长三角淳安地区二次颗粒物污染形成机制
|
摘要
二次组分是长三角区域PM_(2.5)颗粒物的主要组成部分,研究二次细颗粒物污染特征以及形成机制对污染控制至关重要.本文揭示了长三角背景地区颗粒物的有机与无机组分的构成,实现了对二次有机气溶胶(SOA)总量的核算;并进一步结合气溶胶热力学模型,模拟颗粒物的理化性质,深入探讨颗粒相的水含量与酸碱度对二次污染物形成的影响.结果表明,长三角背景区域细颗粒的年平均浓度为33μg·m~(-3),主要成分为硫酸盐、硝酸盐、铵盐和有机物,其平均贡献分别为19%、15%、12%和19%.颗粒相中的硝酸盐主要为局地生成,其质量浓度主要受到温度与颗粒相铵盐浓度的影响;硫酸盐的生成受到区域传输与局地生成的耦合作用的影响.气溶胶热力学模型模拟的结果显示,长三角背景地区颗粒物总体呈现强酸性,其酸度受季节影响不大,但显著受到了颗粒相水含量的影响;颗粒相水含量对春季SOA生成的促进作用较夏季更为显著;夏季SOA在PM_(2.5)中质量浓度占比高达40%,其形成主要受到大气氧化性的影响.
The study of the sources,compositions,and formation mechanisms of pollutants at the background site is crucial for the understanding of episodic events in the Yangtze River Delta(YRD). Secondary species are major components of PM_(2.5) particles. In this work,the compositions and concentrations of organic matter and secondary organic aerosol(SOA) at a background site of the YRD region were determined. The acidity and liquid water content of aerosol particles were modeled to investigate the impact of the physicochemical properties of aerosol particles on the formation of secondary species. The annual mean PM_(2.5) concentration in Chunan is 33 μg·m~(-3),with major contributions from inorganic sulfate(19%),nitrate(15%),ammonium(12%),and organic matter(19%). Nitrate is mainly locally formed,while sulfate is more affected by regional transport,except in winter. We found that the particles at the background site of the YRD have a high acidity and no seasonal variation was observed. The SOA formation at the background site of the YRD is enhanced by the liquid water content of the aerosol in spring,while it is more affected by the concentration of the oxidant,that is,O3,in summer. The contribution of SOA to PM_(2.5) in summer is as high as 40%.
The study of the sources,compositions,and formation mechanisms of pollutants at the background site is crucial for the understanding of episodic events in the Yangtze River Delta(YRD). Secondary species are major components of PM_(2.5) particles. In this work,the compositions and concentrations of organic matter and secondary organic aerosol(SOA) at a background site of the YRD region were determined. The acidity and liquid water content of aerosol particles were modeled to investigate the impact of the physicochemical properties of aerosol particles on the formation of secondary species. The annual mean PM_(2.5) concentration in Chunan is 33 μg·m~(-3),with major contributions from inorganic sulfate(19%),nitrate(15%),ammonium(12%),and organic matter(19%). Nitrate is mainly locally formed,while sulfate is more affected by regional transport,except in winter. We found that the particles at the background site of the YRD have a high acidity and no seasonal variation was observed. The SOA formation at the background site of the YRD is enhanced by the liquid water content of the aerosol in spring,while it is more affected by the concentration of the oxidant,that is,O3,in summer. The contribution of SOA to PM_(2.5) in summer is as high as 40%.
引文
[1]李莉,安静宇,严茹莎.基于细颗粒物来源追踪技术的2013年12月上海市严重污染过程中PM2. 5的源贡献分析[J].环境科学,2015,36(10):3543-3553.Li L,An J Y,Yan R S. Source contribution analysis of the fine particles in Shanghai during a heavy haze episode in December,2013 based on the particulate matter source apportionment technology[J]. Environmental Science,2015,36(10):3543-3553.
[2]李莉,陈长虹,黄成,等.长江三角洲地区大气O3和PM10的区域污染特征模拟[J].环境科学,2008,29(1):237-245.Li L, Chen C H, Huang C, et al. Regional air pollution characteristics simulation of O3and PM10over Yangtze River Delta Region[J]. Environmental Science,2008,29(1):237-245.
[3]周敏,陈长虹,乔利平,等. 2013年1月中国中东部大气重污染期间上海颗粒物的污染特征[J].环境科学学报,2013,33(11):3118-3126.Zhou M, Chen C H, Qiao L P, et al. The chemical characteristics of particulate matters in Shanghai during heavy air pollution episode in central and eastern China in January 2013[J]. Acta Scientiae Circumstantiae,2013,33(11):3118-3126.
[4] Huang R J,Zhang Y,Bozzetti C,et al. High secondary aerosol contribution to particulate pollution during haze events in China[J]. Nature,2014,514(7521):218-222.
[5]王倩,陈长虹,王红丽.上海市秋季大气VOCs对二次有机气溶胶的生成贡献及来源研究[J].环境科学,2013,34(2):424-433.Wang Q,Chen C H,Wang H L. Forming potential of secondary organic aerosols and sources apportionment of VOCs in autumn of Shanghai,China[J]. Environmental Science,2013,34(2):424-433.
[6] Odum J R, Jungkamp T P W, Griffin R J, et al. The atmospheric aerosol-forming potential of whole gasoline vapor[J].Science,1997,276(5309):96-99.
[7] Heald C L,Jacob D J,Park R J,et al. A large organic aerosol source in the free troposphere missing from current models[J].Geophysical Research Letters,2005,32(18):109-127.
[8] Volkamer R,Jimenez J L,Martini F S,et al. Secondary organic aerosol formation from anthropogenic air pollution:rapid and higher than expected[J]. Geophysical Research Letters,2006,33(17):254-269.
[9] George I J,Abbatt J P D,et al. Heterogeneous oxidation of atmospheric aerosol particles by gas-phase radicals[J]. Nature Chemistry,2010,2(9):713-722.
[10] Gaston C J,Riedel T P,Zhang Z,et al. Reactive uptake of an isoprene-derived epoxydiol to submicron aerosol particles[J].Environmental Science&Technology,2014,48(19):11178-11186.
[11] Jang M, Czoschke N M, Lee S, et al. Heterogeneous atmospheric aerosol production by acid-catalyzed particle-phase reactions[J]. Science,2002,298(5594):814-817.
[12] Lim H J,Turpin B J. Origins of primary and secondary organic aerosol in Atlanta:results of time-resolved measurements during the Atlanta supersite experiment[J]. Environmental Science&Technology,2002,36(21):4489-4496.
[13]吕子峰,郝吉明,段菁春,等.北京市夏季二次有机气溶胶生成潜势的估算[J].环境科学,2009,30(4):969-975.LüZ F,Hao J M,Duan J C,et al. Estimate of the formation potential of secondary organic aerosol in Beijing summertime[J].Environmental Science,2009,30(4):969-975.
[14] Feng Y L,Chen Y J,Guo H,et al. Characteristics of organic and elemental carbon in PM2. 5samples in Shanghai,China[J].Atmospheric Research,2009,92(4):434-442.
[15]程艳丽,李湉湉,白郁华,等.珠江三角洲区域大气二次有机气溶胶的数值模拟[J].环境科学,2009,30(12):3441-3447.Cheng Y L,Li T T,Bai Y H,et al. Numerical simulation study of SOA in Pearl River Delta region[J]. Environmental Science,2009,30(12):3441-3447.
[16] Du W J,Zhang Y R,Chen Y T,et al. Chemical characterization and source apportionment of PM2. 5during spring and winter in the Yangtze River Delta,China[J]. Aerosol and Air Quality Research,2017,17(9):2165-2180.
[17] Yang Y J,Zhou R,Yu Y,et al. Size-resolved aerosol watersoluble ions at a regional background station of Beijing,Tianjin,and Hebei,North China[J]. Journal of Environmental Sciences,2017,55:146-156.
[18] Wang Y,Zhuang G S,Zhang X Y,et al. The ion chemistry,seasonal cycle,and sources of PM2. 5and TSP aerosol in Shanghai[J]. Atmospheric Environment,2006,40(16):2935-2952.
[19] Hennigan C J,Izumi J,Sullivan A P,et al. A critical evaluation of proxy methods used to estimate the acidity of atmospheric particles[J]. Atmospheric Chemistry and Physics,2015,15(5):2775-2790.
[20] Liu M X,Song Y,Zhou T,et al. Fine particle pH during severe haze episodes in northern China[J]. Geophysical Research Letter,2017,44(10):5213-5221.
[21] Song S J,Gao M,Xu W Q,et al. Fine-particle pH for Beijing winter haze as inferred from different thermodynamic equilibrium models[J]. Atmospheric Chemistry and Physics Discussion,2018,18(10):7423-7438.
[22] Pinder R W,Gilliland A B,Dennis R L. Environmental impact of atmospheric NH3emissions under present and future conditions in the eastern United States[J]. Geophysical Research Letters,2008,35(12):L12808.
[23]周佳佳,石金辉,李丽平,等.青岛大气中酸碱气体及PM2. 5中水溶性离子的浓度特征和气粒平衡关系[J].环境科学,2015,3(9):3135-3143.Zhou J J,Shi J H,Li L P,et al. Concentrations of acidic gases,ammonia and related water-soluble ions in PM2. 5and gas-particle partitioning in Qingdao[J]. Environmental Science,2015,3(9):3135-3143.
[24] Weber R J,Guo H Y,Russell A G,et al. High aerosol acidity despite declining atmospheric sulfate concentrations over the past15 years[J]. Nature Geoscience,2016,9(4):282-285.
[25] Li J J,Wang G H,Wu C,et al. Characterization of isoprenederived secondary organic aerosols at a rural site in North China Plain with implications for anthropogenic pollution effects[J].Scientific Reports,2018,8:535.
[26] Wang D F,Zhou B,Fu Q Y,et al. Intense secondary aerosol formation due to strong atmospheric photochemical reactions in summer:observations at a rural site in eastern Yangtze River Delta of China[J]. Science of the Total Environment,2016,571:1454-1466.
[27] Griffith S M,Huang X H H,Louie P K K,et al. Characterizing the thermodynamic and chemical composition factors controlling PM2. 5, nitrate:insights gained from two years of online measurements in Hong Kong[J]. Atmospheric Environment,2015,122:864-875.
[28] Wang H L,Qiao L P,Lou S R,et al. Chemical composition of PM2. 5and meteorological impact among three years in urban Shanghai,China[J]. Journal of Cleaner Production,2016,112:1302-1311.
[29] Liu G,Li J H,Wu D,et al. Chemical composition and source apportionment of the ambient PM2. 5in Hangzhou,China[J].Particuology,2015,18:135-143.
[30] Ming L L,Jin L,Li J,et al. PM2. 5in the Yangtze River Delta,China:chemical compositions,seasonal variations,and regional pollution events[J]. Environmental Pollution,2017,223:200-212.
[31]李贵玲,周敏,陈长虹,等. 2011年春季沙尘天气影响下上海大气颗粒物及其化学组分的变化特征[J].环境科学,2014,35(5):1644-1653.Li G L,Zhou M,Chen C H,et al. Characteristics of particulate matters and its chemical compositions during the dust episodes in Shanghai in spring,2011[J]. Environmental Science,2014,35(5):1644-1653.
[32] Zhang Q,Canagaratna M R,Jayne J T,et al. Time-and sizeresolved chemical composition of submicron particles in Pittsburgh:implications for aerosol sources and processes[J].Journal of Geophysical Research,2005,110(D7):D07S09.
[2]李莉,陈长虹,黄成,等.长江三角洲地区大气O3和PM10的区域污染特征模拟[J].环境科学,2008,29(1):237-245.Li L, Chen C H, Huang C, et al. Regional air pollution characteristics simulation of O3and PM10over Yangtze River Delta Region[J]. Environmental Science,2008,29(1):237-245.
[3]周敏,陈长虹,乔利平,等. 2013年1月中国中东部大气重污染期间上海颗粒物的污染特征[J].环境科学学报,2013,33(11):3118-3126.Zhou M, Chen C H, Qiao L P, et al. The chemical characteristics of particulate matters in Shanghai during heavy air pollution episode in central and eastern China in January 2013[J]. Acta Scientiae Circumstantiae,2013,33(11):3118-3126.
[4] Huang R J,Zhang Y,Bozzetti C,et al. High secondary aerosol contribution to particulate pollution during haze events in China[J]. Nature,2014,514(7521):218-222.
[5]王倩,陈长虹,王红丽.上海市秋季大气VOCs对二次有机气溶胶的生成贡献及来源研究[J].环境科学,2013,34(2):424-433.Wang Q,Chen C H,Wang H L. Forming potential of secondary organic aerosols and sources apportionment of VOCs in autumn of Shanghai,China[J]. Environmental Science,2013,34(2):424-433.
[6] Odum J R, Jungkamp T P W, Griffin R J, et al. The atmospheric aerosol-forming potential of whole gasoline vapor[J].Science,1997,276(5309):96-99.
[7] Heald C L,Jacob D J,Park R J,et al. A large organic aerosol source in the free troposphere missing from current models[J].Geophysical Research Letters,2005,32(18):109-127.
[8] Volkamer R,Jimenez J L,Martini F S,et al. Secondary organic aerosol formation from anthropogenic air pollution:rapid and higher than expected[J]. Geophysical Research Letters,2006,33(17):254-269.
[9] George I J,Abbatt J P D,et al. Heterogeneous oxidation of atmospheric aerosol particles by gas-phase radicals[J]. Nature Chemistry,2010,2(9):713-722.
[10] Gaston C J,Riedel T P,Zhang Z,et al. Reactive uptake of an isoprene-derived epoxydiol to submicron aerosol particles[J].Environmental Science&Technology,2014,48(19):11178-11186.
[11] Jang M, Czoschke N M, Lee S, et al. Heterogeneous atmospheric aerosol production by acid-catalyzed particle-phase reactions[J]. Science,2002,298(5594):814-817.
[12] Lim H J,Turpin B J. Origins of primary and secondary organic aerosol in Atlanta:results of time-resolved measurements during the Atlanta supersite experiment[J]. Environmental Science&Technology,2002,36(21):4489-4496.
[13]吕子峰,郝吉明,段菁春,等.北京市夏季二次有机气溶胶生成潜势的估算[J].环境科学,2009,30(4):969-975.LüZ F,Hao J M,Duan J C,et al. Estimate of the formation potential of secondary organic aerosol in Beijing summertime[J].Environmental Science,2009,30(4):969-975.
[14] Feng Y L,Chen Y J,Guo H,et al. Characteristics of organic and elemental carbon in PM2. 5samples in Shanghai,China[J].Atmospheric Research,2009,92(4):434-442.
[15]程艳丽,李湉湉,白郁华,等.珠江三角洲区域大气二次有机气溶胶的数值模拟[J].环境科学,2009,30(12):3441-3447.Cheng Y L,Li T T,Bai Y H,et al. Numerical simulation study of SOA in Pearl River Delta region[J]. Environmental Science,2009,30(12):3441-3447.
[16] Du W J,Zhang Y R,Chen Y T,et al. Chemical characterization and source apportionment of PM2. 5during spring and winter in the Yangtze River Delta,China[J]. Aerosol and Air Quality Research,2017,17(9):2165-2180.
[17] Yang Y J,Zhou R,Yu Y,et al. Size-resolved aerosol watersoluble ions at a regional background station of Beijing,Tianjin,and Hebei,North China[J]. Journal of Environmental Sciences,2017,55:146-156.
[18] Wang Y,Zhuang G S,Zhang X Y,et al. The ion chemistry,seasonal cycle,and sources of PM2. 5and TSP aerosol in Shanghai[J]. Atmospheric Environment,2006,40(16):2935-2952.
[19] Hennigan C J,Izumi J,Sullivan A P,et al. A critical evaluation of proxy methods used to estimate the acidity of atmospheric particles[J]. Atmospheric Chemistry and Physics,2015,15(5):2775-2790.
[20] Liu M X,Song Y,Zhou T,et al. Fine particle pH during severe haze episodes in northern China[J]. Geophysical Research Letter,2017,44(10):5213-5221.
[21] Song S J,Gao M,Xu W Q,et al. Fine-particle pH for Beijing winter haze as inferred from different thermodynamic equilibrium models[J]. Atmospheric Chemistry and Physics Discussion,2018,18(10):7423-7438.
[22] Pinder R W,Gilliland A B,Dennis R L. Environmental impact of atmospheric NH3emissions under present and future conditions in the eastern United States[J]. Geophysical Research Letters,2008,35(12):L12808.
[23]周佳佳,石金辉,李丽平,等.青岛大气中酸碱气体及PM2. 5中水溶性离子的浓度特征和气粒平衡关系[J].环境科学,2015,3(9):3135-3143.Zhou J J,Shi J H,Li L P,et al. Concentrations of acidic gases,ammonia and related water-soluble ions in PM2. 5and gas-particle partitioning in Qingdao[J]. Environmental Science,2015,3(9):3135-3143.
[24] Weber R J,Guo H Y,Russell A G,et al. High aerosol acidity despite declining atmospheric sulfate concentrations over the past15 years[J]. Nature Geoscience,2016,9(4):282-285.
[25] Li J J,Wang G H,Wu C,et al. Characterization of isoprenederived secondary organic aerosols at a rural site in North China Plain with implications for anthropogenic pollution effects[J].Scientific Reports,2018,8:535.
[26] Wang D F,Zhou B,Fu Q Y,et al. Intense secondary aerosol formation due to strong atmospheric photochemical reactions in summer:observations at a rural site in eastern Yangtze River Delta of China[J]. Science of the Total Environment,2016,571:1454-1466.
[27] Griffith S M,Huang X H H,Louie P K K,et al. Characterizing the thermodynamic and chemical composition factors controlling PM2. 5, nitrate:insights gained from two years of online measurements in Hong Kong[J]. Atmospheric Environment,2015,122:864-875.
[28] Wang H L,Qiao L P,Lou S R,et al. Chemical composition of PM2. 5and meteorological impact among three years in urban Shanghai,China[J]. Journal of Cleaner Production,2016,112:1302-1311.
[29] Liu G,Li J H,Wu D,et al. Chemical composition and source apportionment of the ambient PM2. 5in Hangzhou,China[J].Particuology,2015,18:135-143.
[30] Ming L L,Jin L,Li J,et al. PM2. 5in the Yangtze River Delta,China:chemical compositions,seasonal variations,and regional pollution events[J]. Environmental Pollution,2017,223:200-212.
[31]李贵玲,周敏,陈长虹,等. 2011年春季沙尘天气影响下上海大气颗粒物及其化学组分的变化特征[J].环境科学,2014,35(5):1644-1653.Li G L,Zhou M,Chen C H,et al. Characteristics of particulate matters and its chemical compositions during the dust episodes in Shanghai in spring,2011[J]. Environmental Science,2014,35(5):1644-1653.
[32] Zhang Q,Canagaratna M R,Jayne J T,et al. Time-and sizeresolved chemical composition of submicron particles in Pittsburgh:implications for aerosol sources and processes[J].Journal of Geophysical Research,2005,110(D7):D07S09.