Title: Derivation of Soil Quality Criteria Based on Chemical Speciation of Pb2 and Cu2
1Derivation of Soil Quality Criteria Based on
Chemical Speciation of Pb2 and Cu2
- S. Sauvé1,2, A. Dumestre1, M. McBride1 and W.
Hendershot2
1Cornell University-Soil Crop and Atmospheric
Sciences (NY) 2McGill University-Macdonald Campus
(QC, Canada) (e-mail sebastien.sauve_at_umontreal.c
a)
2Free Ion Activity Model
- Metal toxicity is controlled by free metal ion
activity in aquatic systems - In soils, we need to
- distinguish between soil total metal (insoluble),
solution dissolved concentrations and solution
free metal activity - quantify the impact of soil pH and soil organic
matter on metal speciation - Bioavailability, mobility and chemical reactivity
depends on the speciation of the metals present
in the soil solution
3Pb Distribution
Sauvé S, Dumestre A, McBride M, Hendershot W.
1998. Derivation of soil quality criteria using
predicted chemical speciation of Pb2 and Cu 2
Environmental Toxicology and Chemistry
171481-1489.
4Experimental Soils
- Soils from various origins
- urban, agricultural, orchard, industrial, forest
- from Ithaca (NY), Québec (Can), Denmark and
France - Contamination pesticides, sewage sludge, battery
recycling and industrial sources - Soil Totals by HNO3 digestions, dissolved
metals by GFAAS of 0.01 M KNO3 extracts and free
metal by ion selective electrode (Cu2) and
differential pulse anodic stripping voltammetry
(Pb2)
5Pb2 and Cu2 Solubility
Sauvé S. 1999. Chemical speciation, solubility
and bioavailability of lead, copper and cadmium
in contaminated soils Ph.D. Dissertation,
Department of Soil, Crop and Atmosphetric
Sciences, Cornell University, Ithaca, NY.
6Adsorption Model
- Assuming competitive binding of H and Me2 to a
deprotonated surface (S)
- with certain assumptions can be simplified to
- Applied with succes to the soil solution
speciation of Cd2, Cu2 and Pb2
7Regressions for Solution Free Metal Activity
Sauvé S, Dumestre A, McBride M, Hendershot W.
1998. Derivation of soil quality criteria using
predicted chemical speciation of Pb2 and Cu 2
Environmental Toxicology and Chemistry
171481-1489.
8Pb2, pH and Total Pb
Sauvé S, McBride M, Hendershot W. 1997.
Speciation of lead in contaminated soils
Environmental Pollution 98149-155.
9Cu2, pH and Total Cu
Sauvé S. 1999. Chemical speciation, solubility
and bioavailability of lead, copper and cadmium
in contaminated soils Ph.D. Dissertation,
Department of Soil, Crop and Atmosphetric
Sciences, Cornell University, Ithaca, NY.
10Soil Solution Free Metal Activity
- Only a very small fraction of the total metal is
free and available for chemical reactions - This free metal fraction can be predicted using
simply soil total metal and pH - A semi-mechanistic model is successful
independently of the soil origin and of the
source of the metal contamination - Soil organic matter can be incorporated into the
regression, soil OM decreases free Cu2 activity
11Bioassay Model
- where the biological endpoint (yield reduction,
process inhibition etc.) were as reported in the
literature and the parameter was either total
soil Cu or Pb or predicted free Cu2 or Pb2, a
and b were fitted by the statistical software
12Inhibition
Sauvé S, Dumestre A, McBride M, Hendershot W.
1998. Derivation of soil quality criteria using
predicted chemical speciation of Pb2 and Cu 2
Environmental Toxicology and Chemistry
171481-1489.
13Inhibition
Sauvé S, Dumestre A, McBride M, Hendershot W.
1998. Derivation of soil quality criteria using
predicted chemical speciation of Pb2 and Cu 2
Environmental Toxicology and Chemistry
171481-1489.
14Inhibition
Sauvé S, Dumestre A, McBride M, Hendershot W.
1998. Derivation of soil quality criteria using
predicted chemical speciation of Pb2 and Cu 2
Environmental Toxicology and Chemistry
171481-1489.
15Soil Criteria
Sauvé S, Dumestre A, McBride M, Hendershot W.
1998. Derivation of soil quality criteria using
predicted chemical speciation of Pb2 and Cu 2
Environmental Toxicology and Chemistry
171481-1489.
16Conclusion
- Soil solution free metal activity of Pb2 and
Cu2 may be predicted using a simple model - Estimated free metal activities are better
predictor of bioavailability than total soil
metal - Soil quality criteria and risk assessment must
consider soil pH to reflect its predominant
influence on soil solution chemical speciation
and bioavailability
17References
- Sauvé S., A. Dumestre, M.B. McBride and W.H.
Hendershot. 1998. Derivation of soil quality
criteria using predicted chemical speciation of
Pb2 and Cu2. Environmental Toxicology and
Chemistry 171481-1489. - Sauvé S., M.B. McBride and W.H. Hendershot. 1997.
Speciation of lead in contaminated soils.
Environmental Pollution. 98149-155. - Sauvé S., M.B. McBride, W.A. Norvell and W.H.
Hendershot. 1997. Copper solubility and
speciation of in situ contaminated soils Effects
of copper level, pH and organic matter. Water,
Air and Soil Pollution. 100133-149. - Sauvé S., M.B. McBride and W.H. Hendershot. 1998.
Soil solution speciation of Pb2 Effects of
organic matter and pH. Soil Science Society of
America Journal 62618-621. - Sauvé S., M. McBride and W. Hendershot. 1998.
Lead phosphate solubility in water and soil
suspensions. Environmental Science and Technology
32388-393. - McBride M.B., Sauvé S. and W.H. Hendershot. 1997.
Solubility control of Cu, Zn, Cd and Pb in
contaminated soils. European Journal of Soil
Science 48337-346. - Sauvé S., M.B. McBride and W.H. Hendershot. 1995.
Ion-selective electrode measurements of
copper(II) activity in contaminated soils.
Archives of Environmental Contamination and
Toxicology. 29373-379.