广州市大气VOCs污染特征及O3生成潜势分析

利用手工及自动监测数据，结合最大增量反应活性(MIR)系数法，对广州市大气挥发性有机物(VOCs)污染特征及臭氧生成潜势(OFP)进行了研究。结果表明：广州市大气VOCs总体积分数为73.85×10^-9,其中，丙烷、甲醛、乙酸乙酯的体积分数最高，分别为5.59×10^-9、4.87×10^-9、4.25×10^-9。组成特征分析结果显示，含氧挥发性有机物(OVOCs)和烷烃为主要污染物种类，分别贡献了总VOCs的34.32%和32.34%。在空间分布上，各站点VOCs体积分数自南向北不断降低，番禺市桥站(南部，76.16×10^-9)>公园前站(中部，75.58×10^-9)>花都梯面站(北部，69.80×10^-9)。广州市大气中甲醛和乙醛的比值为1.22,表明本地排放对广州市醛酮类化合物的贡献较大；乙苯和间/对-二甲苯的比值为0.35,表明广州市气团老化程度低，VOCs主要受本地排放影响；甲苯和苯的比值显示，公园前站苯系物主要受机...

Analysis on Pollution Characteristics and O3 Formation Potential of Ambient VOCs in Guangzhou

Through adopting manual and automatic monitoring data,maximum incremental reaction activity coefficient method (MIR coefficient method) is used to research the characteristics of atmospheric VOCs pollution and ozone formation potential (OFP) in Guangzhou.The results show that the total volume fraction of atmospheric VOCs in Guangzhou is 73.85×10^-9.Propane,formaldehyde and ethyl acetate are the three compounds with highest volume concentration,which are 5.59×10^-9,4.87×10^-9,4.25×10^-9,respectively.The main pollutants are OVOCs and alkanes,of which the ratio are 34.32% and 32.34%,respectively.The characteristics of regional distribution decreasing from south area to north area.The highest volume fraction from three monitoring stations is Panyu Shiqiao (southern area,76.16×10^-9),and then is Gongyuanqian (central area,75.58×10^-9),and the lowest is Huadu Timian (northern area,69.80×10^-9).The ratio of formaldehyde and acetaldehyde in Guangzhou is 1.22,indicating that the local contribution may be larger.The ratios of ethylbenzene and m/p-xylene indicate that the total volume fraction of VOCs mainly influenced by local emissions.The analysis of the values of toluene and benzene ratio shows that the benzene system of Gongyuanqian is mainly affected by motor vehicle emissions or solvent use sources.The ratios of isopentane and n-pentane show that pentane compounds are more influenced by motor vehicle emissions and fuel evaporation.The volume fractions of VOCs in Guangzhou city did not vary significantly from month to month,with the maximum value occurring in December (84.10×10^-9) and the minimum value in October (65.28×10^-9).The daily variation of major VOCs pollutants is mostly high in the morning and evening and low in the afternoon,and there are often large values during the morning peak,indicating that the contribution of motor vehicle emissions to the atmospheric VOCs in Guangzhou cannot be ignored.The main contribution pollutants of ozone formation potential (OFP) are OVOCs and aromatic hydrocarbon,of which the ratio are 37.78% and 36.62%,respectively.M/p-xylene,formaldehyde,toluene,acetaldehyde,o-xylene are the five pollutants that contribute most to ozone formation potential.