重庆市典型城区大气VOCs的臭氧生成潜势与来源解析

Ozone Formation Potentials and Source Analysis of Atmospheric VOCs in Typical Urban Areas of Chongqing City

2016年5—8月,对沙坪坝区大气中VOCs进行观测,分析了VOCs浓度水平、组成特征、臭氧生成潜势和来源。结果表明,沙坪坝区大气中56种VOCs的平均浓度为52.1 ppbv(范围为34.3~90.3 ppbv),主要来源于机动车尾气排放和工业源,贡献比分别为32.31%和21.56%,其组成以烷烃和苯系物为主,表现为烷烃>苯系物>烯烃类>乙炔。大气中各类挥发性有机物的臭氧生成趋势(OFP)贡献表现为苯系物>烯烃>烷烃。从物种来看,间/对二甲苯、乙烯、异戊二烯等10种物质对总OFP的贡献十分显著。

From May to August 2016,the author observed the atmospheric VOCs in Shapingba District and analyzed the concentration level,composition characteristics,ozone formation potentials and source of the VOCs. The results showed that the average concentration of56 kinds of VOCs in the atmosphere of Shapingba District was 52. 1 ppbv（ range from 34. 3 to 90. 3 ppbv）. These VOCs mainly came from vehicle exhaust emissions and industrial sources（ 32. 31% and 21. 56% respectively）,and were mainly composed of alkane and benzene series（ specifically alkane,benzene series,and acetylene in descending order）. The ozone formation potentials（ OFP） of all kinds of VOCs in the atmosphere were ranked in descending order as benzene series,olefin and alkane. From the point of species,10 kinds of materials including m-xylene/p-xylene,ethylene and isoprene contributed significantly to the total OFP.