Removal of Strontium, Cobalt, and Cesium from the Mixed Aqueous Solution Using <i>Arthrobacter </i><i>nicotiane</i> Cells

The removal of strontium, cobalt, and cesium ions from the aqueous solution using biomass was investigated. Arthrobacter nicotianae known for its high capacity to remove cationic metal ions was used for the removal of these metal ions. Several factors affected the removal of these metal ions using A. nicotianae including solution pH, concentration of metal ions, and cell amount. The amount of each metal ion removed increased with the rising pH (1 - 5) of the solution. Meanwhile, the ion uptake per gram of dry biomass (mmol metal ion/g dry wt. cells) increased with increasing metal ion concentration. However, removal efficiency (%) decreased. The metal ion uptake (mmol metal ion/g dry wt. cells) was found to fit the Langmuir isotherm. Conversely, increasing the biomass content enhanced total percentage of metal ions removed (%); however, the amount of each metal ion removed (μmol metal ion/g dry wt. cells) decreased. The removal of strontium using A. nicotianae occurred rapidly, approaching equilibrium within approximately 5 min. The amounts of cobalt and strontium removed were higher than that of cesium removed. The maximum amount of cobalt, strontium and cesium is estimated to be 179, 175, and 56.1 μmol/g dry wt. of cells, respectively.