A study of the use of seeded ultrafiltration for the treatment of thorium-uranium mining waste streams

The use of seeded ultrafiltration for the treatment of radioactive waste streams arising from the nuclear industry has demonstrated its high potential as an efficient process for the removal of radionuclides present in the rad waste streams. The experimental data on simulated mining streams has given indications on the suitability of this technique for the treatment of mining waste streams. The results also show that proper choice of absorbers can reduce not only the radioactivity level but also remove most of the products of both the thorium and uranium decay series. Decontamination factors (D F) for the system using manganese dioxide (Mn O2) are only slightly affected by the preparation method. On the contrary, the D F achieved using titanium hydroxide (HTiO) absorber was found to be dependent on the preparation method. The experimental data shows that total activity levels can be reduced to below to below detection limit (3 E-3 Bq/ml). The extent of decontamination of thorium containing waste streams was found to be dependent on the absorber used; in the order diuranate > HTiO> Fe(OH)3> Mn O2. The use of HTiO reduced the decay product activity of almost all the thorium daughters to nearly background levels. A D F of the order of 300 can easily be achieved using diuranate floe. 10 fig., 5 tab