Membrane permeation combined with complexation was tested for radioactive wastes processing purpose. The ceramic membranes MEMBRALOX((R)) and CeRAM INSIDE(R) were used. To enhance the UF separation effect, different soluble polymers and ferrocyanides, binding cobalt and caesium ions were used. The complexing agents were tested in laboratory to establish the best conditions of the process. The experiments showed a significant increase of decontamination factors while the macromolecular compounds were added. The effectiveness of complexation by each ligand is strongly dependent on pH and alkali metals concentration.