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环境科学学报 1993
CHEMICAL SPECIES AND EQUILIBRIA OF CADMIUM IN SOIL SOLUTIONS
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Abstract:
A simple chemical equilibrium model was developed to speciate Cd in soil solutions of red earth, yellow-brown earth and yellow fluro-aquic soil peviously amended with Cd. Results showed that Cd2+, CdCl+, and CdSO40 were the dominant species of Cd in soil solution. Limimg the red earth reduced free Cd2+ and increased CdSO40 in the species composition. Adding chlorides decreased soil pH and desorbed Cd from solid matrix, and CdCl+ and CdCl20 rised dramatically. Solubility diagram suggested that the soil solution was far undersaturated with respect to all Cd minerals hence Cd activity in soil solution was controlled by sorption-desorption equilibrium of Cd between soil solid and solution phases.
