Abstract
The distribution of labile Cd and Zn in two contrasting soils was investigated using isotopic exchange techniques and chemical extraction procedures. A sewage sludge amended soil from Great Billings (Northampton, UK) and an unamended soil of the Countesswells Association obtained locally (Aberdeen, UK) were used. 114Cd and 67Zn isotopes were added to a water suspension of each soil and the labile metal pool (E-value) determined from the isotope dilution. Samples were obtained at 13 time points from 1h to 50 days. For the sewage sludge amended soil, 29 μg Cd g−1 (86% of total) and 806 μg Zn g−1 (65% of total) were labile and for the Countesswells soil the value was 8.6 μg Zn g−1 (13% of total); limits of detection prevented a Cd E-value from being measured in this soil. The size of the labile metal pool was also measured by growing plants for 90 days and determining the isotopic content of the plant tissue (L-value). Thlaspi caerulescensJ. & C. Presl (alpine penny cress), a hyperaccumulator of Zn and Cd, Taraxacum officinale Weber (dandelion) and Hordeum vulgare L. (spring barley) were used. L-values were similar across species and lower than the E-values. On average the L-values were 23±0.8 μg Cd g−1 and 725±14 μg Zn g−1 for the Great Billings soil and 0.29±0.16 μg Cd g−1 and 7.3±0.3 μg Zn g−1 for the Countesswells soil. The extractable metal content of the soils was also quantified by extraction using 0.1 M NaNO3, 0.01 M CaCl2, 0.5 M NaOH, 0.43 M CH3COOH and 0.05 M EDTA at pH 7.0. Between 1.3 and 68% of the total Cd and between 1 and 50% of the total Zn in the Great Billings soil was extracted by these chemicals. For the Countesswells soil, between 6 and 83% of the total Cd and between 0.1 and 7% of the total Zn was extracted. 0.05 M EDTA and 0.43 M CH3COOH yielded the greatest concentrations for both soils but these were less than the isotopic estimates. On the whole, E-values were numerically closer to the L-values than the chemical extraction values. The use of isotopic exchange provides an alternative estimate of the labile metal pool within soils compared to existing chemical extraction procedures. No evidence was obtained that T. caerulescens is able to access metal within the soil not freely available to the other plants species. This has implications for long term remediation strategies using hyperaccumulating plant species, which are unlikely to have any impact on non-labile Cd and Zn in contaminated soil.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ahnstrom Z A S and Parker D R 2001 Cadmium reactivity in metal-contaminated soils using a coupled stable isotope dilution-sequential extraction procedure. Environ. Sci. Technol. 35, 121–126.
Alloway B J 1995 Heavy Metals in Soils. Blackie, Glasgow, UK.
Ayoub A S 2000 Use of stable isotopes to assess phytoremediation of soils contaminated with cadmium and zinc. Ph.D. Thesis, Robert Gordon University, Aberdeen, UK.
Baker A J M and Proctor J 1990 The influence of cadmium, copper, lead and zinc on the distribution and evolution of metallophytes in the British Isles. Plant Syst. Evol. 173, 91–108.
Beckett P H T 1989 The use of extractants in studies on trace metals in soils, sewage sludges, and sludge-treated soils. Adv. Soil Sci. 9, 143–176.
Chang A C, Page A L, Warneke J E and Grgurevic E 1984 Sequential extraction of soil heavy metals following a sludge application. J. Environ. Qual. 13, 33–38.
Echevarria G, Klein S, Fardeau J C and Morel J L 1997 Mesure de la fraction assimilable del éléments en trace du sol par la méthode des cinétique d'échange isotopique: ca du nickel. C.R. Acad. Sci. Paris 324, 221–227.
Fardeau J C 1996 Dynamics of phosphates in soils. An isotopic outlook. Fertil. Res. 45, 91–100.
Fardeau J C, Guiraud G and Marol C 1996 The role of isotopic techniques on the evaluation of the agronomic effectiveness of P fertilizers. Fert. Res. 45, 101–109.
Fardeau J C, Morel J L and Boniface R 1991 Phosphate ion transfer from soil to soil solution – kinetic-parameters. Agronomie 11, 787–797.
Frossard E, Fardeau J C, Brossard M and Morel J L 1994 Soil isotopically exchangeable phosphorous: a comparison between E and L values. Soil Sci. Soc. Am. J. 58, 846–851.
Gérard E, Echevarria G, Sterckeman T and Morel J L 2000 Cadmium availability to three plant species varying in cadmium accumulation pattern. J. Environ. Qual. 29, 1117–1123.
Gupta S K and Aten C 1993 Comparison and evaluation of extraction media and their suitability in a simple-model to predict the biological relevance of heavy-metal concentrations in contaminated soils. Intern. J. Environ. Anal. Chem. 51, 25–46.
Hamon R, Wundke J, McLaughlin M and Naidu R 1997 Availability of zinc and cadmium to different plant species. Aust. J. Soil Res. 35, 1267–1277.
Heumann K G 1988 Isotope dilution mass spectrometry. In Inorganic Mass Spectrometry. Eds. F Adams, R Gijbels and R Van Grieken. pp. 301–376. John Wiley and Son, New York, USA.
Houba V J G, Lexmond T M, Novozamsky I and Van Der Lee J J 1996 State of the art and future developments in soil analysis for bioavailability assessment. Sci. Total Environ. 178, 21–28.
Hutchinson J J, Young S D, McGrath S P, West H M, Black C R and Baker A J M 2000 Determining uptake of ‘non-labile’ cadmium by Thlaspi caerulescens using isotopic dilution techniques. New Phytol. 146, 453–460.
Kennedy V H, Sanchez A L, Oughton D H and Rowland A P 1997 Use of single and sequential chemical extractants to assess radionuclide and heavy metal availability from soils for root uptake. Analyst 122, 89R–100R.
Larsen S 1952 The use of 32P in studies on the uptake of phosphorus by plants. Plant Soil 4, 1–10.
Lumsdon D G, Evans L J and Bolton K A 1995 The influence of pH and chloride on the retention of cadmium, lead, mercury and zinc by soils. J. Soil. Contam. 4(2), 1–14.
Martin J M, Nirel P and Thomas A J 1987 Sequential extraction techniques: promises and problems. Mar. Chem. 22, 313.
Morel C, Fardeau J C and Blaskiewitz J 1995 Phosphorus supply to plants by soils with variable phosphorus exchange, Soil Sci. 160, 423–430.
Novozamsky I, Lexmond T M and Houba V J G 1993 A single extraction procedure of soil for evaluation of uptake of some heavy metals by plants. Int. J. Environ. Anal. Chem. 51, 47–58.
Quevauviller P, Rauret G, Rubio R, Lopezsanchez J F, Ure A M, Bacon J R and Muntau H 1997 Certified reference materials for the quality control of EDTA-and acetic acid-extractable contents of trace elements in sewage sludge amended soils (CRMs 483 and 484). Fresenius J. Anal. Chem. 357, 611–618.
Schwartz C, Morel J L, Saumier S, Whiting S N and Baker A J M 1999 Root development of the zinc-hyperaccumulator plant Thlaspi caerulescens as affected by metal origin, content and localization in soil. Plant Soil 208, 103–115.
Sinaj S, Frossard E and Fardeau J C 1997 Isotopically exchangeable phosphate in size fractionated and unfractionated soils. Soil Sci. Soc. Am. J. 61, 1413–1417.
Smolders E, Brans K, Földi A and Merckx R 1999 Cadmium fixation in soils measured by isotopic dilution. Soil Sci. Soc. Am. J. 63, 78–85.
Soil Survey of Scotland 1982 Eastern Scotland, The Macaulay Land Use Research Institute, Aberdeen.
Stanhope K G, Young S D, Hutchison J J and Kamath R 2000 Use of isotopic dilution to assess the mobilization of nonlabile Cd by chelating agents in phytoremediation. Environ. Sci. Technol. 34, 4123–4127.
Whiting S N, Leake J R, McGrath S P and Baker A J M 2001 Assessment of Zn mobilization in the rhizosphere of Thlaspi caerulescens by bioassay with non-accumulator plants and soil extraction. Plant Soil 237, 147–156.
Young S D, Tye A, Carstensen A, Resende L and Crout N 2000 Methods for determining labile cadmium and zinc in soil. Eur. J. Soil Sci. 51, 129–136.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Ayoub, A.S., McGaw, B.A., Shand, C.A. et al. Phytoavailability of Cd and Zn in soil estimated by stable isotope exchange and chemical extraction. Plant and Soil 252, 291–300 (2003). https://doi.org/10.1023/A:1024785201942
Issue Date:
DOI: https://doi.org/10.1023/A:1024785201942