Abstract

Laboratory-based leaching tests are frequently used for in situ risk assessments of contaminant leaching to groundwater and surface waters. This study evaluated the ability of three standardised leaching tests to assess leaching of lead (Pb), zinc (Zn), arsenic (As) and antimony (Sb) from four intact soil profiles, by considering particulate (0.45-8 mu m; percolation test), colloidal (10 kDa-0.45 mu m) and truly dissolved (<10 kDa) fractions of these elements. Deionised water was used as the percolation test leachant, while either deionised water or 1 mM CaCl2 was used in batch tests. Data from an irrigation experiment were used as reference. The results indicated that in percolation tests, leachate should be collected at a liquid:solid ratio (L/S) range of 2-10, instead of 0-0.5 or 0.5-2. Even at L/S = 2-10, the percolation test overestimated total Pb concentration, mainly because of greater mobilisation of particle-bound Pb, but appeared suitable for categorising soils into high/low risk with respect to mobilisation of particulate and colloidal contaminants. The batch test performed better with CaCl2 than with deionised water when standard membrane filtration (0.45 gm) was used, as the high Ca2+ concentration reduced colloidal mobilisation, avoiding overestimation of concentrations of elements such as Pb. However, the higher Ca2+ concentration and lower pH could result in overestimated concentrations of weakly sorbed elements, e.g. Zn. (C) 2019 The Authors. Published by Elsevier Ltd.

Keywords

Standardised leaching test; Intact soil column; Metals; Risk assessment; Contaminated soil

Published in

Chemosphere
2019, Volume: 222, pages: 453-460
Publisher: PERGAMON-ELSEVIER SCIENCE LTD

SLU Authors

• Löv, Åsa

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Larsbo, Mats

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Sjöstedt, Carin

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Cornelis, Geert

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Gustafsson, Jon-Petter

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Berggren Kleja, Dan

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    
  • Swedish Geotechnical Institute (SGI)

Sustainable Development Goals

Ensure availability and sustainable management of water and sanitation for all


UKÄ Subject classification

Environmental Sciences
Soil Science


Publication identifier

DOI: https://doi.org/10.1016/j.chemosphere.2019.01.148

Permanent link to this page (URI)

https://res.slu.se/id/publ/99509