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891.
Nataliya Viktorovna Yurkevich Natalya Aleksandrovna Abrosimova Svetlana Borisovna Bortnikova Yuriy Grigoryevich Karin Olga Petrovna Saeva 《毒物与环境化学》2017,99(9-10):1328-1345
Sulfide-containing mill wastes of the Komsomolsk ore processing plant situated in the Kemerovo region (Russia) were examined in 2013–2015. Multipurpose studies of the mine tailings determined the composition of waste, pore water, mine drainages, and affected groundwater. Electrical resistivity tomography was used to trace the geoelectric zoning of the waste samples. Layers with low resistivity indicated areas with pore spaces filled with highly mineralized solutions with Fe, Cu, Zn, Cd, As, and Sb at total concentrations of up to 50 g/L. Anomalous zones can be specified as ‘geochemical barriers’ – specific layers where the mobility of the elements is reduced due to pH conditions, redox potential, and Fe(III) hydroxide precipitation. The zones of increased conductivity in oxidized mine tailings indicated local areas with high acid production potential and coexisting acidic pore solution. In non-oxidized tailings, high conductivity of the mineral skeleton was observed. There was a migration of drainage outside the tailings, its direction monitored by geophysical data. Chemical analysis confirmed that the concentrations of As in groundwater samples were higher than the maximum permissible concentration. 相似文献
892.
Improvements in Fluvial Stability Associated with Two‐Stage Ditch Construction in Mower County,Minnesota
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Lori Krider Joseph Magner Brad Hansen Bruce Wilson Geoffrie Kramer Joel Peterson John Nieber 《Journal of the American Water Resources Association》2017,53(4):886-902
Water quality and stream habitat in agricultural watersheds are under greater scrutiny as hydrologic pathways are altered to increase crop production. Agricultural drainage ditches function to remove water quickly from farmed landscapes. Conventional ditch designs lack the form and function of natural stream systems and tend to be unstable and provide inadequate habitat. In October of 2009, 1.89 km of a conventional drainage ditch in Mower County, Minnesota, was converted to an alternative system with a two‐stage channel to investigate the improvements in water quality, stability, and habitat. Longitudinal surveys show a 12‐fold increase in the pool‐riffle formation. Cross‐sectional surveys show an average increase in bankfull width of approximately 10% and may be associated to an increased frequency in large storm events. The average increase in bankfull depth was estimated as 18% but is largely influenced by pool formation. Rosgen Stability Analyses show the channel to be highly stable and the banks at a low risk of erosion. The average bankfull recurrence interval was estimated to be approximately 0.30 years. Overall, the two‐stage ditch design demonstrates an increase in fluvial stability, creating a more consistent sediment budget, and increasing the frequency of important instream habitat features, making this best management practice a viable option for addressing issues of erosion, sediment imbalance, and poor habitat in agricultural drainage systems. 相似文献
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Sbastien Denys Guillaume Echevarria Louis Florentin Elisabeth Leclerc Jean-Louis Morel 《Journal of environmental radioactivity》2009,100(10):884-889
Parameters regarding fate of 63Ni in the soil–plant system (soil: solution distribution coefficient, Kd and soil plant concentration ratio, CR) are mostly determined in controlled pot experiments or from simple models involving a limited set of soil parameters. However, as migration of pollutants in soil is strongly linked to the water migration, variation of soil structure in the field and seasonal variation of evapotranspiration will affect these two parameters. The aim of this work was to explore to what extent the downward transfer of 63Ni and its uptake by plants from surface-contaminated undisturbed soil cores under cultivation can be explained by isotopic dilution of this radionuclide in the pool of stable Ni of soils. Undisturbed soil cores (50 cm × 50 cm) were sampled from a brown rendzina (Rendzic Leptosol), a colluvial brown soil (Fluvic Cambisol) and an acidic brown soil (Dystric Cambisol) using PVC lysimeter tubes (three lysimeters sampled per soil type). Each core was equipped with a leachate collector. Cores were placed in a greenhouse and maize (DEA, Pioneer®) was sown. After 44 days, an irrigation was simulated at the core surfaces to supply 10 000 Bq 63NiCl2. Maize was harvested 135 days after 63Ni input and radioactivity determined in both vegetal and water samples. Effective uptake of 63Ni by maize was calculated for leaves and kernels. Water drainage and leaching of 63Ni were monitored over the course of the experiment. Values of Kd in surface soil samples were calculated from measured parameters of isotopic exchange kinetics. Results confirmed that 63Ni was strongly retained at the soil surface. Prediction of the 63Ni downward transfer could not be reliably assessed using the Kd values, since the soil structure, which controls local water fluxes, also affected both water and Ni transport. In terms of 63Ni plant uptake, the effective uptake in undisturbed soil cores is controlled by isotope dilution as previously shown at the pot experiment scale. 相似文献
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Effects of acid and nitrogen depositions on soil microbial activities were studied in a laboratory-based experiment. Five treatments were added to forest soil for five weeks, and soil enzyme activities were determined along with chemical properties. There was little change in pH and nitrogen availability. Dehydrogenase, phosphatase and arylsulphatase activities were decreased by all the acidic treatments compared to the control, while urease activity was increased by the pH 4 treatment. at the same pH treatment, different nitric acid contents induced different urease activities. the results suggest that acid deposition would inhibit microbial activities and that more study is needed to elucidate the impact on nitrogen cycling in forests. 相似文献
896.
Indicators to distinguish between fecal coliforms of human and animal origin were investigated in water from storm sewer outfalls to a coastal lake during wet and dry weather. The ratio of fecal coliform relative to fecal streptococci count was used as the microbiological indicator. Concentrations of human-activities originated caffeine, anionic surfactant, fluoride, and fluorescence whitening agent (FWA) were used as chemical indicators. The ratio of fecal coliform to fecal streptococci ranged from 0.2 to 3.0, during wet weather making it difficult to interpret the origin of fecal pollution. However, concentrations of caffeine, anionic surfactant, fluoride, and FWA in storm water outflow during wet weather were much higher than those in the lake water during dry weather, indicating the presence of human waste at storm water outfall. Strong correlation between fecal coliform counts and chemical parameter values further indicated the human contribution to the fecal coliform count. In addition, a strong correlation among the chemical parameters suggested that only one of them is needed as chemical tracer to detect the presence of human input. 相似文献
897.
矿井水污染控制及资源化 总被引:12,自引:0,他引:12
本文分析了我国煤矿矿井水净化与资源化现状,指出了矿井水资源化的途径和技术,并对提高矿区生活用水质量的措施进行了探讨。 相似文献
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