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1.
Tracing leachates at landfills is usually carried out using either geophysical methods or chemical analyses of groundwater.
There are often problems with fingerprinting pollution sources or clarifying the spreading pattern due to a wide variety of
possibilities giving similar anomalies. The aims of the project were to evaluate the advantages of combining results from
multigeophysical modelling and statistical/chemical modelling in order to identify pollution sources and the spreading pattern
and to test a new technique for chemical fingerprinting. The project was carried out at a landfill in central Sweden using
geophysical measurements and modelling of CVES, GPR and VLF as well as chemical modelling using M3 (multivariate mixing and
mass balance calculations). The results indicate that by combining geophysical modelling and chemical calculations, the possibilities
of fingerprinting the origin of pollution as well as delineating the spreading pattern are significantly increased. 相似文献
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3.
I. Th. Rosenqvist 《Lithos》1970,3(4):327-334
Concretions of vivianite attaining 0.5 g occur in the upper 4 m of the bottom sediments of the Åsrum lake, Vestfold, S. Norway. The vivianite-bearing zone is of lacustrine origin. Vivianite is absent in the underlying lagunal and marine sediments. Electro-chemical and chemical data are given for the interstitial water and the clay.
Solubility product of vivianite is determined. The equilibrium constant is K = 10−40 for the reaction 3 Fe++ + 2 HPO4− + 2 OH− = vivianite. The concretions grew by diffusion from a slightly supersaturated interstitial water phase. The degree of supersaturation is calculated. The stability relations of vivianite and hydroxyl apatite are discussed. 相似文献
4.
An experimental investigation has been carried on the solubility of CO2 in water and 1 M NaCl between 0.3 and 4 MPa, in order to test the validity of the results given by various modelling codes. In addition to experiments with pure fluids, the effect of a range of likely reservoir minerals on CO2–water interactions, including K-feldspar, kaolinite, calcite, Ca-montmorillonite and Na-montmorillonite were also investigated. In addition to measurements of CO2 solubility, the pH of the CO2-saturated suspensions was also measured directly at pressures of up to 1 MPa. The results demonstrate that predictions of CO2 solubility made with PHREEQC and Geochemist’s Workbench agree to within 20% with the experimental value, provided corrections are first made off-line for the fugacity coefficient of CO2, while predictions from standalone models are slightly more accurate. In the presence of mineral suspensions, PHREEQC and Geochemist’s Workbench give good results for calcite and kaolinite but underestimate the pH of montmorillonite-bearing assemblages while slightly overestimating the pH of K-feldspar suspensions. These results are significant because they indicate that CO2-charged fluids reacted with clays may be less acidic than indicated by the models, which will impact predictions of the potential for dissolution of reservoir and cap rock minerals, as well as the potential for leaching of toxic metals. 相似文献
5.
Michael C. Davis Jörgen Rosenqvist Susan L. Brantley 《Geochimica et cosmochimica acta》2011,75(2):401-415
The dissolution-precipitation of quartz controls porosity and permeability in many lithologies and may be the best studied mineral-water reaction. However, the rate of quartz-water reaction is relatively well characterized far from equilibrium but relatively unexplored near equilibrium. We present kinetic data for quartz as equilibrium is approached from undersaturation and more limited data on the approach from supersaturated conditions in 0.1 molal NaCl + NaOH + NaSiO(OH)3 solutions with pH 8.2-9.7 at 398, 423, 448, and 473 K. We employed a potentiometric technique that allows precise determination of solution speciation within 2 kJ mol−1 of equilibrium without the need for to perturb the system through physical sampling and chemical analysis. Slightly higher equilibrium solubilities between 423 and 473 K were found than reported in recent compilations. Apparent activation energies of 29 and 37 kJ mol−1 are inferred for rates of dissolution at two surface sites with different values of connectedness: dissolution at Q1 or Q2 silicon sites, respectively. The dissolution mechanism varies with ΔG such that reactions at both sites control dissolution up until a critical free energy value above which only reactions at Q1 sites are important. When our near-equilibrium dissolution rates are extrapolated far from equilibrium, they agree within propagated uncertainty at 398 K with a recently published model by Bickmore et al. (2008). However, our extrapolated rates become progressively slower than model predictions with increasing temperature. Furthermore, we see no dependence of the postulated Q1 reaction rate on pH, and a poorly-constrained pH dependence of the postulated Q2 rate. Our slow extrapolated rates are presumably related to the increasing contribution of dissolution at Q3 sites far from equilibrium. The use of the potentiometric technique for rate measurement will yield both rate data and insights into the mechanisms of dissolution over a range of chemical affinity. Such measurements are needed to model the evolution of many natural systems quantitatively. 相似文献
6.
The aim was to introduce a new method, the DAZ method (drainage area zonation), to quantify environmental parameters, such as bedrocks, soil type, and land use in drainage areas. The work was carried out within the framework of the Swedish project Liming—mercury. Two important points in the project are that there are quantifiable relationships between the character of the drainage area and the lake and that several limnological and morphometric parameters may have an impact on the Hg content in fish. The DAZ method accounts for the fact that, for example, a certain soil type does not have an even distribution in the whole drainage area. To get a simple yet relevant measure of the influence of, for example, soil type on the lake character, the drainage areas were divided into zones using a special transparent paper placed on the map. The method gives normalized values depending on: (1) distance between the object and the given lake, (2) the main direction of water flow in the drainage area, and (3) the area of the environmental parameter (for example, area of bedrock). In the DAZ method, dot counting is used for determination of area. The dot-counting method has been compared with other methods for area determination (planimeter and square counting). Dot counting is the fastest and the counting of squares the most time consuming. The statistical reliabilities of the dot method and the planimeter method were compared. The planimeter is best for large homogeneous objects. Dot counting, on the other hand, is very well suited for heterogeneous objects. The statistical certainty of area determination depends on size, heterogeneity, and form of the objects, as well as the time dedicated to the determination. A nomogram is also given, which illustrates the relationship between the number of counts, that is, the number of times the transparent dotted paper is put on the map and the dots counted, the error in the area determination, and the statistical reliability. 相似文献
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Rosenqvist J Drossart P Combes M Encrenaz T Lellouch E Bibring JP Erard S Langevin Y Chassefiere E 《Icarus》1992,98(2):254-270
Global Martian atmospheric results derived from the infrared imaging spectrometer ISM flown aboard the Phobos 2 Soviet spacecraft are presented. Over low altitude regions the expected CO mixing ratio of (8 +/- 3) x 10(-4) is measured. Variations of the 2.35-micrometers feature are inconsistent with this value over the Great Martian Volcanoes. If the 2.35-micrometers band is entirely attributable to carbon monoxide, the CO mixing ratio is typically depleted by a factor of 3 over these high altitude areas. Orography should play a major role in the existence of this CO "hole." If, however, these spectral variations at 2.35 micrometers are due to the surface composition, the fraction of the surface covered by the responsible mineral must smoothly decrease as the surface elevation decreases. This phenomenon implies a strong interaction between the surface and the atmosphere for the Great Martian Volcanoes. Diurnal behavior and latitudinal variations of water vapor are globally consistent with Viking measurements. During the Phobos observations, the water vapor amounts over the bright equatorial regions range around 11 pr-micrometers during the day. These amounts are slightly larger than those inferred from 1976 to 1979. The lack of global dust storms during 1988-1989 could explain the enhancement of H2O in the atmosphere. 相似文献
8.
Strid A Jörundsdóttir H Päpke O Svavarsson J Bergman A 《Marine pollution bulletin》2007,54(9):1514-1522
The Greenland shark (Somniosus microcephalus) is a high-trophic fish species present in Arctic waters. The present study aimed to determine concentrations of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs), dioxin-like (DL) PCBs and six non-dioxin-like (NDL) PCBs in muscle and liver from 10 female Greenland sharks collected between 2001 and 2003 from Icelandic waters. The mean total concentrations of PCDDs/Fs were 13 and 530pg/g fat for muscle and liver, respectively, and show enrichment in the liver. Concentrations of DL-non-ortho PCBs were also higher in liver compared to muscle with mean concentrations of 7.8 and 0.36ng/g fat, respectively. No enrichment in the liver was found for DL-mono-ortho- and NDL-PCBs. No correlation was found between the size range studied and total concentrations of the compounds analyzed. Total WHO-TEQs (PCDDs/Fs and DL-PCBs) ranged between 7.1-70 and 54-1500pg/g fat in muscle and liver, respectively. 相似文献
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Almeida-Filho R. Rosenqvist A. Shimabukuro Y.E. dos Santos J.R. 《Geoscience and Remote Sensing Letters, IEEE》2005,2(4):409-412
Japanese Earth Resources Satellite 1 (JERS-1) synthetic aperture radar (SAR) data were evaluated to map areas of deforestation in a Brazilian Amazo/spl circ/nia test-site. The results were compared with information derived from a Landsat TM multitemporal series. Unambiguous detection of deforested areas was observed only when the entire deforestation process (slash, burning, and terrain clearing) had already occurred. This result recommends further investigations on the effectiveness of horizontal polarization SAR data to map deforestation in a consistent basis. The cross-polarized (horizontal-vertical) channel designed to be in the ALOS/PALSAR system is expected to improve the distinction between forested and recently deforested areas. 相似文献
10.
S. Osterman J. Green C. Froning S. B��land E. Burgh K. France S. Penton T. Delker D. Ebbets D. Sahnow J. Bacinski R. Kimble J. Andrews E. Wilkinson J. McPhate O. Siegmund T. Ake A. Aloisi C. Biagetti R. Diaz W. Dixon S. Friedman P. Ghavamian P. Goudfrooij G. Hartig C. Keyes D. Lennon D. Massa S. Niemi C. Oliveira R. Osten C. Proffitt T. Smith D. Soderblom 《Astrophysics and Space Science》2011,335(1):257-265
The Cosmic Origins Spectrograph (COS) was installed in the Hubble Space Telescope in May, 2009 as part of Servicing Mission 4 to provide high sensitivity, medium and low resolution spectroscopy at far- and near-ultraviolet wavelengths (FUV, NUV). COS is the most sensitive FUV/NUV spectrograph flown to date, spanning the wavelength range from 900 Å to 3200 Å with peak effective area approaching 3000 cm2. This paper describes instrument design, the results of the Servicing Mission Orbital Verification (SMOV), and the ongoing performance monitoring program. 相似文献