Influence of the filtration modes on colloid adsorption on the membrane in submerged membrane bioreactor

The influence of three different filtration modes on the colloid adsorption in a submerged membrane bioreactor (SMBR) was evaluated and the feasibility for the characterization of the colloid adsorption on the membrane using a modified Freundlich isothermal adsorption equation qe=X/A=aCe1/n was also explored in this study. Under the same operating conditions, the adsorption equations determined in this study were 0.519Ce1.1623,7.416Ce0.7305and2.590Ce1.0449 for modes of vacuum pump dragging with air back washing, vacuum and suction pumps dragging without air back washing, respectively. Compared with the filtration mode of suction pump or vacuum pump dragging without air back washing, the mode of 10 min vacuum pump dragging with 5 min air back washing could reduce the colloid adsorption. The results also demonstrated the modified Freundlich isothermal adsorption equation, qe=X/A=aCe1/n, was applicable to characterize the colloid adsorption on the membrane in the SMBR. Except the characterization of colloid adsorption, this approach also could be used for the optimization of operational conditions, the selection of membrane materials and the evaluation of module configuration, consequently alleviating the membrane fouling in a SMBR.