Santos Patrícia S M, Santos Eduarda B H, Duarte Armando C
CESAM - Centre for Environmental and Marine Studies, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
CESAM - Centre for Environmental and Marine Studies, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
J Environ Manage. 2014 Dec 1;145:71-8. doi: 10.1016/j.jenvman.2014.04.022. Epub 2014 Jul 5.
Bulk deposition can remove atmospheric organic and inorganic pollutants that may be associated with gaseous, liquid or particulate phases. To the best of our knowledge, few studies have been carried out, which simultaneously analyse the presence of organic and inorganic fractions in rainwater. In the present work, the complementarity of organic and inorganic data was assessed, through crossing data of some organic [DOC (dissolved organic carbon), absorbance at 250 nm (UV250nm), integrated fluorescence] and inorganic [H(+), NH4(+), NO3(-), non sea salt sulphate (NSS-SO4(2-))] parameters measured in bulk deposition in the coastal urban area of Aveiro. The organic and inorganic parameters analysed were positively correlated (p<0.001) except for H(+), which suggests that a constant fraction of chromophoric dissolved organic matter (CDOM) came from anthropogenic sources. Furthermore, the inverse correlations observed for the organic and inorganic parameters with the precipitation amount suggest that organic and inorganic fractions were incorporated into the rainwater partially by below-cloud scavenging of airborne particulate matter. This is in accordance with the high values of DOC and NO3(-) found in samples associated with marine air masses, which were linked in part to the contribution of local emissions from vehicular traffic. DOC of bulk deposition was the predominant constituent when compared with the constituents H(+), NH4(+), NO3(-) and NSS-SO4(2-), and consequently bulk deposition flux was also highest for DOC, highlighting the importance of DOC and of anthropogenic ions being simultaneously removed from the atmosphere by bulk deposition. However, it was verified that the contribution of anthropogenic sources to the DOC of bulk deposition may be different for distinct urban areas. Thus, it is recommended that organic and inorganic fractions of bulk deposition are studied together.
湿沉降可以去除大气中的有机和无机污染物，这些污染物可能与气态、液态或颗粒相有关。据我们所知，很少有研究同时分析雨水中有机和无机成分的存在情况。在本研究中，通过交叉分析在阿威罗沿海城市地区湿沉降中测量的一些有机参数[溶解有机碳（DOC）、250nm处的吸光度（UV250nm）、积分荧光]和无机参数[H(+)、NH4(+)、NO3(-)、非海盐硫酸盐（NSS-SO4(2-)）]的数据，评估了有机和无机数据的互补性。除H(+)外，分析的有机和无机参数呈正相关（p<0.001），这表明一定比例的发色溶解有机物（CDOM）来自人为源。此外，有机和无机参数与降雨量的负相关表明，有机和无机成分部分是通过云下对空气中颗粒物的清除而进入雨水的。这与在与海洋气团相关的样本中发现的高DOC和NO3(-)值一致，这部分与车辆交通的本地排放贡献有关。与H(+)、NH4(+)、NO3(-)和NSS-SO4(2-)成分相比，湿沉降中的DOC是主要成分，因此DOC的湿沉降通量也最高，突出了DOC和人为离子通过湿沉降同时从大气中去除的重要性。然而，已证实人为源对不同城市地区湿沉降中DOC的贡献可能不同。因此，建议同时研究湿沉降的有机和无机成分。
