| 不同浓度臭氧对单颗粒气溶胶化学组成的影响 |
| 摘要点击 2142 全文点击 712 投稿时间：2019-10-18 修订日期：2019-12-15 |
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| 中文关键词 臭氧 单颗粒气溶胶 二次气溶胶 醛酮化合物 光化学氧化 |
| 英文关键词 ozone single particles secondary aerosols aldone compounds photochemical oxidation |
| 作者 | 单位 | E-mail | | 吴梦曦 | 暨南大学质谱仪器与大气环境研究所, 广州 510632
广东省大气污染在线源解析系统工程技术研究中心, 广州 510632 | 1565330787@qq.com | | 成春雷 | 暨南大学质谱仪器与大气环境研究所, 广州 510632
广东省大气污染在线源解析系统工程技术研究中心, 广州 510632 | | | 黄渤 | 暨南大学质谱仪器与大气环境研究所, 广州 510632
广东省大气污染在线源解析系统工程技术研究中心, 广州 510632
广州禾信仪器股份有限公司, 广州 510530 | | | 李梅 | 暨南大学质谱仪器与大气环境研究所, 广州 510632
广东省大气污染在线源解析系统工程技术研究中心, 广州 510632 | limei2007@163.com | | 陈多宏 | 广东省环境监测中心, 国家环境保护区域空气质量监测重点实验室, 广东省环境保护大气二次污染研究重点实验室, 广州 510308 | chenduohong@139.com |
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| 中文摘要 |
| 为探讨高浓度臭氧（O3）对气溶胶生成与老化过程的影响，本研究利用单颗粒气溶胶质谱仪（SPAMS）于2018年10月在广东省鹤山大气环境超级监测站进行观测.观测期间根据O3浓度的高低，定义了高臭氧浓度（PH）时段和低臭氧浓度（PL）时段，其中PH时段O3平均浓度为117μg·m-3，PL时段平均浓度为25μg·m-3.依据化学组成的不同，观测期间单颗粒主要包含老化元素碳颗粒（EC-aged）、二次颗粒（Sec）和老化有机碳颗粒（OC-aged）.PH时段单颗粒总数（348085）高于PL时段（224797），且PH时段Sec颗粒（37.1%）的占比显著高于PL时段（27.8%），而EC-aged颗粒（32.1%）则低于PL时段（44.1%），OC-aged颗粒（13.5%）略高于PL时段（10.4%）.含硝酸盐（nitrate）和硫酸盐（sulfate）的颗粒数浓度在PH时段有显著的昼夜变化，而在PL时段无昼夜变化，Sec颗粒和EC-aged颗粒中硝酸盐和硫酸盐的峰面积PH时段高于PL时段，表明在PH时段通过二次反应过程生成硝酸盐和硫酸盐的量多于PL时段.此外，Sec颗粒中硝酸盐和硫酸盐的峰面积显著高于EC-aged颗粒，表明Sec颗粒的老化程度更深.本研究选取了乙酸根（59CH3CO2-）和乙二醛（73C2HO3-）来代表醛酮化合物在单颗粒气溶胶中的变化特征.PH时段Sec和OC-aged颗粒中59CH3CO2-和73C2HO3-的数浓度与峰面积显著高于PL时段，且在PH时段呈现显著的日变化特征，峰值出现在O3浓度高峰后2 h，在PL时段峰值显著降低，该变化趋势与Sec和OC-aged颗粒的数浓度变化特征相同，表明高浓度O3有利于VOCs氧化生成59CH3CO2-和73C2HO3-.综上，高臭氧浓度时段光化学反应较强，二次气溶胶组分的含量显著增加，光化学反应增强是PH时段臭氧浓度升高和单颗粒中二次组分增加的主要原因. |
| 英文摘要 |
| To investigate the effect of high concentration of ozone (O3) on the aerosol formation and aging process, this study made observations using a single-particle aerosol mass spectrometer (SPAMS) at Heshan Atmospheric Environment Supervision Station in Guangdong Province in October 2018. During the observation period, a high ozone concentration period (PH) and a low ozone concentration period (PL) were defined according to the level of O3 concentration. The average O3 concentration during PH was 117 μg·m-3, and that of PL was 25 μg·m-3. According to the difference in chemical composition, single particles mainly included aging element carbon particles (EC-aged), secondary particles (Sec), and aging organic carbon particles (OC-aged) during the observation period. The total number of single particles in PH (348085) was higher than in PL (224797), and the proportion of Sec particles (37.1%) in PH was significantly higher than in PL (27.8%), whereas the proportion of EC-aged particles in PH (32.1%) was lower than in PL (44.1%). The proportion of OC-aged particles in PH (13.5%) was slightly higher than in PL (10.4%). The concentration of particles containing nitrate and sulfate showed significant diurnal changes during PH, but no diurnal changes during PL. The peak area of nitrate and sulfate in the Sec particles and EC-aged particles in PH was higher than in PL, which indicates that the amount of nitrate and sulfate produced by the secondary reaction process in PH was more than in PL. In addition, the peak areas of nitrate and sulfate in the Sec particles were significantly higher than those in the EC-aged particles, indicating that the age of the Sec particles was greater. In this study, acetate (59CH3CO2-) and glyoxal (73C2HO3-) were selected to represent the changing characteristics of aldehyde and ketone compounds in single-particle aerosols. The number concentration and peak area of 59CH3CO2- and 73C2HO3- in Sec and OC-aged particles in PH were significantly higher than those in PL, and showed significant diurnal variation characteristic during PH. The peak appeared 2 h after the peak of O3 concentration. In PL, the peak value was significantly reduced, and the change trend was the same as that of the number concentration of Sec and OC-aged particles, indicating that high concentration of O3 is beneficial to the oxidation of VOCs to 59CH3CO2- and 73C2HO3-. In summary, high concentration of O3 and enhancement of secondary species in single particles were due to the strong photochemical reactions during PH. |
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