Dynamics of the soil solution cationic composition in a limed soddy-podzolic soil contaminated with Co and Cd at variable pH

Abstract

The dynamics of the cationic composition in the liquid phase of a soddy-podzolic soil contaminated with Co and Cd under different pH (changed by addition of H+ ions) was studied in a long-term experiment (for 470 days). Soil solutions were extracted with vacuum samplers installed in the soil for the time of the experiment. It was shown that the concentrations of Co and Cd, as well as those of K, Na, Ca, and Mg, in the solution changed during 3–4 weeks after moistening the air-dry soil to 70% of the maximum water capacity and increased during 5–6 months after addition of H+. This indicated the low rate of the processes and reactions occurring in the soil. The addition of Co and Cd to the soil affected the interphase distributions of K, Ca, and Mg; the effect of Co was higher than that of Cd by 3–4 times. When added together, the Co increased the concentration of Cd in the soil solution by 4–6 times, and the effect of Cd on the content of Co was no higher than 1.5 times.