Membrane bioreactor (MBR) is an effective wastewater treatment process in which the membrane separates technology integrated with the activated sludge system. The suspended solids are completely separated from the treated water by the ceramic membrane unit, and all bio-mass are kept in the bioreactor. Because of such advantages as good chemical stability, favorable mechanical strength, good antimicrobe ability and high separation efficiency, the ceramic membrane is suitable for comprising ceramic membrane bioreactor (CMBR) with activated sludge. For the CMBR process, the high energy requirement of recirculation needed to maintain a high cross-flow velocity combined with maintaining the membrane permeability is a major problem hindering the widespread application of membrane separation processes. In order to improve membrane flux, and reduce cyclic volume and energy consumption, studying of the enhancement process is necessary. This work investigated the effect of different kinds of turbulence promoter on flux of ceramic membrane filtration. Three kinds of insert were used in ceramic membrane bioreactor. The flux under the same operation condition increased about 2.5 times with the introduction of the winding insert. Both microfiltration and ultrafiltration gave a steady flux for 30 days without chemical washing. The average reduction rate of COD was greater than 95% for municipal wastewater. (C) 2003 Published by Elsevier Science B.V.