Membrane technology has been chosen for this treatment, based
on good results of activity removal from low-medium activity wastes
in several treatment plants currently in operation. As it is known that
part of the 125I is under ionic form in RIA wastes [28], reverse osmosis
process must be applied for complete activity removal. Furthermore,
due to the organic content of the wastes, and because it has been
experimentally proved that part of the radioisotope is labeled to
proteins [29], a pretreatment by ultrafiltration should be applied.
Ultrafiltration is aimed to remove organic and biological content of
the waste, thus improving performance of reverse osmosis. Fig. 1
shows a diagram of the treatment process applied to RIA wastes.