Recovery of137Cs from Laboratory Waste using Solvent Extraction with Sodium Tetraphenylboron (TPB)

The paper describes a method for the recovery of 137Cs from an aqueous radioactive laboratory waste solution containing 137Cs (2 µg/mL) in the presence of high concentration of Na+ using solvent extraction technique. The method comprises of adjustment of pH to the acidic range (pH = 2), contacting the aqueous radioactive solution with sodium tetraphenylboron (TPB) in nitrobenzene, whereby 137Cs binds with tetraphenylboron anions and gets separated. Results of this investigation indicate that 137Cs could be efficiently and selectively extracted from an aqueous solution media containing high concentration of Na+ under mildly acidic pH into an organic phase and back extracted with small volume of 3 M HNO3, thus enabling concentration. The proposed method was successfully applied in real samples.