Exchange Adsorption of Trace Quantities of Cadmium in Soils Treated with Chlorides of Aluminum, Calcium and Sodium1
- J. V. Lagerwerff and
- D. L. Brower2
The exchange adsorption of Cd has been studied in Cecil sandy loam (clay fraction 45% kaolinite and 25% vermiculite), Winsum clay loam (clay fraction 80% illite), and Yolo silt loam (clay fraction 47% montmorillonite and 22% mica). Experimental variables were the major cations Al3+, Ca2+, and Na+, salt (chloride) levels (from 5 to 50 meq/liter), and the initial concentration of CdCl2 (from 22 to 170 µeq/liter). The exchange of Cd2+ in Al3+- and Ca2+-treated soils was normal in that the adsorption was greater in the presence of Ca2+ than of Al3+, and decreased with increasing concentration of AlCl3 or CaCl2. In the Na+-treated, alkalized soils, Cd2+ did not precipitate. The exchange was unusual because the adsorption of Cd2+ decreased as NaCl concentrations decreased. The same behavior was shown by 109Cd2+. At NaCl concentrations decreasing below 30 meq/liter, the adsorption of Ca2+ by Na+-treated soils also decreased, as did the adsorption of Na+. The result was attributed to decreasing soil exchange capacity with decreasing NaCl concentration due to increased adsorption of products derived from alkaline corrosion of the soil matrix.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © .