Biofouling Reduction in Electro Coagulation Integrated Membrane Bioreactor using Quorum Quenching Technique

Abstract

Membrane fouling reduction is requisite for effective operation of membrane treatment technologies. During Phase 1, four electro bioreactors were operated at different electric exposure modes i.e., 5’ON-10’OFF, 5’ON-20’OFF, 5’ON-30’OFF, 5’ON-40’OFF besides control reactor and their effect on sludge characteristics was studied. 5’ON-30’OFF and 5’ON-40’OFF modes were optimized from stage 1 and further used with and without Quorum Quenching (QQ) Beads in stage 2. From stage 2, 5’ON-30’OFF (QQ) was selected for further study. During Phase 2, continuous operation of submerged membrane electro-bioreactor (SMEBR(QQ)) and submerged membrane bioreactor (SMBR(QQ)) was studied in which hollow cylindrical (HC) beads having Rhodococcus sp. (BH4) specie were used for membrane biofouling reduction. Porous aluminum anode and stainless steel cathode were used as electrodes in SMEBR(QQ). Various parameters including Mixed Liquor Suspended Solids (MLSS), Sludge Volume Index (SVI), Time to Filter (TTF), Particle Size Distribution (PSD), COD and nutrients removal and Transmembrane pressure (TMP) were examined to visualize the microbial and sludge activity. By introducing HC QQ beads TMP rise delayed from 44 to 46 days and with the addition of electrocoagulation as SMEBR(QQ) TMP rise further delayed to 30KPa within 58 to 60 days. This showed that, SMEBR(QQ) reduced the fouling rate more than SMBR(QQ) depicting long filtration time in membrane bioreactor (MBR).