南京地区大气PM_(2.5)潜在污染源硫碳同位素组成特征

Investigations on Sulfur and Carbon Isotopic Compositions of Potential Polluted Sources in Atmospheric PM_(2.5) in Nanjing Region

基于南京地区大气PM_(2.5)潜在污染源,采用EA-IRMS技术分别测定了样品中硫碳同位素组成,并分析不同污染源之间的关联性.结果表明,南京地区煤炭烟灰δ^(34)S值范围为1.8‰~3.7‰,δ^(13)C值范围为-25.50‰^-23.57‰;机动车尾气δ^(34)S值范围为4.6‰~9.7‰,δ^(13)C值范围为-26.32‰^-23.57‰;生物质烟灰δ^(34)S值范围为5.2‰~9.9‰,δ^(13)C值范围为-19.30‰^-30.42‰;扬尘δ^(13)C值为-13.45‰.南京地区煤炭烟灰颗粒物的硫同位素较轻,扬尘的碳同位素较重.对比国内外不同污染源δ^(34)S与δ^(13)C值,南京地区大气PM_(2.5)中的潜在污染源的δ^(34)S与δ^(13)C具有明显的区域性.因此,潜在污染源的δ^(34)S、δ^(13)C值可为南京地区大气PM_(2.5)的源解析提供同位素组成源谱支持.

Potential pollution sources of atmospheric PM2.5 in Nanjing region were collected,and sulfur and carbon isotopic compositions were determined by EA-IRMS synchronously.The results showed that 8 S and 8 C values ranged from 1.8‰-3.7‰ and-25.50‰-- 23.57‰ in coal soot particles;4.6‰-9.1‰ and- 26.32‰-- 23.57‰ in vehicle exhaust;5.2‰-9.9‰ and- 19.30‰-30.42‰ in straw soot particles,respectively.Besides,the δ^13 value of dust was- 13.45‰.It can be observed that sulfur isotopic compositions in coal soot were lower,while the carbon isotopic composition in dust was higher.Comparing with δ^34 and δ^13values in domestic and foreign polluted sources,we found that sulfur and carbon isotopes in atmospheric PM2.5 in Nanjing region presented an obvious regional characteristics.Therefore,the source spectrum of sulfur and carbon isotopic compositions in Nanjing region might provide an insight into source apportionment of atmospheric PM2.5.