[en] Preliminary study on the treatment of low level radioactive wastewater was performed using supported liquid membranes (SLMs) containing CMPO/TBP/dodecane. The feed solution contained Ce(III), Fe(III), Cr(III) and Ca(II) dissolved in aqueous HNO₃/NaNO₃ solution and the permeate side solution contained chelating agents such as sodium citrate. The effect of experimental conditions on the permeation behavior of Ce(III), which is considered to be similar to that of Am(III), was systematically investigated A stirred permeation cell and plate-and-frame type modules were used. The higher the NaNO₃ concentration in the feed, the larger the distribution coefficient of Ce between the feed and the membrane solution, which resulted in rapid uphill transport of Ce(III). Raising the temperature was also effective. In the experiments using modules, twenty fold enrichment of Ce(III) was achieved and decontamination factor was as high as 1000. The SLM could be stabilized by circulating a small amount of membrane solution through the stripping side of the module. The required membrane area was found to be rather small, which suggests the possibility of commercial application of the SLM. (authors)