Siudek Patrycja, Frankowski Marcin, Siepak Jerzy
Department of Water and Soil Analysis, Faculty of Chemistry, Adam Mickiewicz University in Poznań, Umultowska 89b Street, 61-614, Poznań, Poland,
Environ Sci Pollut Res Int. 2015 Jul;22(14):11087-96. doi: 10.1007/s11356-015-4356-3. Epub 2015 Mar 22.
Spatial and temporal variability of carbon species in rainwater (bulk deposition) was studied for the first time at two sites located in urban area of Poznań City and protected woodland area (Jeziory), in central Poland, between April and December 2013. The mean concentration of total carbon (TC) for the first site was 5.86 mg L(-1), whereas for the second, 5.21 mg L(-1). Dissolved organic carbon (DOC) concentration accounted for, on average, 87 and 91 % of total carbon in precipitation at urban and non-urban sites, respectively. Significant changes in TC concentrations in rainwater were observed at both sites, indicating that atmospheric transformation, transport, and removal mechanisms of carbonaceous particles were affected by seasonal fluctuations in biogenic/anthropogenic emission and meteorological conditions (i.e., precipitation height and type, atmospheric transport). During the warm season, the DOC concentration in rainwater was mostly influenced by mixed natural and anthropogenic sources. In contrast, during the cold season, the DOC concentration significantly increased mainly as a result of anthropogenic activities, i.e., intensive coal combustion, domestic wood burning, high-temperature processes, etc. In addition, during the winter measurements, significant differences in mean DOC concentration (Kruskal-Wallis test, p < 0.05) were determined for rain, mixed rain-snow, and snow samples. It was found that rainwater TOC concentration measured in Poznań and Jeziory reflected a combination of local, regional, and distant sources. Backward trajectory analysis showed that air masses advected from polluted regions in western Europe largely affect the DOC amount in rainwater, both at urban and non-urban sites. These data imply that carbonaceous compounds are of crucial importance in atmospheric chemistry and should be considered as an important parameter while considering wet deposition, reactions with different substances, especially over polluted environments.
2013年4月至12月期间，首次在波兰中部波兹南市区的两个地点以及受保护的林地（Jeziory）研究了雨水中（总体沉降）碳物种的时空变异性。第一个地点总碳（TC）的平均浓度为5.86 mg L(-1)，而第二个地点为5.21 mg L(-1)。溶解有机碳（DOC）浓度在城市和非城市站点的降水中分别平均占总碳的87%和91%。在两个站点均观察到雨水中TC浓度的显著变化，这表明含碳颗粒物的大气转化、传输和去除机制受生物源/人为源排放以及气象条件（即降水高度和类型、大气传输）的季节性波动影响。在温暖季节，雨水中的DOC浓度主要受自然和人为混合源的影响。相比之下，在寒冷季节，DOC浓度显著增加主要是由于人为活动，即密集的煤炭燃烧、家庭木材燃烧、高温过程等。此外，在冬季测量期间，确定了雨、雨夹雪和雪样本的平均DOC浓度存在显著差异（Kruskal-Wallis检验，p < 0.05）。研究发现，在波兹南和Jeziory测量的雨水中总有机碳（TOC）浓度反映了本地、区域和远距离源的综合影响。后向轨迹分析表明，从西欧污染地区平流而来的气团对城市和非城市站点雨水中的DOC含量都有很大影响。这些数据表明，含碳化合物在大气化学中至关重要，在考虑湿沉降、与不同物质的反应时，尤其是在污染环境中，应将其视为一个重要参数。
