College of Environment, Zhejiang University of Technology, Hangzhou, 310032, China.
Zhejiang Ecological and Environmental Monitoring Center, Hangzhou, 310012, China.
Chemosphere. 2022 Sep;303(Pt 3):135026. doi: 10.1016/j.chemosphere.2022.135026. Epub 2022 May 26.
Fine particulate matter (PM) significantly impacts global air quality and human health due to its smaller particle size and larger specific surface area. Nitrogen and carbon aerosols, as the main components of PM, play key roles in air pollution. This study identified the sources and seasonal variation of nitrogen and carbon aerosols in PM in typical cities of Zhejiang. The annual average PM concentrations of Hangzhou (HZ), Ningbo (NB), and Huzhou (HUZ) were 39.8 ± 19.1 μg m, 40.0 ± 21.5 μg m, and 50.1 ± 22.6 μg m, respectively, which exceeded the Chinese air quality limit of 35.0 μg m. The results showed that the concentrations of nitrogen aerosols (NO and NH) in water-soluble inorganic ions were higher at 9.6 ± 4.6 μg m, 9.0 ± 4.5 μg m and 11.5 ± 5.4 μg m in HZ, NB and HUZ, respectively, especially in winter, accounting for over 60% of the total. The annual average δN values of PM were 6.2 ± 1.9‰, 6.4 ± 2.2‰ and 6.7 ± 1.9‰ in HZ, NB and HZ, respectively; the δN values in winter were relatively low. A Bayesian isotopic mixing model was employed to analyse the sources of nitrogen aerosols in winter; the results showed that nitrogen concentration was mainly affected by NH and NO emitted by motor vehicle exhaust, coal combustion, biomass combustion, biogenic soil emissions, animal wastes and ocean evaporation (NB). In addition, the carbon component analysis of PM showed that the annual average mass concentration of TC accounted for 18.7%, 16.4% and 20.1% of PM in HZ, HUZ and NB, respectively. The same isotope model was used to analyse the sources of carbon aerosols; the results showed that carbon aerosols were mainly affected by the sources of motor vehicle exhaust, coal combustion, biomass combustion and dust. In the PM in Zhejiang, the most contributory sources of nitrogenous aerosols and carbon aerosols were motor vehicle exhaust sources.
细颗粒物（PM）由于其较小的粒径和较大的比表面积，对全球空气质量和人类健康有重大影响。氮和碳气溶胶作为 PM 的主要成分，在空气污染中起着关键作用。本研究确定了浙江省典型城市 PM 中氮和碳气溶胶的来源和季节性变化。杭州（HZ）、宁波（NB）和湖州（HUZ）的年平均 PM 浓度分别为 39.8±19.1μg m、40.0±21.5μg m 和 50.1±22.6μg m，超过中国 35.0μg m 的空气质量限值。结果表明，水溶性无机离子中氮气溶胶（NO 和 NH）的浓度较高，分别为 9.6±4.6μg m、9.0±4.5μg m 和 11.5±5.4μg m，尤其是在冬季，占总浓度的 60%以上。HZ、NB 和 HUZ 的 PM 年平均 δN 值分别为 6.2±1.9‰、6.4±2.2‰和 6.7±1.9‰；冬季 δN 值相对较低。采用贝叶斯同位素混合模型分析冬季氮气溶胶的来源；结果表明，氮浓度主要受机动车尾气、煤燃烧、生物质燃烧、生物土壤排放、动物废物和海洋蒸发（NB）排放的 NH 和 NO 的影响。此外，PM 中的碳成分分析表明，TC 的年平均质量浓度分别占 HZ、HUZ 和 NB 中 PM 的 18.7%、16.4%和 20.1%。同样的同位素模型被用于分析碳气溶胶的来源；结果表明，碳气溶胶主要受机动车尾气、煤燃烧、生物质燃烧和扬尘的影响。在浙江省的 PM 中，氮气溶胶和碳气溶胶的最主要贡献源是机动车尾气源。
