USE OF PVC PLASTICIZED MEMBRANES FOR UPTAKE OF RADIOACTIVE CESIUM ANDSTRONTIUM

A new type of sorbent for the selective uptake of elements based on th e use of PVC plasticized membranes, commonly used in electrochemistry as ion selective (ISE) membranes, is described. It is theoretically de rived that the material acting as a selective ion sensor of ISE must b e also effective as a sorbent. In experimental verification of the hyp othesis,; the cobalt dicarbollide and sodium tetraphenylborate with th e addition of a synergist of the polyethyleneglycol type were dissolve d in several solvents mixed with a tetrahydrofurane solution of 5% PVC and evaporated to produce a membrane used for the sorption experiment s. It was found that PVC, besides functioning as a solid support, does not influence significantly the behavior of the prepared materials; h owever, the kinetics are slower than for the analogous solvent extract ion techniques. Practical applications of such membranes for the isola tion of radioactive cesium and strontium from acidic and alkaline solu tions with a high of Na+ ions content are shown, with emphasis on nont oxic solvents as substitutes for the toxic nitrobenzene.