Cadmium speciation in soil solutions

Journal Article · · Journal of Environmental Quality; (United States)

DOI:https://doi.org/10.2134/jeq1990.00472425001900030003x· OSTI ID:5466987

Hirsch, D; Banin, A ^[1]

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1. Hebrew Univ. of Jerusalem (Israel)

Total Cd concentration was measured in the saturation extract of three unpolluted arid-zone forest soils to which Cd was added as Cd(NO{sub 3}){sub 2} solution (0.1 mg Cd kg{sup {minus}1} soil). The ratio of free to total Cd (Cd{sup 2+}/Cd{sub t}) in the extracted soil solution was measured using a Cd selective electrode by an addition method. A chemical equilibrium model including the major complexation reactions of Cd with anionic ligands was used to estimate Cd speciation in solution and was validated by the agreement between the calculated and measured Cd{sup 2+}/Cd{sub t} ratios. Free Cd{sup 2+} and CdHCO{sub 3}{sup +} were each estimated to constitute 35% to 45%, respectively, of total soluble Cd in the calcareous soil solutions studied, which had pH values between 7.5 and 8.5. Agreement between measured and calculated Cd{sup 2+}/Cd{sub t} ratios improved slightly after destruction of organic matter by UV irradiation of the extracted solutions. Organo-Cd complexes were shown to be present in relatively minor amounts in these soils.

• OSTI ID: 5466987
• Journal Information: Journal of Environmental Quality; (United States), Journal Name: Journal of Environmental Quality; (United States) Vol. 19:3; ISSN JEVQA; ISSN 0047-2425
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540220* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
BIOLOGICAL AVAILABILITY
CADMIUM
CADMIUM COMPOUNDS
CHEMISTRY
ELECTROMAGNETIC RADIATION
ELEMENTS
FORESTS
MEASURING METHODS
METALS
RADIATIONS
SOIL CHEMISTRY
SOILS
ULTRAVIOLET RADIATION