共查询到17条相似文献,搜索用时 46 毫秒
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利用2022年9月嘉兴市光化学站小时分辨率的挥发性有机物(volatile organic compounds,VOCs)和臭氧(O3)数据,分析了O3和VOCs的污染特征;采用基于观察数据的(observation-based model,OBM)模型,分析嘉兴市O3敏感性;并通过正定矩阵因子分析(positive matrix factorization,PMF)模型进行了环境VOCs来源解析研究。结果表明:高温(28.8~33℃)、低湿(69%~74%)、小风(1.4~2.0 m/s)等不利的气象条件有利于O3浓度升高。嘉兴市VOCs组分含量烷烃(6.7×10-9)>芳香烃(5.0×10-9)>烯烃(1.7×10-9)>炔烃(0.6×10-9),臭氧生成潜势(ozone formation potential,OFP)芳香烃(74.0μg/m3)>烯烃(19.8... 相似文献
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太原市环境空气中TSP和PM_(10)来源解析 总被引:2,自引:0,他引:2
2001年到2002年,在太原市5个采样点分别采集了环境空气中的总悬浮颗粒物(TSP)和可吸入颗粒物(PM10)。用化学质量平衡模型和二重源解析技术解析了TSP和PM10的来源,结果表明,各主要源类对TSP的分担率依次为燃煤尘28%、扬尘24%、建筑水泥尘14%、硫酸盐10%、机动车尾气尘10%、土壤风沙尘5%、钢铁尘4%、硝酸盐4%、其它1%;对PM10的分担率依次为扬尘30%、燃煤尘18%、机动车尾气尘15%、硫酸盐11%、土壤风沙尘9%、建筑水泥尘7%、硝酸盐4%、其它1%。 相似文献
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采集北京市某一地下停车场内环境空气样品,利用气相色谱-质谱/氢火焰离子化检测器(GCMSD/FID)测定了挥发性有机物(VOCs)的组成,分析其浓度特征、组分特征和影响因素,运用特征物种比值法和正定矩阵因子分析模型(PMF)解析VOCs来源,采用健康风险评估模型定量评估部分VOCs的健康风险.结果表明,地下停车场内VOCs平均浓度为514.16μg·m-3,其中烷烃占比最大(43.76%),其次是芳香烃(28.89%)、烯烃(10.97%).影响停车场内VOCs浓度的主要因素包括机动车运行工况、机动车进出车次及扩散条件.冷启动工况、较多的出入车次和不利的扩散条件会导致VOCs浓度显著上升.苯/乙苯和苯/甲基叔丁基醚(MTBE)的均值分别为1.5和0.8,表明机动车尾气和汽油挥发是地下停车场内VOCs的主要来源. PMF解析结果表明地下停车场内VOCs的首要来源为机动车尾气源(44.58%),汽油挥发源和汽车内饰挥发源分别贡献24.56%和9.18%.其中,汽油挥发源在08:00—10:00时段贡献最大,机动车尾气源在16:00—18:00时段贡献最大.健康风险评估... 相似文献
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室内空气中挥发性有机物污染与防治 总被引:12,自引:0,他引:12
李亚新 《城市环境与城市生态》2003,16(1):11-12
论述了室内空气质量的重要性以及室内挥发性有机物(VOC)污染来源,介绍了评价V0C污染的量化指标VDC和减少室内VOC污染的措施和技术。 相似文献
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近年来中国城市O3污染问题日益突出,近地面O3已成为沈阳市的主要空气污染物之一。基于沈阳市2019年近地面臭氧(O3)及其前体物(VOCs和NO2)的逐时数据,结合同期气象观测资料,研究了2019年沈阳大气O3的季节变化特征,分析了VOCs和NO2以及气象条件对O3生成的影响;利用最大增量反应活性法(MIR)估算了沈阳大气VOCs的臭氧生成潜势(OFP),并运用正交矩阵因子分解法(PMF)进行了沈阳夏季VOCs的来源解析。结果表明:2019年沈阳市O3平均质量浓度夏季最高,其次是春季和秋季,冬季最低;四季O3日变化特征均表现为单峰型,质量浓度峰值出现在14:00左右,谷值出现在07:00左右。沈阳市O3质量浓度与温度、风速均呈现正相关关系(P=0.001,P=0.005),与相对湿度呈负相关关系(P=0.005);当温度达到30.0℃以上,O3质量... 相似文献
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Concentrations of volatile organic compounds (VOCs) of the city air in Oba Akran road, Lagos were investigated. The chlorinated VOCs and xylene in Oba Akran were high. The average benzene/toluene ratio in Oba Akran was 1.7 suggesting that vehicular emission was a possible VOC source in most areas of Oba Akran. The toluene/(m+p-xylene) ratio also suggests a common source of toluene and xylene at these sites, presumably organic solvent used by industries located at Oba Akran. Our results showed that 7.10 tons of CO 2 equivalents of VOCs are being emitted per year from Oba Akran. Xylenes were found to be the largest contributor to the ozone formation followed by trichloroethylene. A multivariate statistical analysis (Factor analysis extracted with Principal Component Analysis) has been applied to a set of data, and it was found that the main principal components, extracted from the air VOC pollution data, were related to gasoline and oil combustion/industrial activities. 相似文献
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太原市土壤重金属污染空间分布及评价 总被引:2,自引:0,他引:2
以太原市土壤作为研究对象,系统研究了太原市城市土壤及工业区土壤中Cr、Ni、Cu、Zn、As、Cd、Pb的污染水平和分布,并对污染状况进行了评价.研究表明,太原市土壤中重金属的含量分别为Cr:35.35—848.80mg·kg-1,Ni:4.00—99.57 mg·kg-1,Cu:4.89—266.99 mg·kg-1,Zn:45.16—677.01 mg·kg-1,As:0.66—35.46 mg·kg-1,Cd:nd—1.00 mg·kg-1,Pb:15.61—1240.41 mg·kg-1.其中城市土壤重金属含量较低,工业区土壤重金属含量较高,受到多种重金属的复合污染.以土壤环境质量国家二级标准值作为评价标准,用单项污染指数和综合污染指数对太原市土壤重金属污染进行评价,结果显示太原市大部分城市土壤未受7种重金属污染,只有6.7%的地区处于轻污染水平;工业区土壤污染严重,污染程度从高至低为化工厂(重污染)热电厂(重污染)化肥厂(重污染)第一电厂(中度污染)建筑工地(中度污染)焦化厂(轻污染).7种重金属在太原市土壤中的空间分布规律不同,且均与工业区分布相关,工业区是太原城市土壤重金属污染的重要来源. 相似文献
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Bo Han Xiaohui Bi Yonghua Xue Jianhui Wu Tan Zhu Baogui Zhang Jianqing Ding Yuanxin Du 《Frontiers of Environmental Science & Engineering》2011,5(4):552-563
A total of 168 PM10 samples were collected during the year of 2005 at eight sites in the city of Wuxi in China. Fifteen chemical elements, three water-soluble ions, total carbon and organic carbon were analyzed. Six source categories were identified and their contributions to ambient PM10 in Wuxi were estimated using a nested chemical mass balance method that reduces the effects of colinearity on the chemical mass balance model. In addition, the concentrations of secondary aerosols, such as secondary organic carbon, sulfate and nitrate, were quantified. The spatially averaged PM10 was high in the spring and winter (123 ??g·m?3 and low in the summer-fall (90 ??g·m?3). According to the result of source apportionment, resuspended dust was the largest contributor to ambient PM10, accounting for more than 50% of the PM10 mass. Coal combustion (14.6%) and vehicle exhaust (9.4%) were also significant source categories of ambient PM10. Construction and cement dust, sulfates, secondary organic carbon, and nitrates made contributions ranging between 4.1% and 4.9%. Other source categories such as steel manufacturing dust and soil dust made low contributions to ambient PM10. 相似文献
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为研究乌鲁木齐市米东区大气降水中的化学组分特征及来源,对2017-2019年降水中主要离子浓度及来源进行了分析.研究结果显示,米东区2017-2019年降水的雨量加权pH年均值为7.95,雨量加权平均电导率年均值为16.15 mS·m-1,雨量加权平均总离子浓度为72.75-95.89 μeq·L-1,年均浓度为81.... 相似文献
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Sihua Lu Ying Liu Min Shao Shan Huang 《Frontiers of Environmental Science & Engineering》2007,1(2):147-152
Volatile organic compounds (VOCs) were measured at six sites in Beijing in August, 2004. Up to 148 VOC species, including C3 to C12 alkanes, C3 to C11 alkenes, C6 to C12 aromatics, and halogenated hydrocarbons, were quantified. Although the concentrations differed at the sites, the chemical compositions were similar, except for the Tongzhou site where aromatics were significantly high in the air. Based on the source profiles measured from previous studies, the source apportionment of ambient VOCs was preformed by deploying the chemical mass balance (CMB) model. The results show that urban VOCs are predominant from mobile source emissions, which contribute more than 50% of the VOCs (in mass concentrations) to ambient air at most sites. Other important sources are gasoline evaporation, painting, and solvents. The exception is at the Tongzhou site where vehicle exhaust, painting, and solvents have about equal contribution, around 35% of the ambient VOC concentration. As the receptor model is not valid for deriving the sources of reactive species, such as isoprene and 1,3-butadiene, other methodologies need to be further explored. 相似文献
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Hengyi DUAN Xiaotu LIU Meilin YAN Yatao WU Zhaorong LIU 《Frontiers of Environmental Science & Engineering》2016,10(1):73-84
Volatile organic compounds (VOCs) and carbonyl compounds were measured both indoors and outdoors in 50 residences of Beijing in heating (December, 2011) and non-heating seasons (April/May, 2012). SUMMA canisters for VOCs and diffusive samplers for carbonyl compounds were deployed for 24 h at each site, and 94 compounds were quantified. Formaldehyde, acetone and acetaldehyde were the most abundant carbonyl compounds both indoors and outdoors with indoor median concentrations being 32.1, 21.7 and 15.3 μg·m−3, respectively. Ethane (17.6 μg·m−3), toluene (14.4 μg·m−3), propane (11.2 μg·m−3), ethene (8.40 μg·m−3), n-butane (6.87 μg·m−3), and benzene (5.95 μg·m−3) showed the high median concentrations in indoor air. Dichloromethane, p-dichlorobenzene (p-DCB) and toluene exhibited extremely high levels in some residences, which were related with a number of indoor emission sources. Moreover, isoprene, p-dichlorobenzene and carbonyls showed median indoor/outdoor (I/O) ratios larger than 3, indicating their indoor sources were prevailing. Chlorinated compounds like CFCs were mainly from outdoor sources for their I/O ratios being less than 1. In addition, indoor concentrations between two sampling seasons varied with different compounds. Carbonyl compounds and some chlorinated compounds had higher concentrations in the non-heating season, while alkanes, alkenes, aromatic compounds showed an increase in the heating season. Indoor concentration of VOCs and carbonyls were influenced by locations, interior decorations and indoor activities, however the specific sources for indoor VOCs and carbonyls could not be easily identified. The findings obtained in this study would significantly enhance our understandings on the prevalent and abundant species of VOCs as well as their concentrations and sources in Beijing residences. 相似文献