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1.
用苔藓组织硫含量、S/N比值探讨江西省大气硫沉降   总被引:2,自引:0,他引:2  
本文通过对江西省"r"型酸控区19个采样点88个细叶小羽藓样品进行分析,发现在大气硫浓度高的地区苔藓组织硫含量也高,说明细叶小羽藓可以作为监测植物指示大气硫污染。江西省苔藓组织硫含量从南往北递增,赣东北苔藓组织有着高的硫含量。南昌市和贵溪市市区苔藓组织硫含量和其相应的郊区苔藓组织硫含量有显著性差异(P<0.01),且市区苔藓组织硫含量明显高于郊区苔藓组织硫含量,说明这两个城市市区苔藓受到了点污染源的影响。对细叶小羽藓组织硫含量和大气SO2浓度进行线性回归分析,发现细叶小羽藓的组织硫含量(y)和大气SO2浓度(x)存在显著线性正相关(y=6.09x+0.16,R2=0.95,P=0.003)。用S/N=0.15把江西省采样点分为两组,贵溪市贵溪冶炼厂周围有着高的大气硫沉降量(组Ⅰ),其它采样点均是硫缺乏或者说是氮过量(组Ⅱ)。  相似文献   

2.
Surface snow samples have been analysed for the heavy metals Cd, Cu, Pb and Zn to investigate the spatial scale of local sources of pollution in Antarctica. Samples from around an isolated petrol generator showed vastly increased levels (up to 800,000 times background) directly under the exhaust. Concentrations fell sharply with distance from the exhaust, reaching background levels at 40 m, even in the downwind direction. Snow was also collected at various distances from a manned scientific station. The data are more difficult to interpret, but the influence of the station could not be detected beyond 10 km. These findings indicate the areas that are influenced by local emissions, and that are therefore unsuitable for air and snow sampling intended to study larger-scale pollution input.  相似文献   

3.
沈阳市降雪中PFOS和PFOA污染现状调查   总被引:4,自引:0,他引:4  
通过调查降雪中PFOS和PFOA的浓度,阐明了沈阳市大气中PFOS和PFOA的污染状况和污染规律.2006-02-06采集沈阳市区和郊区共计36个采样点的降雪样品,2006-02-25在其中5个采样点再次采集降雪样品.固相萃取融雪水中的PFOS和PFOA,利用LC-MS-SIM法测定样品中PFOS和PFOA浓度.全部样品中均检出PFOS和PFOA.2006-02-06降雪中PFOS和PFOA的浓度几何平均值分别为2.0 ng·L-1(范围:0.4~46.2 ng·L-1)和3.6 ng·L-1(范围:1.6~22.4 ng·L-1),95%置信区间分别为1.5~2.8 ng·L-1和3.1~4.2 ng·L-1.PFOS和PFOA的最高浓度同时出现在郊区采样点朱尔屯,市中心区2种物质的浓度呈显著正相关.2006-02-25的5个采样点降雪中PFOS和PFOA的浓度几何平均值均为2.2 ng·L-1.2次降雪中PFOS浓度差异不显著,2006-02-25降雪中PFOA浓度高于2006-02-06.结果表明,沈阳市区和郊区降雪中广泛存在PFOS和PFOA污染,局部区域可能存在共同的PFOS和PFOA污染来源;沈阳地区有较稳定的PFOS来源持续向大气中输送该类物质;PFOS和PFOA的环境行为可能不同.  相似文献   

4.
基于光谱分析的生物结皮提取研究——以毛乌素沙地为例   总被引:2,自引:0,他引:2  
利用典型地物高光谱数据和TM遥感影像,对毛乌素沙地处于旺盛生长期(7-9 月)的由苔藓结皮主导的生物结皮进行了提取研究.结果表明:① 苔藓结皮在生长期具有与绿色植物相似的光谱曲线变化趋势;红边参数显示,二者除红边位置非常接近外,红边振幅、红边宽度和红边面积差异均较大;在近红外区域,苔藓结皮比绿色植物的反射率低很多;苔藓结皮无明显的553 nm反射峰;低盖度苔藓结皮(33%)、藻类结皮和植被枯落物在整个波段光谱曲线比较接近,与裸沙相比,三者反射率均较低.② 基于TM影像,用生物结皮指数(BSCI)、归一化植被指数(NDVI)、监督分类和坡度分级相结合的方法提取生物结皮,发现苔藓结皮的像元面积为0.72×104 km2,占研究区总面积的6.43%.  相似文献   

5.
2013年1月8~14日,北京出现了严重的霾污染.霾污染时高浓度的大气颗粒物增加了暴露人群的健康风险,而大气中的微生物也可能带来一些风险,但目前对霾污染时大气中微生物组成了解较少.本研究选取了2013年1月8~14日北京7d的PM2.5和PM10采样样本,通过对细菌16S rRNA基因V3区扩增和Mi Seq测序,得到PM2.5和PM10中的细菌群落结构特征,并将结果与相同采样样本的宏基因组测序结果及三项国外基于16S rRNA基因测序方法的大气中细菌研究结果进行了比较.研究发现7 d连续采样条件下,PM2.5中细菌群落结构在门和属的水平上均差别不大.在属级别上,节杆菌属(Arthrobacter)和弗兰克氏菌属(Frankia)是北京冬季大气中细菌群落的主要类群.16S rRNA基因测序与宏基因组测序结果对比分析发现,在属级别上,两种分析方法中有39个相同的属类群(两种分析方法丰度前50的细菌类群合并所得),弗兰克氏菌属(Frankia)和副球菌属(Paracoccus)在16S rRNA基因测序分析结果中相对含量较多,而考克氏菌属(Kocuria)和地嗜皮菌属(Geodermatophilus)在宏基因组测序结果中相对含量较高.在门和属的水平上,PM2.5和PM10中细菌群落结构特征呈现出相似的规律.在门水平上,放线菌门(Actinobacteria)在PM2.5中的相对百分比较大,而厚壁菌门(Firmicutes)在PM10中的相对百分比较大.在属水平上,梭菌属(Clostridium)在PM10中的相对百分比较大.与三项国外基于16S rRNA基因测序研究结果对比发现,尽管在采样地点和采样时间上有较大差异,大气中普遍存在一些相同的细菌类群,且近地面大气细菌群落结构特征相似度较高,区别于高空对流层中细菌群落结构特征.  相似文献   

6.
Environmental estrogen-like compounds (i.e. xenoestrogens) are a variety of pollutants, ranging from synthetic to natural occurring molecules, that are found in surface and waste waters over a wide range of concentrations. In aquatic environment, the overall estrogenic activity is often due to the presence of a mixture of chemicals and their degraded products which can induce synergistic effects. Current strategies for monitoring estrogen-like chemicals are based on the use of a battery of in vivo and in vitro ecotoxicological tests. In this regard, the aim of the present work was to carry out a bio-monitoring study for testing estrogenicity of the Chienti river (Marche Region, Italy) by using both an E-screen and a vitellogenin (Vtg) induction assay in juvenile goldfish. Three sites were used for analysis, localized at the mouth (sampling point 1), in the middle (sampling point 2) and at the origin (sampling point 3) of Chienti river. For most of the water samples (i.e. samples collected at sampling points 2 and 3), clear estrogenic activity was detected in the E-screen assay suggesting different proliferation activities in function of the collecting site. In contrast, the Vtg ELISA demonstrated that water samples collected from each sampling point were estrogenic. Overall, we showed for the first time that the estrogenic activities in water samples from the Chienti river were significant in both in vivo and in vitro; we also observed a different sensitivity between bioassays.  相似文献   

7.
采用超高效液相色谱-串联质谱仪(HPLC-MS/MS)分析了南京雪水中的13种有机磷酸酯阻燃剂(Organophosphate esters,OPEs),研究了其浓度水平及污染特征,利用主成分分析阐述了OPEs可能的来源,并评估了其健康风险.结果表明,雪水中共检出11种OPEs,11种检出OPEs总浓度水平范围为229.1~1175.0ng/L,平均浓度为746.0ng/L,其中∑11OPEs的最大值区域为商业区和住宅区密集的马群,最小值区域为城郊的化工园区.磷酸三(1,3-二氯-2-丙基)酯(Tris(1,3-dichloropropyl)phosphate,TDCPP)和磷酸三(2-丁氧基乙基)酯(Tris(2-butoxyethyl)phosphate,TBEP)是雪水中主要的OPEs污染单体,两者的贡献率分别为26.6%、20.4%.主成分分析表明雪水中TBEP与磷酸三(2-氯异丙基)酯(Tris(1-chloro-2-propyl)phosphate,TCPP)、磷酸三甲酯(TriMethyl Phosphate,TMP)与磷酸三乙酯(Triethyl phosphate,TEP)两两之间可能存在共同的来源,大气的远距离迁移和干湿沉降可能是雪水中附着OPEs的重要原因.不同人群通过饮水摄入11种OPEs的日均暴露量范围为26.6~39.0ng/(kg·d),通过饮水摄入的OPEs的非致癌风险和致癌风险均低于理论风险值,研究区内雪水中OPEs所致人体健康风险处于较低水平.  相似文献   

8.
Simultaneous aerosol and snow sampling was performed during a field campaign at the Alpine site Weissfluhjoch Davos, Switzerland (2540 m a.s.1.) from 1 January through 30 March 1988. In addition, a snow pit was sampled on 30 March 1988. Very good agreement between the new snow and pit snow samples was found for the measured major ions as well as for the stable isotopes δ18O and δD. Thus, snow pit samples obtained at this site during the winter months yield representative deposition patterns with a conserved stratigraphy. Generally, concentrations in snow were very low, with 3.5, 8.5, 5.2 and 2.4 μeq ℓ−1 for Cl, NO3, SO42−, respectively. The 36Cl and 10Be concentrations as well as the 10Be/36Cl ratios were comparable to the ones measured at Arctic sites. With the exception of NO3, no linear relation was obtained between atmospheric and snow concentrations, showing that the concept of scavenging ratios must be used with caution when looking at single snowfall events. The following precipitation-weighted mean scavenging ratios were found: 300 for NH4+, 350 for SO42−, 940 for total NO3(NO3+HNO3), 175 for 210Pb, and 750 for 10Be.  相似文献   

9.
不同金属矿山选冶活动造成的矿区及周边土壤中重金属的分布累积特征不同.为了解密云水库上游金矿和铁矿矿区土壤中重金属地球化学特征的异同及污染状况,对区域内典型的金矿和铁矿矿区进行土壤样品采集,应用地球化学方法研究了2种土壤中重金属的污染特征,并应用地累积指数法评价了其污染状况.结果表明,2种土壤中除As外的其它重金属含量明显高于北京市土壤重金属背景值,金矿矿区土壤重金属含量普遍高于铁矿矿区.相关性分析表明,金矿矿区土壤中Cu含量与Pb、Zn(p<0.01)及Cr、有机质(OM)含量(p<0.05)之间显著相关,pH值与Pb含量(p<0.01)及Hg含量(p<0.05)呈显著负相关,而铁矿矿区土壤中重金属含量之间的相关性不显著.金矿尾砂中重金属含量明显高于铁矿尾砂,与矿区土壤污染状况一致.地累积指数法评价结果显示,金铁矿区土壤中重金属的污染程度均已十分严重,金矿矿区土壤污染程度高于铁矿,金矿矿区土壤重金属的污染程度由高到低依次为:Pb>Hg>Cd>Cr>Cu>Zn>Co>As;铁矿矿区土壤重金属的污染程度由高到低依次为:Pb>Cd>Cr>Co>Cu>Zn>Hg>As.该研究数据可为同一区域内不同金属矿区重金属污染的有效监控与治理提供科学依据.  相似文献   

10.
The horizontal distribution and levels of heavy metals in the biggest snowstorm in Shenyang since 1904 were investigated by analyzing 4 metals (As,Cd,Pb,and Cu) in a series of ultraclean samples collected from 17 sites distributed in different regions of the Shenyang area,China.The results showed that the concentrations of all the 4 heavy metals in snow from the industrial regions were high,up to 7.3 (As),2.2 (Cd),850.0 (Pb),and 0.197-20.2 (Cu)μg/kg,respectively.In the suburb,in contrast,their concentrat...  相似文献   

11.
王幼奇  白一茹  王建宇 《环境科学》2014,35(7):2714-2720
确定农田土壤重金属分布及其污染状况,对于评价农业生态环境质量、保障食品安全和人类健康都具有重要作用.以宁夏引黄灌区农田土壤为研究对象,在10 m(L尺度)和1 m(M尺度)两种尺度上网格取样,共取耕层土样(0~20 cm)223个,利用经典统计和地统计相结合的方法对土壤铜(Cu)、锌(Zn)、铬(Cr)、镉(Cd)和铅(Pb)的空间变异性进行研究,并利用单因子指数(Pi)和内梅罗综合指数(P综)评价土壤重金属的污染程度.结果表明,两种尺度下,Cu、Zn、Cr、Cd、Pb均属中等变异性,其变异系数(CV)顺序为:Cd>Pb>Cr>Zn>Cu.地统计分析表明,L尺度下Cd和M尺度下Pb块金系数为100%,表现为纯块金效应,主要受随机因素影响,具较弱的空间相关性.其它重金属元素在两种尺度下块金系数均小于25%,说明主要受结构性因素的影响,具有强烈的空间相关性.结合Pi和P综值可知,两种尺度下除了Cu外,其它4种重金属元素出现轻度污染的样点数较多,表明研究区已出现重金属富集的趋势.  相似文献   

12.
积融雪控制下土壤大气间汞交换通量特征   总被引:1,自引:0,他引:1  
张刚  王宁  艾建超  张蕾  杨净  刘子琪 《环境科学》2013,34(2):468-475
位于松花江上游流域的夹皮沟金矿曾是我国采金量最大的矿区,广泛使用的混汞法提金工艺导致了严重的区域环境介质汞污染.为研究稳定性季节积雪及融雪控制过程土壤(雪)大气间汞交换通量特征,选择区域内典型"山-谷"地形结构单元,沿坡面等距进行布点,使用动态通量箱法测定了各采样点土壤(雪)大气间汞交换通量,使用塞曼效应汞分析仪(LUMEX Zeeman RA915+)测定了各采样点近地面(0~150 cm)垂直方向上大气汞浓度分布,分析了同步气象因子、积融雪控制下地表性质和近地面大气汞的垂直分布各因素对土壤(雪)大气间汞交换通量特征的影响.结果表明,冬季积雪和融雪期间,大气中汞均有沿山坡向谷底汇集的趋势,在积雪冷源性下垫面所致逆温层结控制下,汞交换通量表现为明显的由大气向土壤(雪)的沉降过程.融雪期间雪融后地表土壤大气间汞交换通量表现为释放与沉降过程交替,仍然积雪地表大气间汞交换通量沉降水平明显弱于积雪期.分析土壤(雪)大气间汞交换通量与其影响因素间关系发现,积雪期土壤(雪)大气间汞交换通量与大气汞浓度和大气温度间均具有显著的负线性相关关系;融雪期土壤(雪)大气间汞交换通量与大气汞浓度间具有明显的负线性相关关系,与大气温度间具有正线性相关关系;雪融后裸露土壤大气间汞交换通量与地温间呈现一定的正线性相关关系.  相似文献   

13.
In the present article we characterized the emissions at the exhaust of a Common Rail (CR) diesel engine, representative of lightduty class, equipped with a catalyzed diesel particulate filter (CDPF) in controlled environment. The downstream exhausts were directly analyzed (for PM, CO, CO2, O2, HCs, NOx) by infrared and electrochemical sensors, and SEM-EDS microscope; heavy metals were chemically analyzed using mosses and lichens in bags, and glass-fibre filters all exposed at the engine exhausts. The highest particle emission value was in the 7–54 nm size range; the peak concentration rose until one order of magnitude for the highest load and speed. Particle composition was mainly carbonaceous, associated to noticeable amounts of Fe and silica fibres. Moreover, the content of Cu, Fe, Na, Ni and Zn in both moss and lichen, and of Al and Cr in moss, was significantly increased. Glass-fibre filters were significantly enriched in Al, B, Ba, Cu, Fe, Na, and Zn. The role of diesel engines as source of carbonaceous nanoparticles has been confirmed, while further investigations in controlled environment are needed to test the catalytic muffler as a possible source of silica fibres considered very hazardous for human health.  相似文献   

14.
The principal objective of this study was to compare bioaccumulative properties of two terrestrial moss species Hylocomium splendens and Pleurozium schreberi from the Kielce area (south-central Poland), using various statistical techniques. Forty-six moss samples from 23 sampling sites located within the city limits were analyzed for 33 trace elements. The results indicated that 17 elements (Ba, Ce, Co, Cu, Eu, Fe, Gd, Hg, La, Mo, Nd, Ni, Pb, Pr, Sm, V, Y) dominated in H. splendens, whereas only three elements (Mn, Sr, Zn) occurred in excessive amounts in P. schreberi. No differences in the distribution pattern of Dy, Er, Ho, Sn, Tb, Th and Yb were observed. The element concentration ratio (PI/Hy) varied from 0.50 to 1.19. For 14 elements (Ce, Co, Cu, Fe, Gd, Hg, La, Mo, Nd, Ni, Pb, Sm, Th, V), PI/Hy < 1; for 4 elements (Cd, Mn, Sr, Zn), PI/Hy > 1; for 7 elements (Ba, Dy, Er, Eu, Pr, Y, Yb), PI/Hy = equalled 1. Czekanowski’s method showed similarities in rare earth element concentrations for both moss species. The cluster analysis exhibited three significant clusters at D link /D max × 100 < 50 for both moss species. Strong positive Spearman correlations between both moss species were recorded for the following pairs:Ba-Ba, Co-Co, Er-Er, Eu-Eu, Gd Gd, Mn-Mn, Ni-Ni, Pb-Pb, Pr-Pr, Sm-Sm, Th-Th, Y-Y, and Yb-Yb. Nonparametric tests (Sign test, Wilcoxon tests) showed statistically significant differences only for Cd, Ce, Co, Cu, Hg, Mo, Ni, Pb and Sr. The scanning electron microscope study of H. splendens and P. schreberi revealed a different morphology of these species with no injuries.  相似文献   

15.
杭州地区城区降雪中全氟化合物的污染特征   总被引:1,自引:3,他引:1  
通过调查杭州降雪中16种全氟化合物(PFCs)的质量浓度,考察了杭州地区大气中PFCs的污染状况.2016年1月20~22日,在杭州市城区及主要郊县建成区共计11个采样点采集降雪样品,应用固相萃取净化、富集与超高效液相色谱-串联质谱联用相结合的方法,测定样品中PFCs质量浓度.所有采样点降雪均有不同浓度的PFCs检出,全部样品共检出包括C_4和C_8全氟烷基磺酸以及C_4~C_6、C_8和C_9全氟烷基羧酸等7种中短链PFCs.ΣPFCs质量浓度范围为2.85~35.1 ng·L~(-1),其中全氟辛酸(PFOA)质量浓度范围2.15~23.0 ng·L~(-1),为主要污染因子,全氟辛烷磺酸(PFOS)检出浓度较低,为0~0.46 ng·L~(-1).与国内外其它地区相比杭州降雪中PFOA含量居于中等水平,PFOS含量则处于相对较低水平.污染物空间分布城区略高于郊县,其中富阳最高,建德和淳安较低.本次调查,在研究区域降雪中普遍检出以PFOA为主较高浓度的PFCs,表明湿沉降已经成为杭州地区土壤、地表水和地下水等生态系统PFCs污染一个不可忽视的污染源,需要有关部门引起足够的重视.研究结果揭示了杭州地区大气中广泛存在以PFOA为主的PFCs污染,大气因素可能已成为当地人群和生态环境暴露PFCs的重要途径之一.  相似文献   

16.
长江口沉积物重金属的分布、来源及潜在生态风险评价   总被引:15,自引:8,他引:15  
为了解长江口潮滩沉积物中重金属的污染特征,采用电感耦合等离子体发射光谱法(ICP-AES)分析了长江口北支、南支和杭州湾27个表层沉积物中Cu、Pb、Ni、Ag、As、Cd、Zn、Sn、Sb和Hg 10种重金属的含量,并对其分布、来源及生态风险进行了评价.结果表明,沉积物中10种重金属的含量和介于102.9 ~ 326.4 mg· kg-1之间,北支、南支和杭州湾的平均值分别为180.9、244.7和155.6 mg·kg-1.方差分析结果表明,南支与北支、杭州湾平均含量之间均存在显著性差异(p<0.01),南支因受沿岸工业污水和生活污水的影响污染加重.来源分析表明,沉积物中大多数重金属的来源具有一定的相似性,主要来源于各种工农业废水、船舶运输、农药和化肥污染,而Ag和Hg具有不同的来源.地积累指数评价结果表明,10种重金属的平均污染程度由高到低依次为:Cd> Hg> Sb> Ag> As> Cu >Zn> Ni> Sn> Pb,Hg和Cd在多数采样点分别为中度污染和偏重污染,南支Cd和Ag的污染程度高于北支和杭州湾,而在杭州湾Hg的污染程度高于北支和南支.潜在生态风险系数评价结果表明,长江口沉积物7种重金属潜在生态风险系数从高到低依次为:Cd>Hg>As>Cu >Ni>Pb >Zn,长江口沉积物的潜在生态风险主要由Cd和Hg引起,两者的贡献分别为62.6%和34.0%,各采样点7种重金属的潜在生态风险指数(RI)介于565.9~1601之间,均达到极强生态风险.  相似文献   

17.
Monthly bulk and daily wet only samples have been collected at two sites in Sweden and analyzed for trace metals (Cd, Cu, Fe, Mn, Pb, Zn, Cr, Ni and V). Concentrations in the daily samples varied over four orders of magnitude with the most pristine samples (lowest 10th percentile) approaching levels found in Greenland snow. A comparison of deposition estimates from the two data sets indicates that Cd, Fe, Pb, Zn, Cr, Ni and V wet deposition can be reasonably estimated by monthly bulk sampling. Due to contamination from the forest canopy Mn wet deposition is overestimated by the bulk method. For Cu, contamination of the samples occurred in both collectors and indicates that new sampling protocols are needed for accurately determining wet deposition fluxes.  相似文献   

18.
天山东部雪冰中硝酸根浓度对中亚生物质燃烧的响应研究   总被引:3,自引:3,他引:3  
研究了天山东部雪冰中NO3-浓度对中亚哈萨克斯坦生物质燃烧的响应情况.在天山乌鲁木齐河源1号冰川持续采集了52组表层雪与雪坑样本,分析了雪样中NO3-等成分的浓度,运用HYSPLIT模型模拟了空气轨迹,目的是考察雪冰中NO3-与2002年哈萨克斯坦草原大火的关系,探讨由生物质燃烧产生的NO3-在高海拔山岳冰川雪层中的沉...  相似文献   

19.
Surface snow from Windless Bight, Ross Ice Shelf, Antarctica has been analyzed for its Hg content. Ultra-clean techniques were used for field extraction of Hg onto gold-coated sand, followed by photo-acoustic analysis within 24 h. Results yield a mean mercury content of 2.7 pg g−1. However, the true level is probably < 1 pg g−1, as measured amounts decreased throughout the period of sampling, indicating that the first samples were probably contaminated and that later results are likely to be more accurate. Our results suggest that previous studies of Antarctic snow have suffered from major contamination problems. Refinement of techniques should allow historical trends in atmospheric Hg levels to be identified from a snow pit at a suitable remote site.  相似文献   

20.
选取流域两岸富含有色金属矿产资源的乐安河及至鄱阳湖段的典型湿地区域,分别于2012年4月(平水期)、8月(丰水期)、11月(枯水期)等不同时段采集不同样点底泥、表土、上覆水等环境样品,监测分析重金属Cu、Pb、Cd的含量,并借助统计分析方法识别乐安河湿地重金属污染的时空分布特征及其来源.结果表明,乐安河流域各样点的重金属Cu含量最高,且各样点重金属的含量值均表现为Cu>Cd>Pb.以丰水期的重金属污染最严重,平水期次之,枯水期的重金属污染最轻.重金属Cu含量的高值区出现在乐安河上游;而重金属Pb含量的高值区出现在乐安河下游及入湖区域;重金属Cd的高值区出现在乐安河中游.表征重金属Cu污染的主成分贡献率为36.99%,表征重金属Cd的主成分贡献率为30.12%.底泥Cu和上覆水Cu、河滩表土Cu含量具有较强的相关性;底泥Cd和表土Cd的含量也表现出强相关性.以上结果反映出水体、底泥和土壤中的Cu污染或Cd污染的来源具有一致性,主要来源于矿山开采排放的重金属酸性污废水;而其余组分间的相关性则表现不甚明显,反映出不同污染物的来源存在一定的差异性.  相似文献   

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