Measurement and model calculation of Cd, Cu, Ni, Pb and Zn speciation in soil solution
The use of metal speeiation in risk assessment as with the Free Ion Activity Model and the Biotic Ligand Model asks for good speciation measurement techniques and good model concepts to predict metal speciation in natural soil waters. The Donnan Membrane Technique (DMT) which can measure the Free Metal Ion (FMI) activity for several metals simultaneously gives a good opportunity to test and validate ion binding models like NICA and WHAM. Here we test both models on several soil waters measured with DMT. Models predict the FMI activity within an average deviation of 0.5 log concentration unit with measurements. On average the models underestimated metal binding to dissolved organic matter (DOM), especially for lead (Pb). For all metals, except Pb, ratios of modeled and measured FMI correlate well. This points at a common cause for the deviation, which could be the fraction of active DOM used in the calculations.. For cadmium (Cd), copper (Cu), nickel (Ni) and zinc (Zn), metal binding was overestimated at high dissolved organic carbon (DOC) concentrations whereas at low concentrations it was underestimated.
Donnan membrane technique free metal ion metal speciation speciation model
Jan E. Groenenberg Tatiana Pampura Gerwin. F. Koopmans
Soil Science Centre, Wageningen University and Research, P. O. Box 47, 6700 AA, Wageningen, The Neth Institute of Physicochemical and Biological Problems in Soil Science, Pushchino, Russia
国际会议
第九届痕量元素生物地球化学国际会议(9th International Conference on the Biogeochemistry of Trace Elements)
北京
英文
774-775
2007-07-15（万方平台首次上网日期，不代表论文的发表时间）