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1.
沙尘暴降尘的化学组份和粒径分布特征   总被引:9,自引:0,他引:9  
对发生在我国西北地区沙尘暴降尘沉积物,采用中子活化法和X射线吸收--沉降法对其中的38种元素和粒径分布特征进行了分析和研究。并分别以地壳元素和本区域土壤背景值为参考,讨论了沙尘暴沉降物的富集因子等问题。  相似文献   

2.
沙尘暴对大气背景值的影响及遥感技术应用研究   总被引:3,自引:0,他引:3  
对近十多年来发生在我国西北地区的较大沙尘暴,及其对甘肃大气背景值的影响、沙尘暴降尘的沉降量、区域分布、化学组份、粒度分布,应用则沙尘暴和沙尘暴的危害等内容,进行了为期二年的调查、取样和研究,回答了沙尘暴研究者所关心的一些问题。  相似文献   

3.
通过在2012年5月-2013年4月1个周期年内,对修复基地和对照点每月大气降尘中铅、镉、砷沉降量的监测,结果表明:修复基地大气降尘中铅、镉、砷含量明显较对照点高,年总沉降量分别是对照点的17.6倍、16.3倍和14.1倍,表明铅冶炼企业对基地大气降尘中铅、镉、砷含量影响显著;大气降尘中铅、镉、砷沉降量受位置和时间影响较大,在相距不到100 m的测点间,沉降量相差1倍以上,冬季主导风明显、地面植被少、二次扬尘大,使处于铅冶炼企业下风向的基地降尘中铅、镉、砷沉降量较大。沉降量时空不均匀与土壤污染不均匀现状一致,也验证了铅冶炼企业是基地大气和土壤重金属污染的主要来源。以降尘缸模拟土壤进行测算,结果表明大气降尘中镉对土壤污染速度最快,风险最大。  相似文献   

4.
酸雨做为一个环境问题在中国只有不到二十年的历史,从有组织的观测至今不超过十五年.与北欧最早的酸雨观测相比,我们晚了三十年;与北美的酸雨研究性观测晚了二十年.1972年联合国人类环境会议上,瑞典政府提出了“跨越国界的大气污染——大气和沉降物中硫对环境的影响”的报告,此后酸性大气沉降物——酸雨(包括干、湿沉降)才引起各国政府的普遍重视,成为当今世界范围内重要的环境问题之一.  相似文献   

5.
3 放射性核素从大气向陆地和水环境迁移3.1 湿沉降和干沉降自然界中的放射性核素分为天然放射性核素和人工放射性核素2种,核试验和核电站泄漏事故向大气中排放的放射性核素主要是后者。放射性沉降对海域、陆地和地表水产生污染,并经历化学反应、形态变化、生物浓缩、沉降吸收或吸附等反应过程后,一部分污染物蓄积在土壤、水系或生物体内[14,15]。天然放射性核素包括地球形成以来原始的放射性核素以及宇宙射线生成的放射性核素,一般存在于海洋、地壳内和地表面,而且会迁移至水环境,与人工放射性核素具有同样复杂的迁移转化行为。核试验和核…  相似文献   

6.
沙尘暴--一种跨区域的大气环境污染物   总被引:1,自引:0,他引:1  
文章对十多年来发生在我国西北地区的较大沙尘暴,沙尘暴尘的沉降量、沉降范围、化学组分、粒径分布、对大气环境降尘背景值的影响等问题进行了调查、分析,综述了这方面的一些研究成果。  相似文献   

7.
以四川农业大学成都校区为监测点,采用大气主动采样法(AA)、大气干表面法(ADS)及大气湿表面法(AWS)3种常用干沉降采集方法做大气磷干沉降通量对比试验。结果表明,3种采样方法获得的大气磷干沉降通量间具有显著的差异性及相关性(P0.05),三者间可以进行换算统一;AA法适用于较短采样周期的连续性监测研究,ADS法适用于较长采样周期(5 d)的监测研究,而AWS法更适用于在长采样周期(月)内选取一段时间作为干沉降监测的研究。  相似文献   

8.
太湖氮磷大气干湿沉降时空特征   总被引:6,自引:0,他引:6  
为了探索太湖氮磷营养盐干湿沉降特征及对太湖营养盐输入的贡献,于2011年不同季节采集太湖不同位点的大气干湿沉降样品,分析干湿沉降中氮(N)和磷(P)的形态和沉降量。研究结果表明,输入太湖的磷以干沉降为主,而氮以湿沉降为主。在太湖干沉降中总无机氮(TIN)占总氮(TN)的77.1%,溶解性磷(DIP)占总磷(TP)的77.9%。干沉降中TIN主要以NH+4-N为主。西太湖是TN与TP通过大气干湿沉降输入太湖的最高湖区。太湖全年大气TN沉降总量为20 978 t,TP沉降总量为1 268 t,因此,氮磷大气干湿沉降是太湖营养盐输入的重要来源之一。  相似文献   

9.
为初步了解兰州市大气降尘中有机物的污染特征,采集了兰州市的大气降尘样品,分析了其中的16种多环芳烃和16种多氯联苯。结果表明,兰州市大气降尘中16种多环芳烃的总量为28.9 mg/kg,主要浓度组分为苊、苊烯、茚并[1,2,3-CD]芘和苯并[a]芘;16种多氯联苯的总量为172μg/kg,主要组分为PCB_(169)和PCB_(138)。生态风险评价的结果表明,兰州市22.2%的大气降尘样品多环芳烃总量处于低风险,66.7%的样品处于中等风险,多氯联苯总量以中等风险和高风险为主。  相似文献   

10.
IC法分析大气颗粒物水溶性离子的国内外研究进展   总被引:2,自引:1,他引:2  
结合近十多年来国内外在大气颗粒物水溶性离子分析应用方面的研究状况,分别对大气颗粒物中水溶性离子基本特征、分布状况;离子色谱法对大气颗粒物水溶性阴、阳离子的分析方法;大气颗粒物水溶性离子与主要大气污染物和降水化学组成之间的关系;大气颗粒物中水溶性离子与大气降水化学组成之间的关系;大气降尘和沙尘暴尘(沙尘气溶胶)中的水溶性离子等有关的研究内容作了综述和展望.  相似文献   

11.
针对在新疆特殊干旱气候条件下PM10仪器多年来运行中暴露出的问题,研究和探讨PM10自动监测仪在干旱、风沙多发地区数据的适应性和准确性,提出仪器软硬件方面的改进措施以及减少测量误差的方法,为今后研究干旱区城市沙尘污染变化和改进国产自动监测仪器对干旱风沙区的适应性等提供一些参考。  相似文献   

12.
滨海新区在大力发展工业的同时,面临水资源紧缺与水环境恶化等问题,基于2020年至2021年滨海新区内15个监测站位的丰水期、枯水期实测数据,通过改进型加拿大水质指数模型对滨海新区地表水进行水质评价,在水质评价的基础上,利用相关性分析与绝对主成分-多元线性回归模型分析影响地表水水质状况的污染源。15个水质监测站位水质评价结果表明:丰水期水质指数为32.27~82.80,良好水质站位1个,中等水质站位6个,较差水质站位7个,差等水质站位1个;枯水期水质指数为47.28~81.36,良好水质站位1个,中等水质站位12个,较差水质站位2个。污染源分析结果表明:丰水期中,污染源为生活污水、农业面源污染、养殖尾水点源污染;枯水期中,主要污染源为工业废水、生活污水、养殖尾水面源污染。  相似文献   

13.
本研究利用大气超级站对乌鲁木齐市4月9日至10日沙尘天气过程,粒径谱、离子和重金属组成及变化进行分析。研究结果表明激光雷达观测结果与环境空气质量监测基本一致;小粒径颗粒在沙尘和非沙尘时段含量最多,但在沙尘时段大粒径颗粒的增长幅度远大于小粒径;沙尘过程中的离子主要来源于土壤一次源;沙尘过程中地壳元素浓度及占比均显著升高,会稀释环境空气中人为污染元素。  相似文献   

14.
Al, Cd, Cr, Cu, Fe, Mn, Pb, Zn, NH4+, Mg2+, Ca2+, Na+, K+, Cl-, NO3- and SO4(2-), along with pH were determined in wet and dry deposition samples collected at Al-Hashimya, Jordan. Mean trace metal concentrations were similar or less than those reported for other urban regions worldwide, while concentrations of Ca2+ and SO4(2-) were the highest. The high Ca2+ concentrations were attributed to the calcareous nature of the local soil and to the influence of the Saharan dust, while the high concentrations of SO4(2-) were attributed to the influence of anthropogenic sources and Saharan dust soil. Except for SO4(2-), NO3-, and Ca2+, dry deposition fluxes of measured metals and ions were higher than their corresponding wet deposition fluxes. The high annual average pH values recorded for wet and dry deposition samples were attributed to the neutralization of acidity by alkaline species. Cd, Cr, Cu, Pb, Zn, NO3- and SO4(2-) were enriched in wet and dry deposition samples relative to crustal material, and a significant anthropogenic contribution to these elements and ions is tentatively suggested. Finally, the possible sources and the main factors affecting the concentrations of the measured species are discussed.  相似文献   

15.
2009年—2010年,研究了刘家峡水库的藻类群落特征。共鉴定出8门11纲 16目33科55 属114种藻。丰水期优势类群是金藻门(占27%),次优势类群是硅藻门(21.5%);枯水期优势类群是硅藻门,占总数34%(羽纹纲占33%),次优势类群是金藻门(18%)。对刘家峡水库水质初步评价结果显示:水库上游水质较清洁(1#—2#站点),中下游为轻度—偏中度污染(3#—4#站点),下游为中度—偏重度污染(5#—6#站点)。对藻类群落特征与6项水环境因子的Pearsong相关性分析表明,枯水期影响藻类群落特征的环境因子依次是DO﹥TN﹥pH值﹥T﹥Mcb(粪大肠杆菌);丰水期则是DO﹥Mcb﹥pH值﹥TN。  相似文献   

16.
Alumina used in the production of primary aluminium contains Be which partly vaporises from the cryolite bath into the workroom atmosphere. Since Be may be toxic at lower exposure levels than previously thought, the personal exposure to Be among workers in 7 Norwegian primary smelters has been assessed. In total, 480 personal Respicon? virtual impactor full shift air samples have been collected during 2 sampling campaigns and analysed for water soluble Be, Al and Na using inductively coupled plasma optical emission spectrometry. In addition, water soluble F(-) has been measured by ion chromatography. The Be air concentrations in the inhalable, thoracic and respirable aerosol fractions have been calculated. The Be concentrations in the inhalable aerosol fraction vary between the different smelters. The highest GM concentration of Be in the inhalable fraction (122 ng m(-3), n = 30) was measured in the prebake pot room of a smelter using predominantly Jamaican alumina where also the highest individual air concentration of 270 ng m(-3) of Be was identified. The relative distribution of Be in the different aerosol fractions was fairly constant with the mean Be amount for the two sampling campaigns between 44-49% in the thoracic fraction expressed as % of the inhalable amount. Linear regression analysis shows a high correlation between water soluble Be, Al, F and Na describing an average measured chemical bulk composition of the water soluble thoracic fraction as Na(5.7)Al(3.1)F(18). Be is likely to be present as traces in this particulate matter by replacing Al atoms in the condensed fluorides and/or as a major element in a nanoparticle sized fluoride. Thus, the major amount of Be present in the work room atmosphere of Al smelter pot rooms will predominantly be present in combination with substantial amounts of water soluble Al, F and Na.  相似文献   

17.
Urban areas of different land uses can be distinguished by their specific patterns of atmospheric dust and trace element precipitation. Dusts emitted from industrial areas with fossil fuel processing, for instance, are enriched in V, Ni and Co. Cluster analysis groups sampling sites based on their specific element patterns. The resulting groups correspond to the surrounding land use: Urban sampling sites were identified showing similar patterns of dust and trace element precipitation as a reference site; dusts of other urban sites were influenced by diffuse pollution (caused by non-point and dispersed pollution sources), or by specific industrial emissions. Cluster analysis was also used to characterize the chemical dust composition. Three clusters of typical element associations were distinguished. These clusters represent the dust matrix, diffuse urban pollution and pollution due to fossil fuel processing. Dust precipitation and chemical dust composition show seasonal variations. Dust precipitation and concentrations of trace elements in the precipitated dust are negatively correlated during the annual courses. The highest concentrations of trace elements occur during winter, whereas the highest precipitations of dust were found during summer. This finding stresses that both, precipitation and concentration have to be addressed for the environmental assessment of urban dusts.  相似文献   

18.
Metallic pollution caused by elements Zn, Cu, Fe, Pb, Ni, Cd, and Hg in water and sediments of Aras River within a specific area in Ardabil province of Iran is considered. Water and sediment samples were collected seasonally and once respectively from the five selected stations. Regarding WHO published permissible values, only Ni concentration in spring and summer water samples has exceeded the acceptable limit up to four times greater than the limit. The concentration of metals Ni, Pb, and Fe in river water shows a direct relationship with river water discharge and the amount of precipitation. Enhanced soil erosion, bed load dissolution, and runoffs may play a key role in remarkable augmentation of metallic ions concentration. Furthermore, excessive use of pesticides which contain a variety of metallic ions (mainly Cu) in spring and summer may also result in an increase in the metals’ concentration. The potential risk of Ni exposure to the water environment of the study area is assigned to juice, dairy products, edible oil, and sugar cane factories as well as soybean crop lands which are located within the sub-basin of Aras River in the study area. Regarding the sediment samples, the bioavailable metal concentrations indicate an ascending order from the first station towards the last one. In comparison with earth crust, sedimental and igneous rocks the reported metallic concentration values, except for Cd, lie within the low-risk status. Regarding Cd, the reported values in some stations (S2, S4, and S5) are up to ten times greater than that of shale which may be considered as a remarkable risk potential. The industrial and municipal wastewater generated by Parsabad moqan industrial complex and residential areas, in addition to the discharges of animal husbandry centers, may be addressed as the key factors in the sharp increase of metallic pollution potential in stations 4 and 5.  相似文献   

19.
对石河子市空气环境质量状况进行了评价,对影响石河子市环境质量的主要因素进行了分析,得出石河子市空气污染属煤烟沙尘型,提出了相应的治理措施和建议。  相似文献   

20.
This paper presents simulations of climate change impacts on water quality in the upstream portion of the Cau River Basin in the North of Vietnam. The integrated modeling system GIBSI was used to simulate hydrological processes, pollutant and sediment wash-off in the river basin, and pollutant transport and transformation in the river network. Three projections for climate change based on emission scenarios B1, B2, and A2 of IPCC Special Report on Emission Scenarios (SRES) were considered. By assuming that the input pollution sources and watershed configuration were constant, based on 2008 data, water quality in the river network was simulated up to the terminal year 2050. For each climate change scenario, patterns of precipitation in wet and dry year were considered. The change in annual and monthly trends for dissolved oxygen (DO), biochemical oxygen demand (BOD), and ammonium ions (NH4+) load and concentration for different portions of the watershed have been analyzed. The results of these simulations show that climate change has more impact on changing the seasonal water quality parameters than on altering the average annual load of the pollutants. The percent change and change pattern in water quality parameters are different for wet and dry year, and the changes in wet year are smaller than those in dry year.  相似文献   

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