Due to rapid urbanization and industrialization, heavy metals in road-deposited sediments(RDSs) of parks are emitted into the terrestrial, atmospheric, andwater environment, and have asevere impact on residents' and tourists' health. To identify the distribution and characteristic ofheavy metals in RDS and to assess the road environmental quality in Chinese parks, sampleswere collected fromBeijing Olympic Park in the present study. The results indicated that particleswith small grain size (<150 μm) were the dominant fraction. The length of dry period was one ofthe main factors affecting the particle size distribution, as indicated by the variation of sizefractionwith the increase of dry days. Theamount of heavymetal (i.e., Cu, Zn, Pb and Cd) contentwas the largest in particles with small size (<150 μm) among all samples. Specifically, thepercentage of Cu, Zn, Pb and Cd in these particleswas 74.7%, 55.5%, 56.6% and 71.3%, respectively.Heavy metals adsorbed in sediments may mainly be contributed by road traffic emissions. Thecontamination levels of Pb and Cd were higher than Cu and Zn on the basis of the mean heavymetal contents. Specifically, the geoaccumulation index (Igeo) decreased in the order:Cd>Pb>Cu>Zn. This study analyzed the mobility of heavy metals in sediments using partialsequential extractionwith the Tessier procedure. The results revealed that the apparentmobilityand potential metal bioavailability of heavy metals in the sediments, based on the exchangeableand carbonate fractions, decreased in the order: Cd>Zn≈Pb>Cu.© 2015 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences
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