摘要

An investigation on spatial distribution, possible pollution sources, and affecting factors of heavy metals in the urban soils of Weinan (China) was conducted using geographic information system (GIS) technique and multivariate statistics. The results indicated that the levels of 10 heavy metals (Pb, Cr, Ba, Zn, V, Mn, Co, Cu, Ni and As) distribution measured by wavelength dispersive X-ray fluorescence spectrometry (WDXRF) in urban soil of Weinan were As varied from 2.60 to 11.50 mg kg(-1), Co was 8.00-14.50 mg kg(-1), Cr from 74.90 to 157.00 mg kg(-1). Cu from 14.60 to 34.70 mg kg(-1). Ba from 413.00 to 1137.60 mg kg(-1), Mn from 431.30 to 653.70 mg kg(-1), Ni from 20.80 to 35.8 mg kg(-1), Pb from 19.00 to 89.50 mg kg(-1), V from 63.80 to 89.50 mg kg(-1), Zn from 44.50 to 196.80 mg kg(-1), respectively. The mean enrichment factors (EFs) decreased in the order of Pb > Cr > Ba > Cu > Zn > Ni > V > Mn > Co > As, indicating Ba, Cu, Pb, Cr and Zn were significant enriched in the study areas. Spatial distribution maps of heavy metal contents, based on geostatistical analysis and GIS mapping, indicated that Pb and Cr had similar patterns of spatial distribution, likewise, between Ba, Cu and Zn, and among As, Co, Mn, V as well. Multivariate statistical analysis (correlation analysis, principal component analysis, and clustering analysis) showed distinctly different associations among the studied metals, suggesting that the heavy metals, Ba, Cu, Pb, Cr and Zn were associated with anthropic activities (industrial sources, combined with coal combustion as well as traffic factor), whereas Mn, V, Co, As and Ni in study area mainly controlled by parent materials and therefore had natural sources. A comprehensive environmental management strategy should be concerned by the local government to address soil pollution in urban areas.