贵阳市PM_(2.5)主要污染源源成分谱分析

Analysis of the source componential spectrum of PM_(2.5) emission in Guiyang

为建立贵阳市PM_(2.5)主要污染源的源成分谱,将主要污染源划分为土壤风沙尘、城市扬尘、道路尘、建筑水泥尘、钢铁尘、燃煤尘和汽车尾气尘7类,分别采集各类污染源样品,然后进行再悬浮采样,并采用电感耦合等离子体质谱仪、离子色谱仪及热光碳分析仪分别分析样品中20种无机元素、3种水溶性离子和碳组分的质量分数。结果表明,7类污染源成分谱之间存在明显的区别,其中土壤风沙尘、建筑水泥尘、钢铁尘、汽车尾气尘、燃煤尘5类污染源谱都有明显的标识元素,分别为Si、Ca、Fe、OC、EC和Se,而道路尘和城市扬尘属混合尘源,无单一标识元素,道路尘显示出土壤风沙尘、建筑水泥尘、燃煤尘、机动车尾气和工业排放的混合污染特征,城市扬尘则主要受土壤风沙尘和建筑水泥尘的影响。

The present article is dedicated to an analysis of the spectrum profile of the source componential elements of PM_（2.5）e-mission in Guiyang. In order to establish the PM_（2.5）source profile of the city,we have chosen the representative components of the pollution sources in the city,which can be identified as the soil dust,and those of the urban fugitive pollutants,and those of the road dust,the construction,the gas-combustion exhausts,etc.And,then,we have all sampled the dust waste exhausts based on the identification and apportion of the sources of PM_（2.5）and further treated by the re-suspension sampling system. We have also analyzed carbon component,water-solubility component and inorganic components in those samples with ICP- MS,the chromatography and TOR,respectively from testing the samples. The results of our investigation and analysis indicate that it is necessary to select the dominant pollutant marker for each source profile. For example,we have chosen the marker element of soil dust Si as the representative one,whereas Ca and cement dust as the dominant marker element for the construction dust. And,in the same way,Fe is the marker element of the steel dust whereas OC is the marker element of automobile exhausts,and EC and Se are marker element of coal dust. Meanwhile,it has been verified that,the road dust and urban fugitive dust belong to the same sort of mixed sources,though they may not have the same marker elements.For example,the road dust is mainly composed of soil dust,while the construction and cement dust,coal dust,and the motor vehicle exhaust,should be categorized into the industrial pollutant emission. Among all the pollution markers,the urban fugitive dust is mainly affected by the soil dust and the construction and cement dust. What is more,the emission inventory for the chemical components should be derived by multiplying PM_（2.5）emission by the mass fractions of all the aforementioned components in the representative source profile. Statistically speaking,the maximum content in the soil dust and urban fugitive dust is Si,whose mass contribution to the entire pollution emission account for 31. 86%and 22. 56%,respectively; Nevertheless,the maximum content of the pollution markers in the road dust and the construction dust are Ca, whose mass fraction takes up about 27. 37% and33. 57%,respectively. As to the maximum content in steel dust,the emission of the waste metal is Fe,whose mass fraction occupies 37. 17%. And,last of all,the maximum pollutant in the coal dust is EC,whose mass fraction is 20. 07%,whereas the maximum content in the car tail exhaust emission is OC,whose mass contribution to the total emission of PM_（2.5）is 19. 18%. All the above statistics results have been confirmed by the published literatures as to the source profile approximates for PM_（2.5）emission in the urban areas of Guiyang.