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1.
基于2016—2020年莆田市监测站O3逐小时质量浓度观测资料和边界层高度数据,分析5年间4次夜间O3质量浓度超标的过程。沿海各市的O3数据、后向轨迹和MEIC污染排放清单表明,O3污染前体物来源于长三角地区和福州地区。4次夜间O3污染期间,O3与NOx整体相关性小,相关系数为0.23,外来源输送导致出现O3与NOx整体相关性较小的现象。4次夜间O3质量浓度超标成因是外来源输送的O3在夜间时段随着后向轨迹向本地区输送时,O3因缺少NO的滴定作用而无法分解,且垂直方向上边界层高度降低。  相似文献   

2.
基于漯河市大气灰霾站在线观测数据,分析2022年10月12—19日PM2.5-O3复合污染过程中VOCs的污染特征及来源,以期判别复合污染过程中需要优先管控的VOCs物种及来源,为PM2.5和O3协同管控提供依据。结果表明:污染期间VOCs平均质量浓度(96.7μg/m3)显著高于污染前(49.4μg/m3)和污染后(54.8μg/m3),以烷烃和卤代烃占比较高;整个污染过程中质量浓度较高的物种包括乙醛、乙烷、丙烷、异戊烷、氟利昂-12、二氯甲烷、甲苯、苯、一氯甲烷、氟利昂-11、正丁烷和1,2-二氯乙烷;污染期间正丁烷、异戊烷、丙烷、二氯甲烷、一氯甲烷和苯的质量浓度增幅均超过100%。漯河市VOCs的O3生成潜势(OFP)以OVOC和烯烃占比较高,二次有机气溶胶生成潜势(SOAp)以芳香烃占比最高。OFP贡献较高物种为乙醛、乙烯、甲苯和丙烯,SOAp贡献较高物种为甲苯、苯、间、对二甲苯、乙苯和邻二甲苯;污染期间...  相似文献   

3.
于2020年1月1日—3月31日,采用TH-300B型气相色谱-氢火焰离子化检测器/质谱联用(GC-FID/MS)在线分析仪对上海市典型石化园区大气挥发性有机物(VOCs)进行了连续自动观测,测定了包括含氧挥发性有机物在内的102种VOCs,分析了不同阶段VOCs的组成特征、日变化特征、大气光化学活性及来源变化。结果表明,春节期间,上海市典型石化园区 φ(VOCs)为17.1×10-9,较春节前下降59.0%;与溶剂使用和石化化工相关的芳香烃和卤代烃贡献率下降明显,芳香烃贡献率由17.7%下降至11.1%,卤代烃贡献率由13.7%下降至8.8%;臭氧生成潜势显著下降,关键活性组分为乙烯、甲苯、丙烯、间/对-二甲苯和正丁烷。VOCs来源分析结果显示,春节前,观测点位主要受附近石化园区和精细化工园区人为源排放和机动车尾气的共同影响;春节期间,观测点位主要受石化排放、机动车尾气排放、溶剂使用以及燃烧过程等多源的综合影响,但溶剂使用企业排放的影响明显减弱;逐步复工阶段,精细化工园区排放的影响开始逐步增加,但尚未完全恢复至春节前的活动水平。对比分析了石化园区的管控措施对VOCs浓度变化及光化学活性的影响,以期为后续VOCs减排与控制措施的制定提供科学支撑。  相似文献   

4.
为探究威海市秋季挥发性有机物(VOCs)污染特征及来源,于2021年9月10—20日采用手工加密监测法对威海市秋季大气中VOCs进行监测,分析了气象因素对臭氧(O3)及其前体物的影响和VOCs污染特征,并利用正交矩阵因子模型(PMF)方法对VOCs来源进行了研究。结果表明,威海市温度对O3生成影响明显,尤其是高温、低湿、扩散较差气象条件下,有利于O3前体物的反应消耗,促使O3生成及累积。观测期间,威海市秋季φ(VOCs)平均值为47.84×10-9,VOCs中体积分数占比最高的为含氧挥发性有机物(OVOCs),占比为58.0%,其次为烷烃(21.6%)、卤代烃(10.2%)。O3生成潜势(OFP)平均值为393.95μg/m3,对OFP的贡献占比最高的为OVOCs(74.1%),其次为芳香烃(12.6%)、烷烃(7.0%)和烯烃(5.4%)。PMF源解析结果显示,机动车尾气排放源、工艺过程源、船舶尾气排放源和溶剂使用源是威海市秋季VOCs排放主要来源,贡献占比分别为30.4%,23.9%,21.1%,16.5%。控制机动车排放和工艺过程排放是控制威海市秋季VOCs污染的重要途径。  相似文献   

5.
基于2014—2020年重庆市中心城区北碚区环境监测数据及地面观测气象要素,分析了北碚区大气污染特征,利用KNN算法建立大气污染的评估模型,对空气质量改善效果进行评估。结果表明,重庆市中心城区北碚区的PM2.5浓度逐年呈明显下降趋势,O3浓度除夏季有一个弱的下降趋势外,其余3个季节和年平均值整体均呈上升趋势。全年以优良天气为主且呈增加趋势。O3与气温、日照时间呈正相关,与相对湿度呈负相关性,PM2.5与气温、降水及风速呈负相关。基于KNN算法对空气质量改善状况评估表明,减排对O3污染平均贡献率在-4.7%左右,对PM2.5污染平均贡献率为-52%,气象条件对O3污染的平均贡献率在17%左右,对PM2.5污染的平均贡献率在-7%左右。该大气污染评估模型能够有效地评估空气改善效果。  相似文献   

6.
综合利用环境空气质量常规监测、挥发性有机物(VOCs)在线监测,以及后向轨迹聚类分析、权重潜在源区分析和正交矩阵因子分解法等多种监测分析方法,基于合肥市经历的一次典型臭氧(O3)污染过程(2020年9月1—10日),系统分析了合肥市O3污染的典型特征及成因。结果显示,此次污染过程的O3小时平均浓度高达96 μg/m3,且O3浓度波动较大,在9月6日13:00达到了224 μg/m3,呈现出快速生成、快速消耗的污染特征,并在夜间呈现出非典型的二次峰值过程。污染期间,合肥市基本处于VOCs控制区,芳香烃对O3生成潜势的贡献最大(45.2%),其次是烷烃(31.8%)和烯烃(21.5%);污染阶段的VOCs主要来自机动车排放源(44.1%)、燃烧源(21.3%)、工业源(15.3%)、溶剂使用源(12.4%)和天然源(6.9%),累积阶段和污染阶段均受机动车尾气排放和溶剂使用的影响较大。此外,台风外围下沉气流和高温、低湿、低风速等气象条件是引发此次O3污染过程的主要外因,而合肥市周边的高污染区域则是此次O3污染过程的潜在外部源区。  相似文献   

7.
为找到对成都空气质量有改善作用的气象要素等级,量化成都气象条件对大气污染物的影响,对2015—2018年成都环境监测站空气质量监测数据和温江国家气候观象台同时段的气象观测资料进行了研究分析。结果表明:(1)成都中部地区的空气质量污染较为严重,全年主要以PM2.5和O3污染为主,占比达75%,2015—2018年成都的PM2.5污染呈下降趋势,而O3污染虽有所波动但没有显著改善。(2)PM2.5持续重污染过程中,过去12 h降水量和过去24 h降水量均大于1 mm,均为有效降水,大于2.5 mm对PM2.5污染的改善作用显著增强;相对湿度低于70%对中度及以上PM2.5污染的改善作用同步增加,低于40%对轻度PM2.5污染的改善作用较为明显,优良天气的发生概率显著增加;风速大于1 m/s时PM2.5浓度随风速的增大而减小,大于2 m/s对PM2.5浓度的改善作用显著加强。...  相似文献   

8.
选取2016—2022年攀枝花市环境空气质量监测数据,基于年度、季度、月度、小时时间尺度评价环境空气质量综合指数贡献率。结果表明,攀枝花市污染类型已由传统的单一工业型污染转变为复合型污染,且污染物在不同时间尺度下的分布特征明显。从季度尺度来看,第一季度细颗粒物(PM2.5)综合指数贡献率较大,第二和第三季度臭氧(O3)综合指数贡献率较大,第四季度二氧化氮(NO2)及PM2.5综合指数贡献率较大。从月度尺度来看,O3在3—8月的贡献较大,PM2.5、NO2、可吸入颗粒物(PM10)、一氧化碳(CO)、二氧化硫(SO2)在1—2月及11—12月的贡献较大。从小时尺度来看,O3在13—19点贡献较大,PM10、PM2.5、CO在8—13点贡献较大,SO2在9—13点贡献较大,NO2在8—1...  相似文献   

9.
2020年7月对兰州市城区大气挥发性有机物进行连续24 h测定,研究其污染特征和臭氧生成潜势等,并进行来源解析。结果表明:兰州超级站点 VOCs的平均质量浓度为99.59 μg/m3,各类挥发性有机物中烷烃占比最大,占总挥发性有机物浓度的33.81%;对挥发性有机物进行臭氧生成潜势分析,排名靠前的物种为甲苯、乙烯、乙酸乙烯酯;利用PMF模型对挥发性有机物进行源解析,结果显示VOCs来源贡献为机动车源(31.30%)、油气挥发或泄漏(24.10%)、溶剂使用源(18.60%)、燃烧和化工工艺源(17.20%)、天然源(8.80%)。建议将控制机动车排放、油气挥发和泄漏、溶剂使用等作为消减城市大气挥发性有机物和臭氧污染的重点。  相似文献   

10.
通过区域空气质量模型CAMx对大连市2015年8月近地面臭氧(O_3)污染进行模拟,探讨了O_3及其生成前体物(NOx和VOCs)的来源,O_3生成控制区,并根据敏感性分析结果对前体物排放的控制效果进行了定量评估。结果表明:本地NOx排放对大连地区的NOx浓度贡献占90%以上,本地VOCs排放对大连地区的VOCs浓度贡献占80%以上,而本地NOx和VOCs排放对大连地区O_3浓度贡献仅占29%;大连市整体上为VOCs控制区,控制VOCs能有效降低O_3污染,还能有效削减O_3的峰值浓度;通过敏感性分析结果计算得出,削减大连本地工业源VOCs和民用源VOCs能够有效降低大连地区O_3浓度,削减10%的工业源VOCs能使市区O_3平均浓度降低2%左右,削减10%的民用源VOCs能使大连市区平均O_3浓度降低1%左右。建议NOx与VOCs削减比例为1∶2,对大连市O_3和PM2.5污染进行协同控制。  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:2,自引:0,他引:2       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.
基于城市超级站对2018年12月—2019年2月南京市在线水溶性离子污染特征进行研究。结果表明:监测期间水溶性无机离子(WSIs)质量浓度均值为45.7μg/m3,占PM2.5的67.8%,各离子排序为NO3-> SO42->NH4+>Cl->K+>Ca2+>Na+>Mg2+。二次离子(SNA)是PM2.5主要组分,大气气溶胶呈中性。各离子日变化存在差异,SNA变化趋势和WSIs基本一致。南京市冬季存在明显SO2和NO2向SO42-和NO3-二次转化;NO3-/SO42-均值为1.96,移动源增量大于固定源。通过相关性和三相聚类分析可知,SNA主要结合方式为(NH4)2SO4和NH4NO3。主成分分析表明,南京市冬季PM2.5中水溶性离子主要来源是二次转化,燃煤、生物质燃烧和土壤建筑扬尘也有贡献。  相似文献   

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