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在分析１９６６年—１９８５年间太原盆地发生的１４起震群序列资料的基础上。叙述了这些震群分布区的新构造特征、空间分布特征、震群活动区特征、震群迁移特征、震群的震源深度、震群所反映的现代局部应力场等。 相似文献
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Iron migration forms and variations of its concentrations in water and bottom sediments of the Vygozero Reservoir were studied in period from 1993 to 2014. The decrease in wastewater volume discharged from the pulp and paper mill in the early 1990s caused stabilization of water oxidation regime and accumulation of iron in bottom sediments, from which it returns into the water mass when the environmental conditions change in the seasonal oxygen cycle. 相似文献
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Günther Meinrath Broder Merkel Arvid
degaard‐Jensen Christian Ekberg 《洁净——土壤、空气、水》2004,32(2):154-160
Assessment of the likely outcome of engineered invention strategies in acid mine drainage often involves complex geochemical modelling activities. Geochemical modelling is based on chemical thermodynamic data. In addition sorption models, kinetical reaction rates and transport tools are included into the modelling codes because the interactions between solution components and surfaces, reaction time and transport are considered important features characterising the site‐specific situation. In the determination of both thermodynamic data and sorption coefficients, speciation calculations play an important role. By applying the probabilistic speciation code Ljungskile to some simplified acid mine drainage scenarios, the strong impact of chemical speciation on the complete measurement uncertainty budget of geochemical modelling predictions is shown. The complete measurement uncertainty budget in combination with other metrological concepts like traceability is an essential element of quality assurance for experimental data. The elements of quality assurance are provided by international agreements and normative documents on national and international levels. The following discussion will focus on some metrological issues of sorption data. 相似文献
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Byproduct Formation During the Reduction of TCE by Zero-Valence Iron and Palladized Iron 总被引：4，自引：0，他引：4
Liyuan Liang Nic Korte J.D. Goodlaxson Jay Clausen Quintus Fernando Rosy Muftikian 《Ground Water Monitoring & Remediation》1997,17(1):122-127
Trichloroethene (TCE) was reduced with zero-valence iron and palladized iron in zero-head-space extractors. Progress of the reaction in these batch studies was monitored with purge-and-trap gas chromatography and a flame ionization detector. When a 5 ppm initial concentration of TCF. reacts with zero-valence iron, approximately 140 ppb of vinyl chloride persists for as long as 73 days. The concentration of vinyl chloride (approximately If) ppb) remaining with palladized iron is approximately an order of magnitude less than when zero-valence iron is the reductant. These data suggest that volatile byproducts may be under-represented in oilier published data regarding reduction with zero-valence metals. These results also demonstrate that the reduction of TCE with palladized iron (0.05 percent palladium) is more than an order of magnitude faster than with zero-valence iron. Wilh a 5:1 solution-to-solid ratio the TCE half-life with zero-valence iron is 7.41 hours. but is only 0.59 hours with the palladized iron. 相似文献
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Natural and Anthropogenic Variations of the Concentrations of Iron,Copper, and Zinc in Water Streams of the Republic of Bashkortostan 总被引：1，自引：0，他引：1
The natural and anthropogenic sources of iron, copper, and zinc in water streams in the Republic of Bashkortostan are considered. Statistical analysis of long-term hydrochemical monitoring data was used to establish the spatial year-to-year and annual regularities in metal concentrations in water streams. The acceptability of river water quality for different types of water use was estimated. The exceedance probabilities of metal MAC values in streams were evaluated. 相似文献
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Barry J. Allred 《Ground Water Monitoring & Remediation》2012,32(2):81-95
Agricultural subsurface drainage waters containing nutrients (nitrate/phosphate) and pesticides are discharged into neighboring streams and lakes, frequently producing adverse environmental impacts on local, regional, and national scales. On‐site drainage water filter treatment systems can potentially prevent the release of agricultural contaminants into adjacent waterways. Zero valent iron (ZVI) and sulfur‐modified iron (SMI) are two types of promising filter materials that could be used within these treatment systems. Therefore, water treatment capabilities of three ZVI and three SMI filter materials were evaluated in the laboratory. Laboratory evaluation included saturated falling‐head hydraulic conductivity tests, contaminant removal batch tests, and saturated solute transport column experiments. The three ZVI and the three SMI filter materials, on average, all had a sufficient hydraulic conductivity greater than 1 × 10–3 cm/s. Batch test results showed a phosphate decrease of at least 94% for all tests conducted with the ZVI and SMI. Furthermore, the three SMI filter materials removed at least 86% of the batch test nitrate originally present, while batch tests for one of the ZVI filter materials exhibited an 88% decrease in the pesticide, atrazine. Saturated solute transport column experiments were carried on the best ZVI filter material, or the best SMI filter material, or both together, in order to better evaluate drainage water treatment effectiveness and efficiency. Results from these column tests additionally document the drainage water treatment ability of both ZVI and SMI to remove the phosphate, the ability of SMI to remove nitrate, and the ability of a select ZVI material to remove atrazine. Consequently, these findings support further investigation of ZVI and SMI subsurface drainage water treatment capabilities, particularly in regard to small‐ and large‐scale field tests. 相似文献
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Stefania Bilardi Paolo S. Calabrò Sabine Caré Nicola Moraci Chicgoua Noubactep 《洁净——土壤、空气、水》2013,41(9):835-843
Current knowledge of the basic principles underlying the design of Fe0 beds is weak. The volumetric expansive nature of iron corrosion was identified as the major factor determining the sustainability of Fe0 beds. This work attempts to systematically verify developed concepts. Pumice and sand were admixed to 200 g of Fe0 in column studies (50:50 volumetric proportion). Reference systems containing 100% of each material have been also investigated. The mean grain size of the used materials (in mm) were 0.28 (sand), 0.30 (pumice), and 0.50 (Fe0). The five studied systems were characterized (i) by the time dependent evolution of their hydraulic conductivity (permeability) and (ii) for their efficiency for aqueous removal of CuII, NiII, and ZnII (about 0.3 mM of each). Results showed unequivocally that (i) quantitative contaminant removal was coupled to the presence of Fe0, (ii) additive admixture lengthened the service life of Fe0 beds, and (iii) pumice was the best admixing agent for sustaining permeability while the Fe0/sand column was the most efficient for contaminant removal. The evolution of the permeability was well‐fitted by the approach that the inflowing solution contained dissolved O2. The achieved results are regarded as starting point for a systematic research to optimize/support Fe0 filter design. 相似文献
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Research into torrent erosion has focused on bedload transport dynamics, debris flow propagation during flood events, and fan sedimentation. Studies have frequently been biased towards specific events and have not considered sediment delivery in the catchment as a whole. The aim of this study is to examine spatial variations and process controls on sediment transfer in an upland torrent system (hillslopes, channel and fan). The study site is Iron Crag, a small torrent system (catchment area 2·4 ha) situated in the northern Lake District, UK. Particle size analysis of hillslope sediments trapped during transport suggests sediment calibre is controlled primarily by sediment source. Freeze–thaw and rainfall processes impart a weak but recognizable size sorting signature on the trapped sediments. However, these variations are less significant in determining sediment supply to the basal fan, than those operating in the channel system. Channel sediment movement is strongly influenced by storm events, the type of flow process (debris flow or fluvial flow), the sediment characteristics, and the local channel topography. The importance of the channel–fan coupling is clearly demonstrated in that more than 90 per cent of fan sedimentation is derived from channel sediment sources. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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The rivers across Sanjiang Plain are an important path in transferring total dissolved iron (TDFe) into Okhotsk Sea. Distribution of TDFe in main rivers (Amur River, Ussuri River, and Songhua River) and marshy rivers (Yalv River, Bielahong River, and Naoli River) of Sanjiang Plain from 2005 to 2008 was investigated. TDFe concentrations ranged from 0.05 to 6.40 mg L?1 (mean 0.76 mg L?1) and the TDFe species are in the following order: Colloidal iron > ionic iron > complexed iron. Compared with the main rivers, the marshy rivers showed higher TDFe concentration and dissolved organic carbon concentration (DOC), and lower pH value. TDFe concentrations were influenced by several factors, whereas, the concentration of DOC, , and showed remarkable correlation through Spearman correlation coefficient analysis. The rivers mostly showed high TDFe concentration on May and October when the farm activities frequently occur. After 50 years' cultivation of wetlands, the free iron (Fe2+ and Fe3+) showed distinct decrease from 195 to 88.2t in Naoli River. Land use change had decreased TDFe output in rivers of Sanjiang Plain because of the changed concentration and component of DOC, which had higher affinity and selectivity with iron. 相似文献
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A large amount of lignite‐derived water is created during the process of refining lignite. The concentration of Fe, Mn, phenol, and some other organic pollutants of the lignite‐derived water is above the discharge permit or circulating cooling water reuse standard in China. A laboratory‐scale upflow biological aerated filter (UBAF) was developed to treat this lignite‐derived water. Three kinds of coke powders, as waste products in the coal chemical industry with 0.1–0.4 mm, 0.5–1.0 mm, and 1.0–2.0 mm in diameter, were tested as the UBAF's carrier materials. A comparative study of gas–water ratio for the UBAF is presented. The studies presented in this paper demonstrate that with coke powder diameter of 0.5–1.0 mm and gas/water ratio of 7:1, the UBAF reactor can achieve optimal removal efficiency. After the UBAF treatment, the removal efficiency of Fe, Mn, and phenol was found to be 38.4–62.5%, 56.6–74.3%, and 89.5–94.3%, respectively. The lignite‐derived water can meet the discharge permit to surface water and reuse standard for circulating cooling water after the treatment by UBAF. The coke powder, as a waste material, can be used as a support material for UBAF very well. 相似文献
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经资料整理与实地调研：老挝已发现铁矿床（点）42处。重要矿床为万象省（P．Vientiane）万荣（Vang—viang）铁矿、川圹省（P．Xiangkhouang）富诺安（Phou．Nhouan）铁矿、万象省（P．Vientiane）帕莱（PhaLek）铁矿、甘蒙省（P．Khammouan）班农洛（BanNonglao）铁矿。重要矿床的矿体呈似层状、脉状产出,矿石质量较好,矿床属接触交代矿床、热液矿床。据地层条件、岩浆岩条件、构造条件、铁矿床（点）的分布情况,老挝划分出琅勃拉邦（Louangphabang）、孟佩（MuangPek）、桑怒（Xam—Nua）3个成矿预测区。 相似文献
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Recently, increased industrial and agriculture activities have resulted in toxic metal ions, which has increased public concern about the quality of surface and groundwater. Various types of physical, biological, and chemical approaches have been developed to remove surface and groundwater metal ions contaminants. Among these practices, zero‐valent iron (ZVI) is the most studied reactive material for environmental clean‐up over the last two decade and so. Although ZVI can remove the contaminants even more efficiently than any other reactive materials. However, low reactivity due to its intrinsic passive layer, narrow working pH, and the loss of hydraulic conductivity due to the precipitation of metal hydroxides and metal carbonates limits its wide‐scale application. The aim of this work is to document properties, synthesis, and reaction mechanism of ZVI for the treatment of metal ions from the surface and groundwater in recent 10 years (2008–2018). So far, different modified techniques such as conjugation with support, bimetal alloying, weak magnetic field, and ZVI/oxidant coupling system have been developed to facilitate the use of ZVI in various environmental remediation scenarios. However, some challenges still remain to be addressed. Therefore, development and research in this field are needed to overcome or mitigate these limitations. 相似文献
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The distributions of dissolved and of particulate iron in the Dead Sea during the period which preceeded its overturn and thereafter (1977–1980) are reported. During 1977–1978, the vertical profiles of the iron phases revealed facets of the mixing pattern: the progressive deepening of the pycnocline, restricted mixing within the upper water mass and penetration of surface waters into the deepest layer. The inventories of particulate iron suggest resuspension of bottom sediments in November 1978 and after the overturn the gradual disappearance from the water column of iron sulfides and iron oxy-hydroxides. Fluxes of iron from and to the lake in the undisturbed meromictic Dead Sea have been estimated: it appears that diffusion of divalent iron from bottom sediments was the major source for the standing crop of iron in the lower water mass. Low settling velocities of solid particles in the dense and viscous Dead Sea is one of the causes for the relatively large concentrations of particulate iron. The rate constant for oxidation of divalent iron in Dead Sea sediment interstitial waters is larger by two orders of magnitude than in other natural waters. 相似文献