1. Soil review Complexity of soils Intensity and capacity concepts
Weathering
Florida soils
Collected from over a dozen books

2. Decontaminating Contaminating
PbO
Pb(OH)2
PbCO3
Minerals of different solubility: which one controls?
The least soluble controls the solubility-then we don’t have to worry since nature takes care of itself?
Kinetics & dynamics: N2NH3
Pump and treat:
Intensity factor: elemental concentration in soil solution
Capacity factor: ability of solid phases in soils to replenish depleted elements in solution
Lindsay (1979)

3. Interactions between soil components and compartments: dynamic disequilibria in soils
What determine the metal concentrations in soils??
Kabata-Pendias and Pendias (1992)

4. Familiar with logK, written as dissolution, metal concentrations are really low, similar to pH
Read activity-pH graph, Increase SO4 reduce Pb, then keep adding more, think about total soluble Pb
Take a sample, analyze Pb2+ conc, close PbCO3, but see Pb(OH)2?
Lindsay (1979)

5. Essington, M.E. 2003. Soil and Water Chemistry. CRC Press.
Google book
Mn and CrIII oxidation

6. Ross, 1994 Which is the dominant specie in a typical soil?
Metals are generally less soluble at higher oxidation states
Why pH dependent??
Ross, 1994

7. Fig. 2.1 Equilibrium redox relationships of aqueous systems.
The inscribed area is representative of most soils
pH 5
CrVI
CrIII
MnIII
MnII
FeIII
FeII
CuII
CuI
HgII
HgI
MnIV
pH 8
pH: 4 to 9
pe: -4 to 12
Eh: -0.3 to 0.7 v
Pe = 16.9 E
In soils, Cr occurs predominately in the +3 and +6 oxidation states.
HW: figure out the dominant redox species of these elements in typical soils.
Kinetics, intensity and capacity
Lindsay (1979)