廊坊市O_(3)骤增(降)过程VOCs浓度变化及臭氧生成潜势分析

Analysis of VOCs Concentration Change and Ozone Formation Potential during O_(3) Sudden Increase(drop)Process in Langfang City

为了解廊坊市夏季O_(3)骤增骤降污染天气过程中VOCs浓度及臭氧生成潜势的变化特征,统计分析2016年~2020年夏季廊坊市区监测所得的53种VOCs质量浓度数据和近地面臭氧(O_(3))浓度数据,并采用臭氧生成潜势方法估算VOCs对O_(3)生成的贡献进行分析。结果表明:整个污染过程及不同时段,烷烃类总质量浓度最大,占比在62%~65%之间,其次是烯/炔烃类和芳香烃类,而烯/炔烃类的臭氧生成潜势(OFP)最大,高浓度阶段其百分比(OFP*)较骤增前、骤降后高6.5和3.8个百分点,其次是烷烃或芳香烃。O_(3)骤增骤降污染整个过程及不同阶段,VOCs质量浓度最大的前十物种中烷烃类占有5~7种,OFP前十位中烯/炔烃占有5~6种,两种统计中相同物种有9个,OFP*前十VOCs物种相对固定,前7位以烯/炔烃为主,反-2-丁烯最高。控制或减少反-2-丁烯等重要烯/炔烃类VOCs物质的排放,可有效控制廊坊O_(3)的生成,降低O_(3)污染程度。通过研究,筛选出了优先控制的VOCs物种,为廊坊城区VOCs减排及O_(3)污染控制措施的制定提供科学依据。

In order to understand the variation characteristics of VOCs concentration and ozone formation potential in the process of ozone sudden increase and sudden drop in summer in Langfang City,the mass concentration data of 53 VOCs and ozone(O_(3))concentration data near the surface from 2016 to 2020 were statistically analyzed,and the contribution of VOCs to O_(3)formation was estimated by ozone formation potential method.The results showed that the total concentration of alkanes was the largest in the whole pollution process and different periods,accounting for 62%~65%,followed by alkenes/alkynes and aromatic hydrocarbons,and alkenes/alkynes had the largest ozone formation potential(OFP),and the percentage of OFP*of alkenes/alkynes in the high concentration stage was 6.5 and 3.8 percentage points higher than that before and after the sudden increase and sudden drop,followed by alkanes or aromatic hydrocarbons.During the whole process and different stages of O_(3)sudden increase and sudden drop pollution,5~7 alkanes were found in the top ten species with the largest VOCs mass concentration,5~6 alkenes/alkynes were found in the top 10 OFP species,and 9 of the same species were found in the two statistics.The top 10 VOCs species of OFP*were relatively fixed,and the top 7 were mainly alkenes/alkynes with the highest trans-2-butene.Controlling or reducing the emission of trans-2-butene and other important olefin/alkyne VOCs can effectively control the formation of O_(3)in Langfang and reduce the degree of O_(3)pollution.Through the research,the priority VOCs species were selected,which provided scientific basis for VOCs emission reduction and O_(3)pollution control measures in Langfang city.