Speciation of zinc in contaminated soils.
The chemical speciation of zinc in soil solutions is critical to the understanding of its bioavailability and potential toxic effects. We studied the speciation of Zn in soil solution extracts from 66 contaminated soils representative of a wide range of field conditions in both North America and Europe. Within this dataset, we evaluated the links among the dissolved concentrations of zinc and the speciation of Zn(2+), soil solution pH, total soil Zn, dissolved organic matter (DOM), soil organic matter (SOM) and the concentrations of different inorganic anions. The solid-liquid partitioning coefficient (K(d)) for Zn ranged from 17 to 13,100 L kg(-1) soil. The fraction of dissolved Zn bound to DOM varied from 60% to 98% and the soil solution free Zn(2+) varied from 40% to 60% of the labile Zn. Multiple regression equations to predict free Zn(2+), dissolved Zn and the solid-liquid partitioning of Zn are given for potential use in environmental fate modeling and risk assessment. The multiple regressions also highlight some of the most important soil properties controlling the solubility and chemical speciation of zinc in contaminated soils.
Stephan
Chadi H
CH
Department of Chemistry, Université de Montréal, P.O. Box 6128, Centre-Ville, Montréal, QC H3C 3J7, Canada.
Courchesne
François
F
Hendershot
William H
WH
McGrath
Steve P
SP
Chaudri
Amar M
AM
Sappin-Didier
Valérie
V
Sauvé
Sébastien
S
D000327:Adsorption; D002170:Canada; D005591:Chemical Fractionation; D004784:Environmental Monitoring / Q000379:methods*; D005060:Europe; D008906:Mining; D008962:Models, Theoretical; D012984:Software; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D015032:Zinc / Q000032:analysis / Q000737:chemistry*
D012987:Soil; D012989:Soil Pollutants; D015032:Zinc