深圳市秋季VOCs空间分布特征与关键减排物种

于2019年11月6~9日开展了深圳全市11点位105种VOCs组分的离线观测，评估了深圳市不同区域的臭氧生成潜势（OFP）和二次有机气溶胶生成潜势（SOAFP）的空间分布特征.结果表明：观测期间深圳市总VOCs，总OFP和总SOAFP分别为44.3×10^-9，272.6和1.1μg/m³.从空间分布来看，VOCs，OFP与SOAFP具有相似特征，均呈现西高东低，北高南低的趋势，西北部工业区存在较多工业排放源，是削减VOCs的关键区域.从物种组成来看，体积浓度较高的物种有丙酮、二氯甲烷、乙烷；OFP较高的物种有1，3-丁二烯、甲苯、乙醛；SOAFP较高的物种有甲苯和二甲苯；且甲苯/苯比值表明溶剂排放等工业源对VOCs影响显著.从空间分布差异来看，正丁烷、甲苯和2，3-二甲基丁烷区域差异性较大.综合以上分析得出，正丁烷、异丁烷、甲苯、二甲苯和1，3-丁二烯作为化学活性较高且本地排放特征最显著的物种，是深圳市区域性O₃和PM_2.5协同防治的关键VOCs组分.

Spatial distribution characteristics of VOCs and key emission reduction species in autumn Shenzhen

Off-line measurements were conducted to obtain 105 VOCs at 11 sites across Shenzhen during November 6~9 in 2019. The spatial distribution characteristics of ozone generation potential (OFP) and secondary organic aerosol generation potential (SOAFP) were further analyzed. The results showed that total VOCs (TVOCs), total OFPs and total SOAFPs were 44.3×10^-9, 272.6 and 1.1μg/m³, respectively. The spatial distributions of TVOCs, OFP and SOAFP had a similar trend with a higher level in the west and north region and a lower level in the east and south region, which indicated that mitigating industrial emissions in the northwestern industrial area is essential for VOCs reduction. Among the different VOC species, acetone, dichloromethane and ethane had higher volume concentrations; 1,3-butadiene, toluene, acetaldehyde had higher OFPs; and toluene and xylene had higher SOAFPs. The ratio of toluene to benzene suggested that industrial sources such as solvent emission made a significant effect on VOCs. Additionally, n-butane, toluene and 2, 3-dimethylbutane had larger regional differences. In conclusion, n-butane, isobutane, toluene, xylenes and 1,3-butadiene, as the most active and local emitting species, were the key VOCs for the coordinated control of O₃ and PM_2.5 in Shenzhen.