Elsevier

Pedosphere

Volume 26, Issue 6, December 2016, Pages 848-860
Pedosphere

Distribution and Transport of Residual Lead and Copper Along Soil Profiles in a Mining Region of North China

https://doi.org/10.1016/S1002-0160(15)60090-XGet rights and content

Abstract

Residual heavy metals are commonly considered to be immobile in soils, leading to an underestimation of their environmental risk. This study investigated the distribution and transport of residual heavy metals along soil profiles, using the Xiaoqinling gold mining region in North China as a case study. Soil samples were collected at three depths from three locations near the tailing heap. The speciation of copper (Cu) and lead (Pb) (exchangeable, carbonate-bound, Fe-Mn oxide-bound, organic matter-bound, and residual fractions) was determined using a sequential extraction procedure. The residual fraction's morphology was observed using scanning electron microscopy (SEM). Results showed that metal fraction distributions along the soil profiles were influenced by each fraction's mobility. Residual fraction with high chemical stability can not be transformed from or into other fractions. This led to the conclusion that the high concentration of residual metals in soils mainly resulted from residual fraction transport. The SEM analysis showed that fine particles (submicrons) were mainly attached to large particles and were likely released and transported by water flow. The more sorptive fractions (non-residual fractions) were mainly retained in the top soil, and the more mobile fractions (residual fraction) were mainly leached to the deep soil. Cu and Pb concentrations in the residual fraction decreased slightly and those in the non-residual fractions decreased significantly with soil depth. These suggest a relatively higher residual metal mobility along the soil profiles. Therefore, residual metals can be transported in soils and their environmental risk can not be ignored in assessing soil contamination.

References (49)

  • S Gier et al.

    Heavy metal-adsorption on micas and clay minerals studied by X-ray photoelectron spectroscopy

    Appl Clay Sci

    (2000)
  • Y Guo et al.

    Leaching of heavy metals from Dexing copper mine tailings pond

    T Nonferr Metal Soc

    (2013)
  • E Kovacs et al.

    Influence of hydrology on heavy metal speciation and mobility in a Pb-Zn mine tailing

    Environ Pollut

    (2006)
  • B Koz et al.

    Heavy metal analysis around Murgul (Artvin) copper mining area of Turkey using moss and soil

    Ecol Indic

    (2012)
  • M Kumar et al.

    Potential mobility of heavy metals through coupled application of sequential extraction and isotopic exchange: comparison of leaching tests applied to soil and soakaway sediment

    Chemosphere

    (2013)
  • Q S Li et al.

    The behavior of heavy metals in tidal flat sediments during fresh water leaching

    Chemosphere

    (2011)
  • Z Li et al.

    A review of soil heavy metal pollution from mines in China: pollution and health risk assessment

    Sci Total Environ

    (2014)
  • P Martínez-Pagán et al.

    A multidisciplinary study for mining landscape reclamation: A study case on two tailing ponds in the Region of Murcia (SE Spain)

    Phys Chem Earth

    (2011)
  • C Monterroso et al.

    Heavy metal distribution in mine-soils and plants growing in a Pb/Zn-mining area in NW Spain

    Appl Geochem

    (2014)
  • K Nemati et al.

    Speciation of heavy metals by modified BCR sequential extraction procedure in different depths of sediments from Sungai Buloh, Selangor, Malaysia

    J Hazard Mater

    (2011)
  • F Pagnanelli et al.

    Sequential extraction of heavy metals in river sediments of an abandoned pyrite mining area: pollution detection and affinity series

    Environ Pollut

    (2004)
  • P Peltola et al.

    Lead and Cu in contaminated urban soils: extraction with chemical reagents and bioluminescent bacteria and yeast

    Sci Total Environ

    (2005)
  • D Proust et al.

    Impacts of weathering and clay mineralogy on heavy metals sorption in sludgeamended soils

    Catena

    (2013)
  • M N Rashed

    Monitoring of contaminated toxic and heavy metals, from mine tailings through age accumulation, in soil and some wild plants at Southeast Egypt

    J Hazard Mater

    (2010)
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