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1.
2013年4月—2014年1月,按季节在都匀劳动局楼顶采集PM_(10)样品,对样品中的水溶性无机离子的特征和来源进行分析。结果表明,PM_(10)中总水溶性无机离子年平均质量浓度为53.76μg/m~3,其中SO~(2-)_4、NO~-_3、NH~+_4为主要离子,年平均质量浓度分别为34.69μg/m~3、7.15μg/m~3和6.60μg/m~3;PM_(10)中水溶性无机离子总质量浓度呈现出春季最高,冬秋季次之,夏季最低的特征,主要离子也呈现出相似的分布规律;离子平衡表明,4个季节PM_(10)均显弱酸性,CE/AE年均值为0.73;NO~-_3/SO~(2-)_4年均值低于0.3,表明采样期间PM_(10)污染主要来自固定源;主成分分析结果表明,二次污染、扬尘、工业活动排放以及生物质燃烧等是PM_(10)的主要污染来源。  相似文献   

2.
为研究北京地区冬季PM_(2.5)载带的水溶性无机离子组分污染特征,2013年1月在中国环境科学研究院内采用在线离子色谱(URG-9000B,AIM-IC)对PM_(2.5)中水溶性无机离子(SO_4~(2-)、NO_3~-、Cl~-、NH_4~+、Na~+、K~+、Mg~(2+)、Ca~(2+))进行监测与分析。结果表明,采样期间总水溶性无机离子(TWSI)浓度为61.0μg/m~3,其中二次无机离子SO_4~(2-)、NO_3~-、NH_4~+(SNA)占比达72.3%,在PM_(2.5)中占比为40.29%,表明北京市PM_(2.5)二次污染严重。重污染天[NO_3~-]/[SO_4~(2-)]表明,固定源污染较移动源更为显著。三元相图表明,在空气质量为优的情况下,NH_4~+(在SNA中占比为30.3%~65.5%,下同)主要以NH_4NO_3的形式存在,较少比例以(NH_4)_2SO_4存在;严重污染时,NH_4~+(47.3%~77.9%)主要以(NH_4)_2SO_4形式存在,其次以NH_4NO_3的形式存在,其余的NH_4~+以NH_4Cl的形式存在。[NO_3~-]/[SO_4~(2-)]日变化表明,早、晚机动车高峰影响北京重污染发生。  相似文献   

3.
为了解广州地区灰霾天气成因,基于城市超级站,对2013年12月1日—12月8日期间2次灰霾天气过程的水溶性无机离子污染特征进行研究。结果表明:监测期间二次离子(SNA)SO_4~(2-)、NO_3~-、NH_4~+分别占PM_(2.5)质量浓度的15.8%、7.4%、7.0%;2次污染过程SNA对PM_(2.5)贡献显著,机动车排放和燃煤是PM_(2.5)的主要污染来源。广州冬季属于富氨区,2次污染过程都伴随着NH_4~+显著增加,NH_4~+主要以(NH_4)_2SO_4和NH_4NO_3形式存在。  相似文献   

4.
于2017年3月1日—5月31日监测分析了连云港市大气PM_(2.5)中主要水溶性无机离子质量浓度的日变化规律,以及与气象因子、PM10、PM_(2.5)相关性。结果表明,水溶性无机离子质量浓度与环境空气中NO_2、CO、PM_(10)、PM_(2. 5)显著相关,与气温、风速、能见度等呈负相关;日变化呈明显单峰型,峰值出现在08:00左右;水溶性无机离子季度均值为27. 2μg/m~3,占ρ(PM_(2.5))平均50%左右,ρ(NO_3~-)、ρ(SO_4~(2-))和ρ(NH_4~+)占ρ(水溶性无机离子)总85%以上;指出,SO_4~(2-)主要受远距离传输的影响,NO_3~-和NH_4~+主要受局地源的影响。  相似文献   

5.
运用大气PM_(2.5)水溶性组分及其气态前体物在线监测系统(GAC-IC)于2017年3月5—12日对武汉市大气PM_(2.5)中水溶性组分进行了在线监测,分析了PM_(2.5)中主要水溶性离子的化学特征和作用机制。结果表明:实验期间武汉市大气PM_(2.5)中水溶性组分与气态前体物间存在明显的二次转化过程,二次反应是PM_(2.5)的重要来源。监测期间,PM_(2.5)中NO_3~-、SO_4~(2-)和NH_4~+的平均质量浓度分别为24.3、16.9、15.0μg/m~3,是PM_(2.5)中重要的水溶性无机离子,占PM_(2.5)质量浓度的40%~70%。硫氧化率(SOR)和氮氧化率(NOR)平均值分别为0.52和0.27,表现出较为明显的二次污染特征。通过相关性分析发现:监测点位周边大气PM_(2.5)中NH_4~+与NO_3~-、SO_4~(2-)有良好的相关性,且表现为富氨状态,大气中铵能较好地中和SO_4~(2-)和NO_3~-。  相似文献   

6.
利用TEOM1405F型PM_(2.5)测量仪、MARGA水溶性离子在线分析仪和激光雷达对苏州市2016年8月24日—9月6日PM_(2.5)、水溶性离子和气溶胶垂直分布进行了观测,结合气象数据分析了水溶性离子的变化规律及其主要来源。结果表明,观测期间PM_(2.5)平均值为43.4μg/m3,与2014和2015年同期相比下降了42.9%和40.3%。总水溶性无机离子平均值为24.18μg/m~3,约占ρ(PM_(2.5))55.7%,其中ρ(SO_4~(2-))、ρ(NH_4~+)和ρ(NO_3~-)分别占ρ(总离子)的46.0%、25.8%、21.0%。夜间边界层降低,大气垂直扩散条件较差,是造成ρ(PM_(2.5))及ρ(水溶性离子)显著升高的主要原因。ρ(NO_3~-)/ρ(SO_4~(2-))为0.056~1.939,平均值为0.432,表明固定源(燃煤源)仍然是PM_(2.5)的主要来源;PCA方法表明苏州水溶性离子的主要来源于二次污染和燃烧源、海盐和土壤源以及地面扬尘、建筑尘。  相似文献   

7.
为探究衡阳冬季PM_(2.5)和水溶性离子污染特征及其来源,于2019年1月在衡阳市城区采集大气PM_(2.5)样品,使用重量法和离子色谱法测得PM_(2.5)和水溶性离子组分质量浓度,并分析其浓度特征、酸碱度和来源等问题。结果表明:采样期间衡阳大气PM_(2.5)平均质量浓度为94.25μg/m~3,总水溶性离子质量浓度为52.94μg/m~3,占PM_(2.5)总质量浓度的56.43%;阴阳离子当量之比为1.12,PM_(2.5)呈酸性,其中SNA(SO_4~(2-)、NO_3~-和NH_4~+)占总水溶性离子质量浓度的95.06%。污染期间二次转化明显,SNA主要以(NH_4)_2SO_4和NH_4NO_3形式存在。源解析发现大气PM_(2.5)受化石燃料和生物质燃烧、垃圾焚烧、建筑扬尘、气态前体物二次转化、外来输送等多重因素影响,其中机动车尾气排放的NO_x在大气中二次转化形成的硝酸盐是衡阳重污染的最主要原因。  相似文献   

8.
选取桂林市5个代表性监测点,采用单颗粒气溶胶飞行时间质谱仪在线分析该市夏季大气PM_(2.5)的化学组成及化学成分分布。结果表明:5个监测点,80%的PM_(2.5)分布在0.2μm~1.0μm的小粒径范围,20%的PM_(2.5)分布在1.0μm~2.5μm大粒径范围;大气PM_(2.5)中离子成分包含Na~+、K~+、NH~+4、C2H3~+/Al~+、Fe~+、HSO~-_4、NO~-_3、NO~-_2、CNO~-、CN~-、SO~-_3、O~-和元素碳离子;PM_(2.5)中离子按成分特征可分为元素碳、有机碳、元素碳有机碳混合颗粒、富锰颗粒、富铁颗粒、富钾颗粒、矿物质、左旋葡聚糖以及其他金属等9类,各监测点元素碳占比均超过50%;元素碳与硫酸盐、铵盐、硝酸盐发生内混合的程度极高,其中各监测点元素碳与硫酸盐混合程度最高,均达到90%左右。  相似文献   

9.
重庆市主城区大气水溶性离子在线观测分析   总被引:3,自引:0,他引:3  
2015年12月—2016年3月期间,利用在线气体与气溶胶成分监测仪(IGAC)在重庆市大气超级站开展连续观测分析,并捕捉到2次持续时间较长的空气重污染过程。对PM_(2.5)中9种水溶性离子及5种气态前体物的观测结果分析表明:NO_3~-、NH_4~+和SO_4~(2-)是重庆市主城区PM_(2.5)中主要的水溶性离子成分,其浓度均表现出明显的日变化特征,主要以(NH4)_2SO_4和NH_4NO_3的形式存在。NH_3和SO_2是最主要的气态污染物。2次重污染过程的水溶性离子组分有明显差异,细颗粒物累积型污染的NH_4~+、SO_4~(2-)、NO_3~-浓度高,二次转化十分明显;春节期间烟花爆竹集中燃放,Cl~-、K~+浓度高,主要属于一次排放;污染期间主要离子组分的同源性特征显著。  相似文献   

10.
基于2021年12月1日-2022年2月28日合肥市细颗粒物(PM_(2.5))及其水溶性离子连续观测数据,分析了合肥市冬季PM_(2.5)中水溶性离子化学特征以及不同污染程度下水溶性离子化学特征。结果表明:采样期间合肥市PM_(2.5)污染较重,不同污染程度下PM_(2.5)浓度差异较大,中度及以上污染天的ρ(PM_(2.5))平均值分别是清洁天和轻度污染天的2.8和1.3倍。二次水溶性无机离子[硝酸根离子(NO_(3)^(-))、铵根离子(NH+4)和硫酸根离子(SO_(2)-4),简称SNA]是合肥市PM_(2.5)的重要组成部分,随着污染程度的加重,PM_(2.5)二次生成比例随之下降。NH+4是合肥市水溶性离子中中和能力最强的离子,易与NO_(3)^(-)和SO_(2)-4结合分别形成NH_(4)NO_(3)和(NH_(4))_(2)SO_(4)。合肥市SO_(2)和NO_(2)均易发生二次转化,且SO_(2)较NO_(2)更容易发生二次转化。钙离子(Ca^(2+))和镁离子(Mg^(2+))相关性较高,说明合肥市PM_(2.5)可能受扬尘影响较大;钾离子(K^(+))是生物质燃烧的指示离子,氯离子(Cl^(-))与K^(+)相关性较好,说明合肥市PM_(2.5)组分中的Cl^(-)和K^(+)主要来自生物质燃烧。PM_(2.5)中水溶性离子受降水和温度影响较大。  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.
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
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   

20.
Indoor and outdoor measurements of nitrous acid and nitrogen dioxide were conducted at four homes and two offices in residential areas in Greater Cairo during winter (2000-2001) and summer (2001) seasons. Indoor nitrogen dioxide concentrations were higher than outdoor levels at the four homes, whereas indoor concentrations of nitrogen dioxide were lower than outdoor levels at the two offices, during both seasons. Indoor nitrous acid concentrations were higher than outdoor levels at all homes and offices during the period of study. The mean indoor nitrous acid concentrations were 6.8 ppb and 3.67 ppb in the four homes, whereas they were 1.42 ppb and 1.24 ppb in the two offices, during the winter and summer seasons, respectively. Indoor/outdoor ratios of nitrous acid concentration were 6.94 in the winter and 5.03 in the summer for all of the homes. However, the ratios were 1.31 and 1.61 during the winter and summer seasons, respectively, for the two offices. Insignificant positive correlation coefficients were found between indoor and outdoor concentrations of nitrous acid at homes and offices. The maximum outdoor nitrous acid concentrations were recorded during the winter season. Significant positive correlation coefficients were found between nitrous acid and nitrogen dioxide and relative humidity in homes and offices. The ratios of nitrous acid to nitrogen dioxide concentrations ranged from 0.045 to 0.16, with a mean of 0.1, in the four homes, whereas the ratios ranged from 0.026 to 0.09, with a mean of 0.059, in the two offices.  相似文献   

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