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Thirty four elements dissolved in water and 33 elements bound in particulate matter were analysed in the small river Saale (Thuringia, Germany, MQ=23 m3/s) in 1996 and the results were compared with those obtained in 1950 (44 elements). Monthly sampling was used to eliminate fluctuations caused by seasons and weather. Comparison of the element contents of a river over a 40-year-time span provides interesting insight into the anthropogenic change in the catchment area of the river with regard to „global change”.Without taking into consideration systematic errors, the analysed elements can be divided into three groups:
- (a) Elements whose average annual analytical values in 1996 were lower by >50% than those in 1950: Al, As, Ba, Fe, Pb, Zn (in solution), and As, B, Cr, Li, Mn, Pb, Se, Sn, U (suspended).
- (b) Elements whose average annual analytical values in 1996 are in the range of those in 1950, i.e., are within 50–150%: Ca, Co, Cr, F, K, Li, Mn, Na, Si, Sr, Ti, U (in solution), and Hg, Cr, Cu, Sc, Sr, Ti, Zn (suspended).
- (c) Elements whose average annual analytical values in 1996 were higher by >150% than those in 1950: B, Cd, Mg, Ni, Rb, Sc (in solution), and Ba, Ni, P, Zr (suspended).
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G. Proft 《洁净——土壤、空气、水》1983,11(6):631-636
The method after Strickland and Parsons is modified for fresh water as follows: filtration on glass-fibre paper, oxidation with K2Cr2O7 in cone. H2SO4 for 2 h at 130 °C, dilution to 2.5 times the volume by aqua dest., centrifuging-off of the turbidity and extinction measurement at 445 nm against the blank value, the sample solution being balanced to the transmission of 100% (extinction = 0). Here, the following calibration line holds for the concentration C and the quantity of oxidation solution Ox: C = E1cmc · 0.162 · Ox, C in mg filter. The oxidation solution contains 4.8 g K2Cr2O7 as dissolved in 20 ml aqua dest. and made up with conc. H2SO4 to 11. With 5 ml of this solution one is able to determine 0.05 … 1 mg C/filter. Calibration is performed with 125 mg/l glucose solution. Comparative investigations have shown a good agreement with elementary-analytically obtained measured values. The occurring errors have been determined mainly by sampling. In the range of very small values we have to take into account a blank value of the filter due to the adsorption of dissolved organic substances on the filter. 相似文献
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Vadym Aizinger Jennifer Proft Clint Dawson Dharhas Pothina Solomon Negusse 《Ocean Dynamics》2013,63(1):89-113
In this work, we present results of a numerical study of Corpus Christi Bay, Texas and surrounding regions and compare simulated model results to recorded data. The validation data for the year 2000 include the water elevation, velocity, and salinity at selected locations. The baroclinic computations were performed using the University of Texas Bays and Estuaries 3D (UTBEST3D) simulator based on a discontinuous Galerkin finite element method for unstructured prismatic meshes. We also detail some recent advances in the modeling capabilities of UTBEST3D, such as a novel turbulence scheme and the support for local vertical discretization on parts of the computational domain. All runs were conducted on parallel clusters; an evaluation of parallel performance of UTBEST3D is included. 相似文献
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G. Proft 《洁净——土壤、空气、水》1998,26(6):355-361
Carbon Turnover by Respiration in the River Ilm (Thuringia, Germany) In the river Ilm, the organic carbon content of water and sediments was analyzed inclusively the C turnover by CO2-respiration with IR-measurement. A comparison of the unpolluted rhithral (headwater) with the polluted epipotamal (lower course) gives downstream an increase of DOC and CO2-respiration of 50...100 mg/(m3 · h) C. In the headwater region, the respiration of the sediments is dominant, in the underflow the respiration of the water. Permeable sand and gravel beds are important for the degradation of the organic load. The sediments of the river are covered with a biofilm of 1...2 g/m2 Corg. A turnover of the Corg. content from 20...400 days is calculated by the respiration measurements. 相似文献
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G. Proft 《洁净——土壤、空气、水》1994,22(4):177-184
The BSi content has been investigated in the surface sediments of lakes of different trophic state in the Mecklenburgian Lake District. The BSi content differs between 1 to 1000 mg BSi/g dry matter. High values were found in deep eutrophic lakes. Litoral sediments and shallow eutrophic lakes have lower contents. BSi content was found to be correlated with lake morphometry, depth, trophic level, sediment composition and especially with calcite. With the CaCO3/BSi-value, 3 groups of lakes can be characterized:
- CaCO3/BSi = 0 oligotrophic and dystrophic lakes
- CaCO3/BSi ≤ 10 mesotrophic and eutrophic deep lakes
- CaCO3/BSi ≤ 10 eutrophic shallow lakes
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