1. Soil processes and trace metals
Have some ideas about metal concentrations in soils
Get familiar with FDEP Soil Cleanup Target Levels and regulations by different countries
Background metal concentrations in Florida soils
Factors controlling metal behaviors in soils

2. Metal mobility & sorption in soilsIP
Formation of hydrolysis species
Soil
Fe/Al/Mn oxides OM
Environments pH pe

3. Concentrations of trace metals in equilibrium solutions of sandy Spodisols
Precipitation
hydrolysis Cu Pb
The best way to draw the lines?
Kabata-Pendias and Pendias (1992)

4. Precipitation/hydrolysis
logk
Cu2+ + 2H2O  Cu(OH)2 + 2H+
-8.68
Cu2+ + H2O  CuOH- + H+
-7.70
Cu2+ + 2H2O  Cu(OH)2 + 2H+
-13.8
Log (Cu2+) = log k – 2 pH
Log (CuOH-) = log k + log (Cu2+) + pH
Log (Cu(OH)2) = log k + log (Cu2+) + 2 pH

5. Solubility of hydrous oxide (Lindsay, 1979)
Cd(OH)2 + 2H+  Cd2+ + 2H2O 13.7
Zn(OH)2 + 2H+  Zn2+ + 2H2O 11.8
Cu(OH)2 + 2H+  Cu2+ + 2H2O 8.68
Pb(OH)2 + 2H+  Pb2+ + 2H2O 8.16
Cd2+ + H2O  CdOH+ + H /-20.3
Cu2+ + H2O  CuOH+ + H /-13.8
Pb2+ + H2O  PbOH+ + H /-17.8
Zn2+ + H2O  ZnOH+ + H /-16.8
Stability of hydrolysis species (Lindsay, 1979)

6. Kabata-Pendias and Pendias (1992)

7. Mobility of metals as influenced by soil pHCd Cu Pb Zn Fe Cr Al
pH of hydrous oxide formation
Kabata-Pendias and Pendias (1992)

8. Sposito, 1984

9. Siegel, 2002 pH<6: Cd mobility increases
pH<5: Zn mobility increases
All except Mn and Ni are chalcophile elements
Siegel, 2002