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811.
安徽省宿州市煤矿周边农田土壤重金属含量及污染评价   总被引:1,自引:0,他引:1  
首先对宿州市朱仙庄矿、芦岭矿、祁南矿和桃园矿以100m、300m和500m为步点进行采样,利用X-Ray荧光光谱仪对Zn、Cr、Cd、Pb、As、Cu等六种重金属元素进行测定。针对多数综合评价研究中存在的信息遗漏和主观问题,采用物元分析法和主成分方法对宿州市煤矿周边农田土壤重金属污染程度进行评价。结果显示:1)在距矿100m处,Cr元素只有在朱仙庄矿属于中度污染,其余三矿均属于严重污染;Cd和As元素都属于轻度污染。距矿区300m处,Cr元素在祁南矿属于严重污染,其余三矿属于中度污染;As元素都属于轻度污染。在距矿500m处,除Cr和As元素外,其余元素大多属于清洁等级。2)对于区域综合关联度,各矿区在100m处均隶属于轻度污染,而在300m和500m处均属于清洁等级。3)在随着距矿距离增大时,土壤污染程度都在下降,即使属于同一等级,隶属度也在减弱。  相似文献   
812.
苏州河水系水动力模型建立及应用   总被引:5,自引:0,他引:5  
应用MIKE11模型系统建立了以苏州河以及其支流为重点的全市感潮河网水动力数学模型。模型在天然河网的基础上,以骨干河道为基础,进行合理的河道和湖泊概化,并将上海市河网水系划分为14个水利片,分片考虑区域降雨径流对河网水量的影响。模型可应用于水系水量调度分析及非点源污染分析,并对对苏州河沿岸泵站雨天溢流进行模拟计算。结果表明,建立的苏州河水系水动力模型可为苏州河整治工程提供科学决策工具。  相似文献   
813.
株洲高新区以长株潭(长沙市、株洲市、湘潭市)两型社会示范建设为契机,规划建设以低碳经济为主体产业的国家生态工业示范园区。株洲高新区在有色金属深加工、先进制造等行业的科研创新体系日趋完善,且产业集群初具规模,已具备了创建国家生态工业示范园区的有利条件。通过国家生态工业示范园区创建工作,将进一步优化区域产业结构,推动产业联动发展。园区建设总体上分为产业循环体系、污染控制体系和保障体系三部分。  相似文献   
814.
为了解红松湿生演替系列过程中土壤生境及土壤细菌多样性的变化规律,以小兴安岭汤旺河国家公园的白桦次生林、人工针阔混交林和原始云冷杉红松林为研究对象,分别代表湿生演替系列的演替先锋群落、演替中期群落和演替顶级群落,采用高通量测序的方法分析森林土壤细菌的多样性变化规律.结果表明:汤旺河国家公园从先锋演替到顶级演替阶段,森林土壤中w(OC)、w(TN)、w(AN)、w(AP)和w(AK)升高,而pH降低.此次分析土壤细菌包括16门27纲52目60科75属,其中Acidobacteria、Proteobacteria、Actinobacteria、Bacteroidetes为共有的优势菌门(相对丰度>1%).演替先锋阶段(白桦次生林)Proteobacteria相对丰度最高,然而演替后期(云冷杉红松林)Acidobacteria相对丰度最高.通过冗余分析和相关性分析发现,不同演替阶段的森林土壤细菌多样性与土壤中w(OC)呈显著负相关,与土壤中w(TK)呈显著负相关,与土壤中w(AK)呈极显著负相关.研究显示,土壤细菌群落结构和多样性在不同湿生演替阶段有明显差异,主要可能受到土壤中w(OC)、w(TK)和w(AK)的影响.   相似文献   
815.
针对铁矿区尾矿回收利用和处理的需求,本文提出在矿区进行生态工业园建设以达到资源、环境、经济可持续发展的观点,并且探讨了铁矿区生态工业园规划建设的具体内容。  相似文献   
816.
Analyzing determinants that influence polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran(PCDD/F) emissions is helpful for decision-makers to find effective and efficient ways to mitigate PCDD/F emissions. The PCDD/F emissions and the contributions of the scale effect, structure effect and technology effect to emissions from eight main industrial sectors in2006, 2008 and 2010 in Shandong Province, were calculated in this article. Total PCDD/F emissions in Shandong increased by 52.8% in 2008(614.1 g I-TEQ) and 49.7% in 2010(601.8 g I-TEQ) based on 2006(401.9 g I-TEQ). According to the decomposition method, the largest influencing factor on PCDD/F emission changes was the composition effect(contributed 43.4%in 2008 and 120.6% in 2010 based on 2006), which was also an emission-increasing factor.In this case, the present industrial restructuring policy should be adjusted to control the proportion of production capacities with high emission factors, such as iron ore sintering and steelmaking and the secondary non-ferrous metal sector. The scale effect increased the emissions in 2008(contributed 21.9%) and decreased the emissions in 2010(contributed-28.0%). However, as a source control measure, the excess capacity control policy indeed had a significant role in emission reduction. The main reason for the technology effect(contributed 34.7% in 2008 and 7.4% in 2010 based on 2006) having an emission-increasing role was the weakness in implementing policies for restricting industries with outdated facilities. Some specific suggestions were proposed on PCDD/F reduction for local administrators at the end.  相似文献   
817.
Increasing habitat fragmentation and human population growth in Africa has resulted in an escalation in human–elephant conflict between small‐scale farmers and free‐ranging African elephants (Loxodonta Africana). In 2012 Kenya Wildlife Service (KWS) implemented the national 10‐year Conservation and Management Strategy for the Elephant in Kenya, which includes an action aimed at testing whether beehive fences can be used to mitigate human–elephant conflict. From 2012 to 2015, we field‐tested the efficacy of beehive fences to protect 10 0.4‐ha farms next to Tsavo East National Park from elephants. We hung a series of beehives every 10 m around the boundary of each farm plot. The hives were linked with strong wire. After an initial pilot test with 2 farms, the remaining 8 of 10 beehive fences also contained 2‐dimensional dummy hives between real beehives to help reduce the cost of the fence. Each trial plot had a neighboring control plot of the same size within the same farm. Of the 131 beehives deployed 88% were occupied at least once during the 3.5‐year trial. Two hundred and fifty‐three elephants, predominantly 20–45 years old entered the community farming area, typically during the crop‐ ripening season. Eighty percent of the elephants that approached the trial farms were kept out of the areas protected by the beehive fences, and elephants that broke a fence were in smaller than average groups. Beehive fences not only kept large groups of elephants from invading the farmland plots but the farmers also benefited socially and financially from the sale of 228 kg of elephant‐friendly honey. As news of the success of the trial spread, a further 12 farmers requested to join the project, bringing the number of beehive fence protected farms to 22 and beehives to 297. This demonstrates positive adoption of beehive fences as a community mitigation tool. Understanding the response of elephants to the beehive fences, the seasonality of crop raiding and fence breaking, and the willingness of the community to engage with the mitigation method will help contribute to future management strategies for this high human–elephant conflict hotspot and other similar areas in Kenya.  相似文献   
818.
Explosions of vessels containing high pressure gases or superheated liquids are a common accident in the chemical industry. Fragments are the most information-rich physical evidence in accident analysis. A method is presented to calculate the total explosion energy based on the characteristics of fragments from the scene of an accident, such as mass, horizontal displacement, etc. The implicit expressions of the initial velocity can be obtained through analysing the trajectory equations of the fragments and the data obtained from the scene of the accident. The total energy is calculated from the relationship between the total explosion energy and the kinetic energy of the fragment. During the calculation there are some uncertain parameters, e.g., the energy factor and the initial angle. To solve the parameter uncertainties, a Monte-Carlo simulation is introduced. Analysis of an industrial accident shows that it is feasible to estimate the total explosion energy using the maximum probability density interval with the proposed methodology.  相似文献   
819.
Due to rapid urbanization and industrialization, heavy metals in road-deposited sediments (RDSs) of parks are emitted into the terrestrial, atmospheric, and water environment, and have a severe impact on residents' and tourists' health. To identify the distribution and characteristic of heavy metals in RDS and to assess the road environmental quality in Chinese parks, samples were collected from Beijing Olympic Park in the present study. The results indicated that particles with small grain size (< 150 μm) were the dominant fraction. The length of dry period was one of the main factors affecting the particle size distribution, as indicated by the variation of size fraction with the increase of dry days. The amount of heavy metal (i.e., Cu, Zn, Pb and Cd) content was the largest in particles with small size (< 150 μm) among all samples. Specifically, the percentage of Cu, Zn, Pb and Cd in these particles was 74.7%, 55.5%, 56.6% and 71.3%, respectively. Heavy metals adsorbed in sediments may mainly be contributed by road traffic emissions. The contamination levels of Pb and Cd were higher than Cu and Zn on the basis of the mean heavy metal contents. Specifically, the geoaccumulation index (Igeo) decreased in the order: Cd > Pb > Cu > Zn. This study analyzed the mobility of heavy metals in sediments using partial sequential extraction with the Tessier procedure. The results revealed that the apparent mobility and potential metal bioavailability of heavy metals in the sediments, based on the exchangeable and carbonate fractions, decreased in the order: Cd > Zn ≈ Pb > Cu.  相似文献   
820.
苏州河非点源污染负荷研究   总被引:20,自引:5,他引:20       下载免费PDF全文
将模拟试验、GIS技术和非点源污染模型相结合,探讨了苏州河流域的非点源污染负荷及时空演变规律.结果表明,研究区域内非点源成为主要的污染源,其中非点源污染负荷CODCr约为6 740 t/a,TN,TP和NH4+-N分别达914,184和298 t/a;水田和村居民点是主要的污染贡献者;非点源污染负荷均表现为梅雨>秋雨>春雨>冬雨明显的季节性规律.   相似文献   
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