共查询到19条相似文献，搜索用时 312 毫秒
1.
根据杭州市40个土壤全铅和38个可溶相铅的统计分析,土壤中全铅平均含量为49.6×10-6,可溶相铅平均为21.4×10-6,城区表土的全铅高达76.1×10-6,显著高于全国土壤平均值。分析结果还显示,从农村→远郊→近郊→公路旁,土壤可溶相铅含量逐渐增加,且土壤的可溶相铅含量与深度具明显的负相关关系。表明杭州市土壤受到了不同程度的铅污染,污染程度由农村→远郊→近郊→公路旁→城区有明显的增高趋势。通过对茶园土壤中可溶相铅、残渣态铅及城区表土全铅的同位素组成对比分析发现,从土壤残渣态(代表土壤背景)→土壤可溶相→城区表层土壤全铅206Pb/207Pb比值有明显的降低。208Pb/(206Pb+207Pb)也有类似的变化趋势。将土壤与杭州市的汽车尾气、大气等环境样品进行对比发现,随着土壤受污染程度的增加,铅同位素组成逐渐向汽车尾气铅漂移,表明汽车尾气排放的铅为其主要污染源。 相似文献
2.
通过对西湖茶园的植物和土壤样品进行一系列的调查,以着力寻找茶叶的铅污染源。利用铅同位素技术对西湖茶园的土壤、茶叶和城区的燃煤、大气气溶胶、汽车尾气进行铅同位素示踪研究。研究表明,茶园土壤铅物质的可溶相具同源性和残查态偏于多源性。清洗后的茶叶铅含量显著降低,但其同位素组成不发生明显改变,显示出茶叶中的铅与叶面空气沉降物中的铅同源。不同介质铅同位素对比值平均值呈现表土、大气(气溶胶)、煤的w(206Pb)/w(207Pb)与茶叶趋于相近,汽油低之;表土、大气(气溶胶)、汽油的w(208Pb)/〔w(206Pb)+w(207Pb)〕与茶叶趋于相近,煤略高之。不同区域茶叶铅物质具同源性,与种植的农业地质背景无关。在煤燃烧、气化过程中,Pb进入大气,通过大气沉降或被茶树吸收或附着在茶叶叶面;汽车尾气的排放是茶树铅污染的重要原因之一。 相似文献
3.
成都市城市环境铅同位素地球化学特征 总被引：13，自引：0，他引：13
应用铅同位素示踪原理,对成都市的城市环境包括土壤、大气降尘、主要河流水系表层沉积物的铅同位素地球化学特征进行了研究。土壤的铅同位素组成基本落在燃油铅和燃煤铅的范围,表明燃油铅和燃煤铅是其主要的污染源,交通流量大的城区铅同位素组成与燃油铅接近,郊区则呈现燃煤铅的特征。大气降尘铅同位素组成主要接近燃油铅,部分落在燃油铅与燃煤铅之间,表明大气铅污染主要来自于机动车尾气排放及少量燃煤扬尘。水系表层沉积物的铅同位素组成则主要落在燃煤铅的范围,揭示燃煤铅是其主要污染源。 相似文献
4.
长春市城市土壤铅同位素组成特征及其来源解析 总被引：3，自引：0，他引：3
为查明长春市土壤铅的污染来源,采集了长春市表层(0～20 cm)土壤及城市环境污染端元(燃煤尘、汽车尾气尘,建筑尘)样品,采用X荧光光谱法(XRF)测定土壤Pb含量,用质谱仪测定各样品的铅同位素组成.分析结果表明,长春市表层土壤Pb平均质量分数44.72×10-6,是长春市土壤背景值(19.06×10-6)的2.35倍,已受到一定程度铅污染;长春市土壤铅同位素208Pb/207Pb和206Pb/207Pb比值变化较大,分别为2.249～2.473和1.158～1.213;各污染端元物质铅同位素组成差异较大,能很好区别各端元物质.运用铅同位素示踪技术追踪土壤铅的污染来源结果表明,长春市中心城区土壤铅污染主要来源于以热电二厂为代表的工业燃煤排放和历史汽车尾气残留,而与当前汽车尾气排放关系不大;建筑尘也一定程度上对城市土壤产生了影响. 相似文献
5.
铅同位素示踪在大气降尘重金属污染来源解析中的应用 总被引：1，自引：0，他引：1
为了分析大气降尘中铅的污染来源,解析各污染源对大气降尘铅的相对贡献值,在厦门市不同功能区采集了29个大气降尘样品。用热电质谱仪测定了大气降尘的总铅同位素组成,用ICP-MS测定样品酸可溶相铅同位素组成。结果表明,厦门市大气降尘铅同位素206Pb/207Pb值变化较大,为1.111 9~1.173 8;酸可溶相铅206Pb/207Pb值与福建土壤残渣相206Pb/207Pb值相差较大,表明厦门市大气降尘受人类活动来源铅的影响较大;酸可溶相铅206Pb/207Pb值明显小于总量铅206Pb/207Pb值。铅同位素示踪表明,厦门市大气降尘铅主要来源是燃煤,其次是自然来源和汽车尾气。三元混合模型分析表明,燃煤、自然来源、汽车尾气对厦门市大气降尘总量铅的贡献率分别为48.57%、20.29%、31.14%。 相似文献
6.
贵阳市及邻近地区地表和地下水的化学与Sr同位素组成变化反映了典型喀斯特地区地表/地下水文系统的水-岩反应和城市污染特征:水体中的化学溶解物质主要来源于碳酸盐岩(石灰岩和白云岩)的风化作用和膏岩层的溶解,其次为人为污染物的输入;污染物以K+,Na+,Cl-,SO2-4,NO-3为主,枯水期因大气降水补给小而受人为活动影响较大;丰水期和枯水期地表/地下水的化学组成变化说明地表/地下水交换活跃,地下水环境容易受到人为活动影响。 相似文献
7.
成都市近地表大气尘的矿物学特征及其环境指示意义 总被引：9，自引：0，他引：9
通过对成都市近地表大气尘X射线衍射、电镜扫描分析等研究显示:其主要由石英、长石、伊利石、绿泥石、方解石、石膏等矿物组成;就其形状看有致密的不规则粒状、片状单矿物、不规则粒状聚合体、浑圆形球状飘珠、聚合体放大观察可见片状的粘土矿物和细小的粒状单矿物,偶见藻类;矿物形貌特征及矿物组成空间分布特征的研究显示:球形状飘珠及伊利石、绿泥石、石膏的空间分布特征与工业布局和表层土壤的pH值密切相关,成都市近地表大气尘主要为地表扬尘和工业烟尘的混合物;与土壤的矿物组成比较可见,近地表大气尘重金属污染除土壤贡献外,还有其他污染贡献;石膏在本次研究中平均含量高达8.2%,推测可能成为成都市往年燃煤量大而无明显酸雨现象的原因之一。 相似文献
8.
万龙山矿床是云南都龙锡矿田南段的一个大型锌锡多金属矿床,本次通过矿床地质特征及其同位素方法研究得出：硫化物矿石的硫同位素测试结果显示,δ34S值范围-1.1×10-3~5×10-3,峰值集中在0~2×10-3之间,具有明显的塔式效应,与岩浆熔体硫同位素组成范围较为吻合,与海底喷流沉积型矿床的硫同位素特征有较明显的区别;推测硫源主要为岩浆来源,与老君山期岩浆作用有关,但有明显的幔源硫的参与和一定程度地层硫的混染。铅同位素208Pb/204Pb变化范围为38.472~39.2,207Pb/204Pb变化范围为15.618~15.76,206Pb/204Pb变化范围为18.312~19.156;μ值分布范围为9.51~9.73,平均9.63,介于原地幔（μ=7.80）与地壳（μ=9.81）之间,反映出壳幔混合铅的特征,据此判断矿区岩（矿）石的铅源以上地壳为主要来源,并有部分来自上地幔或下地壳的铅。结合矿床地质特征及硫、铅同位素特征,认为成矿作用主要与燕山晚期的岩浆热液有关,矿床类型为矽卡岩型锌锡多金属矿床。 相似文献
9.
核取证分析中需要实施纳克级（ng）铅的同位素全谱分析,质谱测量中要求铅的电离效率较高（大于10-3）。传统硅胶-磷酸技术多用于微克级（μg）铅分析,电离效率一般为10-4~10-3;尽管后来发展的硅胶-硼酸技术可以得到10-3以上的发射效率,但是由于铅在电离过程中存在离子流反复升高-衰减的过程,导致离子流发射不稳定,质谱测量条件难以掌握。本文改进了传统的硅胶发射剂,建立了一种新型硅胶加载体系——硅胶-高铼酸体系。与硅胶-硼酸技术相比,采用硅胶-高铼酸体系可显著提高铅的发射效率并获得稳定的离子流。对于1 ng铅的同位素质谱全谱测量,204Pb/206Pb、207Pb/206Pb、208Pb/206Pb的相对标准偏差分别为0.4%、0.2%和0.1%,测试精度优于采用其他硅胶技术。通过实验比较了硅胶-高铼酸体系与多种传统硅胶发射剂体系对铅离子流的发射效果,优化了硅胶试剂用量为0.5~3.0 μL,采用“夹心饼干”的涂样顺序,对1~100 ng铅样品的发射效率达到6.0×10-3~4.6×10-2,比传统硅胶-磷酸体系的发射效率（10-4~10-3）高了近10倍,与硅胶-硼酸技术的发射效率相当（10-3~10-2）,但铅离子发射更为稳定。本文建立的硅胶-高铼酸体系在测量精度上可满足核取证研究中铅作为地域指示剂的需求。 相似文献
10.
南京栖霞山铅锌矿区铅同位素示踪 总被引：3，自引：0，他引：3
南京栖霞山铅锌矿已开采50余年,环境问题日益突出。为了了解污染来源和污染传播方式,采集了该地水、土、植物、大气沉降、燃油灰尘、矿石、人血和生物等多种样品进行重金属元素含量和铅同位素示踪分析。结果表明矿区重金属污染严重,且污染随着靠近矿区而逐渐加重,重金属元素Pb、As、Cd、Cu、Zn之间相关性明显,初步反映了污染与矿山有关;同位素分析显示,矿区大气沉降样品、大部分植物样品、部分土壤和部分生物样品铅同位素组成与矿石铅同位素组成相似,证实了污染源为矿山。另外,大气沉降与植物样品铅含量高且它们的铅同位素组成相当,反映了大气沉降是污染传播方式之一。 相似文献
11.
用扫描电镜技术识别广州市大气颗粒物主要种类 总被引：19，自引：2，他引：19
利用扫描电镜技术对大气颗粒物的来源进行识别，采取手动分析与自动分析两种方法，得出的结果在总趋势上相互一致。手动方法和自动方法各有特点。自动分析在细颗粒，特别是含硫颗粒分析方面有优势，而手动分析在形貌观测和确定有机粗颗粒污染状况方面有独到之处。实验结果表明，大气颗粒物的来源是多样的，治理措施也应是综合性的，既要注意工业点源的污染治理和排放控制，如燃煤飞灰，钙质颗粒富铁颗粒等，也要注意面源排放，如土壤扬尘和碳质颗粒，碳质颗粒的来源复杂，可以是工业过程，燃烧过程，机动车尾气，生物质燃，树木自然排放。 相似文献
12.
在济南市城区对大气降尘及不同污染端元样品进行采集,系统分析了大气降尘和污染端元元素含量特征,并对大气降尘空间分布及污染来源进行研究。结果表明:不同污染端元中元素含量差别明显,燃煤尘中As、Cd、F、Pb是汽车尾气尘的3倍以上,是交通尘、冶炼尘、建筑尘等其他端元尘的1.26~2.35倍,对环境影响较大;汽车尾气尘中Cr、Ni、S、Zn含量最高,冶炼尘中Co、Ni、Pb、F含量偏高,而建筑尘中多数元素含量为所有端元尘中最低。与土壤背景值相比,济南市大气降尘中Cr、Cu、Pb、Zn、Cd、F、S富集程度较高,受到不同程度人为污染;相关分析和因子分析结果表明,Cd、Cu、Hg、Pb、As主要来源于企业燃煤,大气降尘中这些元素高含量区与热电厂、冶炼厂、化工厂等燃煤污染源空间分布相一致;F、S可能与汽车尾气排放有关,而As、Cr主源于交通污染,这3种污染源是济南市大气降尘污染的主要来源,对降尘的贡献约占60.42%。研究表明,工业燃煤排放已逐渐代替汽车尾气成为大气降尘中Pb元素的主要来源。 相似文献
13.
Magnetic Influences of Cement Dust on Soil in Industrial Area and Its Environmental Implications 总被引：1，自引：0，他引：1
To monitor environmental implications of cement dust on soil in industrial area, magnetic parameters and mineral compositions were measured by the samples of the cement dust, cement factory dustfall, cement, coal ash, topsoil of green space in the factory and topsoil outside the factory. Results showed that the major magnetic minerals in the samples were magnetite, the magnetic mineral particle size of cement dust, dustfall, cement and coal ash was coarse Multi-Domian (MD) and Pseudo-Single-Domain (PSD). As topsoil of green space in the factory and topsoil outside the factory were polluted by cement dust, their magnetic properties had been obviously changed; the concentration of magnetic minerals elevated and particle size became coarser. The magnetic parameters (χfd,χARM/χ,χARM/SIRM) value can reflect the pollution level of the soil, the lower its value was, the more serious soil was polluted. X-ray diffraction results showed that the mineral compositions of the topsoil of green space in the factory and topsoil outside the factory were quartz and calcite, which were the same as cement dust. Magnetic parameters combination characteristics of topsoil can monitor the soil environmental changes in cement industry area. 相似文献
14.
P. K. Mukhopadhyay G. Lajeunesse A. L. Crandlemire 《International Journal of Coal Geology》1996,32(1-4)
Systematic changes in mineralogy, enrichment and depletion of selected elements, and mineralogical speciation of selected elements in fly ash and bottom ash samples from the Lingan Power Plant were compared to run-of-mine and pulverized feed coal from the Sydney coalfield, Nova Scotia, eastern Canada. The analytical techniques used were an electron microprobe equipped with energy and wavelength X-ray dispersive spectrometers, X-ray diffraction, neutron activation, scanning electron microscopy with energy dispersive X-ray and incident light petrography. Three types of glasses (Fe/O-rich, Fe/Al/Si/O-rich and or Al/Si/O-rich) were identified in the combustion residues; they were formed as a result of the interaction of melted pyrite and clay minerals. Compared to the feed coal, most elements were enriched 10 to20 times in the fly ash. The concentration of the elements in both the fly ash and bottom ash are comparable to coal ash that is generated by the low temperature asher in the laboratory. Some chalcophile elements such as arsenic and lead occurred as a solid solution in pyrite in the feed coal and were concentrated in the float fraction (density: <2.81 g/cm3) of the fly ash with non-crystalline Fe-oxides. X-ray mapping of arsenic in the fly ash and bottom ash indicates that arsenic was evenly distributed as oxide within the Fe/O- and Fe/Al/Si/O-rich glass and crystalline phases in the fly ash, possibly in solid solution. Arsenic is associated with Fe/O and Fe/S crystalline phases in the bottom ash. 相似文献
15.
The Pb concentrations of atmospheric aerosol in the Chukchi Sea of the Arctic vary within the range of 0.167-0.962ng/m^2,with an average of 0.532ng/m^3,These concentration values are 200 times higher than the natural background values of snow samples there.Calculation of the Pb enrichment factor of aerosol indicates that the ocean-and continent-source lead account for 9.23% and 0.01%,respectively,but industrially released Pb accounts for more than 90% of the atmospheric Pb.The Pb isotopic composition of aerosol has revealed that the sources of lead from industrial lead that causes pollution include mainly the western part of North America,East Europe and the former Soviet union.The calculation of the total fallout flux of Pb indicates that the mean value of input flux into the Chukchi Sea is 0.02mgm^-2a^-1,equivalent to that of southern Pacific but slightly lower than that of northern Indian Sea and southern Atlantic.It is evidenced that the Pb input flux into the Chukchi Sea is far lower than that off the Baltic Sea,the North Sea and the Mediterranean Sea. 相似文献
16.
探讨了六盘水市煤岩资源开发过程中产生的废弃物,煤矸石、矿区废水、废气对其环境的危害性,指出其环境治理的紧迫性,应加强综合治理。 相似文献
17.
Using regression model to identify and evaluate heavy metal pollution sources in an open pit coal mine area,Eastern Junggar,China 总被引：1，自引：0，他引：1
Rukeya Sawut Tashpolat Tiyip Abdugheni Abliz Nijat Kasim Ilyas Nurmemet Memet Sawut Nigara Tashpolat Arzune Ablimit 《Environmental Earth Sciences》2017,76(24):822
This study aims at identifying multi-source heavy metal pollution from natural and anthropogenic sources using a regression model, principal component analysis, and five different indices (geo-accumulation index (I geo), the modified degree of contamination, pollution load index (PLI), enrichment factor, and ecological risk factor. Results revealed that: (1) although the average concentrations of soil heavy metals (Cu, Cr, Pb, Hg, As, Zn) were generally low, Hg, As, and Cr concentrations exceeded national standard values by approximately 0.91, 1.84, and 0.91 times with maximum concentrations up to 0.41, 78.6, and 175.2 μg/g, respectively; (2) PLI results showed that the industrial park and Wucaiwan open coal mining area were the most polluted (PLI of 1.98, 1.71). The potential ecological hazards index indicated that the E i r of three heavy metals (Cu, Hg, As) in the soil were relatively high, presenting potential ecological risk factors of 74.89, 16.71, 4.15%, respectively; (3) stepwise regression model and principal component analysis suggest that Cu and Zn were primarily effected by the natural geological condition and atmospheric dust fall. Cr, Hg, Pb are mainly derived from anthropogenic sources, particularly coal mining activities and industrial sources. Results of this research have some significant implications for heavy metal pollution prevention and the sustainable development of the economy and ecology of arid regions in China. 相似文献
18.
The isotopic compositions of S (δ34S) and C (δ13C) were determined for the coal utilized by a power plant and for the fly ash produced as a by-product of the coal combustion in a 220-MW utility boiler. The coal samples analyzed represent different lithologies within a single mine, the coal supplied to the power plant, the pulverized feed coal, and the coal rejected by the pulverizer. The ash was collected at various stages of the ash-collection system in the plant. There is a notable enrichment in 34S from the base to the top of the coal seam in the mine, with much of the variation due to an upwards enrichment in the δ34S values of the pyrite. Variations in δ34S and in the amount of pyritic S in the coal delivered to the plant show that there was a change of source of coal supplied to the plant, between week one and week two of monitoring, supporting a previous study based on metal and sulfide geochemistry for the same plant. The fly ash has a more enriched δ34S than the pulverized coal and, in general, the δ34S is more enriched in fly ashes collected at cooler points in the ash-collection system. This pattern of δ34S suggests an increased isotopic fractionation due to temperature, with the fly ash becoming progressively depleted in 34S and the flue gas S-containing components becoming progressively enriched in 34S with increasing temperatures. Substantially less variation is seen in the C isotopes compared to S isotopes. There is little vertical variation in δ13C in the coal bed, with δ13C becoming slightly heavier towards the top of the coal seam. An 83–93% loss of solid phase C occurs during coal combustion in the transition from coal to ash owing to loss of CO2. Despite the significant difference in total C content only a small enrichment of 0.44–0.67‰ in 13C in the ash relative to the coal is observed, demonstrating that redistribution of C isotopes in the boiler and convective passes prior to the arrival of the fly ash in the ash-collections system is minor. 相似文献
19.
北京、郑州和深圳三城市空气中气溶胶单颗粒特征的扫描电镜分析 总被引：1，自引：0，他引：1
分别采集北京、深圳和郑州3个城市气溶胶样品,使用场发射扫锚电镜-能谱仪观察气溶胶单颗粒的显微形貌和元素组成,并利用图像分析系统对PM2.5的粒径进行了分析。结果表明,城市气溶胶单颗粒类型以矿物颗粒、烟尘和球形颗粒(飞灰和二次粒子)为主。对比3个城市气溶胶中不同颗粒类型数量百分比发现,矿物颗粒数量最多的城市是北京,飞灰和烟尘数量最多的城市是郑州,而规则矿物颗粒数量最多的城市是深圳。3个城市气溶胶单颗粒的数量-粒径分布均呈单峰分布。深圳气溶胶中颗粒物的粒径相对较小,其次为郑州、北京。3个城市气溶胶中颗粒物来源不同程度上都受到交通污染源影响,而燃煤源对北京和郑州气溶胶中颗粒物来源影响仍然不容忽视。 相似文献