Soil Chemical Properties Controlling Zinc2+ Activity in 18 Colorado Soils
Kathryn M. Catlett*,a,
Dean M. Heilb,
Willard L. Lindsayc and
Michael H. Ebingerd
a Neptune and Company, 1505B 15th Street, Los Alamos, NM 87544
b Dep. of Soil & Crop Sciences, Colorado State Univ., Fort Collins, CO 80523
c 205 Woodside Drive, Provo, UT 89604
d MS J495, Los Alamos National Lab., Los Alamos, NM 87545
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Fig. 1. For Soil 1, the final mole fractions (MFf) of ZnEDTA2- are plotted with the initial MFs of ZnEDTA2-. The equilibrium MF (MFeq) is found at the intersection of the data with the identity line (y = x).
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Fig. 2. Log of Zn2+ activities plotted with pH for the 18 Colorado soils. Error bars are based on one standard deviation.
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Fig. 3. Log Zn2+ activity versus percentage of soil organic C. Soil 12, the outlier, is labeled. Error bars are based on one standard deviation.
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Fig. 4. Three-Dimensional plot of log (Zn2+) versus pH and percentage of organic matter (OM) for the 18 Colorado soils.
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Fig. 5. Log Zn2+ activity versus pH including data from this study and other studies from the literature. The solid lines correspond to the franklinite-soil Fe, soil-Zn, and franklinite-maghemite lines of Lindsay (1979). Only the data for the uncontaminated soils from Ma and Lindsay (1993) were used.
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Fig. 6. Log of Zn2+ activities are plotted with pH. Two possible trend lines are drawn. Region 1 represents adsorption of Zn to organic matter or other surface. Region 2 represents precipitation of a Zn mineral, such as franklinite.
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Copyright © 2002 by the Soil Science Society of America.
