College of Geosciences and Engineering, North China University of Water Resources and Electric Power, Zhengzhou, Henan 450046, China.
College of Resources and Environmental Engineering, Guizhou University, Guiyang, Guizhou 550025, China.
Sci Total Environ. 2019 Feb 10;650(Pt 1):566-574. doi: 10.1016/j.scitotenv.2018.09.033. Epub 2018 Sep 4.
Twenty-six pairs of PM and PM samples were collected during haze episodes in Zhengzhou (113°28' E, 34°37' N), a highly populated city in North China. The samples were used to examine the inorganic ion chemistry of particulate matter (PM) of local origin at light (PM < 60 μg m and PM < 135 μg m), medium (PM: 60-170 μg m and PM: 135-325 μg m), and severe (PM > 170 μg m and PM > 325 μg m) pollution levels. At the light and severe pollution levels, the increase of PM was accounted for by the increase of PM, and the variation of PM was small. In contrast, the increase of PM at the medium pollution level was caused by the increase in both PM and PM. Sulfate (SO), nitrate (NO), ammonium (NH), and chloride in the form of ammonium chloride (Cl) accounted for 47.8% and 60.3% of the PM mass at the light and severe levels, respectively. These values indicate a large contribution of secondary inorganic species to the PM growth. As the pollution level changed from light to medium, the contribution of SO to the growth of PM decreased from 49.0% to 15.1%, while those of NO and Cl increased from 25.1% and 0.6% to 32.5% and 2.8%, respectively, indicating the substantial production of nitrate and chloride. At the severe level, the contribution of SO was 30.1%, while those of NO and Cl were 5.9% and 0.5%, respectively, suggesting a hindering effect of sulfate on the production of nitrate and chloride. These results indicate that the production of secondary species with the increase of PM was dominated by sulfate-associated conversions at the light and severe pollution levels and was substantially influenced by nitrate- and chloride-associated conversions at the medium pollution level. The estimation of carbonate presence in the PM indicates that part of the carbonate in coarse particles (PM) of crustal origin enhanced sulfate production via heterogeneous surface reactions. Quantification of the contribution of primary and secondary species to PM showed that it was dominated by both primary and secondary particles at the light pollution level, and it was mainly composed of secondary species at the severe pollution level.
在华北人口稠密的城市郑州（113°28' E，34°37' N），在雾霾期间收集了 26 对 PM 和 PM 样本。这些样本用于检查当地来源的颗粒物（PM）的无机离子化学特性，PM 值处于轻污染（PM<60μg/m 和 PM<135μg/m）、中污染（PM：60-170μg/m 和 PM：135-325μg/m）和重污染（PM>170μg/m 和 PM>325μg/m）水平。在轻污染和重污染水平下，PM 的增加是由 PM 的增加引起的，而 PM 的变化较小。相比之下，中污染水平下 PM 的增加是由 PM 和 PM 的增加共同引起的。硫酸盐（SO）、硝酸盐（NO）、铵（NH）和氯化铵（Cl）形式的氯离子占轻污染和重污染水平下 PM 质量的 47.8%和 60.3%。这些值表明二次无机物种对 PM 增长的贡献很大。随着污染水平从轻污染变为中污染，SO 对 PM 增长的贡献从 49.0%下降到 15.1%，而 NO 和 Cl 的贡献从 25.1%和 0.6%增加到 32.5%和 2.8%，表明硝酸盐和氯化物的大量生成。在重污染水平下，SO 的贡献为 30.1%，而 NO 和 Cl 的贡献分别为 5.9%和 0.5%，表明硫酸盐对硝酸盐和氯化物的生成有抑制作用。这些结果表明，随着 PM 的增加，二次物种的生成主要受轻污染和重污染水平下硫酸盐相关转化的控制，而中污染水平下受硝酸盐和氯化物相关转化的显著影响。对 PM 中碳酸盐存在的估算表明，部分地壳来源的粗粒子（PM）中的碳酸盐通过非均相表面反应增强了硫酸盐的生成。对 PM 中一次和二次物种贡献的定量表明，在轻污染水平下，它主要由一次和二次粒子组成，在重污染水平下，它主要由二次物种组成。
