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991.
Factor analysis applied to a geochemical study of suspended sediments from the Gediz River, western Turkey 总被引:1,自引:0,他引:1
M. Bakaç; 《Environmental geochemistry and health》2000,22(2):93-111
Suspended sediment particles collected from 33 sampling points at a site located close to industrial and geological areas in Gediz river, western Turkey were analysed for 15 elements (Ca, Ti, Mn, Zn, Rb, Sr, Y, Zr, Ba, La, Ce, Ra, U, Th and 40K) by Energy Dispersive X-ray Fluorescence Spectroscopy (XRF), Gamma Spectroscopy (GS), and Collector Chamber Method (CCM). Both varimax and oblimin factor rotations were applied to the data, but varimax rotated factor analysis was used for source identification of suspended sediments. Three factors were extracted from the suspended data, which account for about 70% of the total data variance. These factors are interpreted as economy, mine and radioactivity/mine/agriculture. 相似文献
992.
Geographic information systems (GIS) are increasingly used for integrating data from different sources and substantive areas, including in humanitarian action. The challenges of integration are particularly well illustrated by humanitarian mine action. The informational requirements of mine action are expensive, with socio-economic impact surveys costing over US$1.5 million per country, and are feeding a continuous debate on the merits of considering more factors or 'keeping it simple'. National census offices could, in theory, contribute relevant data, but in practice surveys have rarely overcome institutional obstacles to external data acquisition. A positive exception occurred in Lebanon, where the landmine impact survey had access to agricultural census data. The challenges, costs and benefits of this data integration exercise are analysed in a detailed case study. The benefits are considerable, but so are the costs, particularly the hidden ones. The Lebanon experience prompts some wider reflections. In the humanitarian community, data integration has been fostered not only by the diffusion of GIS technology, but also by institutional changes such as the creation of UN-led Humanitarian Information Centres. There is a question whether the analytic capacity is in step with aggressive data acquisition. Humanitarian action may yet have to build the kind of strong analytic tradition that public health and poverty alleviation have accomplished. 相似文献
993.
Matthias Koschorreck René Frömmichen Peter Herzsprung Jörg Tittel Katrin Wendt-Potthoff 《Water, Air, & Soil Pollution: Focus》2002,2(3):97-109
The addition of straw in combination with Carbokalk, a by-product from the sugar-industry, was successfully used to stimulate microbial alkalinity generation in an acidic mining lake. To get detailed information about functions of straw, anenclosure experiment was carried out. Straw bundles were placedat the sediment surface of an acidic mining lake (ML 111) and thephysiochemical conditions and the microbiology of the sediment-water contact zone were studied. Straw was degraded by anaerobic microorganisms and dissolved organic carbon (DOC) leached from straw bundles. Pigmented flagellates responded to the DOC supply in the water column anda considerable amount of algal carbon was transported to the sediment. Straw addition led to microbial reduction of iron andsulfate in the sediment. Sulfate reduction was observed at a pHof 5.5. The pH, however, was not high enough to precipitate H2S completely. Thus, some H2S diffused into the watercolumn, where it was reoxidized. Straw did not create orstabilize an anoxic water body above the sediment. Microbial sulfate reduction and pyrite formation only took place in the sediment,whereas iron reduction also took place in the straw. Straw, however, altered the flow conditions above the sediment surfaceand prevented complete mixing of the profundal water. Straw didnot serve as a substratum for a reactive biofilm. We conclude that the most important function of straw for mining lake remediation is to be a long-term nutrient source for microbialalkalinity generation in the sediment. 相似文献
994.
煤矿安全评价若干问题的研究与探讨 总被引:1,自引:0,他引:1
笔者结合煤矿安全评价工作的经验,就煤矿安全评价工作若干问题进行研讨,主要内容包括:资料收集及分析处理,法律、法规引用,危险辨识,确定评价范围和划分评价单元,选择评价方法及确定评价深度,提高对策措施针对性,完善风险判别指标体系,正确得出评价结论,规避评价风险等9个方面。通过对煤矿安全评价工作若干问题的研讨和提出的对策,为安全评价机构提高煤矿安全评价水平,促进安全评价工作健康发展,有重要参考价值。 相似文献
995.
将工业废弃物锰矿尾渣与壳聚糖混合制得一种高效吸附斛,并应用扫描电镜、X射线衍射对其结构进行了表征。采用正交表设计试验,分别考察了pH值、吸附时间、温度、复合吸附剂的投加量等4个影响因素对Pb^2+吸附的影响,最佳吸附条件为:pH值为7,吸附时问为40mjn,温度为20℃,复合吸附剂的投加量为0.10g。处理后的水符合国家污水综合排放标准(GB8978.1996)中的一级标准。复合吸附剂对Pb^2+的吸附符合Langmuir和Freundlich吸附等温方程。 相似文献
996.
Niyogi Dev K. Mcknight Diane M. Lewis William M. 《Water, Air, & Soil Pollution: Focus》2002,2(2):329-341
Rates of aspen litter breakdown were measured at 40 sites in streams of the Rocky Mountains of Colorado, U.S.A. The sites encompassed a range of effects of mine drainage, from pristine (no effects) to highly stressed. The pH, concentrations of dissolved zinc, and deposition rates of metal oxides (the three main stresses from mine drainage) were measured in each stream. Rates of litter breakdown were estimated from changes in mass of aspen leaves in litterbags. The biological communities associated with litter breakdown also were evaluated by measuring the biomass of shredding invertebrates in litterbags and the rate of microbial respiration on litter. Of the stresses from mine drainage, concentration of zinc and deposition rate of metal oxides were most closely related (negatively) to rate of litter breakdown. Biomass of shredding invertebrates was also negatively related to concentration of dissolved zinc and deposition of metal oxides. Microbial respiration was negatively related to deposition rate of metal oxides and positively related to concentration of nutrients. Both shredder biomass and microbial respiration were positively related to litter breakdown rate and, together, accounted for 79% of its variation. Recovery of litter breakdown in streams affected by mine drainage requires remediation that limits both dissolved and deposited metals. 相似文献
997.
针对新桥矿通风系统存在的问题,结合矿山当前生产实际,提出并实施了降低风阻和提高风量率等优化改造措施。 相似文献
998.
999.
Lloyd R. Stark Robert P Brooks Frederick M. Williams S. Edward. Stevens Luise K Davis 《Journal of the American Water Resources Association》1994,30(4):639-650
ABSTRACT: Flow rates, pH, iron concentration, and manganese concentration were measured during several storm events at two constructed wetlands receiving mine water. During a substantial rain event, flow rates at both the wetland outlets surpassed flow rates at the wetland inlets, reflecting incident rainfall and differences in wetland area at the two sites. A significant positive correlation existed between local rainfall and outflow rates at the larger wetland, but not between rainfall and inflow rates. During storm events, outlet pH, relative to inlet pH, was slightly elevated at the larger wetland, and depressed at the smaller wetland. However, over the course of one year, rainfall was uncorrelated to outlet pH in the larger wetland. A substantial rain event at the smaller wetland resulted in a temporary elevation in outlet iron concentrations, with treatment efficiency reduced to near zero. However, in the larger wetland, outlet iron concentrations were not significantly affected by storm events. Although rainfall and outlet iron concentration were not significant correlates at the larger wetland, flow rate was positively correlated to outlet iron concentration. A normal manganese treatment efficiency of 50 percent at the smaller wetland was reduced to zero during a heavy rain. 相似文献
1000.
Robert C. Hoehn Dallas R. Sizemore 《Journal of the American Water Resources Association》1977,13(1):153-160
ABSTRACT: A study was conducted to 1) chemically characterize three AMD streams entering Chestnut Creek in southwestern Virginia below the town of Galax, Virginia, and 2) to assess the biological and chemical alterations in the creek. Over a six mile reach, the benthic macroinvertebrate population was reduced to zero, the naturally low alkalinity (~25mg/1) of the stream was reduced to less than 5 mg/1, and the pH was reduced from 7.2 to 6.3. Increased concentration of iron from less than 0.01 mg/I to more than 4.0 mg/1 were accompanied by the deposition of a coating of iron hydroxide up to 0.25 in. thick in the stream bed, a phenomenon most likely responsible for the absence of benethic macroinvertebrates. In situ bioassays with bluegill sunfish and one snail species showed that the creek water, after confluence with all the AMD streams, was not toxic in 192 hours to fish, and snails survived 96 hours before they began to die. The undiluted AMD itself was highly toxic. 相似文献