成都市城市环境铅同位素地球化学特征

GEOCHEMICAL FEATURES OF THE URBAN ENVIRONMENTAL LEAD ISOTOPE IN CHENGDU CITY

应用铅同位素示踪原理,对成都市的城市环境包括土壤、大气降尘、主要河流水系表层沉积物的铅同位素地球化学特征进行了研究。土壤的铅同位素组成基本落在燃油铅和燃煤铅的范围,表明燃油铅和燃煤铅是其主要的污染源,交通流量大的城区铅同位素组成与燃油铅接近,郊区则呈现燃煤铅的特征。大气降尘铅同位素组成主要接近燃油铅,部分落在燃油铅与燃煤铅之间,表明大气铅污染主要来自于机动车尾气排放及少量燃煤扬尘。水系表层沉积物的铅同位素组成则主要落在燃煤铅的范围,揭示燃煤铅是其主要污染源。

By applying the theory of lead isotope tracing, this paper studied the geochemical features of the urban environmental lead isotope in Chengdu, including soil, atmospheric dust, and the sediment on the surface of some main river systems. The Pb isotopic compositions of soil are mainly close to those of the fuel and coal fly ash, which indicates that the contamination sources are mainly from coal fly ash, gasoline and diesel oil. In the zone with heavy traffic, the Pb isotopic composition of soil is close to that of fuel, in suburb it takes on the characteristic of coal fly ash. And the Pb isotopic compositions of atmospheric dust are mainly close to the fuel Pb, partly between fuel Pb and coal Pb, indicating that the Pb mainly comes from automotive emissions and a small quantity from coal fly ash. The Pb isotopic compositions of the river sediment are mainly within the range of the coal Pb, which reveals that the coal Pb is the dominating polluting sources.