School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, China.
Atmospheric environment department, Shandong Provincial Eco-environment Monitoring Center, Jinan, China.
Sci Rep. 2020 May 6;10(1):7654. doi: 10.1038/s41598-020-64519-x.
Online monitoring concentrations of PM at five sites were obtained from 01/01/2016 to 31/12/2016 in Laiwu, China, and PM filters were manually sampled for total 34 days at the same sites in four seasons in 2016. PM pollution sources, including soil dust, urban dust, construction dust, coal-fired power plants dust, steel plant dust and motor vehicle exhaust dust were sampled, respectively. The overall mean PM/PM ratio (0.57) in Laiwu was at a relatively lower level compared with that in other Chinese cities, which was higher in winter, indicating fine particulate was the main contributor of atmospheric pollution in this period. NH mainly existed in the form of NHNO and (NH)SO during the sampling periods. Higher sulfate and NH concentrations were in summer while higher nitrate concentrations prevailed in winter. The annual value of OC/EC was (5.38 ± 1.70), higher in summer and lower in winter, and the calculated SOC/OC value (%) was (43.68 ± 12.98)%. The characteristic components were Si, Fe and Ca in urban dust and soil dust; Ca, Mg, and NH in construction dust; Fe, Ca and SO in steel dust; OC, EC and Si in motor vehicle exhaust dust; SO, Al and NH in power plant dust. Compared with other cities at home and abroad, it was found that the concentrations of metal elements in Laiwu were significantly higher than those in foreign cities, and at a medium level in China. With the improved CRAESCMB model, the urban dust was regarded as the receptor and the source of PM and apportioned its secondary sources contributions to PM. The CMB results showed the contributions of secondary sources including sulfate (17%), nitrate (17%) and SOC (13%) to PM accounted for nearly half of all sources. Therefore, more attentions should be paid on secondary sources from the primary emission sources of the motor vehicle exhaust, coal combustion sources especially.
从 2016 年 1 月 1 日至 12 月 31 日，在中国莱芜的五个地点在线监测了 PM 的浓度，并在 2016 年四个季节的同一地点手动采集了总计 34 天的 PM 滤膜。分别采集了土壤尘、城市尘、建筑尘、燃煤电厂尘、钢厂尘和机动车尾气尘等 PM 污染源。莱芜的 PM/PM 比值（0.57）总体平均值相对较低，冬季较高，表明细颗粒物是这一时期大气污染的主要贡献者。在采样期间，NH 主要以 NHNO 和（NH）SO 的形式存在。硫酸盐和 NH 的浓度在夏季较高，而硝酸盐浓度在冬季较高。OC/EC 的年平均值为（5.38±1.70），夏季较高，冬季较低，计算得到的 SOC/OC 值（%）为（43.68±12.98）%。城市尘和土壤尘中的特征成分是 Si、Fe 和 Ca；建筑尘中的特征成分是 Ca、Mg 和 NH；钢厂尘中的特征成分是 Fe、Ca 和 SO；机动车尾气尘中的特征成分是 OC、EC 和 Si；电厂尘中的特征成分是 SO、Al 和 NH。与国内外其他城市相比，莱芜的金属元素浓度明显高于国外城市，处于国内中等水平。利用改进的 CRAESCMB 模型，将城市尘作为 PM 的受体和来源，分配其二次源对 PM 的贡献。CMB 结果表明，硫酸盐（17%）、硝酸盐（17%）和 SOC（13%）等二次源对 PM 的贡献占所有来源的近一半。因此，应更加关注机动车尾气、燃煤等主要污染源的二次源。
