Validation of transfer functions predicting Cd and Pb free metal ion activity in soil solution as a function of soil characteristics and reactive metal content.
Pampura, T.; Groenenberg, J.E.; Lofts, S.; Priputina, I.. 2007 Validation of transfer functions predicting Cd and Pb free metal ion activity in soil solution as a function of soil characteristics and reactive metal content. Water, Air and Soil Pollution, 184 (1-4). 217-234. 10.1007/s11270-007-9410-4Before downloading, please read NORA policies.
According to recent insight, the toxicity of metals in soils is better related to the free metal ion (FMI) activity in the soil solution than to the total metal concentration in soil. However, the determination of FMI activities in soil solution is a difficult and time-consuming task. An alternative is to use empirical equations (so called transfer functions (TFs)) that relate FMI activity in solution to the reactive metal concentration in the solid phase and to soil properties (pH and organic matter content). Here we test the applicability of two sets of TF for Cd and Pb using independent data from a wide range of soil types and regions that are not represented in the datasets used to derive the TFs. From these soils, soil solution was extracted using four different methods. For all these extracts, FMI activities were calculated from total concentrations in solution using the speciation program WHAM VI. In some of the soils, Cd and Pb FMI activities were also measured using a Donnan membrane technique. Most of these FMI activities deviated from the TF predictions by less than one order of magnitude and were within the 95% confidence interval of the TFs, irrespective of the method used to extract soil solution. Predictability was higher for Pb than for Cd and differed also between the two TF sets.
|Programmes:||CEH Programmes pre-2009 publications > Biogeochemistry > SE01B Sustainable Monitoring, Risk Assessment and Management of Chemicals > SE01.4 Monitoring and predicting the distribution of chemicals in terrestrial and freshwater ecosystems|
|Additional Information:||The original publication is available at www.springerlink.com|
|Additional Keywords:||heavy metals, free metal ion, critical limit, transfer function, soil solution extraction, Donnan membrane technique|
|NORA Subject Terms:||Agriculture and Soil Science
Ecology and Environment
|Date made live:||18 Sep 2007 09:27|
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