Abstract
Water soluble and/or dissolved metals represent the most ecotoxicologically relevant fraction of metals in the environment. However, water extractions may be prone to errors. This study aims to evaluate the performance of 5 filters as well as Rhizon soil moisture samplers, with respect to metal adsorption and/or release by the filter. In addition, the effect of equilibration time on water extractions of different types of soils was evaluated (silty loam, silty clay loam, loamy sand). Filtrations of synthetic solutions containing 40 μg 1−1 Zn, 20 μg 1−1 Cu, Ni and Pb, 10 μg 1−1 Cr and 2 μg 1−1 Cd were conducted using the different filters. The synthetic solutions either contained (i) no other competitive cations (Ca, Mg, Na, K, Fe, Mn, Al) (A 1), (ii) competitive cations at concentrations similar to those observed in soil solutions (A 2), (iii) competitive cations at 10 times lower concentrations than those in the synthetic soil solution (A 3). Whiteband filters were observed to retain considerable amounts of trace metals (except Cr), both in the presence and absence of other competitive cations. Millipore filters did not exhibit metal retention. Rhizon soil moisture samplers did not retain trace metals from the synthetic soil solution (A 2), whereas at lower concentrations of competitive cations (A 1, A 3) retention of Cu and Pb was observed. Whiteband filters without a predefined pore diameter allowed colloidal material of unknown particle size to pass into the filtrate, making interpretation of results very difficult and comparison between studies using different filters impossible. Millipore filters with a predefined pore diameter are to be recommended for this purpose. However, particular attention must be paid to potential constitutive Zn release by the sintered glass filter holders, the effect of which can be reduced by rigorous acid washing prior to and following every use. Rhizon samplers were also considered to be useful tools with well-defined and sufficiently small pore diameters to withhold colloidal material. However, in the absence or at reduced concentrations of competitive cations (A 1, A 3) retention of trace metals by the Rhizons, particularly Cu and Pb, was observed. Finally, short equilibration times may be insufficient for full assessment of the water extractable pool of trace metals in the soil.
Article PDF
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Avoid common mistakes on your manuscript.
References
Allison, L. E.: 1965, ‘Methods of soil analysis. Part 2. Chemical and microbiological properties’, in C. A. Black et al. (eds), Agronomy Monograph 9 (2nd edn.), ASA, Madison, Wisconsin, pp. 1367–1378.
Arnold, R. E., Hodson, M. E., Black, S. and Davies, N.A.: 2003, ‘The influence of mineral solubility and soil solution concentration on the toxicity of copper to Eisenia fetida Savigny’, Pedobiologia 47, 622–632.
Boyd, W. A. and Williams, P. L.: 2003, ‘Availability of metals to the nematode Caenorhabditis elegans: Toxicity based on total concentrations in soil and extracted fractions’, Environ. Toxicol. Chem. 22, 1100–1106.
Bufflap, S. E. and Allen, H. E.: 1995a, ‘Comparison of pore water sampling techniques for trace metals’, Wat. Res. 29, 2051–2054.
Bufflap, S. E. and Allen, H. E.: 1995b, ‘Sediment pore water collection methods for trace metal analysis: A review’, Wat. Res. 29, 165–177.
Carr, R. S. and Nipper, M.: 2001, ‘Summary of a SETAC technical workshop: Pore water toxicity testing: Biological, chemical, and ecological considerations with a review of methods and applications, and recommendations for future areas of research’, SETAC, Pensacola, FL, USA.
Chapman, P. M., Wang, F., Germano, J. D. and Batley, G.: 2002, ‘Pore water testing and analysis: The good, the bad, and the ugly’, Mar. Pollut. Bull. 44, 359–366.
Crommentuijn, T., Doornekamp, A. and Van Gestel, C. A. M.: 1997, ‘Bioavailability and ecological effects of Cadmium on Folsomia candida (Willem) in an artificial soil substrate as influenced by pH and organic matter’, Appl. Soil Ecol. 5, 261–271.
Darmawan and Wada, S. I.: 1999, ‘Kinetics of speciation of copper, lead and zinc loaded to soils that differ in cation exchanger composition at low moisture content’, Commun. Soil Sci. Plan. 30, 2363–2375.
Förstner, U.: 2004, ‘Traceability of sediment analyses’, Trac-Trends. Anal. Chem. 23, 217–236.
Grossman, J. and Udluft, P.: 1991, ‘The extraction of soil water by the suction-cup method: A review’, J. Soil Sci. 42, 83–93.
Keller, C. and Védy, J. C.: 1994, ‘Distribution of Copper and Cadmium fractions in two forest soils’, J. Environ. Qual. 23, 987–999.
Knight, B. P., Chaudri, A. M., McGrath, S. P. and Giller, K. E.: 1998, ‘Determination of chemical availability of cadmium and zinc in soils using inert soil moisture samplers’, Environ. Pollut. 99, 293–298.
Ludwig, B., Meiwes, K. J., Khanna, P., Gehlen, R., Fortmann, H. and Hildebrand, E. E.: 1999, ‘Comparison of different laboratory methods with lysimetry for soil solution composition – experimental and model results’, J. Plant Nutr. Soil Sc. 162, 343–351.
Luo, Y., Qiao, X., Song, J., Christie, P. and Wong, M.: 2003, ‘Use of a multi-layer column device for study on leachability of nitrate in sludge-amended soils’, Chemosphere 52, 1483–1488.
Ma, L. Q. and Dong, Y.: 2004, ‘Effects of incubation on solubility and mobility of trace metals in two contaminated soils’, Environ. Pollut. 130, 301–307.
Ma, L. Q. and Rao, G. N.: 1997, ‘Chemical fractionation of Cadmium, Copper, Nickel, and Zinc in contaminated soils’, J. Environ. Qual. 26, 259–264.
Meers, E., Unamuno, V. R., Vandegehuchte, M., Vanbroekhoven, K., Geebelen, W., Roeland, S., Vangronsveld, J., Diels, L., Ruttens, A., Du Laing, G. and Tack, F. M. G.: 2005, ‘Soil solution speciation of Cd as affected by soil characteristics in unpolluted and polluted soils’, Environ. Toxicol. Chem. 24, 499–509.
Seguin, V., Gagnon, C. and Courchesne, F.: 2004, ‘Changes in water extractable metals, pH and organic carbon concentrations at the soil-root interface of forested soils’, Plant Soil 260, 1–17.
Sinaj, S., Máchler, F. and Frossard, E.: 1999, ‘Assessment of isotopically exchangeable Zinc in polluted and unpolluted soils’, Soil Sci. Soc. Am. J. 63, 1618–1625.
Svete, P., Milacic, R. and Pihlar, B.: 2000, ‘Optimisation of an extraction procedure for determination of total water-soluble Zn, Pb and Cd and their species in soils from a mining area’, Ann.Chim. Rome 90, 323–334.
Tack, F. M. G. and Verloo, M. G.: 1995, ‘Chemical speciation and fractionation in soil and sediment heavy metal analysis: A review’, Int. J. Environ. Anal. Chem. 59, 225–238.
Tack, F. M. G., Dezillie, N. and Verloo, M.G.: 2002, Metal concentrations in soil paste extracts as affected by extraction ratio, The Scientific World Journal 2, 966–971.
Tessier, A., Campbell, P. G. C. and Bisson, M.: 1979, ‘Sequential extraction procedure for the speciation of particulate trace metals’, Anal. Chem. 51, 844–850.
Tiensing, T., Preston, S., Strachan, N. and Paton, G. I.: 2001, ‘Soil solution extraction techniques for microbial ecotoxicity testing: A comparative evaluation’, J. Environ. Monitor. 3, 91–96.
Van Ranst, E., Verloo, M., Demeyer, A. and Pauwels, J. M.: 1999, Manual for the Soil Chemistry and Fertility Laboratory, Ghent University, Faculty Agricultural and Applied Biological Sciences, Gent, Belgium, 243 pp.
Vandecasteele, B., De Vos, B. and Tack, F. M. G.: 2002, ‘Heavy metal contents in surface soils along the upper scheldt river (Belgium) affected by historical upland disposal of dredged materials’, Sci. Total Environ. 290, 1–14.
Wenzel, W. W. and Wieshammer, G.: 1995, ‘Suction cup materials and their potential to bias trace metal analyses of soil solutions: A review’, Int. J. Environ. Anal. Chem. 59, 277–290.
Weltje, L., den Hollander, W. and Wolterbeek, H. T.: 2003, ‘Adsorption of metals to membrane filters in view of their speciation in nutrient solution’, Environ. Toxicol. Chem. 22, 265–271.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Meers, E., Laing, G.D., Unamuno, V.G. et al. Water Extractability of Trace Metals from Soils: Some Pitfalls. Water Air Soil Pollut 176, 21–35 (2006). https://doi.org/10.1007/s11270-005-9070-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11270-005-9070-1