2.4.3. Effect of drag force on bacterial adhesion
To estimate the effect of the drag force on bacterial adhesion, the pre-formed biofilm on the membrane surface was exposed to different permeate flux, and the remaining biofilm was analyzed by CLSM. The biofilm was pre-formed by 24 h in the biofouling experiment using the same protocol described in Section 2.4.1 at 1.50 MPa of the TMP
and 300 rpm of the stirring rate. Then, we continuously supplied 0.85wt.% NaCl aqueous solution for 24 h into the cell at the various permeate flux from 0 to 0.4m3/m2 day, to prevent further bacterial growth and to eliminate the effect of the CP of nutrients. The permeate fluxwas adjusted by the backpressure valve on the permeate water side. The
TMP and stirring rate were maintained at 1.50 MPa and 300 rpm, respectively.