Multiple methods for the identification of heavy metal sources in cropland soils from a resource-based region

• Published in: The Science of the total environment 2019-02, Vol.651 (Pt 2), p.3127-3138
• Main Authors: Dong, Bo, Zhang, Renzhi, Gan, Yandong, Cai, Liqun, Freidenreich, Ariel, Wang, Kepeng, Guo, Tianwen, Wang, Hongbin
• Format: Article
• Language: English
• Subjects: Heavy metal; Loess Plateau; Positive matrix factorization (PMF); Soil pollution; Source appointment
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2018.10.130

Examination of heavy metal sources in soils from a resource-based region is essential for source identification and implementation of restoration strategies regarding soil contamination. A total of 1069 samples were collected from cropland soils in the Baiyin District (Loess Plateau, Northwest China), a characteristically resource-based region to investigate the sources of arsenic (As), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), vanadium (V), and zinc (Zn). Source identification was analyzed by multiple methods including spatial deviation (SD), correlation analysis (CA), enrichment factor (EF), principal component analysis (PCA), geographic information system (GIS), and positive matrix factorization (PMF). The results showed the combined applications of PMF, GIS, and PCA were accurate, pragmatic, and effective for source apportionment. Three origins were identified and the contribution rates were calculated as follows: approximately 95% of As came from wastewater irrigation; 75, 88, 60, and 76% of Cr, Mn, Ni, and V were separately derived from natural origins; and 81, 93, and 70% of Cu, Pb, and Zn originated from industrial sources, respectively. Natural origins, industrial sources, and wastewater irrigation were the three main contributors of heavy metals to cropland soils in this region. [Display omitted] •Six methods were compared for source identification of heavy metals in soils.•95% of As came from wastewater irrigation.•75, 88, 60, and 76% of Cr, Mn, Ni, and V were derived from natural origins.•81, 93, and 70% of Cu, Pb, and Zn originated from industrial sources.•Natural origins, industrial sources, and wastewater irrigation were main sources.