Lei Wenkai, Li Xingru, Yin Zhongyi, Zhang Lan, Zhao Wenji
College of Resource Environment and Tourism, Capital Normal University, Beijing 100048, China.
Department of Chemistry, Capital Normal University, Beijing 100048, China.
Toxics. 2024 Mar 5;12(3):202. doi: 10.3390/toxics12030202.
Black carbon (BC) aerosols are important for absorbing aerosols, affecting global climate change and regional air quality, and potentially harming human health. From March to May 2023, we investigated black carbon aerosol levels and air pollution in Beijing. Employing methods such as linear regression, Potential Source Contribution Function (PSCF) and Concentration-Weighted Trajectory (CWT), we analyzed the characteristics and sources of black carbon aerosols in the region. Results indicate that the light absorption coefficients of BC and BrC decrease with increasing wavelength, with BrC accounting for less than 40% at 370 nm. Daily variations in BC and PM concentrations exhibit similar trends, peaking in March, and BC displays a distinct bimodal hourly concentration structure during this period. Aethalometer model results suggest that liquid fuel combustion contributes significantly to black carbon (1.08 ± 0.71 μg·m), surpassing the contribution from solid fuel combustion (0.31 ± 0.2 μg·m). Furthermore, the significant positive correlation between BC and CO suggests that BC emissions in Beijing predominantly result from liquid fuel combustion. Potential source area analysis indicates that air masses of spring in Beijing mainly originate from the northwest (40.93%), while potential source areas for BC are predominantly distributed in the Beijing-Tianjin-Hebei region, as well as parts of the Shandong, Shanxi and Henan provinces. Moreover, this study reveals that dust processes during spring in Beijing have a limited impact on black carbon concentrations. This study's findings support controlling pollution in Beijing and improving regional air quality.
黑碳气溶胶作为吸光性气溶胶，对全球气候变化、区域空气质量有着重要影响，并可能危害人体健康。2023年3月至5月，我们对北京的黑碳气溶胶水平和空气污染状况展开了调查。运用线性回归、潜在源贡献函数（PSCF）和浓度加权轨迹（CWT）等方法，分析了该区域黑碳气溶胶的特征与来源。结果显示，黑碳（BC）和棕碳（BrC）的光吸收系数随波长增加而降低，在370nm处BrC占比不到40%。BC和PM浓度的日变化趋势相似，3月达到峰值，且在此期间BC呈现出明显的每小时浓度双峰结构。黑碳测定仪模型结果表明，液体燃料燃烧对黑碳的贡献显著（1.08±0.71μg·m），超过了固体燃料燃烧的贡献（0.31±0.2μg·m）。此外，BC与CO之间的显著正相关表明，北京的BC排放主要源于液体燃料燃烧。潜在源区分析表明，北京春季的气团主要来自西北方向（40.93%），而BC的潜在源区主要分布在京津冀地区以及山东、山西和河南的部分省份。此外，该研究还表明，北京春季的沙尘过程对黑碳浓度的影响有限。本研究结果为北京的污染控制和区域空气质量改善提供了支持。
