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171.
 Mining activity in the Boccheggiano-Fontalcinaldo area (Southern Tuscany) dates back at least to the 16th century AD and lasted up to very recent times. Copper-rich hydrothermal veins, massive pyrite deposits, and their gossans were exploited. Two mine waste dumps (Fontalcinaldo, Fontebona), one flotation tailings impoundment (Gabellino), and one roasting/smelting waste dump (Merse-Ribudelli) in the study area were selected to ascertain the environmental effects of such protracted mining activity. Primary waste mineralogy is mainly characterized by pyrite, gypsum, quartz, carbonates, chlorites, and micas. Secondary oxidation mineralogy includes Fe and Cu sulfates and hydroxy sulfates, Cu carbonates, Fe and Al oxyhydroxides, and other phases [neogenic cassiterite at Fontalcinaldo; probable calkinsite, (Ce,La)2(CO3)3· 4H2O, at Fontebona]. Mine waste samples show extremely variable contents of toxic elements (Cu, Pb, Zn, Bi, Cd, As), with average values in the order of hundreds to thousands of parts per million (except for Bi and Cd). In some samples, the abundance of proper minerals of these metals cannot account for the entire metal load. Conceivably, either solid solution substitutions or adsorption processes contribute to the intake of released metals into newly formed minerals. Release and transport of pollutants was affected to variable degrees by acid-neutralization processes. The highest metal and acid concentrations occur close to the investigated wastes and rapidly decrease moving downstream some hundreds of meters or less, with the partial exception for Mn and Fe. Other than dilution effects, this phenomenon may be ascribed to metal adsorption and precipitation of solid phases. Received: 16 April 1995 · Accepted: 14 December 1995  相似文献   
172.
 About 50 million tonnes/year of waste rock from coal-mining is generated in the limited area of the thickly populated Upper Silesian Coal Basin (USCB) in Poland. There are 380 coal-mining waste dumps, including 76 active dump sites covering over 2,000 ha. About 15-16 million tonnes/year of waste rock is being reused for civil engineering purposes in the same area. This brings about a problem of ground water deterioration by constituents leached from waste rock exposed to atmospheric conditions. The major factors determining the ground water contamination potential from waste rock are chloride salinity, sulfur content and acid generation potential. The concept behind the presented studies was to provide data for correct evaluation and prediction of contaminant release from the waste rock, based on the characterization of coal-mining waste properties, as well as on long-term laboratory, lysimetric and field studies. The results show that coal-mining waste dumps can be a long-term source of ground water contamination, lasting for decades and increasing with time. Ground water down-gradient from the disused 15–30-years-old part of the studied dump displays high and increasing acidification, high TDS, SO4, and the highest, still increasing concentrations of Mn, Fe and Zn. Cost-effective and efficient pollution control measures, similar to the presented design and construction elements of the dump site, can mitigate the negative environmental impacts. Received: 3 July 1997 · Accepted: 9 September 1998  相似文献   
173.
实验研究了含高浓度硫酸废水的一种资源化利用方法─—与废铁屑反应生成化工原料七水硫酸亚铁。给出了酸浓度、反应时间、反应温度、剩余酸等各种因素对产品产量的影响。提供了处理工艺,并且把自制品与分析纯试剂及理论计算值进行了比较,三者基本在同一质量水平上。  相似文献   
174.
经过车花加工后的首饰、表面残留有丁烷橡胶胶质、芳香剂、有机酸等污垢,使首饰表面失去光泽。这些污垢可以用表面活性剂清洗,也可以用溶剂汽油(行话称白电油)清洗。如用白电油清洗,清洗后的白电油颜色发黄,粘度变大,极易造成环境的污染。对清洗废油处理是首饰厂家的棘手问题。现在的处理方式有三种:1)燃烧。会产生较大的浓烟,造成环境污染;2)分馏。由于批量小,分馏器不能常开,分馏的能耗较大;3)粘土处理。能耗低,但粘土脚料难于处理,首饰厂家只能采取交纳治污费和定期把废油送往特种废料处理站烧掉的办法,这增加了废…  相似文献   
175.
大气中粘性效应对三维地形波及其波动阻力的影响   总被引:3,自引:0,他引:3  
采用两层大气模式, 通过引入瑞利摩擦系数来定性描述大气中粘性机制, 讨论了粘性效应对三维简单地形波及其波动阻力的影响。结果表明,无论低层大气为稳定层结还是不稳定层结, 大气中粘性的存在将减弱地形波的强度, 减小其产生的波动阻力  相似文献   
176.
采取多种手段相结合的研究方法,对山东兖州煤田16号煤层的成煤植物进行了详细的研究。研究了16号煤层中的煤核植物群,还通过孢粉分析及分散角质层的研究,对成煤植物群及其在垂向上的演化进行了细致的研究。结合煤岩光片中煤植体的研究,并对照煤系地层大化石所反映的成煤期前后的植物群面貌恢复了16号煤层的成煤植物群。分析并讨论了上述研究方法在反映成煤植物及其演化方面的作用,认为只有通过这种综合研究才可以较准确地反映成煤植物群面貌及其在成煤过程中的变化。  相似文献   
177.
煤岩学随着煤炭工业的发展而发展起来,并被应用于许多科学技术领域。重点评述了煤岩学的应用,并对其发展前景做了初步展望。  相似文献   
178.
A significant criterion in evaluating disposal strategies for high-level nuclear waste is the assessment of the isolation capacity for the most radiotoxic radionuclides, the actinides. Important processes pertinent to potential mobilization from the waste forms, retention in secondary phases and migration of actinides in the geochemical environment of the near field of disposal locations are summarized. Criteria are formulated for assessing engineered barrier performance as a geochemical barrier for actinide long-term retention.  相似文献   
179.
SKB (Svensk Kärnbränslehantering AB) is responsible for all handling, transport and storage of the nuclear wastes outside the Swedish nuclear power stations. According to Swedish law, SKB is responsible for an R&D-programme needed to take care of the radwastes. The programme comprises, among others, a general supportive geo-scientific R&D and the Äspö Hard Rock Laboratory (HRL) for more in-situ specific tasks.

Sweden is geologically located in the Fennoscandian shield which is dominated by gneisses and granitoids of Precambrian age. The Swedish reference repository concept thus considers an excavated vault at ca. 500 m depth in crystalline rocks. In this concept (KBS-3), copper canisters with high level waste will be emplaced in deposition holes from a system of tunnels. Blocks of highly compacted swelling bentonite clay are placed in the holes leaving ample space for the canisters. At the final closure of the repository, the galleries are backfilled with a mixture of sand and bentonite. This repository design aims to make the disposal system as redundant as possible. Although the KBS-3 concept is the reference concept, alternative concepts and/or repository lay-outs are also studied. The main alternative, currently under development at SKB, is disposal in boreholes with depths of 4–5 km. The geoscientific research will to a great extent be guided by the demands posed by the performance and safety assessments, as well as the constuctability issues. Some main functions of the geological barrier are fundamental for the long-term safety of a repository. These are: bedrock mechanical stability, a chemically stable environment as well as a slow and stable groundwater flux. The main time-table for the final disposal of long-lived radioactive waste in Sweden foresees the final selection of the disposal system and site during the beginning of next decade.  相似文献   

180.
本文综合国内外有关资料,简要介绍了高放废物地质处置库水文地质条件研究的内容和技术方法,并与常规水文地质勘察进行了比较。  相似文献   
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