Reducing fouling and boundary-layer by application of helical flow in ultrafiltration module employed for radioactive wastes processing

Application of helical Couette–Taylor flow (CTF) for reduction of membrane fouling in the process of radioactive wastes treatment was considered. The experiments were carried out with model solutions of cobalt ions (Co2+). Ultrafiltration process combined with complexation with polyacrylic acid or adsorption on activated carbon seeds was applied. The influence of hydrodynamic conditions in the module on the permeate flux and separation efficiency was tested. It was noticed that the helical flow influenced filtration efficiency: with increase of rotation frequency of the inner cylinder in the module, up to 3-fold enhancement of permeate flux was observed. The estimated thickness of residual polymer layer developed on the membrane surface depended on rotation frequency, too. Slight increase of retention factors was observed when dynamic conditions were applied