铜陵市冬春季PM10和PM2.5中元素特征及来源分析

目的了解铜陵市颗粒物中的元素特征和主要来源。方法选择2014年冬季和春季的部分时段,在铜陵市国家环境空气监测站——新民污水处理厂(工业区)采集PM_(10)和PM_(2.5)样品,使用X射线荧光光谱(XRF)法进行元素的定量测试。采样期间,冬季的空气质量以良和中、轻度污染为主;春季以中度和重度污染天气为主,采样期间出现了明显的重污染。结果 PM_(2.5)和PM_(10)中S和Si元素的浓度均比其余元素高,P和Cu元素的浓度远低于其余元素。空气污染的指数越高,Fe、Mg、Al、Si则更易富集在PM_(10)上,而K、Cu、Na、Cl、S元素更易富集在PM_(2.5)上,Ca和P这两种元素在PM_(10)和PM_(2.5)上的富集程度相当。空气颗粒物中,富集最多的元素是K,其次为Fe和Mg;元素Cu、K、Cl在PM_(10)中的富集程度要高于PM_(2.5)。结论扬尘(包括地面扬尘和建筑尘)是PM_(10)的最大来源,其次是开采矿山和燃烧生物质,燃煤、炼铜等工企业排放贡献最小;对于PM_(2.5)而言,最大的来源是风沙、扬尘和开采矿山,其次是燃煤、燃烧生物质和其他的工企业排放,炼铜的贡献最小。

Characteristics and Sources of Elements in PM10 and PM2.5 during Spring and Winter in Tongling City

Objective To understand the characteristics and main sources of elements in particulate matters in Tongling City. Methods PM10 and PM2.5 were collected at the National Ambient Air Automatic Monitoring Station-Tongling Xinmin Sewage Treatment Plant (industrial zone) during the winter (January 25 to February 13) and spring (May 16-27) of 2014 to carry out quantitative test on the elements with XRF. During the sampling period, the air quality was mainly at level II or III in the winter, and level IV or V in the spring. There was apparent heavy pollution. Results Compared with the other elements, the concentrations of S and Si in PM2.5 and PM10 were higher, and the concentrations of P and Cu were much lower. With the different air quality index, the higher the air quality index was, the more concentrated elements were detected in a unit volume. K, Cl, Na, Cu and S were more likely to be enriched on PM2.5, while Fe, Al, Mg and Si were more likely to be enriched on PM10. The enrichment of Ca and P in the PM2.5 and PM10 were basically the same. The highest enriched element was K, followed by Mg and Fe, and the enrichment factors of K, Cl and Cu in PM10 were higher than those in PM2.5. Conclusion The dust (including ground dust and building dust) has the largest contribution to PM10, followed by mining and biomass burning, then coal combustion, copper smelting and other industrial enterprise emissions. While the largest contribution to PM2.5 was mainly brought by soil dust, construction dust, road dust and mining, followed by coal combustion, biomass burning and other industrial enterprises emissions, then copper smelting enterprise emissions.