The present investigation was intended to study the state of Pm-147 in solution and its adsorbed state on membrane filters by varying the concentrations of Pm-147 solution and its pH.
Also, the study on the coprecipitation of Pm-147 with Fe(OH)₃ was carried out by varying amounts of Fe (OH)₃ and pH of the solution.
The carrier-free Pm-147 exists in an ionic state of Pm^(3+) in solution, and is adsorbed on membrane filter in filtration process. The adsorbed state of Pm-147 on the membrane filter shows various ionic state at" a constant ionic strength of 0.1M NaCl, that is, Pm^(3+) state exists until pH value of 5.0, then gradually Pm(OH)^(2+) state appears between pH value of 5.0 to 6.0, and the state of Pm(OH)₂^(+) and Pm(OH)₃ would be expected at the higher pH value of 6.0.
Coprecipitation of Pm-147 on Fe(OH)₃ is an adsorption penomenon in an ionic state of Pm^(3+) in acidic condition. At higher pH and larger amount of Fe carrier, the adsorbed state of Pm-147 shows Pm(OH)^(2+) and Pm(OH)₂^(+) state.
As a results of the present studies, it is seen that the characteristic of carrier free radioisotopes is not due to the radioactivity, but due to the adsorption of ultramicroquantity of radioisopes. Therefore, the knowledge on the ultramicroquantity of radioisotopes could help for the solution of decontamination in handing and chemical procedure with radioisotopes
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