中国六个主要城市的酸芳香化合物:不同形成机制对光吸收特性的影响
Shasha Huang1, Zhenxing Shen1, Xueting Yang1
1Department of Environmental Sciences and Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
The Science of the total environment
|April 25, 2024
概括
中国大城市中的酸芳香化合物 (NACs) 有助于棕色碳吸收光. 煤炭燃烧和二次形成是关键来源,其中酸甲醇可显著增加气溶的吸收.
科学领域:
- 大气化学 大气化学
- 气溶科学 气溶科学
- 环境化学环境化学
背景情况:
- 酸芳香化合物 (NACs) 是在气溶中发现的显著吸光和活性的有机化合物.
- 了解NAC的来源,分区和对棕色碳 (BrC) 属性的影响对于空气质量评估至关重要.
研究的目的:
- 在中国六个主要城市调查NAC的度,来源,气体颗粒分离以及它们对BrC光吸收的贡献.
- 确定NAC的主要组成部分及其在气溶光学特性中的不同作用.
主要方法:
- 在冬季和夏季从中国六个大城市收集的PM2.5样本中分析了NAC (酸甲醇,酸,酸盐酸).
- 对污染物种的相关性分析以确定NAC的来源 (例如,煤炭燃烧,生物质燃烧,二次形成).
- 量化NAC对BrC光吸收和质吸收效率 (MAE) 的贡献.
主要成果:
- 在冬季 (9.15158.8 ng/m3) 和夏季 (2.029.39 ng/m3) 之间,NAC的度有显著的变化.
- 煤炭和生物质燃烧是北方城市在冬季的主要NACs来源,而夏季在南方城市占主导地位的二次形成.
- 亚甲基醇表现出最高的质量吸收效率,显著增强气溶光吸收,而亚醇和亚盐酸的吸收贡献较低.
结论:
- 在中国大城市的BrC光吸收中,NAC起着显著的作用,其来源和成分因季节和区域而异.
- 甲醇是光吸收的关键贡献者,而甲和甲酸对光吸收的影响较小.
- NACs的形成途径,特别是catechols和guaiacols的氧化和化,直接影响气溶的光学特性.
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