The treatment of radioactive wastewater by chemical precipitation method has the advantages of being simple

wide application and large amount of water treatment. Membrane separation technology can improve the effectiveness of solid liquid separation. In this paper

precipitation and membrane separation technology were combined to treat the simulated wastewater containing radioactive iodide on a laboratory scale. The initial iodide concentration was approximately 5 mg·L-1. The concentration of added Na2SO3 used for removing oxygen from the influent was 40 mg·L-1 and the dosage of CuCl used as a precipitant was 260 mg·L-1. The entire system was under the protection of nitrogen gas that was recycled after drying. The whole process was operated continuously

which was controlled by programmable logic controller (PLC). The I- removal mechanism was the formation of sparingly soluble CuI. Besides that

Cu2O and Cu(II) ion were produced in this reaction system

which were demonstrated by solid phase analysis. This study investigated I- removal efficiency and other water quality parameters under different temperatures and the effects of two membrane flux 4.17×10-6 m·s-1 and 8.33×10-6 m·s-1 on membrane fouling. The operation time was 168 h and the volumes of treated wastewater were 1540 L. In two tests

the average I- removal efficiency was 94.8% with stable effluent water qualities. However

the Cu(II) ion concentrations in the effluent were higher and it was required for the subsequent removal. Under the conditions that the membrane fluxes were 4.17×10-6 m·s-1 and 8.33×10-6 m·s-1

the final membrane specific flux decreased to 65.0% and 55.0% of the initial one

respectively

and the membrane specific flux values of the membrane modules were recovered to 90.0% and 79.0% of the initial one

respectively after physical and chemical cleaning. Furthermore

the average concentration factor value was 2.02×103

and the volume of the sludge produced in the experiment was small.