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Adsorption of Cadmium on Soil Constituents in the Presence of Complexing Ligands
Author(s) -
Chubin R. G.,
Street J. J.
Publication year - 1981
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1981.00472425001000020021x
Subject(s) - cadmium , adsorption , environmental chemistry , chemistry , chelation , inorganic chemistry , organic chemistry
The objective of this study was to evaluate the effect of natural and synthetic complexing agents on Cd 2+ adsorption characteristics of metal hydroxides and silicate clay minerals. The solution pH at which 50% of the initial solution Cd 2+ was adsorbed was 5.40, 7.00, 7.80, and 8.30 for Al(OH) 3 , Fe(OH) 3 , montmorillonite, and kaolinite, respectively. The presence of citrate (C 6 H 5 O 7 3‐ ) depressed Cd adsorption on Al(OH) 3 , by approximately 25% in acidic solutions. The addition of EDTA (C 10 H 16 O 8 N 2 ) depressed the Cd adsorption on both Al and Fe hydroxides, montmorillonite, and kaolinite in acidic and alkaline solutions. The water‐soluble organic fraction from sewage sludge enhanced Cd adsorption by both kaolinite and montmorillonite in alkaline solutions. The water‐soluble organic fraction from an organic soil (Terra Ceia muck) increased Cd adsorption by Fe(OH) 3 only under acidic conditions. Preliminary results indicated that considerations of Cd retention by soil constituents should include not only the aqueous chemistry of Cd and the surface chemistry of the adsorbent, but also the chemistry of natural and synthetic complexing agents. The interaction of Cd and various complexing agents can play an important part in determining the fate of this metal in the soil‐water‐plant environment.