Comparison of membrane filtration performance between biofilm-MBR and activated sludge-MBR

Both a moving bed biofilm (BF)-MBR and an activated sludge (AS)-MBR pilots were operated in parallel to investigate and directly compare the membrane filtration performances. Experimental results show that a slightly bett er permeate quality and less membrane fouling were observed in the AS-MBR. Membrane feed quality parameters (i.e., SS, FCOD, CST, PSD, Zeta potential) were compared for the two MBR systems. Several measurements indicate a large amount of submicron and colloidal particles are found in the biofilm reactor. To obtain a sustainable operation of a BF-MBR with low fouling rates it is therefore very important to choose operating conditions and system configurations in which the submicron colloidal component is managed and controlled.