某化学工业区挥发性有机物组成特征及大气化学反应活性

The Composition and Chemical Reactivity of Volatile Organic Compounds(VOCs) in a Certain Chemical Industry Park

采用在线气相色谱法对某化学工业区大气中52种VOCs进行连续90 d的在线观测,以VOCs中不同组分的质量浓度、体积分数、OH消耗速率及最大增量反应活性MIR为统计方法,分析该工业区大气VOCs的组成特征及大气化学反应活性。结果显示,与城区大气中VOCs各类别分担率相比,该工业区大气VOCs中烯烃浓度较高,质量浓度和体积分数分担率分别为32.2%和48.3%。以OH消耗速率及MIR法计,烯烃分别贡献了总大气VOCs反应活性和臭氧生成潜力的85.8%和53.9%,均为首要组分。计算得出该工业区大气VOCs平均KOH为13.52×1012 cm3.mol-1.s-1,高于乙烯,与邻二甲苯相当。烯烃中浓度较高的物种为乙烯与丙烯,以OH消耗速率计,烯烃中反应活性最大的5个物种为异戊二烯、乙烯、顺式-2-丁烯、丙烯及异丁烯;以MIR法计,烯烃中最大臭氧生成潜力排名靠前的5个物种为丙烯、顺式-2-丁烯、异戊二烯、1-丁烯及反式-2-丁烯。

Online GC method was adopted to monitor 52 kinds of VOCs from the ambient air in a certain chemical industrial park for 90 consecutive days.Different mass concentration,volume concentration,OH consumption rate and maximum incremental activity（MIR） of different components of VOCs were used as the statistical method.Composition characteristics and atmospheric chemical reaction of VOCs were analyzed in the chemical industrial park.Results showed that the concentration of alkene in the chemical industrial park was higher that in the central area of the city,whose mass concentration and volume concentration percentage were 32.2% share and 48.3%.Alkene contributed 85.8% and 53.9% to the total VOCs reactivity and ozone formation potential respectively.The average KOH of VOCs was 13.52×1012 cm3·mol-1·s-1 in the chemical industry park,which was similar as that of o-xylene and higher than that of ethylene.Higher concentration of species in the alkene was ethylene and propylene.The reactivity of isoprene,ethylene,cis-2-butene,propylene and isobutylene were higher than other alkenes.Propylene,cis-2-butene,isoprene,1-butene and trans-2-butene were the top five of ozone formation potential.