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近年来,我国大气污染一直为公众和研究者关注的热点,对细颗粒物(PM2.5)的相关研究[1-3]也越来越多. PM2.5主要由水溶性无机离子(WSIIs)、含碳组分和无机元素等多种化学组分组成[4-5],其中WSIIs一直被认为是造成雾霾和大气污染的主要化学物质之一[6],它不仅影响大气能见度[7],而且会引发人体的心肺功能、免疫系统等多方面的疾病[8-9].
太原市地处华北平原以西,太原盆地北部. 近年来,太原市经济水平迅速提升,经济转型持续升级,第三产业占比也逐年升高,但煤炭、水泥、焦化等重工业产业整体占比仍然较高,大气环境问题依然严峻. 现有研究表明,太原市PM2.5污染现象依然严重[10],大气首要污染物为颗粒物的占比依然较高[11],冬季PM2.5中WSIIs占比最高(约48.6%),二次粒子为其主要组分,大气中存在较强的二次转化过程[12].
为进一步厘清太原市采暖季大气PM2.5中WSIIs的污染特征及来源,本研究采集了2018年太原市采暖季(2018.11—2019.03) 的89个大气PM2.5样品,运用离子色谱分析、相关性统计分析等方法技术研究了太原市大气PM2.5中WSIIs变化规律,重点剖析了采暖季PM2.5中S/N变化规律,最后运用PMF 模型探讨了WSIIs的主要来源,以期为太原市大气污染防控措施的有效实施提供数据支撑,进一步解决困扰太原市的大气环境问题.
太原市采暖季PM2.5中水溶性无机离子污染特征及来源解析
Pollution characteristics and source apportionment of water-soluble inorganic ions in PM2.5 in Taiyuan City during the heating period
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摘要: 为探究太原市采暖季大气PM2.5中水溶性无机离子(WSIIs)的污染特征及来源,本研究采集了2018年太原市采暖季大气PM2.5样品,用离子色谱测定了其中9种WSIIs浓度,分析了WSIIs的污染特征、存在形态、S/N变化规律等,并运用PMF模型对WSIIs的污染来源进行了解析. 结果表明,太原市采暖季PM2.5中总水溶性离子(TWSI)浓度为51.0 μg·m−3,二次粒子约占77.1%,TWSI 浓度较2016年和2017年采暖季下降明显. WSIIs主要以(NH4)2SO4、NH4NO3、KNO3、KCl和NaCl的形态赋存,控制NH3的排放对降低PM2.5浓度具有重要意义. 太原市采暖季SOR和NOR分别为0.17和0.16,表明太原市采暖季大气中存在较强的二次转化特征,RH和O3浓度是影响SOR和NOR的关键因素. 重污染期间移动源对太原市大气污染的贡献高于固定源. 太原市采暖季PM2.5中WSIIs的主要来源贡献由大到小依次为二次源、燃烧源、土壤扬尘和工业源.Abstract: For this study, in order to investigate the pollution characteristics and sources of water-soluble inorganic ions (WSIIs) in PM2.5 in the heating season of Taiyuan, PM2.5 samples during the heating season of 2018 in Taiyuan were collected, and nine kinds of WSIIs in the PM2.5 samples were determined by ion chromatography. WSIIs were analyzed in the pollution characteristics, existing forms and S/N changes. Finally, the sources of WSIIs in the PM2.5 samples were discussed using the PMF model. The results demonstrated that the total water-soluble ion (TWSI) concentration in PM2.5 during the heating season in 2018 was 51.0 μg·m−3, and the secondary particles accounted for about 77.1%. The TWSI concentration in 2018 was significantly lower than that in 2016 or 2017. WSIIs mainly existed in the form of (NH4)2SO4, NH4NO3, KNO3, KCl and NaCl, and it was deduced that the emission control of NH3 was of great significance to reduce PM2.5 concentration. SOR and NOR were 0.17 and 0.16 respectively in the heating season of Taiyuan city, indicating that there appeared to be a strong secondary conversion in the atmosphere. RH and O3 concentrations were the key factors affecting SOR and NOR. The contributions of mobile sources to air pollution in Taiyuan were greater than the ones of the stationary sources during heavy pollution period. The main sources of WSIIs in PM2.5 were secondary source, combustion source, soil dust and industrial source in descending order according to their contribution.
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Key words:
- PM2.5 /
- water-soluble inorganic ions /
- secondary transformation /
- source apportionment /
- Taiyuan City
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表 1 不同污染水平下水溶性离子质量浓度及气象参数
Table 1. Mass concentration of water-soluble ions and meteorological conditions during different pollution levels
污染等级
Pollution levelsWSIIs/(μg·m−3) SNA/
TWSITWSI/
PM2.5RH/% WS/(m·s−1) T/℃ NO3− SO42- NH4+ Cl− Ca+ Na+ K+ Mg2+ F− TWSI Ⅰ 5.72 5.20 4.33 2.17 1.77 1.04 0.590 0.541 0.081 21.4 71.4% 36.7% 38.7 4.83 0.64 Ⅱ 13.1 8.99 8.25 4.15 1.87 1.32 1.07 0.602 0.049 39.4 77.1% 43.1% 39.1 3.28 1.22 Ⅲ 28.5 15.9 15.0 3.59 1.73 1.02 1.31 0.560 0.072 67.6 87.9% 52.3% 47.9 3.24 4.06 Ⅳ 48.1 28.3 25.3 7.45 1.68 1.11 2.11 0.693 0.079 115 88.6% 60.9% 49.8 2.96 −0.13 采暖季 Heating season 19.3 12.2 11.0 3.91 1.78 1.14 1.13 0.594 0.074 51.0 77.1% 45.6% 42.4 3.70 1.45 注:RH: Relative Humidity(相对湿度), WS: Wind Speed(风速) -
[1] TIAN M, WANG H B, CHEN Y, et al. Characteristics of aerosol pollution during heavy haze events in Suzhou, China [J]. Atmospheric Chemistry and Physics, 2016, 16(11): 7357-7371. doi: 10.5194/acp-16-7357-2016 [2] ZHANG Y, HUANG W, CAI T Q, et al. Concentrations and chemical compositions of fine particles (PM2.5) during haze and non-haze days in Beijing [J]. Atmospheric Research, 2016, 174: 62-69. [3] 薛国强, 朱彬, 王红磊. 南京市大气颗粒物中水溶性离子的粒径分布和来源解析 [J]. 环境科学, 2014, 35(5): 1633-1643. XUE G Q, ZHU B, WANG H L. Size distributions and source apportionment of soluble ions in aerosol in Nanjing. [J]. Environmental Science, 2014, 35(5): 1633-1643(in Chinese).
[4] CALVO A I, ALVES C, CASTRO A, et al. Research on aerosol sources and chemical composition: Past, current and emerging issues [J]. Atmospheric Research, 2013, 120: 1-28. [5] LIN Y L, ZOU J L, YANG W, et al. A review of recent advances in research on PM2.5 in China [J]. International Journal of Environmental Research and Public Health, 2018, 15(3): 438. doi: 10.3390/ijerph15030438 [6] 杨慧慧. 兰州市PM2.5中水溶性离子的污染特征及来源解析[D]. 南昌: 东华理工大学, 2019. YANG H H. Pollution characteristics and source analysis of Water-Soluble Ions in PM2.5 in Lanzhou City[D]. Nanchang: East China University of Technology, 2019(in Chinese).
[7] WU D, ZHANG F, GE X L, et al. Chemical and light extinction characteristics of atmospheric aerosols in suburban Nanjing, China [J]. Atmosphere, 2017, 8(8): 149. [8] REN Y Q, ZHOU B H, TAO J, et al. Composition and size distribution of airborne particulate PAHs and oxygenated PAHs in two Chinese megacities [J]. Atmospheric Research, 2017, 183: 322-330. doi: 10.1016/j.atmosres.2016.09.015 [9] 殷永文, 程金平, 段玉森, 等. 上海市霾期间PM2.5、PM10污染与呼吸科、儿呼吸科门诊人数的相关分析 [J]. 环境科学, 2011, 32(7): 1894-1898. YIN Y W, CHENG J P, DUAN Y S, et al. Correlation analysis between the PM2.5, PM10 which were taken in the hazy day and the number of outpatient about breathing sections, breathing sections of pediatrics in Shanghai [J]. Environmental Science, 2011, 32(7): 1894-1898(in Chinese).
[10] 刘淑丽. 基于SPAMS的太原市冬季PM2组成与来源研究 [J]. 山西大学学报(自然科学版), 2019, 42(3): 698-705. LIU S L. Composition and source of PM2.5 during winter in Taiyuan based on SPAMS [J]. Journal of Shanxi University(Natural Science Edition), 2019, 42(3): 698-705(in Chinese).
[11] 姜洪进. 太原市空气质量与PM2.5污染特征及来源解析研究[D]. 太原: 山西大学, 2019. JIANG H J. Analysis of air quality and PM2.5 pollution characteristics and sources in Taiyuan City[D]. Taiyuan: Shanxi University, 2019(in Chinese).
[12] 刘素, 马彤, 杨艳, 等. 太原市冬季PM2.5化学组分特征与来源解析 [J]. 环境科学, 2019, 40(4): 1537-1544. LIU S, MA T, YANG Y, et al. Chemical composition characteristics and source apportionment of PM2.5 during winter in Taiyuan [J]. Environmental Science, 2019, 40(4): 1537-1544(in Chinese).
[13] PAATERO P, TAPPER U. Analysis of different modes of factor-analysis as least-squares fit problems [J]. Chemometrics and Intelligent Laboratory Systems, 1993, 18(2): 183-194. doi: 10.1016/0169-7439(93)80055-M [14] PAATERO P, HOPKE P K, HOPPENSTOCK J, et al. Advanced factor analysis of spatial distributions of PM2.5 in the eastern United States [J]. Environmental Science & Technology, 2003, 37(11): 2460-2476. [15] PAATERO P, EBERLY S, BROWN S G, et al. Methods for estimating uncertainty in factor analytic solutions [J]. Atmospheric Measurement Techniques, 2014, 7(3): 781-797. doi: 10.5194/amt-7-781-2014 [16] 陈永桥, 张逸, 张晓山. 北京城乡结合部气溶胶中水溶性离子粒径分布和季节变化 [J]. 生态学报, 2005, 25(12): 3231-3236. doi: 10.3321/j.issn:1000-0933.2005.12.017 CHEN Y Q, ZHANG Y, ZHANG X S. Size distribution and seasonal variation of ions in aerosol at semi-urban site in Beijing [J]. Acta Ecologica Sinica, 2005, 25(12): 3231-3236(in Chinese). doi: 10.3321/j.issn:1000-0933.2005.12.017
[17] 吉燕芳, 贾陈忠. 太原市空气中PM2.5和PM10的污染特征分析 [J]. 资源节约与环保, 2018(11): 46-56. doi: 10.3969/j.issn.1673-2251.2018.11.040 JI Y F, JIA C Z. Analysis of pollution characteristics of PM2.5 and PM10 in air of Taiyuan city [J]. Resources Economization & Environmental Protection, 2018(11): 46-56(in Chinese). doi: 10.3969/j.issn.1673-2251.2018.11.040
[18] 丁新航, 梁越, 肖化云, 等. 太原市采暖季清洁天与灰霾天PM2.5中水溶性无机离子组成及来源分析 [J]. 环境化学, 2019, 38(6): 1356-1366. doi: 10.7524/j.issn.0254-6108.2018121102 DING X H, LIANG Y, XIAO H Y, et al. Composition and source analysis of water-soluble inorganic ions of PM2.5 in clean and haze days during heating season in Taiyuan City. [J]. Environmental Chemistry, 2019, 38(6): 1356-1366(in Chinese). doi: 10.7524/j.issn.0254-6108.2018121102
[19] 丁新航. 太原市大气颗粒物PM2.5污染特征及来源解析[D]. 南昌: 东华理工大学, 2019. DING X H. Pollution characteristics and source apportionment of PM2.5 in atmospheric particulate matter in Taiyuan City[D]. Nanchang: East China University of Technology, 2019(in Chinese).
[20] HE Q S, YAN Y L, GUO L L, et al. Characterization and source analysis of water-soluble inorganic ionic species in PM2.5 in Taiyuan city, China [J]. Atmospheric Research, 2017, 184: 48-55. doi: 10.1016/j.atmosres.2016.10.008 [21] ZHANG D Z, IWASAKA Y. Nitrate and sulfate in individual Asian dust-storm particles in Beijing, China in spring of 1995 and 1996 [J]. Atmospheric Environment, 1999, 33(19): 3213-3223. doi: 10.1016/S1352-2310(99)00116-8 [22] 张伟, 姬亚芹, 张军, 等. 辽宁典型城市道路扬尘PM2.5中水溶性无机离子组分特征及来源解析 [J]. 环境科学, 2017, 38(12): 4951-4957. ZHANG W, JI Y Q, ZHANG J, et al. Characteristics and source apportionment of water-soluble inorganic ions in road dust PM2.5 in selected cities in Liaoning Province [J]. Environmental Science, 2017, 38(12): 4951-4957(in Chinese).
[23] ZHAO J P, ZHANG F W, XU Y, et al. Characterization of water-soluble inorganic ions in size-segregated aerosols in coastal city, Xiamen [J]. Atmospheric Research, 2011, 99(3-4): 546-562. doi: 10.1016/j.atmosres.2010.12.017 [24] GUO W, ZHANG Z Y, ZHENG N J, et al. Chemical characterization and source analysis of water-soluble inorganic ions in PM2.5 from a plateau city of Kunming at different seasons [J]. Atmospheric Research, 2020: 234. [25] ZHOU H J, LU C W, HE J, et al. Stoichiometry of water-soluble ions in PM2.5: Application in source apportionment for a typical industrial city in semi-arid region, Northwest China [J]. Atmospheric Research, 2018, 204: 149-160. doi: 10.1016/j.atmosres.2018.01.017 [26] PATHAK R K, CHAN C K. Inter-particle and gas-particle interactions in sampling artifacts of PM2.5 in filter-based samplers [J]. Atmospheric Environment, 2005, 39(9): 1597-1607. [27] YANG L M, WANG S B, DUAN S, et al. Characteristics and formation mechanisms of secondary inorganic ions in PM2.5 during winter in a central city of China: Based on a high time resolution data [J]. Atmospheric Research, 2020: 233. [28] 吕哲. 石家庄市PM2.5水溶性离子化学特征与来源解析[D]. 南昌: 东华理工大学, 2019. LV Z. Chemical characteristics and source apportionment of water-soluble ions in PM2.5 in Shijiazhuang[D]. Nanchang: East China University of Technology, 2019(in Chinese).
[29] PONCZEK M, HAYECK N, EMMELIN C, et al. Heterogeneous photochemistry of dicarboxylic acids on mineral dust [J]. Atmospheric Environment, 2019, 212: 262-271. doi: 10.1016/j.atmosenv.2019.05.032 [30] 曹旭耀. 重庆市PM2.5及化学组分污染特征研究[D]. 重庆: 中国科学院重庆绿色智能技术研究院, 2017. CAO X Y. Characteristics of PM2.5 and chemical compositions in Chongqing, China[D]. Chongqing: Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, 2017(in Chinese).
[31] 张娟, 王炜, 赵颖. 北京市延庆区PM2.5中主要水溶性无机离子特征及来源解析 [J]. 环境工程技术学报, 2020, 10(2): 173-182. doi: 10.12153/j.issn.1674-991X.20190085 ZHANG J, WANG W, ZHAO Y. Characteristics and source analysis of water-soluble inorganic ions in PM2.5 in Yanqing District, Beijing [J]. Journal of Environmental Engineering Technology, 2020, 10(2): 173-182(in Chinese). doi: 10.12153/j.issn.1674-991X.20190085
[32] 陈慕白, 袁明浩, 林秋菊, 等. 郑州市PM2.5组分季节性特征及来源研究 [J]. 中国环境监测, 2020, 36(4): 61-68. CHEN M B, YUAN M H, LIN Q J, et al. Seasonal Characteristics and Source Apportionment of PM2.5 Components in Zhengzhou City [J]. Environmental Monitoring in China, 2020, 36(4): 61-68(in Chinese).