铅稳定同位素在沉积物重金属污染溯源中的应用

Application of stable lead isotopes in tracing heavy-metal pollution sources in the sediments

稳定铅同位素是示踪环境重金属来源的重要手段.通过分析测定泉州湾周边地区常见端元组分及采集自泉州湾洛阳江河口潮间带24个表层沉积物的稳定铅同位素组成,利用铅同位素的指纹参数对沉积物中铅的来源进行示踪.结果表明,潮间带沉积物中的铅主要受汽车尾气、工业生产和污水排放的影响.其中,位于交通繁忙区的采样点因为受到工业及汽车尾气排放的双重影响,污染最为严重.不同来源端元的稳定铅同位素组成相差较大,利用端元组分及沉积物206Pb/207Pb和208Pb/(206Pb+207Pb)比值的差别,可以追溯沉积物中铅的来源.

Stable lead isotope has been widely used to trace the sources of heavy metals in environment. In this paper, the components of stable lead isotopes in the typical point-end matters and 24 surface sediment samples collected from the intertidal zone of Luoyang estuary in Quanzhou Bay were analyzed to trace the lead pollution sources in the sediments. The results showed that the lead pollution in the intertidal sediments was affected mainly by automobile exhaust, industrial effluents and waste water discharge. The samples collected from the busy traffic zones showed the most serious pollution due to the combined effects of the industrial effluents and the automobile emissions. Since different sources are associated with different lead isotope ratios, the components of 206Pb/207Pb and 208Pb/（206Pb＋207Pb）in the point-end matters and the surface sediments could be used to trace the sources of lead contamination in the sediments.