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201.
根据重量法测定空气中PM10的测量方法原理,建立数学模型,从样品现场采样与实验室测试相结合引入各不确定度分量,分析并评定用重量法测定空气中PM10的不确定度,确定合成不确定和扩展不确定度.从各不确定度分量大小,最终确定测量不确定度影响因素并加以有效控制及改进,改善测量方法和手段,从而为空气中PM10浓度测定提高检测数据准确性,提供科学检测依据. 相似文献
202.
2013年1月邯郸市严重霾天气的污染特征分析 总被引:4,自引:3,他引:1
利用河北工程大学大气环境监测站点的PM10、PM2.5、SO2和NOx在线监测数据,并结合能见度、湿度数据,对邯郸市2012年12月1日到2013年1月31日的大气污染状况进行分析,特别是2013年1月持续发生的霾天气,以探讨严重霾污染的过程特征.结果表明,2013年1月,SO2与NOx的平均浓度分别为225.3 μg·m-3和217.8 μg·m-3,PM10和PM2.5的平均浓度分别为328.5 μg·m-3和229.4 μg·m-3,均超过新颁布的环境空气质量标准,是2012年12月平均浓度的1.4~3.5倍.重污染过程分析结果显示,污染峰值附近几天内PM10、PM2.5的时均浓度变化无明显规律.累积阶段的PM2.5/PM10在0.42~0.52之间,峰值前后上升并超过0.70,扩散阶段PM2.5/PM10降到0.70以下,且呈波动式变化.当PM2.5/PM10小于0.40时,能见度基本位于2~18 km之间;当PM2.5/PM10在0.40~0.60之间时,能见度在0.7~8 km之间;当PM2.5/PM10大于0.60时,能见度分布于2 km以下. 相似文献
203.
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205.
We studied the mass-related aerosol properties, simultaneously attwo sites at the urban roof top level in the same city. Nosystematic influence of the wind vector on the difference in theaerosol concentrations between the two locations could be found.These results are compared with results from a second, similarexperiment over a larger distance including one urban and onerural site. Surprisingly, we could not detect a tendency whichwould indicate that sampling air at distance in the order of 1 kmwould be less affected by the heterogeneity than samplingdistanced in the order of 10 km apart. On the contrary, theresults suggest that mass-related properties at two sites in thesame city are not necessarily more similar than at an urban and arural site outside the city. These results stress the limitedhorizontal homogeneity of urban atmospheric aerosol. As aconclusion it is suggested that single-site measurements of mass-related aerosol properties should be considered to berepresentative for an area smaller than 1 km2 on size. 相似文献
206.
Triantafyllou AG 《Environmental monitoring and assessment》2003,89(1):15-34
The results of a 16 year long sampling program in a heavily industrialized area of NW Greece are presented and analyzed. Fourlignite power stations are operated in this area, which account forabout 70% of the total electrical energy produced in Greece.Ambient concentrations of Total Suspended Particles (TSP) over much of the period 1983–1998 as well as of particles of less than10 m aerodynamic diameter (PM10) for three years were measured. Emphasis is given on the assessment of the levels of the daily average concentrations for the data period as well asthe determination of the spatial and temporal variation of suspended particle concentrations. Based on the data analysis, useful information is provided about air quality levels after taking into account air quality standards. The interannual concentrations trend is also investigated and an attempt is madeto examine the effectiveness of antipolluting procedures, which have occasionally been implemented in this industrial area. Finally the results are compared to those in the literature. 相似文献
207.
Airborne particulate matter (PM) concentrations were measured in Iksan, a suburban area in South Korea during April, 2003.
PM2.5 (particles with an aerodynamic diameter less than 2.5 μm) and PM10 (particles with an aerodynamic diameter less than 10 μm) samples were collected, and the chemical characteristics of particles
were examined for diurnal patterns, yellow dust/rainfall influences, and scavenging effects. Average concentrations of PM2.5 and PM10 mass measured were 37.3 ± 16.2 μg m−3 and 60.8 ± 29.5 μg m−3, respectively. The sum of ionic chemical species concentrations for PM2.5 and PM10 was 16.9 ± 7.3 and 23.1 ± 10.1 μg/m3, respectively. A significant reduction in PM mass concentrations during rainfall days was observed for coarse mode (PM2.5 − 10) particles, but less reduction was found for fine (PM2.5) mass concentration. SO4
2−, NH4
+, and K+ predominated in fine particulate mode, NO3
− and Cl− predominated in fine particle mode and coarse particle mode, but Na+, Mg2+, and Ca2+ mostly existed in coarse mode. The high concentration of ammonium due to local emissions and long-range transport neutralized
sulfate and nitrate to ammonium sulfate and ammonium nitrate, which were major forms of airborne PM in Iksan. Average mass
concentrations of PM10 in daytime and at night were 57.6 and 70.0 μg m−3, and those of PM2.5 were 35.4 and 42.5 μg m−3, respectively. NO3
− and Cl− in both PM2.5 and PM10 were about double at night than in the daytime, while the rest of the chemical species were equal or a little higher at night
than in the daytime. The results suggest the formation of ammonium nitrate and chloride when high ammonia concentration and
low air temperature are allowed. Backward air trajectory analyses showed that air masses arriving at the site during yellow
dust period were transported from arid Chinese regions, which resulted in high concentrations of airborne PM mass concentrations.
In the meantime, air mass trajectories during a rainfall period were mostly from the Pacific Ocean or the East China Sea,
along with a relatively low PM concentration. 相似文献
208.
Tim Chatterton Stephen Dorling Andrew Lovett Michael Stephenson 《Water, Air, & Soil Pollution: Focus》2002,2(5-6):173-187
This study uses a combination of data from U.K. monitoringstations and from modelling undertaken with the U.K.Meteorological Office's NAME Model to investigate therelative influences of primary and secondary particulateson total PM10 levels at sites in the United Kingdom. Co-located PM10 and sulphate aerosol measurementsindicate that sulphate has a disproportionately largeinfluence on the variation of PM10 levels incomparison to its contribution to their total mass.Comparisons of measured PM10 at urban centre, roadsideand rural sites suggest that local primary sources havevery little influence on daily mean levels. NAME has beenused to model both primary particles and sulphate aerosolfrom sources across the whole of Europe. The discrepanciesbetween modelled and observed PM10 suggest that coarseparticles, such as windblown dust and resuspended roaddust,may comprise a very large, if not dominant, proportion ofobserved PM10 levels. The apparently minor role ofprimary particles (especially locally-sourced ones) raisesa number of issues regarding the suitability of current U.K.and European legislation to addressing the particle problem. 相似文献
209.
对现场监测环境空气中PM10 的两种测定方法—β射线衰减法和微量振荡天平法的测量作了对比实验。实验表明 ,两种测定方法的结果具有一致性、相关性和可比性 ,能用回归直线方程来描述两者之间的关系。β射线衰减法的测定结果平均高于微量振荡天平法 15 8% ,它们之间平均偏差为 7 5 %。微量振荡天平法在现场测定中受干扰物和不确定因素的影响较少 ,其测量准确性优于 β射线衰减法。两种监测仪的运行费用大致相同 ,维护量和故障率均 较低 相似文献
210.
利用常州市6个环境空气质量评价点PM2.5、PM10、SO2、NO2、CO和水溶性离子数据,结合后向轨迹、激光雷达探空资料、气象资料等,分析了2018年1月29日—2月2日长三角区域一次持续重污染过程。结果表明,重度污染时次高达94 h,PM2.5最高值达235 μg/m3,由外来输送污染物与本地排放的污染物叠加而成,在不利气象条件影响下,污染物在长三角区域长时间滞留;重污染期间,污染物日变化规律显示,PM2.5受外来源影响更显著,而SO2、NO2受本地污染源影响更显著,水溶性粒子组分与常州市本地源存在较大差异,其中NO3-、NH4+、K+、Mg2+和SO42-值增加最为明显,较污染前分别增加了9.1,5.9,4.3,4.2和4.1倍;K+值升高较快,说明污染期间也受到了生物质燃烧的影响。此外,NO3-和SO42-在空气质量较好时,在水溶性离子中的占比日变化幅度较大,而在重污染期间,NO3-和SO42-日变化幅度明显减小。 相似文献