INFLUENCE OF BIOFILM CARRIERS ON MEMBRANE FOULING TENDENCY AND TREATMENT PERFORMANCE IN HYBRID MEMBRANE BIOREACTOR

Abstract

In moving biofilm membrane bioreactor (MB-MBR) sponge carriers for biofilm growth were coupled with conventional submerged membrane bioreactor (C-MBR). This study compared the fouling propensity of C-MBR with MB-MBR and investigated the factors affecting fouling variation in both the systems. Membrane fouling tendencies were monitored in terms of transmembrane pressure (TMP) and the fouling charaterization included membrane fouling resistances in situ and specific cake reistance (SCR) in batch filtration cell. Comparison of TMP profiles depicted prolong filtration periods in MB-MBR. The cake layer resistance (Rc), pore blocking resistance (Rp) as well as SCR were higher in C-MBR. The study reveals that hybrid biomass in MB-MBR creates a relatively more porous cake structure in the absence of filamentous bacteria which were found in abundance in C-MBR. The filamentous bacteria were also responsible for the release of high concentration of carbohydrates in the form of soluble extra polymeric substance (EPS) contribuitng to higher Rp in C-MBR.