Gu Yuan, Li Qing, Huang Wen-Qian, Zhao Zhu-Zi, Ma Shuai-Shuai, Ye Zhao-Lian
School of Chemical and Environmental Engineering, Jiangsu University of Technology, Changzhou 213001, China.
Huan Jing Ke Xue. 2019 Mar 8;40(3):1091-1100. doi: 10.13227/j.hjkx.201807258.
To investigate the characteristics of diurnal variation of humic-like substances (HULIS) in atmospheric aerosols during winter in Changzhou, a total of 64 fine particle (PM) samples were collected from January 1 to February 28, 2017. In this study, the concentration as well as light absorption parameters of humic-like substances of carbon (HULIS-C) were examined. The results showed that the average day PM and HULIS-C concentrations were 122.60 μg·m and 4.18 μg·m, respectively, slightly higher than those (111.72 μg·m and 3.74 μg·m) at night. Via UV-vis analysis, we found that the ratios of absorbance at 250 nm () of HULIS and WSOA (day:77%, night:75%) were significantly higher than the concentration ratios of HULIS-C and WSOC (day:51%, night:50%), indicating that more UV-absorbing substances and poly-conjugated aromatic structures exist in HULIS. The daytime / and SUVA in HULIS were close to the nighttime ones, indicating that there was no obvious difference between day and night in HULIS with reference to aromaticity and molecular weight. There were no significant differences in MAE and AAE of HULIS between day and night. In addition, to obtain the main influencing factors of HULIS in winter in Changzhou, the correlation analysis of HULIS-C and other chemical components were conducted. The results show that biomass burning, fossil fuel combustion, factory emissions, and especially secondary formation, were the main influencing factors. Moreover, daytime HULIS were mainly influenced by secondary reaction of anthropogenic precursor contaminants, while nighttime HULIS were affected not only by secondary formation by but by also primary combustion emissions.
为研究常州市冬季大气气溶胶中类腐殖质（HULIS）的日变化特征，于2017年1月1日至2月28日共采集了64个细颗粒物（PM）样本。本研究考察了类腐殖质碳（HULIS-C）的浓度以及光吸收参数。结果表明，白天PM和HULIS-C的平均浓度分别为122.60 μg·m³和4.18 μg·m³，略高于夜间（111.72 μg·m³和3.74 μg·m³）。通过紫外可见光谱分析，我们发现HULIS和水溶性有机气溶胶在250 nm处的吸光度比值（白天：77%，夜间：75%）显著高于HULIS-C和水溶性有机碳的浓度比值（白天：51%，夜间：50%），这表明HULIS中存在更多的紫外线吸收物质和多共轭芳香结构。HULIS的白天E2/E3和SUVA与夜间相近，表明HULIS在芳香性和分子量方面昼夜无明显差异。HULIS的MAE和AAE在白天和夜间无显著差异。此外，为了获得常州市冬季HULIS的主要影响因素，对HULIS-C与其他化学成分进行了相关性分析。结果表明，生物质燃烧、化石燃料燃烧、工厂排放，尤其是二次生成，是主要影响因素。此外，白天HULIS主要受人为前驱污染物二次反应的影响，而夜间HULIS不仅受二次生成的影响，还受一次燃烧排放的影响。
