Simultaneous removal of cesium and strontium using a photosynthetic bacterium, Rhodobacter sphaeroides SSI immobilized on porous ceramic made from waste glass

This study investigated practical and simultaneous removal of cesium (Cs, initial concentration of 5 mg/L) and strontium (Sr, initial concentration of 5 mg/L) using a photosynthetic bacterium, Rhodobacter sphaeroides SSI, immobilized on recovery-type porous ceramic made from glass waste. When 4 - 8 pieces /L of SSI immobilized ceramic were added to synthetic sewage wastewater containing glucose, almost 100% of Cs and 57% - 61% removal of Sr was observed after 3 day’s aeration treatment. The high potassium (K) concentration in wastewater suppressed Cs removal, but did not affect Sr removal. Other substrates such as lactic, acetic, and propionic acids were useful for Cs and Sr removal. But, removal efficiencies were lower than about 50%. When the practical outdoor removal experiment carried out using1 m3 vessel, almost 100% of Cs and 51% of Sr were removed like a laboratory experiment after 3 day’s aerobic treatment. After treatment, the SSI immobilized ceramic was recovered easily from water using an electromagnet. This SSI immobilized ceramic seem to remove radioactive Cs and Sr from water environments of Fukushima,Japan.