• 关键词：挥发性有机物  体积分数  化学反应活性  OH消耗速率  臭氧生成潜势

• 基金项目：公益性科研专项计划课题(No. 201009001); 环境模拟与污染控制国家重点联合实验室专项经费资助项目(No. 11K05ESPCP); 上海市科委资助项目(No. 10231203802)

• 陈长虹
• 1. 上海市环境科学研究院,上海 200233;
  2. 华东理工大学资源与环境工程学院,上海 200237

• 苏雷燕
• 华东理工大学资源与环境工程学院,上海 200237

• 王红丽
• 上海市环境科学研究院,上海 200233

• 黄成
• 上海市环境科学研究院,上海 200233

• 李莉
• 上海市环境科学研究院,上海 200233

• 周敏
• 华东理工大学资源与环境工程学院,上海 200237

• 乔月珍
• 华东理工大学资源与环境工程学院,上海 200237

• 陈宜然
• 上海市环境科学研究院,上海 200233

• 陈明华
• 上海市环境科学研究院,上海 200233

• 黄海英
• 上海市环境科学研究院,上海 200233

• 张钢锋
• 上海市环境科学研究院,上海 200233

• 摘要：2010年在上海市城区开展了为期一年的连续观测,采用自动在线GC-FID方法定量测试了大气中56个VOCs物种的浓度.结果发现,上海市城区大气VOCs的全年小时体积分数为(2.47~301.48)×10^-9,平均体积分数为(26.45±23.36)×10^-9,其中,烷烃占46.72%,芳香烃占33.18%,烯烃占11.33%,乙炔占8.76%.T/B(甲苯/苯)为3.51±2.40,表明气团除受机动车影响外,受溶剂、油气和LPG挥发等其他VOCs排放的影响也比较突出;E/E(乙烷/乙炔)为0.98±0.68,表明气团存在老化现象,且春冬季节气团光化学年龄相对较短,夏秋季节光化学年龄相对较长.VOCs的浓度水平和组成在不同风向风速影响下存在一定差异,西南部石化和化工企业排放的VOCs对城区的影响明显,其主要物种为芳香烃和烯烃;该地区气团的OH消耗速率常数(K^OH)为8.05×10^-12 cm³·分子^-1·s^-1,平均VOCs最大O₃增量反应活性(4.00 mol·mol^-1)与乙烯相当,平均反应活性较强;对OH消耗速率(L^OH)贡献率最大的是烯烃(42.21%)和芳香烃(40.83%),对臭氧生成潜势(OFP)贡献率最大的是芳香烃(62.75%)和烯烃(21.70%),VOCs的关键活性组分是二甲苯、甲苯、乙苯、乙烯、丙烯、反-2-丁烯及异戊二烯.

• Abstract：The ambient concentration of 56 VOCs species were measured continuously in the urban of Shanghai, China from Jan. 1 to Dec. 31, 2010 by GC-FID instrument. The hourly mixing ratio of ambient VOCs in the urban of Shanghai is (2.47~301.48)×10^-9, and the average mixing ratio is (26.45±23.36)×10^-9. The major compositions of VOCs were alkanes, alkenes, aromatics, and acetylenes, accounting for 46.72%, 33.18%, 11.33%, and 8.76% of the total VOCs, respectively. The ratios of T/B (toluene/benzene) was found at the level of 3.51±2.40, indicating that vehicles were not the only source of ambient VOCs. Others sources, e.g. solvent use, evaporation of gasoline and LPG, made large contribution to VOCs as well. The ratio of E/E (ethane/ethyne) was 0.98±0.68, indicating that the plumes were aged. According to the ratio of E/C (ethyne/CO), the plumes were fresh in spring and winter, and photochemical ages were relatively long in summer and autumn. The constant of ambient VOCs radical loss rate (K^OH) was 8.05×10^-12cm³·molecule^-1·s^-1 and the maximum O₃ incremental reactivity (MIR) was 4.00 mol·mol^-1, which stated that the chemical reactivity of ambient air in urban Shanghai was similar as ethylene. The mixing ratio and composition of VOCs varied with wind direction and wind speed, as a result of different locations of VOCs emission sources. For the OH radical loss rate (L^OH), the alkenes and aromatics were the most important contributors, and accounted for 42.21% and 40.83%, respectively. In the case of ozone formation potential (OFP), the alkenes and aromatics accounted for 21.70% and 62.75%, respectively. The key reactive species were xylene, toluene, ethylbenzene, ethylene, propylene, trans-2-butene, and isoprene.

• Key words：volatile organic compounds  mixing ratio  chemical reactivity  OH radical loss rate  ozone formation potential

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