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91.
巢湖清淤合肥项目区域污染底泥调查研究   总被引:10,自引:0,他引:10  
概述巢湖清淤合肥项目区域污染底泥调查的目的和方法,并对调查结果进行分析。调查研究表明:巢湖污染底泥的分布特征符合湖泊沉积学原理,底泥中污染物浓度的垂直分布特征为:严重污染层〉污染过渡层〉正常湖泥层,巢湖污染底泥清淤是改善水质和恢复湖区生态的重要工程措施。  相似文献   
92.
地下车库汽车废气污染状况调查   总被引:5,自引:0,他引:5  
以上海市静安区两个宾馆的地下车主为研究对象,并以该区某地下会堂为对照,调查了地下车库中废气污染状况,结果表明,废气中CO,Pb浓度明显超标,且与对照无明显差别(P〉0.05),环境小气候,除风速外地下车库与会堂的气温,湿度无显著性差异,结合是地下为受汽车废气污染相当严重,应充分引起重视,为减轻下车库环境污染,须进行合理设计。  相似文献   
93.
柳河新民段沙化状况调查分析与保护对策   总被引:1,自引:0,他引:1  
通过对柳河沙化起因、现状、对流域水环境及生态环境影响的调查分析,有针对性地提出了保护对策和建议。  相似文献   
94.
采用Waters-C18固相萃取柱预处理水样,建立了7种痕量持久性有机污染物的固相萃取-气相色谱-电子捕获(SPE-GC-ECD)分析测试方法。方法的回收率均在82.0%~105.4%的范围内,相对标准偏差(RSD)小于5.5%。采用该方法对湘江长沙段饮用水水源保护区5个监测断面的水样进行分析和调查。研究发现,除饮用水水源保护区下游断面六氯苯和o’,p’-DDT未检出外;其它断面所测的POPs均有检出,且浓度在0.27~2.27 ng/L范围内。针对POPs的污染现状,提出了相应的防治对策。  相似文献   
95.
Sorption of 137Cs, 90Sr, 154Eu and 141Ce by magnetite has been studied at varying pH (4 to 11) in the presence and absence of humic acid. The sorption studies have also been carried out at varying ionic strength (0.01 to 0.2 M NaClO4) and humic acid concentration (2 to 20 mg/L). Percentage sorption of 137Cs and 90Sr was found to be pH dependent, with the sorption increasing with increasing pH of the suspension. At any pH, the percentage sorption of 90Sr was higher than that of 137Cs. The results have been explained in terms of the electrostatic interaction between the positively charged metal ions and the surface charge of the magnetite which becomes increasingly negative with increasing pH. On the other hand, 154Eu and 141Ce were found to be strongly sorbed by the magnetite at all pH values, with the sorption being independent of pH. The strong sorption of trivalent and tetravalent metal ions suggests the role of complexation reactions during sorption, apart from the electrostatic interactions. However, in the case of 141Ce surface precipitation of Ce(III) formed by reduction of Ce(IV) in the presence of magnetite cannot be ruled out. Presence of humic acid (2 mg/L) was found to have negligible effect on sorption of all metal ions.  相似文献   
96.
选择较有代表性的宁波市郊慈镇作为典型,调查分析了铜业乡镇企业对周围农业环境的污染情况。调查结果表明,污染源附近水域水质铜含量为0.009~8.461mg/L,超标率为43.8%,锌为0.02~5.92mg/L,超标率为37.5%。土壤中铜的含量为33.1~326.2mg/kg,超标率为72.2%。粮食中铜含量为2.19~24.20mg/kg,超标率为37.5%。  相似文献   
97.
Many long-lived radionuclides are present in groundwater at the Nevada Test Site (NTS) as a result of 828 underground nuclear weapons tests conducted between 1951 and 1992. In conjunction with a comprehensive geochemical review of radionuclides (3H, 14C, 36Cl, 99Tc and 129I) that are presumably mobile in the subsurface, we synthesized a body of radionuclide activity data measured from groundwater samples collected at 18 monitoring wells, to qualitatively assess their migration at the NTS over distances of hundreds of meters and over timescales of decades. Tritium and 36Cl showed little evidence of retardation, while the transport of 14C may have been retarded by its isotopic exchange with carbonate minerals in the aquifer. Observed local reducing conditions (either natural or test-induced) will impact the mobility of certain redox-sensitive radionuclides (especially 99Tc) that were otherwise soluble and readily transported under oxidizing conditions. Conversely, strongly oxidizing conditions may impact the mobility of 129I which is mobile under reducing conditions. The effect of iodine speciation on its transport deserves further attention. Indication of delayed transport of some “mobile” radionuclides (especially 99Tc) in the groundwater at the NTS suggested the importance of redox conditions of the natural system in controlling the fate and transport of radionuclides, which has implications in the enhanced performance of the potential Yucca Mountain repository, located adjacent to the NTS, to store high-level nuclear wastes as well as management of radionuclide contamination in legacy nuclear operations facilities.  相似文献   
98.
北京城市声环境自动监测系统监测点位布设方法初探   总被引:2,自引:0,他引:2  
噪声自动监测相对手工监测而言,更能真实反映城市声环境质量,随着噪声自动监测技术的不断完善,自动监测替代手工监测已成为必然趋势.但目前我国城市声环境自动监测系统正处于起步阶段,国内还没有对声环境自动监测系统的点位布设提出成熟、合理的方案.文章结合北京市声环境自动监测系统建设的实际工作情况,对监测系统总体框架、自动监测点位布设的原则及方法等进行了阐述并提出近期需要解决的问题.  相似文献   
99.
The benefits of strategic environmental considerations in the process of siting a repository for low- and intermediate-level radioactive waste (LILW) are presented. The benefits have been explored by analyzing differences between the two site selection processes. One is a so-called official site selection process, which is implemented by the Agency for radwaste management (ARAO); the other is an optimization process suggested by experts working in the area of environmental impact assessment (EIA) and land-use (spatial) planning. The criteria on which the comparison of the results of the two site selection processes has been based are spatial organization, environmental impact, safety in terms of potential exposure of the population to radioactivity released from the repository, and feasibility of the repository from the technical, financial/economic and social point of view (the latter relates to consent by the local community for siting the repository). The site selection processes have been compared with the support of the decision expert system named DEX. The results of the comparison indicate that the sites selected by ARAO meet fewer suitability criteria than those identified by applying strategic environmental considerations in the framework of the optimization process. This result stands when taking into account spatial, environmental, safety and technical feasibility points of view. Acceptability of a site by a local community could not have been tested, since the formal site selection process has not yet been concluded; this remains as an uncertain and open point of the comparison.  相似文献   
100.
总结了肇庆市城镇、乡镇和农村饮用水水源地的调查情况,深入分析了影响各水源地水质情况的原因以及产生的影响,并此提出相应的环保建议和改善措施.  相似文献   
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