicated occurrence of indigenous SeM in the soils. In the plant-amended
soil solutions, much greater concentrations of SeM were observed as compared with the soil-only systems. This indicated the
plant material was a more potential source of SeM than the mine soils. A time-dependent loss in solution SeM concentrations
was observed for both soils under 0, 50, 100 μM SeM treatments. For the soil-plant mixtures, the solution SeM concentration
increased initially, reached a maximum after 14 days, and then decreased thereafter. In the plant-amended soil solutions,
SeM concentrations at all time intervals were higher for the sandy as compared to the clayey soil. At 50 and 100 μM SeM treatments,
the solution pH was linearly related to the percentages of SeM disappeared from the solutions; greater percentage of SeM was
removed from solutions at comparatively lower pH levels, which was ≥90% at pH 7.7 for both soils. Solution SeM concentrations
decreased exponentially with time following first-order kinetic reactions. Under all applications (except for the control),
C
0 (SeM concentration at t=0) values for the sandy soil were greater than those determined for the clayey soil, indicating higher solution SeM availability
for the former and more SeM retention by the latter at t=0. Comparison of C
0 in controls (0 μM SeM addition) suggested greater indigenous SeM in the clayey soil. For both soils, C
0 values under different treatments followed the order, (soil+100 μM)>(soil+50 μM)>(soil+0 μM). The specific reaction rate
constants (K
r) of SeM for both soils were similar (0.031 and 0.029 day–1 for sandy and clayey soils, respectively); low K
r values indicated that SeM loss from our reclaimed coal mine soil solutions would follow rather slow kinetics. The half-life
(t
0.5) of SeM varied from 15 to 55 days depending on treatment level. The knowledge obtained from this study should contribute
in developing time-based Se reclamation strategies in coal mine environments.
Received: 18 September 1995 · Accepted: 28 December 1995 相似文献
2.
《Applied Geochemistry》1994,9(1):37-43
Surface coal mining processes may increase the dissolved Mo concentrations in overburden (mine spoils) and in nearby soils. Spoil and soil samples were subjected to solubility studies for determining potential solid phases controlling the dissolved Mo. Additionally, native soil samples were included in the study for comparison. Ion activity products (IAPs) were calculated from the total elemental concentrations of aqueous extracts and compared with solubility products (Ksps) of Mo solid phases. Effects of dissolved organic carbon (DOC) on metal ion complexation were also evaluated. The pH of aqueous extracts ranged from 7.14 to 8.31. DOC in aqueous extracts varied from 17.3 to 58.7 mg/l. Molybdenum concentrations in aqueous extracts ranged between 11.5 and 35.6 μg/l for spoils, 13.5 and 20.0 μg/l for soils near mine site and 14.5 and 29.6 μg/l for native soils. Initially, IAPs suggested varying degrees of supersaturation with respect to wulfenite (PbMoO4). However, when DOC-Pb2+ complexes were considered, the IAPs indicated a close approach to saturation with respect to PbMoO4. Furthermore, the IAPs suggested a high degree of undersaturation with respect to powellite (CaMoO4) and ferrimolybdite (FeMoO4). Results in this study suggest the dissolved Mo concentrations in mine spoils and soils that are near coal mine may be controlled by PbMoO4 solid phase. 相似文献
3.
《Applied Geochemistry》1993,8(2):115-126
The major tributaries draining the Kendrick Reclamation Project (KRP) account for an average of 52% of the total Se load measured in the North Platte River downstream from Casper, Wyoming. The Casper Creek drainage basin contributed the largest Se load of the five tributary sites to the North Platte River. The 4-d average Se concentration in water samples from one site in the part of the North Platte River that receives irrigation return flows exceeded the 5 μg/l U.S. Environmental Protection Agency's aquatic life criterion five time during a 50-d monitoring period in 1989. In agreement with the water-quality data, muscle and liver tissue rom rainbow trout collected from the same part of the North Platte River had Se concentrations exceeding levels known to cause reproductive failure and chronic Se poisoning. On the basis of Se: Cl, 18O/16O and D/H ratios in water from Goose and Rasmus Lee Lakes (closed-basin systems), the large Se concentrations in those lakes were derived by natural evaporation of irrigation water without leaching of soluble forms of Se from soil or rocks. Water samples from Thirtythree Mile Reservoir and Illco Pond (flow-through systems) showed considerable enrichment in Se over evaporative concentration, presumably due to leaching and desorption of Se from soil and rock. The Se: Cl ratios of irrigation drain water collected from the KRP indicate that leaching and desorption of soluble forms of Se from soils and rocks are the dominant processes in drain water. Results of a Wilcoxon matched-pairs test for 43 paired drain-water samples collected during June and August 1988, indicated there is a statistically larger concentration of Se (0.01 significance level) during the June sampling period. The larger concentrations of Se and other chemical constitutents during the early part of the irrigation season probably were due to dissolution of seleniferous salts that have accumulated in soils within the KRP since the last irrigation season. The large Se concentrations in water samples from wetland sites in the KRP were reflected in the aquatic-bird food chain. Most waterfowl and shorebirds nesting at the KRP showed Se concentrations in livers and eggs greater than levels suspected of causing adverse reproductive effects. 相似文献
4.
Mark J. Potts 《Contributions to Mineralogy and Petrology》1972,36(4):249-264
The Preacher Creek ultramafic body is a small, lenticular-shaped intrusion of peridotite exposed in an ancient (2400–2500 m.y.), regionally metamorphosed terrane in southeastern Wyoming, U.S.A. The central core of the body consists of clinopyroxene-olivine peridotite and is surrounded by a marginal rim of peridotite in which orthopyroxene and plagioclase also occur as primary minerals. Alteration of primary minerals is relatively minor. However, at the contact with the country rock progressive alteration of the peridotite to actinolite and chlorite is locally severe. Chemical study of the effect of this alteration indicates that no more than minor changes from the primary composition of the peridotite have occurred. Petrographic studies reveal accumulative textures characteristic of stratiform complexes. Cryptic layering in the body is indicated by partial chemical analyses of the two major primary minerals, olivine and clinopyroxene.The body is inferred to have formed within the earth's crust by fractional crystallization and gravity accumulation of mafic minerals from a gabbroic magma that was differentiating along a tholeiitic trend. Subsequent to (or during) crystallization the body was remobilized, folded, and emplaced in its present site as a tectonic intrusion. Ultramafic intrusions with chemical, mineralogical, and structural features similar to the Preacher Creek body may be best explained perhaps as crystalline accumulates formed in volcanic magma chambers. 相似文献
5.
C. O. Okagbue 《Engineering Geology》1984,20(4):325-341
The mechanical and geotechnical properties of bulk samples and samples extracted from boreholes through a sliding spoil heap at a southwestern Pennsylvania coal mine are examined. Size gradation, moisture content, density and strength are found to vary considerably within the spoil. Gradation results suggest the material type to be more important than the age of spoil in degradation. There is also evidence from analysis that the heterogeneity of spoil and its associated density and strength do not significantly affect stability results. In other words, spoils can be sufficiently heterogeneous for purposes of stability analysis; they can be considered statistically homogeneous with regard to shear strength. 相似文献
6.
Warren D Sharp Kenneth R LudwigOliver A Chadwick Ronald AmundsonLaura L Glaser 《Quaternary Research》2003,59(2):139-150
Reliable and precise ages of Quaternary pedogenic carbonate can be obtained with 230Th/U dating by thermal ionization mass spectrometry applied to carefully selected milligram-size samples. Datable carbonate can form within a few thousand years of surface stabilization allowing ages of Quaternary deposits and surfaces to be closely estimated. Pedogenic carbonate clast-rinds from gravels of glacio-fluvial terraces in the Wind River Basin have median concentrations of 14 ppm U and 0.07 ppm 232Th, with median (230Th/232Th) = 270, making them well suited for 230Th/U dating. Horizons as thin as 0.5 mm were sampled from polished slabs to reduce averaging of long (≥105 yr), and sometimes visibly discontinuous, depositional histories. Dense, translucent samples with finite 230Th/U ages preserve within-rind stratigraphic order in all cases. Ages for terraces WR4 (167,000 ± 6,400 yr) and WR2 (55,000 ± 8600 yr) indicate a mean incision rate of 0.26 ± 0.05 m per thousand years for the Wind River over the past glacial cycle, slower than inferred from cosmogenic-nuclide dating. Terrace WR3, which formed penecontemporaneously with the final maximum glacial advance of the penultimate Rocky Mountain (Bull Lake) glaciation, has an age of 150,000 ± 8300 yr indicating that it is broadly synchronous with the penultimate global ice volume maximum. 相似文献
7.
William H. Orem Calin A. Tatu Harry E. Lerch Cynthia A. Rice Timothy T. Bartos Anne L. Bates Susan Tewalt Margo D. Corum 《Applied Geochemistry》2007
The organic composition of produced water samples from coalbed natural gas (CBNG) wells in the Powder River Basin, WY, sampled in 2001 and 2002 are reported as part of a larger study of the potential health and environmental effects of organic compounds derived from coal. The quality of CBNG produced waters is a potential environmental concern and disposal problem for CBNG producers, and no previous studies of organic compounds in CBNG produced water have been published. Organic compounds identified in the produced water samples included: phenols, biphenyls, N-, O-, and S-containing heterocyclic compounds, polycyclic aromatic hydrocarbons (PAHs), aromatic amines, various non-aromatic compounds, and phthalates. Many of the identified organic compounds (phenols, heterocyclic compounds, PAHs) are probably coal-derived. PAHs represented the group of organic compounds most commonly observed. Concentrations of total PAHs ranged up to 23 μg/L. Concentrations of individual compounds ranged from about 18 to <0.01 μg/L. Temporal variability of organic compound concentrations was documented, as two wells with relatively high organic compound contents in produced water in 2001 had much lower concentrations in 2002. 相似文献
8.
Theodore J. Armbrustmacher 《Precambrian Research》1977,4(1):13-38
Precambrian quartz dolerites and metadolerites of the central Bighorn Mountains form dikes that intrude a Precambrian metamorphic and igneous terrane typical of the Laramide uplifts of the middle Rocky Mountains. They have a restricted range of major- and trace-element compositions and are typical of basalts in the middle stages of tholeiitic fractionation. Fractionation in the direction of iron enrichment occurred by removal of plagioclase. Average element concentrations of the two groups are nearly identical to one another, are comparable to those in Archean metabasalts from numerous shield areas, and are intermediate between those of modern oceanic tholeiites and continental tholeiites. These average concentrations suggest a depth of magma generation and thickness of crust intermediate between those for the oceanic and continental environments. 相似文献
9.
The wettability of coal is studied at scales that range from the microscopic to the core. While contact-angle measurements define wettability at microscopic (pore) and core scales, relative permeability curves define wettability and multiphase flow properties at core and reservoir scales. The microscopic wettability is evaluated based on the Frumkin–Derjaguin equation. Estimates for contact angles are made versus aqueous-phase pH. The calculations suggest a trend that goes through a maximum at a pH around 4. Contact angles become small at low and high pH suggesting an alteration of coal wettability with pH. Water imbibition studies indicate that the core-scale wetness has similar trends as those predicted for the pore scale. Contact angle goes through a maximum at a pH of around 7 and is low in highly acidic and basic solutions. X-ray computed tomography (CT) scanning based imbibition studies also provide a method of understanding multiphase flow in coal systems. Estimates for relative permeability of air–water flow in coal are obtained and reported. The results are encouraging as these are the first steps towards developing relative permeability curves for coal-methane and carbon-dioxide systems. These systems are important with regards to both CO2 sequestration as well as enhanced methane production. 相似文献
10.
Paleomagnetic results from 107 samples of the Chugwater Group near Lander, Wyoming, show a regular progression in pole positions from bottom to top of the sequence. This pole position trend of about 25° matches very well the North American apparent polar wander path between Early Permian and Early Triassic. It could be argued that this “agreement” results in a conflict between the apparent magnetic age (Permian) and the Early to Late Triassic age generally assigned to the Chugwater Group. However, similar progressions of paleomagnetic pole positions have been reported for the Early Triassic Moenkopi Formation in Colorado; thus it appears that long-term variations and swings characterized the geomagnetic field at that time. With detailed paleomagnetic sampling, these features can be utilized for stratigraphic correlation in addition to magnetic-reversal stratigraphy. This will eliminate, to some degree, part of the non-uniqueness inherently present in correlations based on reversal stratigraphy only. 相似文献
11.
《Applied Geochemistry》1995,10(3):285-306
Inflows of metal-rich, acidic water that drain from mine dumps and tailings piles in the Leadville, Colorado, area enter the non-acidic water in the upper Arkansas River. Hydrous iron oxides precipitate as colloids and move downstream in suspension, particularly downstream from California Gulch, which has been the major source of metal loads. The colloids influence the concentrations of metals dissolved in the water and the concentrations in bed sediments. To determine the role of colloids, samples of water, colloids, and fine-grained bed sediment were obtained at stream-gaging sites on the upper Arkansas River and at the mouths of major tributaries over a 250-km reach. Dissolved and colloidal metal concentrations in the water column were operationally defined using tangential-flow filtration through 0.001-pm membranes to separate the water and the colloids. Surface-extractable and total bed sediment metal concentrations were obtained on the <60-μm fraction of the bed sediment. The highest concentrations of metals in water, colloids, and bed sediments occurred just downstream from California Gulch. Iron dominated the colloid composition, but substantial concentrations of As, Cd, Cu, Mn, Pb, and Zn also occurred in the colloidal solids. The colloidal load decreased by one half in the first 50 km downstream from the mining inflows due to sedimentation of aggregated colloids to the streambed. Nevertheless, a substantial load of colloids was transported through the entire study reach to Pueblo Reservoir. Dissolved metals were dominated by Mn and Zn, and their concentrations remained relatively high throughout the 250-km reach. The composition of extractable and total metals in bed sediment for several kilometers downstream from California Gulch is similar to the composition of the colloids that settle to the bed. Substantial concentrations of Mn and Zn were extractable, which is consistent with sediment-water chemical reaction. Concentrations of Cd, Pb, and Zn in bed sediment clearly result from the influence of mining near Leadville. Concentrations of Fe and Cu in bed sediments are nearly equal to concentrations in colloids for about 10 km downstream from California Gulch. Farther downstream, concentrations of Fe and Cu in tributary sediments mask the signal of mining inflows. These results indicate that colloids indeed influence the occurrence and transport of metals in rivers affected by mining. 相似文献
12.
J.W. Granath 《Precambrian Research》1975,2(1):71-91
The Precambrian metamorphic complex in the southern portion of Wind River Canyon is interpreted as being a fragment of an Archaean greenstone belt. The sequence is composed of meta-sediments inferred to have been various types of pelites and psammites, including graywackes and shales, and a silicate facies banded-iron formation. Meta-volcanics are represented by massive amphibolites.The area has undergone three periods of roughly coaxial folding that represent a single tectonic pattern. A period of intrusion of leucogranite with associated pegmatites separates the first two periods of deformation. These rocks appear to have been derived anatectically from sialic material at greater depth, suggesting the possibility of a sialic basement on which the greenstone belt rocks accumulated. Boudinage of the country rocks can be correlated with either or both of the first two folding episodes, and boudinage of the intrusive rocks occurred with different styles in the axial surfaces of the second and third generation folds.One period of amphibolite-facies metamorphism corresponds to the first and second deformational phases. Minor retrograde effects, fracture fillings, and small-scale metasomatism occurred either in the waning stages of the metamorphism or during a minor subsequent thermal event.Numerous Archaean ages from the Wyoming Precambrian province place Wind River Canyon in a region where examples of such greenstone belts might be expected. As no young intrusive or tectonic events have been reported from the area, the youngest deformational features discussed are considered to be not much younger than reported radiometric dates and therefore not of regional significance. 相似文献
13.
Radionuclides in ground water of the Carson River Basin,western Nevada and eastern California,U.S.A.
《Applied Geochemistry》1993,8(5):447-471
Ground water is the main source of domestic and public supply in the Carson River Basin. Ground water originates as precipitation primarily in the Sierra Nevada in the western part of Carson and Eagle Valleys, and flows down gradient in the direction of the Carson River through Dayton and Churchill Valleys to a terminal sink in the Carson Desert. Because radionuclides dissolved in ground water can pose a threat to human health, the distribution and sources of several naturally occurring radionuclides that contribute to gross-alpha and gross-beta activities in the study area were investigated. Generally, alpha and beta activities and U concentration increase from the up-gradient to down-gradient hydrographic areas of the Carson River Basin, whereas222Rn concentration decreases. Both226Ra and228Ra concentrations are similar throughout the study area. Alpha and beta activities and U concentration commonly exceed 100 pCi/l in the Carson Desert at the distal end of the flow system. Radon-222 commonly exceeds 2,000 pCi/l in the western part of Carson and Eagle Valleys adjacent to the Sierra Nevada. Radium-226 and228Ra concentrations are <5pCi/l. Four ground water samples were analyzed for210Po and one sample contained a high concentration of 21 pCi/l. Seven samples were analyzed for210Pb; six contained <3pCi/l and one contained 12 pCi/l. Thorium-230 was detected at concentrations of 0.15 and 0.20 pCi/l in two of four samples.Alpha-emitting radionuclides in the ground water originated from the dissolution of U-rich granitic rocks in the Sierra Nevada by CO2, oxygenated water. Dissolution of primary minerals, mainly titanite (sphene) in the granitic rocks, releases U to the water. Dissolved U is probably removed from the water by adsorption on Fe- and Mn-oxide coatings on fracture surfaces and fine-grained sediment, by adsorption on organic matter, and by coprecipitation with Fe and Mn oxides. These coated sediments are transported throughout the basin by fluvial processes. Thus, U is transported as dissolved and adsorbed species. A rise in the water table in the Carson Desert because of irrigation has resulted in the oxidation of U-rich organic matter and dissolution of U-bearing coatings on sediments, producing unusually high U concentration in the ground water.Alpha activity in the ground water is almost entirely from the decay of U dissolved in the water. Beta activity in ground water samples is primarily from the decay of40K dissolved in the water and ingrowth of238U progeny in the sample before analysis. Approximately one-half of the measured beta activity may not be present in ground water in the aquifer, but instead is produced in the sample after collection and before analysis. Potassium-40 is primarily from the dissolution of K-containing minerals, probably K-feldspar and biotite. Radon-222 is primarily from the decay of226Ra in the aquifer materials. Radium in the ground water is thought to be mainly from alpha recoil associated with the decay of Th in the aquifer material. Some Ra may be from dissolution (or desorption) or Ra-rich coatings on sediments. 相似文献
14.
15.
Steven D. Machemer Julia S. Reynolds Leslie S. Laudon Thomas R. Wildeman 《Applied Geochemistry》1993,8(6)
The wetland constructed at the Big Five Tunnel in Idaho Springs, Colorado was designed to remove, passively, heavy metals from acid mine drainage. In optimizing the design of such a wetland, an improved understanding of the chemical processes operating there was required, particularly SO42− reduction and sulfide precipitation. For this purpose, field and laboratory data were collected to study the balance of S in the system. Field data collected included water analyses of the mine drainage and wetland effluents and measurements of H2S gas emissions from the wetland. The concentration of sulfide in the wetland effluent ranged from 10−4 to 10−3 mol/l. The average rates of H2S emission from the surface of the substrate were 150 nmol/cm2/d in the summer and 0.17 and 0.35 nmol/cm2/d in the winter. This maximum estimated loss of sulfide was not significant in reducing the amount of sulfide available for precipitation with metals. Sequential extraction experiments for S on wetland substrates showed that acid volatile sulfides (AVS) increased with time in the wetland substrate. A serum bottle experiment was conducted to study the S balance in the Big Five wetland by quantitatively measuring the amount of S in different phases as microbial SO42− reduction progressed. The increase in AVS reasonably balanced the decrease in SO42− concentration in the experiment, suggesting that the decrease in SO42− concentration represented the amount of SO42− reduced and that nearly all of the sulfide produced was precipitated as AVS. Sulfide precipitation was determined to be the primary metal removal process in the wetland system and amorphous FeS is the primary iron sulfide formed in the substrate. 相似文献
16.
Flourescence spectral analysis indicates that resinite macerals from Tertiary Hanna Formation coals (Hanna Coal Field, southcentral Wyoming, U.S.A.) can be separated into five distinct groups. The first resinite group fluoresces a a medium green (in blue light); its average spectral maximum occurs at or below 440 mm with a red/green quotient of 0.22. The second resinite group fluoresces yellow-green with an average spectral maximum of 500 nm and a red/green quotient of 0.53. The third resinite group displays a yellow fluorescence having an average spectral maximum of 580 nm and a red/green quotient of 0.86. The fourth resinite group fluorescence orange-brown having an average spectral maximum of 610 nm and a red/green quotient of 1.20. These four groups mostly occur as primary globular resinites exhibiting scratches and fractures, indicating that they are brittle, solid substances. Primary cell-filling and secondary fracture-filling resinites also occur in these four groups. The fifth group only occurs as a secondary void-filling material and lacks evidence of br of brittle properties. It fluoresces a reddish-brown, has a spectral maximum at 690 nm, and a red/green quotient of 1.54. The fifth group has properties resembling exsudatinite. The five resinite groups can be separated on the basis of their nine spectral properties alone, without qualitative petrographic interpretation.The relative quantities of the five resinite groups vary among Hanna Formation coals. The origins of these five resinite groups are probably related to their botanical properties and pre- and post-depossitional conditions. Overall, Hanna Formation resinites have petrographic characteristics similar to other North American resinites; however, only four resinite groups have been distinguished in in certain coals from Utah and New Mexico (U.S.A.), and western Canada. 相似文献
17.
18.
David A. Byers 《Geoarchaeology》2002,17(5):417-440
The Fetterman Mammoth locality, eastern Wyoming, U.S.A., produced the remains of a single subadult mammoth and a small lithic assemblage. This paper employs a fine‐grained taphonomic approach to investigate the events responsible for the deposit's creation. No cultural modifications were noted on any of the specimens. Long axis orientations plotted against a reconstruction of the depositional surface suggest limited postdepositional movement of individual disarticulated elements. Weathering patterns based on in situ upside and downside positioning document two discrete episodes of sedimentation. These results suggest that the mammoth remains and the cultural assemblage may be separated by at least one depositional event and, as such, their association is considered equivocal. © 2002 Wiley Periodicals, Inc. 相似文献
19.
《International Journal of Coal Geology》1986,6(2):139-147
Precise measurements of 54 deformed tree trunks within the subbituminous Wyodak coal seem in northeastern Wyoming were made at eight locations in surface mines along the outcrop north and south of Gillette. Theory of elasticity applied to the individual measurements gives ratios of peat thickness to coal thickness which range from 1.7:1 to 31:1 and average 7.1:1. This result is similar to those previously determined by other methods in other locations. Statistical analysis establishes to a high degree of confidence, however, that the ratios for each mine site vary widely and cannot be considered to be constant or to vary uniformly within the study area. 相似文献
20.
《Applied Geochemistry》1988,3(5):423-440
Vertical line-fault behavior is allowed for within a two dimensional basin simulation model. The fault model permits relative movement of the faulted blocks (normal and reverse), and open or closed fluid flow conditions. Simultaneous simulation of a number of vertical line faults, horst and graben is included, making the 2-D model of great flexibility. Application of this model to the Pinedale anticline, Green River Basin, Wyoming, showed that the model can (1) simulate sedimentation processed, including normal sedimentation, erosion and hiatus, (2) simulate structural development, including general structural styles (anticlinal or synclinal), faults, and horst and grabens, and (3) predict the geothermal history and the evolution of geological parameters such as formation temperature, fluid pressure, abnormal pressure and vitrinite reflectance. From these parameters maturation of organic matter is assessed. Finally, (4) the model can quantify oil generation, migration and accumulation through geological time. The model behaviors are shown to be consistent with downhole data taken at the present time. The results can be output as graphs either in one dimension or in two dimensions, providing a pictorial representation of evolution of the Pinedale Anticline. 相似文献