Sorption of Nickel and Cobalt on a Size-Fraction of Unconsolidated Glaciofluvial Deposits and on Clay Minerals
In earlier studies we investigated the sorption behaviour of cesium, barium and strontium on size fractions of glaciofluvial materials and on the clay minerals montmorillonite, illite and chlorite. Here, we report on sorption and desoiption experiments with nickel and cobalt in synthetic groundwater on the <32 μπι size-fraction of a glaciofluvial deposit, on the clay minerals montmorillonite and illite, and on synthetic Si0 2 and CaC0 3 . In general, sorption and desorption equilibrium is not
... quilibrium is not reached for nickel and cobalt, which is in striking contrast to the behaviour observed for strontium and barium. A significant increase in the distribution ratios was observed for nickel and cobalt up to sorption times of 182 and 56 days, respectively. In most cases, the sorption process was largely irreversible. The sorptive power of the < 32 μπι materials with artificially changed mineralogies is considerably reduced as compared to that of the <32 μπι material with the original mineralogical composition, i. e., during the removal of the carbonates a significant decrease in the sorptive power occurred. A comparison of the sorption behaviour of nickel and cobalt with that of cesium, strontium and barium is also shown.