MEI Yi, QI Liang, ZHAO Zheng

(State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China)

Abstract：Platinum group elements (PGEs) were used as automobile catalytic converters to reduce greenhouse gases, such as carbon monoxide, nitrogen oxides (NOx) and hydrocarbons in the late 1980s. However, the increasing utility of PGEs as catalytic converters had led high concentrations of PGEs in road dusts and roadside soils of urban areas, which is harmful to ecological environment and human health. This paper evaluated contaminations of PGEs in road dusts and roadside soils around the Guiyang city, Guizhou, China. PGEs were analyzed using the isotope dilution method on ICP-MS. Results indicated that all samples showed raised PGE concentrations relative to the background uncontaminated soil, the PGEs concentrations of road rusts were much higher than those of roadside soils, and Pt, Pd and Rh contents were higher than other PGEs (i.e. Ru and Ir). In addition, clear positive correlations among Pt, Pd and Rh were observed in all samples, indicating that automobile catalysts are composed mainly by Pt, Pd and Rh. The concentrations of Ir, Ru and Os were higher in all samples than in the background uncontaminated soil, and the higher was the Os concentration the lower was 187Os/188Os ratios, suggesting that Ir Ru and Os elements also derived from automobile catalytic converters as impurities of the automobile catalysts.

Keywords: PGE; automobile catalyst; Guiyang city; road dust; roadside soil

EARTH AND ENVIRONMENT Vol.46, No.3, Tot No.323, 2018, Page 245-250