Seasonal Variations of Carbonyls and Their Contributions to the Ozone Formation in Urban Atmosphere of Taiyuan, China
Seasonal Variations of Carbonyls and Their Contributions to the Ozone Formation in Urban Atmosphere of Taiyuan, China
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DOI：
10.3390/atmos12040510
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发表时间：
2021-04
期刊：
影响因子：
2.9
通讯作者：
Ze-jun Liu;Yang Cui;Qiusheng He;Li-li Guo;Xueying Gao;Yan-li Feng;Yuhang Wang;Xinming Wang
中科院分区：
文献类型：
--
作者：
Ze-jun Liu;Yang Cui;Qiusheng He;Li-li Guo;Xueying Gao;Yan-li Feng;Yuhang Wang;Xinming Wang
环境中的羰基化合物是臭氧(O3)和二次有机气溶胶(SOA)的关键前体。为了更好地了解太原市大气中羰基化合物的污染特征，对太原市某城区的4个季节进行了现场采样，共检测到13种羰基化合物。大气中的羰基总浓度为19.67±8.56μg/m~3。甲醛(7.70±4.78μg/m~3)、乙醛(2.95±1.20μg/m~3)和丙酮(5.57±2.41μg/m~3)是主要的羰基化合物，占总数的85%以上。甲醛和丙酮的最高值分别出现在夏季和秋季，最低值出现在冬季。乙醛的四季变化不明显。甲醛和丙酮浓度白天明显升高，夜间下降，而乙醛的日变化不明显。较高的温度和较强的日照强度有利于挥发性有机化合物(VOCs)的光化学反应，提高了夏季的臭氧水平。甲醛和乙醛贡献了70-95%的羰基臭氧生成潜力，最高值分别为268.62μg/m~3和38.14μg/m~3。夏季南风和西南风中的羰基化合物浓度最高，表明太原盆地南部的焦炭行业应首先进行控制，以减轻臭氧污染。
Ambient carbonyls are critical precursors of ozone (O3) and secondary organic aerosols (SOA). To better understand the pollution characteristics of carbonyls in Taiyuan, field samplings were conducted, and 13 carbonyls were detected in an urban site of Taiyuan for the four seasons. The total concentration of carbonyls in the atmosphere was 19.67 ± 8.56 μg/m3. Formaldehyde (7.70 ± 4.78 μg/m3), acetaldehyde (2.95 ± 1.20 μg/m3) and acetone (5.57 ± 2.41 μg/m3) were the dominant carbonyl compounds, accounting for more than 85% of the total carbonyls. The highest values for formaldehyde and acetone occurred in summer and autumn, respectively, and the lowest occurred in winter. The variations for acetaldehyde were not distinct in the four seasons. Formaldehyde and acetone levels increased obviously in the daytime and decreased at night, while acetaldehyde did not show significant diurnal variations. Higher temperature and stronger sunlight intensity could facilitate the photochemical reaction of volatile organic compounds (VOCs) and enhance the O3 levels in summer. Formaldehyde and acetaldehyde contributed 70–95% of carbonyls’ ozone formation potential (OFP) caused by carbonyls with the highest totals of 268.62 μg/m3 and 38.14 μg/m3, respectively. The highest concentrations of carbonyls from south and southwest winds in summer suggest that the coke industries in the southern Taiyuan Basin should be, firstly, controlled for the alleviation of ozone pollution.