邯郸市秋季大气挥发性有机物污染特征
|
摘要
大气中VOCs(volatile organic compounds,挥发性有机物)是形成O_3和二次有机气溶胶的重要前体物.通过对2017年10月1—31日邯郸市秋季环境空气中56种VOCs污染物进行在线监测,结合PM_(2. 5)、O_3、NO_x等污染物质量浓度和气象数据,分析了邯郸市VOCs质量浓度水平、时间变化特征、化学反应活性和主要来源.结果表明:邯郸市ρ(VOCs)变化范围较大,为49. 1～358. 4μg/m3,平均值为(102. 2±45. 8)μg/m~3,VOCs的主要组分为烷烃和芳烃.ρ(VOCs)与ρ(PM_(2. 5))、ρ(NO_x)均有很强的相关性,相关系数分别为0. 8和0. 7;而ρ(NO_x)与ρ(O_3)呈明显的负相关性,相关系数为-0. 7.邯郸市VOCs中各类组分化学反应活性大小依次为烯烃>芳烃>烷烃>炔烃,并且国庆期间(10月1—7日) VOCs化学反应活性小于非国庆期间(10月8—31日),烯烃和芳烃对O_3的产生占主导地位.应用主因子分析法对邯郸市VOCs来源进行解析发现,溶剂使用和燃料挥发源、汽油车排放源、工业源、柴油车排放源和燃烧源是VOCs的主要来源,其方差贡献率分别为36. 7%、15. 5%、8. 0%、6. 6%、5. 1%.研究显示,减少邯郸市大气中ρ(VOCs)应以控制溶剂使用和燃料挥发源、交通排放源(汽油车排放源和柴油车排放源)为主.
Volatile organic compounds (VOCs) are important precursors for the formation of ozone and secondary organic aerosols. In recent years,ozone pollution became notably serious in many cities of China. It is important to understand the characteristics and chemical reactivity of the VOCs. This study used on-line observation data of 56 VOCs species in Handan City in October 2017,as well as PM_(2. 5),O_3,NO_x and meteorological data to analyze the pollution characteristics, temporal variations, chemical reactivity and sources apportionment of VOCs. The results showed that the concentrations of VOCs had a wide range from 49. 1 to 358. 4 μg/m3,and the average was (102. 2±45. 8) μg/m~3. Alkanes and aromatics were the most abundant components. We also found that the concentrations of VOCs had good correlation with those of PM_(2. 5) and NO_x ,with correlation coefficients of 0. 8 and 0. 7,respectively. NO_x and O_3 had negative correlation with correlation coefficient of-0. 7. The chemical reactivity of VOCs in Handan City was alkene > aromatic > alkane > alkyne.Chemical reactivity on the National Days (Oct. 1~(st)-7~(th)) was less than non-holiday period (Oct. 8~(th)-31~(st)). Alkenes and aromatics dominated ozone formation. The principal component analysis showed that the major sources of VOCs were solvent use and fuel volatilization,gasoline vehicle emissions,industrial production,diesel vehicle emissions and combustion source,and their variance contributions were 36. 7%,15. 5%,8. 0%,6. 6% and 5. 1% respectively. The research shown that control of VOCs should be mainly reduced by controlling solvent use and fuel volatilization,traffic emission (gasoline vehicle emissions and vehicle emissions) in Handan City.
Volatile organic compounds (VOCs) are important precursors for the formation of ozone and secondary organic aerosols. In recent years,ozone pollution became notably serious in many cities of China. It is important to understand the characteristics and chemical reactivity of the VOCs. This study used on-line observation data of 56 VOCs species in Handan City in October 2017,as well as PM_(2. 5),O_3,NO_x and meteorological data to analyze the pollution characteristics, temporal variations, chemical reactivity and sources apportionment of VOCs. The results showed that the concentrations of VOCs had a wide range from 49. 1 to 358. 4 μg/m3,and the average was (102. 2±45. 8) μg/m~3. Alkanes and aromatics were the most abundant components. We also found that the concentrations of VOCs had good correlation with those of PM_(2. 5) and NO_x ,with correlation coefficients of 0. 8 and 0. 7,respectively. NO_x and O_3 had negative correlation with correlation coefficient of-0. 7. The chemical reactivity of VOCs in Handan City was alkene > aromatic > alkane > alkyne.Chemical reactivity on the National Days (Oct. 1~(st)-7~(th)) was less than non-holiday period (Oct. 8~(th)-31~(st)). Alkenes and aromatics dominated ozone formation. The principal component analysis showed that the major sources of VOCs were solvent use and fuel volatilization,gasoline vehicle emissions,industrial production,diesel vehicle emissions and combustion source,and their variance contributions were 36. 7%,15. 5%,8. 0%,6. 6% and 5. 1% respectively. The research shown that control of VOCs should be mainly reduced by controlling solvent use and fuel volatilization,traffic emission (gasoline vehicle emissions and vehicle emissions) in Handan City.
引文
[1]AN Junlin,ZHU Bin,WANG Honglei,et al.Characteristics and source apportionment of VOCs measured in an industrial area of Nanjing,Yangtze River Delta,China[J].Atmospheric Environment,2014,97:206-214.
[2]SMITH M T,ZHANG L P,MCHALE C M,et al.Benzene,the exposure and future investigations of leukemia etiology[J].Chemico-Biological Interactions,2001,192(12):155-159.
[3]BIGAZZI A Y,FIGLIOZZI M A,LUO W T,et al.Breath biomarkers to measure uptake of volatile organic compounds by bicyclists[J].Environmental Science&Technology,2016,50(10):5357-5363.
[4]WEI Wei,LV Zhaofeng,LI Yue,et al.A WRF-Chem model study of the impact of VOCs emission of a huge petrochemical industrial zone on the summertime ozone in Beijing,China[J].Atmospheric Environment,2018,175:44-53.
[5]WEI Wei,LV Zhaofeng,YANG Gan,et al.VOCs emission rate estimate for complicated industrial area source using an inversedispersion calculation method:a case study on a petroleum refinery in northern China[J].Environmental Pollution,2016,218:681-668.
[6]HUI Lirong,LIU Xingang,TAN Qinwen,et al.Characteristics,source apportionment and contribution of VOCs to ozone formation in Wuhan,Central China[J].Atmospheric Environment,2018,192:55-71.
[7]LI Guohao,WEI Wei,SHAO Xia,et al.A comprehensive classification method for VOC emission sources to tackle air pollution based on VOC species reactivity and emission amounts[J].Journal of Environmental Sciences,2018,67(5):77-88.
[8]XU Zhengning,HUANG Xing,NIE Wei,et al.Influence of synoptic condition and holiday effects on VOCs and ozone production in the Yangtze River Delta Region,China[J].Atmospheric Environment,2017,168(11):112-124.
[9]LI Jing,ZHAI Chongzhi,YU Jiayan,et al.Spatiotemporal variations of ambient volatile organic compounds and their sources in Chongqing,a mountainous megacity in China[J].Science of the Total Environment,2018,627:1442-1452.
[10]MENG Chenchen,WANG Litao,ZHANG Fenfen,et al.Characteristics of concentrations and water-soluble inorganic ions in PM2.5in Handan City,Hebei Province,China[J].Atmospheric Research,2016,171:133-146.
[11]ZHANG Chengyu,WANG Litao,QI Mengyao,et al.Evolution of key chemical components in PM2.5and potential formation mechanisms of serious haze events in Handan,China[J].Aerosol and Air Quality Research,2018,18:1545-1557.
[12]马笑,王丽涛,马思萌,等.邯郸市PM2.5成分的时空分布特征及来源[J].环境化学,2017,36(9):1932-1940.MA Xiao,WANG Litao,MA Simeng,et al.Spatial and temporal distribution and source analysis of components in PM2.5,Handan[J].Environmental Chemistry,2017,36(9):1932-1940.
[13]齐孟姚,王丽涛,张城瑜,等.邯郸市黑炭气溶胶浓度变化及影响因素分析[J].环境科学学报,2018,38(5):1751-1758.QI Mengyao,WANG Litao,ZHANG Chengyu,et al.Variation of black carbon aerosol concentration and its influencing factors in Handan City,Hebei Province[J].Acta Scientiae Circumstantiae,2018,38(5):1751-1758.
[14]张晋,谭少波,王丽涛,等.邯郸市大气颗粒物污染特征的监测研究[J].环境科学学报,2013,33(10):2678-2685.ZHANG Jin,TAN Shaobo,WANG Litao,et al.Characteristics of atmospheric particulate matter pollution in Handan City[J].Acta Scientiae Circumstantiae,2013,33(10):2678-2685.
[15]张玉欣,安俊林,王健宇,等.南京北郊大气BTEX变化特征和健康风险评估[J].环境科学,2017,38(2):453-460.ZHANG Yuxin,AN Junlin,WANG Jianyu,et al.Variation characteristics and health risk assessment of BTEX in the atmosphere of northern suburb of Nanjing[J].Environmental Science,2017,38(2):453-460.
[16]王琴,刘宝献,张大伟,等.北京市大气VOCs的时空分布特征及化学反应活性[J].中国环境科学,2017,37(10):3636-3646.WANG Qin,LIU Baoxian,ZHANG Dawei,et al.Temporal and spatial distribution of VOCs and their role in chemical reactivity in Beijing[J].China Environmental Science,2017,37(10):3636-3646.
[17]王鸣,项萍,牛其恺,等.南阳市冬春交替期大气VOCs污染特征及来源解析[J].环境科学学报,2018,38(6):2233-2241.WANG Ming,XIANG Ping,NIU Qikai,et al.Characteristics and source apportionment of ambient VOCs during alternating period between winter and spring in Nanyang City[J].Acta Scientiae Circumstantiae,2018,38(6):2233-2241.
[18]朱少峰,黄晓峰,何凌燕,等.深圳大气VOCs浓度的变化特征与化学反应活性[J].中国环境科学,2012,32(12):2014-2148.ZHU Shaofeng,HUANG Xiaofeng,HE Lingyan,et al.Variation characteristics and chemical reactivity of ambient VOCs in Shenzhen[J].China Environmental Science,2012,32(12):2014-2148.
[19]ZHANG Yanli,WANG Xinming,BARBARA B,et al.Source attributions of hazardous aromatic hydrocarbons in urban,suburban and rural areas in the Pearl River Delta(PRD)Region[J].Journal of Hazardous Materials,2013,250251(2):403-411.
[20]PERRY R,GEE I L.Vehicle emissions in relation to fuel composition[J].Science of the Total Environment,1995,169(123):149-156.
[21]李雷,李红,王学中,等.广州市中心城区环境空气中挥发性有机物的污染特征与健康风险评价[J].环境科学,2013,34(12):4558-4564.LI Lei,LI Hong,WANG Xuezhong,et al.Pollution characteristics and health risk assessment of atmospheric VOCs in the downtown area of Guangzhou,China[J].Environmental Science,2013,34(12):4558-4564.
[22]ANDREAE M O,MERLET P.Emissions of trace gases and aerosolsfrom biomass burning[J].Global Biogeochemical Cycles,2001,15(4):955-966.
[23]WANG Gang,CHENG Shuiyuan,WEI Wei,et al.Characteristics and source apportionment of VOCs in the suburban area of Beijing,China[J].Atmospheric Pollution Research,2016,7(4):711-724.
[24]GENG Fuhai,TIE Xuexi,XU Jianmin,et al.Characterizations of ozone,NOx,and VOCs measured in Shanghai,China[J].Atmospheric Environment,2008,42:6873-6883.
[25]王晓婷.太原市大气挥发性有机化合物特征与来源[D].太原:太原科技大学,2016:23-24.
[26]唐孝炎,张远航,邵敏.大气环境化学[M].2版.北京:高等教育出版社,2006:256-257.
[27]徐惠,张晗,邢振雨,等.厦门冬春季大气VOCs的污染特征及臭氧生成潜势[J].环境科学,2015,36(1):11-17.XU Hui,ZHANG Han,XING Zhenyu,et al.Pollution characteristics and ozone formation potential of ambient VOCs in winter and spring in Xiamen[J].Environmental Science,2015,36(1):11-17.
[28]CARTER W P L.Development of ozone recativity scales for volatile organic compounds[J].Journal of the Air&Waste Management Association,1994,44(7):881-899.
[29]ATKINSON R,AREY J.Atmospheric degradation of volatile organic compounds[J].Chemical Reviews,2003,103(12):4605-4638.
[30]BARBARA B,SIMONE S,SHERWOOD R,et al.Volatile organic compounds in 43 Chinese cities[J].Atmospheric Environment,2005,39(32):5979-5990.
[31]MICHAEL C M,AKLILU Y A,BROWN S G,et al.Source apportionment of volatile organic compounds measured in Edmonton,Alberta[J].Atmospheric Environment,2013,81(2):504-516.
[32]CHANG C C,WANG J L,LUNG S C C,et al.Source characterization of ozone precursors by complementary approaches of vehicular indicator and principal component analysis[J].Atmospheric Environment,2009,43(10):1771-1778.
[33]陆思华,白郁华,张广山,等.机动车排放及汽油中VOCs成分谱特征的研究[J].北京大学学报(自然科学版),2003,39(4):507-511.LU Sihua,BAI Yuhua,ZHANG Guangshan,et al.Study on the characteristics of VOCs source profiles of vehicle exhaust and gasoline emission[J].Acta Scientiarum Naturalium Universitatis Pekinensis,2003,39(4):507-511.
[34]ZALEL A,YUVAL,BRODAY D M.Revealing source signatures in ambient BTEX concentrations[J].Environmental Pollution,2008,156(2):553-562.
[35]TANG J H,CHAN L Y,CHAN C Y,et al.Characteristics and diurnal variations of NMHCs at urban,suburban,and rural sites in the Pearl River Delta and a remote site in South China[J].Atmospheric Environment,2007,41(38):8620-8632.
[36]张玉欣,安俊琳,王俊秀,等.南京工业区挥发性有机物来源解析即其对臭氧贡献评估[J].环境科学,2018,39(2):502-510.ZHANG Yuxin,AN Junlin,WANG Junxiu,et al.Source analysis of volatile organic compounds in Nanjing industrial area and evaluation of their contribution to ozone[J].Environmental Science,2018,39(2):502-510.
[37]LIU Y,SHAO M,FU L,et al.Source profiles of volatile organic compounds(VOCs)measured in China:part I[J].Atmospheric Environment,2008,42(25):6247-6260.
[38]乔月珍,王红丽,黄成,等.机动车尾气排放VOCs源成分谱及其大气反应活性[J].环境科学,2012,4(33):1071-1079.QIAO Yuezhen,WANG Hongli,HUANG Cheng,et al.Source profile and chemical reactivity of volatile organic compounds from vehicle exhaust[J].Environmental Science,2012,4(33):1071-1079.
[39]安俊琳,朱彬,王红磊,等.南京北郊大气VOCs变化特征及来源解析[J].环境科学,2014,35(12):4454-4464.AN Junlin,ZHU Bin,WANG Honglei,et al.Characteristics and source apportionment of volatile organic compounds(VOCs)in the northern suburb of Nanjing[J].Environmental Science,2014,35(12):4454-4464.
[2]SMITH M T,ZHANG L P,MCHALE C M,et al.Benzene,the exposure and future investigations of leukemia etiology[J].Chemico-Biological Interactions,2001,192(12):155-159.
[3]BIGAZZI A Y,FIGLIOZZI M A,LUO W T,et al.Breath biomarkers to measure uptake of volatile organic compounds by bicyclists[J].Environmental Science&Technology,2016,50(10):5357-5363.
[4]WEI Wei,LV Zhaofeng,LI Yue,et al.A WRF-Chem model study of the impact of VOCs emission of a huge petrochemical industrial zone on the summertime ozone in Beijing,China[J].Atmospheric Environment,2018,175:44-53.
[5]WEI Wei,LV Zhaofeng,YANG Gan,et al.VOCs emission rate estimate for complicated industrial area source using an inversedispersion calculation method:a case study on a petroleum refinery in northern China[J].Environmental Pollution,2016,218:681-668.
[6]HUI Lirong,LIU Xingang,TAN Qinwen,et al.Characteristics,source apportionment and contribution of VOCs to ozone formation in Wuhan,Central China[J].Atmospheric Environment,2018,192:55-71.
[7]LI Guohao,WEI Wei,SHAO Xia,et al.A comprehensive classification method for VOC emission sources to tackle air pollution based on VOC species reactivity and emission amounts[J].Journal of Environmental Sciences,2018,67(5):77-88.
[8]XU Zhengning,HUANG Xing,NIE Wei,et al.Influence of synoptic condition and holiday effects on VOCs and ozone production in the Yangtze River Delta Region,China[J].Atmospheric Environment,2017,168(11):112-124.
[9]LI Jing,ZHAI Chongzhi,YU Jiayan,et al.Spatiotemporal variations of ambient volatile organic compounds and their sources in Chongqing,a mountainous megacity in China[J].Science of the Total Environment,2018,627:1442-1452.
[10]MENG Chenchen,WANG Litao,ZHANG Fenfen,et al.Characteristics of concentrations and water-soluble inorganic ions in PM2.5in Handan City,Hebei Province,China[J].Atmospheric Research,2016,171:133-146.
[11]ZHANG Chengyu,WANG Litao,QI Mengyao,et al.Evolution of key chemical components in PM2.5and potential formation mechanisms of serious haze events in Handan,China[J].Aerosol and Air Quality Research,2018,18:1545-1557.
[12]马笑,王丽涛,马思萌,等.邯郸市PM2.5成分的时空分布特征及来源[J].环境化学,2017,36(9):1932-1940.MA Xiao,WANG Litao,MA Simeng,et al.Spatial and temporal distribution and source analysis of components in PM2.5,Handan[J].Environmental Chemistry,2017,36(9):1932-1940.
[13]齐孟姚,王丽涛,张城瑜,等.邯郸市黑炭气溶胶浓度变化及影响因素分析[J].环境科学学报,2018,38(5):1751-1758.QI Mengyao,WANG Litao,ZHANG Chengyu,et al.Variation of black carbon aerosol concentration and its influencing factors in Handan City,Hebei Province[J].Acta Scientiae Circumstantiae,2018,38(5):1751-1758.
[14]张晋,谭少波,王丽涛,等.邯郸市大气颗粒物污染特征的监测研究[J].环境科学学报,2013,33(10):2678-2685.ZHANG Jin,TAN Shaobo,WANG Litao,et al.Characteristics of atmospheric particulate matter pollution in Handan City[J].Acta Scientiae Circumstantiae,2013,33(10):2678-2685.
[15]张玉欣,安俊林,王健宇,等.南京北郊大气BTEX变化特征和健康风险评估[J].环境科学,2017,38(2):453-460.ZHANG Yuxin,AN Junlin,WANG Jianyu,et al.Variation characteristics and health risk assessment of BTEX in the atmosphere of northern suburb of Nanjing[J].Environmental Science,2017,38(2):453-460.
[16]王琴,刘宝献,张大伟,等.北京市大气VOCs的时空分布特征及化学反应活性[J].中国环境科学,2017,37(10):3636-3646.WANG Qin,LIU Baoxian,ZHANG Dawei,et al.Temporal and spatial distribution of VOCs and their role in chemical reactivity in Beijing[J].China Environmental Science,2017,37(10):3636-3646.
[17]王鸣,项萍,牛其恺,等.南阳市冬春交替期大气VOCs污染特征及来源解析[J].环境科学学报,2018,38(6):2233-2241.WANG Ming,XIANG Ping,NIU Qikai,et al.Characteristics and source apportionment of ambient VOCs during alternating period between winter and spring in Nanyang City[J].Acta Scientiae Circumstantiae,2018,38(6):2233-2241.
[18]朱少峰,黄晓峰,何凌燕,等.深圳大气VOCs浓度的变化特征与化学反应活性[J].中国环境科学,2012,32(12):2014-2148.ZHU Shaofeng,HUANG Xiaofeng,HE Lingyan,et al.Variation characteristics and chemical reactivity of ambient VOCs in Shenzhen[J].China Environmental Science,2012,32(12):2014-2148.
[19]ZHANG Yanli,WANG Xinming,BARBARA B,et al.Source attributions of hazardous aromatic hydrocarbons in urban,suburban and rural areas in the Pearl River Delta(PRD)Region[J].Journal of Hazardous Materials,2013,250251(2):403-411.
[20]PERRY R,GEE I L.Vehicle emissions in relation to fuel composition[J].Science of the Total Environment,1995,169(123):149-156.
[21]李雷,李红,王学中,等.广州市中心城区环境空气中挥发性有机物的污染特征与健康风险评价[J].环境科学,2013,34(12):4558-4564.LI Lei,LI Hong,WANG Xuezhong,et al.Pollution characteristics and health risk assessment of atmospheric VOCs in the downtown area of Guangzhou,China[J].Environmental Science,2013,34(12):4558-4564.
[22]ANDREAE M O,MERLET P.Emissions of trace gases and aerosolsfrom biomass burning[J].Global Biogeochemical Cycles,2001,15(4):955-966.
[23]WANG Gang,CHENG Shuiyuan,WEI Wei,et al.Characteristics and source apportionment of VOCs in the suburban area of Beijing,China[J].Atmospheric Pollution Research,2016,7(4):711-724.
[24]GENG Fuhai,TIE Xuexi,XU Jianmin,et al.Characterizations of ozone,NOx,and VOCs measured in Shanghai,China[J].Atmospheric Environment,2008,42:6873-6883.
[25]王晓婷.太原市大气挥发性有机化合物特征与来源[D].太原:太原科技大学,2016:23-24.
[26]唐孝炎,张远航,邵敏.大气环境化学[M].2版.北京:高等教育出版社,2006:256-257.
[27]徐惠,张晗,邢振雨,等.厦门冬春季大气VOCs的污染特征及臭氧生成潜势[J].环境科学,2015,36(1):11-17.XU Hui,ZHANG Han,XING Zhenyu,et al.Pollution characteristics and ozone formation potential of ambient VOCs in winter and spring in Xiamen[J].Environmental Science,2015,36(1):11-17.
[28]CARTER W P L.Development of ozone recativity scales for volatile organic compounds[J].Journal of the Air&Waste Management Association,1994,44(7):881-899.
[29]ATKINSON R,AREY J.Atmospheric degradation of volatile organic compounds[J].Chemical Reviews,2003,103(12):4605-4638.
[30]BARBARA B,SIMONE S,SHERWOOD R,et al.Volatile organic compounds in 43 Chinese cities[J].Atmospheric Environment,2005,39(32):5979-5990.
[31]MICHAEL C M,AKLILU Y A,BROWN S G,et al.Source apportionment of volatile organic compounds measured in Edmonton,Alberta[J].Atmospheric Environment,2013,81(2):504-516.
[32]CHANG C C,WANG J L,LUNG S C C,et al.Source characterization of ozone precursors by complementary approaches of vehicular indicator and principal component analysis[J].Atmospheric Environment,2009,43(10):1771-1778.
[33]陆思华,白郁华,张广山,等.机动车排放及汽油中VOCs成分谱特征的研究[J].北京大学学报(自然科学版),2003,39(4):507-511.LU Sihua,BAI Yuhua,ZHANG Guangshan,et al.Study on the characteristics of VOCs source profiles of vehicle exhaust and gasoline emission[J].Acta Scientiarum Naturalium Universitatis Pekinensis,2003,39(4):507-511.
[34]ZALEL A,YUVAL,BRODAY D M.Revealing source signatures in ambient BTEX concentrations[J].Environmental Pollution,2008,156(2):553-562.
[35]TANG J H,CHAN L Y,CHAN C Y,et al.Characteristics and diurnal variations of NMHCs at urban,suburban,and rural sites in the Pearl River Delta and a remote site in South China[J].Atmospheric Environment,2007,41(38):8620-8632.
[36]张玉欣,安俊琳,王俊秀,等.南京工业区挥发性有机物来源解析即其对臭氧贡献评估[J].环境科学,2018,39(2):502-510.ZHANG Yuxin,AN Junlin,WANG Junxiu,et al.Source analysis of volatile organic compounds in Nanjing industrial area and evaluation of their contribution to ozone[J].Environmental Science,2018,39(2):502-510.
[37]LIU Y,SHAO M,FU L,et al.Source profiles of volatile organic compounds(VOCs)measured in China:part I[J].Atmospheric Environment,2008,42(25):6247-6260.
[38]乔月珍,王红丽,黄成,等.机动车尾气排放VOCs源成分谱及其大气反应活性[J].环境科学,2012,4(33):1071-1079.QIAO Yuezhen,WANG Hongli,HUANG Cheng,et al.Source profile and chemical reactivity of volatile organic compounds from vehicle exhaust[J].Environmental Science,2012,4(33):1071-1079.
[39]安俊琳,朱彬,王红磊,等.南京北郊大气VOCs变化特征及来源解析[J].环境科学,2014,35(12):4454-4464.AN Junlin,ZHU Bin,WANG Honglei,et al.Characteristics and source apportionment of volatile organic compounds(VOCs)in the northern suburb of Nanjing[J].Environmental Science,2014,35(12):4454-4464.