Remediation of Cadmium-Contaminated Paddy Soils by Washing with Chemicals: Effect of Soil Washing on Cadmium Uptake by Soybean

Remediation of cadmium-contaminated paddy soils by washing with chemicals is reported. A pot experiment is conducted to evaluate the effect of soil washing with CaCl sub(2) on Cd absorption by two soybean cultivars. The results are as follows: Soybean growth is not significantly different in washed and unwashed soils, but the seed Cd concentration for both cultivars decreases significantly, up to 25%, in the washed soils compared with the unwashed soils. In the washed soils, the Cd concentration in the soil solution indicates an obviously lower value from sowing to the flowering stage; however, the change in Cd speciation is not evident in the CaCl sub(2)-washed soil solution.