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1.
2016年武汉市大气污染物时空分布特征及影响因素   总被引:1,自引:0,他引:1  
利用统计学和GIS方法对2016年武汉市各区不同污染物的时空分布特征及相关性进行分析。结果表明:武汉市大气污染季节性特征明显,春季和冬季颗粒物(PM2.5、PM10)及NO2污染突出,夏季O3污染严重。污染物空间差异显著,主城区和东西湖区颗粒物及NO2污染严重,郊区O3污染严重。平均气温、平均水汽压与SO2、NO2、CO、PM2.5和PM10均呈显著负相关,而与O3呈显著正相关;降水量与SO2、NO2和CO呈显著负相关。  相似文献   

2.
选取南京市2017年PM2.5逐时观测数据,分析其颗粒物污染特征,并利用聚类分析、潜在源贡献因子法和GDAS气象数据,分析不同高度、季节下南京市主要气流输送路径及PM2.5污染的主要潜在源区。结果表明:南京市PM2.5污染冬季最严重,夏季最轻,逐时PM2.5浓度变化范围夏季小于冬季;夏季气流轨迹主要来自东南方向,秋冬春等季节以偏西和西北路径为主,且随着高度的增加,气流输送速度逐渐加快;冬季对南京市PM2.5污染的贡献最为显著,低层PM2.5污染贡献源区主要集中在近地区域,且贡献率较高,随着高度的增加,贡献源区由研究区域向四周辐散,贡献范围广,贡献率降低。  相似文献   

3.
基于环境空气质量监测数据和气象观测数据,分析2015年2月5日—14日广西典型空气重污染过程及形成原因。结果表明:重污染期间PM2.5平均质量浓度为118 μg/m3,超标0.57倍,日均质量浓度超标率为92.1%;与2014年1月重污染过程相比,此次污染过程持续时间减短、极端污染天气有所缓解、PM2.5为首要污染物的比例增大。气象条件和气流后向轨迹分析表明,大气层结稳定、近地层逆温明显、风速小、相对湿度大等静稳天气是此次污染过程形成的重要原因,广西本地排放污染物及区域污染传输相叠加是造成重污染的根本原因。  相似文献   

4.
天津市PM10和PM2.5中水溶性离子化学特征及来源分析   总被引:8,自引:3,他引:5  
2011年5月—2012年1月在天津市南开区设立采样点,采集大气中PM10和PM2.5样品。采用离子色谱法测定颗粒物中水溶性无机阴离子、阳离子成分,分析其主要组成、季节变化及污染来源。结果表明,天津市PM10中离子平均浓度为71.2μg/m3,占PM10质量浓度的33.7%。PM2.5中离子平均浓度为54.8μg/m3,占PM2.5质量浓度的39.6%。NH+4、SO2-4、NO-3等二次离子含量较大,且夏季含量均为最高。颗粒物总体呈酸性,PM10中∑阳离子/∑阴离子平均值为0.92,PM2.5中该比值为0.75。来源分析发现,PM10可能主要来源于海盐、工业源、二次反应及土壤和建筑尘等,PM2.5则主要来源于海盐污染源、二次反应及生物质燃烧。  相似文献   

5.
2014年4月,应用热/光碳分析仪测定合肥市春季大气PM10和PM2.5中的有机碳(OC)、元素碳(EC)。结果显示,PM10、PM2.5的平均质量浓度分别为(124.0±34.3)μg/m3和(96.3±29.2) μg/m3,PM10中OC、EC的平均质量浓度分别为(15.1±5.5)μg/m3和(6.0±2.1) μg/m3,PM2.5中OC、EC的平均质量浓度分别为(12.1±3.5)μg/m3和(5.5±2.1) μg/m3。OC、EC在PM2.5中所占的比例均高于在PM10中的比例,说明合肥市春季PM2.5中碳的含量更高。通过分析8个碳组分及OC/EC比值,发现燃煤、机动车尾气和生物质燃烧是主要贡献源; OC易形成二次污染,EC排放以焦炭为主。  相似文献   

6.
利用2014年7月和2015年1月在淮南市不同功能区采集的大气颗粒物样品,分析其水溶性离子时空和粒径分布特征。结果表明:夏季和冬季粗、细粒子中总水溶性离子质量浓度均值分别为(13.45±4.53)μg/m3、(27.81±17.65)μg/m3和(12.87±8.37)μg/m3、(85.08±35.41)μg/m3。淮南市大气颗粒物中主要的水溶性离子为Ca2+、NO-3和SO2-4。冬季各功能区PM2.5中总水溶性离子质量浓度普遍高于夏季。大气颗粒物中水溶性离子主要来源于土壤源、工业污染及二次转化,冬季二次污染源主要以流动源污染为主,而夏季流动源和固定源污染贡献接近。  相似文献   

7.
茂名市大气PM_(2.5)在线源解析   总被引:1,自引:0,他引:1  
于2014年12月31日—2015年1月12日,利用单颗粒气溶胶质谱仪对茂名市大气中PM2.5进行在线监测和分析。结果表明,茂名市大气颗粒物污染来源分布(颗粒数占比)分别为扬尘6%、工业工艺源10.9%、生物质燃烧14.7%、机动车尾气27.5%、燃煤23.4%、二次无机源7.7%和其他9.9%。空气质量从重度污染转为优良天气过程中,机动车尾气的贡献率基本保持在20%以上,而燃煤占比从28.9%降至12.3%;空气质量从优良转为污染天气的过程中,工业工艺源、二次无机源、生物质燃烧、燃煤的占比增加,而机动车尾气占比不断下降。  相似文献   

8.
珠三角秋冬季节长时间灰霾污染特性与成因   总被引:7,自引:6,他引:1  
利用珠三角大气超级站2012年10月与2013年1月能见度、不同粒径颗粒物与BC质量浓度、气溶胶光散射系数、O3、相对湿度等在线监测数据,分析秋冬季节2次持续时间超过10 d的长时间灰霾过程污染特性与成因。结果表明,冬季灰霾过程中气溶胶吸光系数和光散射系数对大气总消光系数的贡献分别为13%和67%;PM2.5、PM1占PM10质量浓度分别为66%和39%;较高的PM2.5与BC日均浓度相关系数(R2=0.88)体现了一次排放对颗粒物质量浓度及能见度的显著影响。秋季灰霾过程中气溶胶吸光系数和光散射系数对大气总消光系数的贡献分别为11%和69%,由BC导致的吸光效应较冬季下降了约20%;PM2.5和PM1占PM10质量浓度比例分别为68%和45%,均高于冬季;O3浓度日最大小时值的平均值接近冬季的2倍;二次来源对PM2.5浓度升高和能见度下降起主导作用。来自不同方向的2种气团在珠三角僵持,大气扩散条件差是导致这2次灰霾过程的重要外在条件,应成为灰霾预报预警的重点关注对象。  相似文献   

9.
石家庄市春节期间大气颗粒物有机碳和元素碳的变化特征   总被引:3,自引:2,他引:1  
为研究石家庄市大气颗粒物的污染特征及其来源,于2013年2月6—19日春节期间在石家庄市采集大气颗粒物TSP、PM10、PM2.5样品,对其有机碳、元素碳进行分析测定。结果表明,石家庄TSP、PM10、PM2.5日平均质量浓度分别为389、330、245μg/m3,颗粒物污染严重;碳组分在颗粒物中占有较大比重,且随着粒径的减少,碳组分比重逐渐增加;存在不严重的次生有机碳污染;OC与EC的相关系数较高,说明两者有较为相似的污染源,主要为燃煤、机动车排放源。各种气象条件对PM2.5、OC、EC浓度和OC/EC的变化都有不同程度的影响。  相似文献   

10.
使用WRF Chem模式模拟分析2014年4月16日—18日一次上海市大气污染过程,探究交通减排对该市PM2.5浓度的影响。结果表明,模式较为成功地再现了污染过程中天气形势及大气污染物时空变化, PM2.5浓度模拟与观测结果IOA达到065。研究时段内交通减排使上海市PM2.5质量浓度平均减少 329 μg/m3,虹口凉城监测站受到交通减排影响最大,对小时平均质量浓度的最大影响超过26 μg/m3,超过此站PM2.5浓度的13%;PM2.5浓度越高,交通减排对上海市PM2.5浓度的影响越显著;交通减排对上海北部地区空气质量的改善效果最明显。  相似文献   

11.
河流沉积物中有机污染物的分析研究进展   总被引:8,自引:2,他引:6  
总结了近年来河流沉积物中有机污染物的研究进展 ,集中评述了国内有关沉积物中多环芳烃、有机氯农药和多氯联苯的分析研究现状 ,包括样品采集、样品前处理和样品分析 ,并对今后河流、湖泊及水库沉积物中污染物的分析工作作了展望  相似文献   

12.
选取位于西藏拉萨的罗布林卡、龙王潭公园、布达拉宫广场,位于林芝的福建公园,以及位于昌都的天津广场等5个城市公园,于2017年5—6月采取样线法对其中的鸟类群落组成和外来鸟种情况进行调查。调查共记录到鸟类9目20科36种,其中属于古北界的有12种,东洋界和广布种也均为12种。36种鸟类中,留鸟24种,夏候鸟6种,冬候鸟2种,旅鸟4种。统计到外来鸟种4种,包括山噪鹛(Garrulax davidi)、八哥(Acridotheres cristatellus)、红嘴相思鸟(Leiothrix lutea)及大紫胸鹦鹉(Psittacula derbiana),占调查鸟种种类的11.1%,外来物种的入侵风险在高原不容忽视。  相似文献   

13.
Quantifying nickel in soils and plants in an ultramafic area in Philippines   总被引:1,自引:0,他引:1  
In this study, concentrations of nickel (Ni) were quantified in the soils and plants in the agricultural areas of Salcedo watershed in Eastern Samar Island, Philippines. The quantity of total Ni in soils (TS-Ni) was significantly high with a mean of 1,409 mg kg?1, while the soil available Ni (SA-Ni) was low with a mean of 8.66 mg kg?1. As the levels of TS-Ni in the Salcedo watershed greatly exceeded the maximum allowable concentrations for agricultural soils, the site is not suitable for agricultural purposes. Despite significant TS-Ni levels, SA-Ni levels were very low due to tight binding between Ni and soil components. Consequently, all plants investigated did not meet the criterion for a Ni hyperaccumulator plant with low Ni contents (mean TP-Ni of 14.7 mg kg?1). Comparison of Ni levels between food plants and its recommended daily intake (RDI) suggests that consumption of food-plants grown in the study area is unlikely to pose health risks. However, caution must be taken against combined consumption of food plants with high Ni levels or their prolonged consumption, as it can induce accumulation of Ni above RDI.  相似文献   

14.
Plants continue to be an important source of new bioactive substances. Brazil is one of the world’s mega-diverse countries, with 20 % of the world’s flora. However, the accelerated destruction of botanically rich ecosystems has contributed to a gradual loss of native medicinal species. In previous study, we have observed a fast and intensive change in trade of medicinal plants in an area of Amazon, where human occupation took place. In this study, we surveyed 15 public markets in different parts of Brazil in search of samples of 40 plants used in traditional medicine and present in first edition of Brazilian Official Pharmacopoeia (FBRAS), published in 1926. Samples of plants commercialized as the same vernacular name as in Pharmacopoeia were acquired and submitted to analysis for authentication. A total of 252 plant samples were purchased, but the laboratory analyses showed that only one-half of the samples (126, 50.2 %) were confirmed as the same plant species so named in FBRAS. The high number of unauthenticated samples demonstrates a loss of knowledge of the original native species. The proximity of the market from areas in which the plant occurs does not guarantee that trade of false samples occurs. The impact of the commerce of the substitute species on their conservation and in public health is worrying. Strategies are necessary to promote the better use and conservation of this rich heritage offered by Brazilian biodiversity.  相似文献   

15.
Implementing good practice social impact assessment (SIA) that meets international standards in countries in transition is problematic. We reflect on the challenges faced when undertaking SIA in the Russian Federation. These challenges restrict meaningful SIA processes from being undertaken and limit public participation and the effective community engagement of project-affected local people. Based on the self-reflexive professional experience of two Russian-based social practitioners, and their discursive interactions with two leading academics in environmental and social impact assessment, as well as on in-depth interviews with prominent Russian and international experts, we identified the key challenges that prevent effective SIA from being implemented in Russia: a lack of understanding of the international standards; discrepancy in the determination of the social area of influence between the national requirements and international standards; difficulties in combining national and international impact assessment processes; and a tendency by companies to restrict stakeholder engagement to the minimum. We hope that by having an awareness of these limitations, improvements to SIA practice in Russia and elsewhere will be made.  相似文献   

16.
HPLC法测定饲料中维生素A、维生素D 3 和维生素E   总被引:3,自引:0,他引:3       下载免费PDF全文
建立了以w(C2H5OH)=95 %乙醇直接提取,高效液相色谱仪在波长280 nm和254 nm处连续测定饲料中维生素A、维生素D3和维生素E的方法.色谱柱为大连依利特Hypersil ODS C18(25 cm×4.6 mm×5 μm),流动相为甲醇-水,流速为1.2 mL/min.维生素A、维生素D3、维生素E的质量浓度分别在1.0 mg/L~20.0 mg/L、0.5 mg/L~15.0 mg/L 、2.5 mg/L~50.0 mg/L范围内与峰面积呈良好的线性关系,检测限分别为0.3×10-6 μg、0.04×10-6 μg、5.0×10-6 μg,相对标准偏差分别为1.6 %、2.7 %、2.4 %,平均回收率分别为99 %、102 %、98 %.  相似文献   

17.
As a part the Italian National Programme of Research in Antarctica (PNRA) a monitoring study has been undertaken to quantify the concentrations of some selected trace elements in human hair of participants in the Antarctic expeditions. Such concentrations may vary as a consequence of the extreme environmental conditions and changes in lifestyle experienced by participants in the expeditions, as some evidence in previous investigations seems to suggest. The present study regards samples collected on the occasion of the 2002-2003 expedition to the Italian Base of Terra Nova Bay (now Mario Zucchelli Base), i.e., just before the expedition and about one month later. Seven essential elements were taken into account, namely, Ca, Cu, Cr, Fe, Mg, Mn and Mo. Determinations were performed by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) and Dynamic Reaction Cell Inductively Coupled Plasma Mass Spectrometry (DRC-ICP-MS). Data obtained were statistically treated by using the non-parametric Friedman test. The concentrations of Ca, Cu and Mg were found to decrease (P < 0.05). The stress caused by the severe environmental conditions might well play a role in the observed decrease.  相似文献   

18.
Concern about nitrogen loads in marine environments has drawn attention to the existence and possible causes of long-term trends in nitrogen transport in rivers. The present study was based on data from the Swedish environmental monitoring programme for surface water quality; the continuity of these data is internationally unique. A recently developed semiparametric method was employed to study the development of relationships between runoff and river transport of nitrogen since 1971; the observed relationships were then used to produce time series of flow-normalised transports for 66 sites in 39 river basins. Subsequent statistical analyses of flow-normalised data revealed only few significant downward trends (p 0.05) during the time period 1971–1994, and the most pronounced of these downward trends were caused by reduced point emissions of nitrogen. The number of significant upward trends was substantially larger (15 for total-N and 18 for NO3-N). Closer examination of obtained results revealed the following: (i) the most pronounced upward trends were present downstream of lakes, and (ii) observed increases in nitrogen transport coincided in time and space with reduced point emissions of phosphorus or organic matter. This indicated that changes in the retention of nitrogen in lakes were responsible for the upward nitrogen trends. The hypothesis that nitrogen saturation of forest soils has caused a general increase in the riverine export of nitrogen from forested catchments in Sweden was not confirmed. Neither did the results indicate that improved agricultural practices have reduced the export of nitrogen from agricultural catchments.  相似文献   

19.
为调查丽水市空气中Pb污染现状,在机动车相对集中的市区布设5个测点,测点高度1.2m;监测周期为1a,每星期采样1d或2d,每天采集1个样,每次采样6h;监测项目为TSP、Pb;评价标准采用GB3095—1996《环境空气质量标准》。结果表明,丽水市各测点空气中Pb最大的季均值、年均值均未超标;常规测点和交通路口测点之间TSP、Pb质量浓度值均存在显著的差异性。  相似文献   

20.
Lead levels in wet and dry deposition were determined within this project. A network of 10 sampling stations was established. The stations were located in areas characterized by heavy traffic volumes, but away from industrial and/or municipal pollution sources. It was assumed, therefore, that lead in the samples collected was coming primarily from automobile emissions. Measurements were carried out over a period of one year. Both rain and snow samples were collected. Lead concentrations in the samples ranged from 0.6 to 141 microg dm(-3). They depended on street topography, traffic volume, average speed of the vehicles, frequency of traffic congestion and atmospheric conditions. The highest lead levels in deposition were observed during the cold season.  相似文献   

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