Environ Sci Pollut Res (2015) 22:1270–1278 DOI 10.1007/s11356-014-3441-3
RESEARCH ARTICLE
Chemical extractability of As and Pb from soils across long-term abandoned metallic mine sites in Korea and their phytoavailability assessed by Brassica juncea Junho Han & Juhee Kim & Minhee Kim & Deok Hyun Moon & Jung-Suk Sung & Seunghun Hyun
Received: 22 May 2014 / Accepted: 11 August 2014 / Published online: 20 August 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract The chemical extractability of As and Pb (by 5 mM CaCl2, 0.1 M HCl, 0.05 M NH4 (H2PO4), and aqua regia) from soils and their phytoavailability (by Brassica juncea) were assessed using 16 soil samples collected as a function of distance from mine pits across three long-term abandoned metallic mine sites. The total concentrations of As and Pb (17–41,000 and 27–10,047 mg kg−1, respectively) decreased with increasing separation distance from the mine pits along a declining slope. However, the percentage of chemically leachable As and Pb mass (e.g., by 5 mM CaCl2, 0.1 M HCl, or 0.05 M NH4(H2PO4)) relative to total mass (e.g., by aqua regia) tended to increase exponentially with distance, indicating more chemically labile fractions present in less contaminated downgradient soils. Among soil components, extractable As concentrations were best described by coupling DCBAl with other Al and Fe oxides. For Pb concentration, pH coupled to DCB-Al or Ox-Al provided a good predictive relationship. The inhibitory growth and uptake by plants were best correlated with the extractable concentrations by 5 mM CaCl2 and 0.1 M HCl. In conclusion, the chemical extractability and phytoavailability of As and Pb are highly Responsible editor: Zhihong Xu Electronic supplementary material The online version of this article (doi:10.1007/s11356-014-3441-3) contains supplementary material, which is available to authorized users. J. Han : J. Kim : M. Kim : S. Hyun (*) Division of Environmental Science and Ecological Engineering, Korea University, Seoul 136-713, Korea e-mail: [email protected] D. H. Moon Department of Environmental Engineering, Chosun University, Gwangju 501-759, Korea J.403 μS cm−1), and high Fe/Al oxide content observed from five mine pit soils (DY1, DY2, DY3, MJ1, and SD1) are speculated to be the result of oxidative weathering of sulfide minerals (e.g., pyrite, arsenopyrite, and galena) during the abandoned period over the last two decades (Kim et al. 2002; Shin and Lin 2003; Navarro et al. 2006). In addition, the low clay content (
RESEARCH ARTICLE
Chemical extractability of As and Pb from soils across long-term abandoned metallic mine sites in Korea and their phytoavailability assessed by Brassica juncea Junho Han & Juhee Kim & Minhee Kim & Deok Hyun Moon & Jung-Suk Sung & Seunghun Hyun
Received: 22 May 2014 / Accepted: 11 August 2014 / Published online: 20 August 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract The chemical extractability of As and Pb (by 5 mM CaCl2, 0.1 M HCl, 0.05 M NH4 (H2PO4), and aqua regia) from soils and their phytoavailability (by Brassica juncea) were assessed using 16 soil samples collected as a function of distance from mine pits across three long-term abandoned metallic mine sites. The total concentrations of As and Pb (17–41,000 and 27–10,047 mg kg−1, respectively) decreased with increasing separation distance from the mine pits along a declining slope. However, the percentage of chemically leachable As and Pb mass (e.g., by 5 mM CaCl2, 0.1 M HCl, or 0.05 M NH4(H2PO4)) relative to total mass (e.g., by aqua regia) tended to increase exponentially with distance, indicating more chemically labile fractions present in less contaminated downgradient soils. Among soil components, extractable As concentrations were best described by coupling DCBAl with other Al and Fe oxides. For Pb concentration, pH coupled to DCB-Al or Ox-Al provided a good predictive relationship. The inhibitory growth and uptake by plants were best correlated with the extractable concentrations by 5 mM CaCl2 and 0.1 M HCl. In conclusion, the chemical extractability and phytoavailability of As and Pb are highly Responsible editor: Zhihong Xu Electronic supplementary material The online version of this article (doi:10.1007/s11356-014-3441-3) contains supplementary material, which is available to authorized users. J. Han : J. Kim : M. Kim : S. Hyun (*) Division of Environmental Science and Ecological Engineering, Korea University, Seoul 136-713, Korea e-mail: [email protected] D. H. Moon Department of Environmental Engineering, Chosun University, Gwangju 501-759, Korea J.403 μS cm−1), and high Fe/Al oxide content observed from five mine pit soils (DY1, DY2, DY3, MJ1, and SD1) are speculated to be the result of oxidative weathering of sulfide minerals (e.g., pyrite, arsenopyrite, and galena) during the abandoned period over the last two decades (Kim et al. 2002; Shin and Lin 2003; Navarro et al. 2006). In addition, the low clay content (
