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The application of insulator-based dielectrophoresis (iDEP) has the potential to enhance membrane fouling suppression in submerged membrane bioreactors without extra energy consumption. In this study, the effect of the insulators shapes and sizes within the interidigitated electrodes (IDE) configuration was investigated for a better dielectrophoresis (DEP) force with a better membrane fouling suppression. Three circular insulators CS 1, CS 1.5 and CS 2 with diameters of 1 mm, 1.5 mm and 2 mm, respectively, were tested. A 2 mm side square section insulator SS 2 was also examined. The numerical simulation results show that the DEP force extension is greater with a similar diameter as the excited electrodes (2 mm in this study) when using circular insulators. The use of square section insulator (SS 2) increases the overall electric field gradient squared (?|E|2) by 16% compared to the 2 mm circular insulator (CS 2). The square section insulator also extends the dielectrophoresis (DEP) force field more uniformly across the membrane surface while generating sufficient force to move the suspended solids away from the membrane. The experimental investigation verified the theoretical simulation prediction and demonstrated that SS 2 membrane modules provide longer membrane service time by maintaining a normalized permeate flux of 55% more than the circular section membrane modules, with a maximum intensification factor of 14 at a 220 V voltage and 50 Hz with a transmembrane pressure of 0.1 bar. This research is made possible by NPRP award (NPRP7-089-2-044) from Qatar National Research Fund (QNRF) Scopus

Membrane bioreactors (MBRs) present a unique opportunity in waste water treatment by combining the activated sludge process with membrane filtration. Although MBRs require less area, produce less volume of sludge and have high purification efficiency, they suffer from high membrane fouling. Membrane fouling can be reduced by applying aeration and Dep voltage. However, application of these two anti-fouling mechanisms would make the process expensive. Thus, a new aeration and DEP scheme of 5 min on – 5 min off is being suggested in this study. With this scheme, it was found that through application of DEP at 100 V and 0.3 L/min.m2 aeration flowrate and reduced lumen size of 6 mm, the membrane permeate flux can be increased by 58% compared to MBR without DEP and aeration. However, through energy analysis the optimum operating parameters were found to be at 0.3 L/min.m2 aeration flowrate and 50 V DEP using the suggested 5 min on-5 min off scheme. At the optimum operating condition, the permeability flux is 54% higher than MBR without DEP and aeration. This research project is made possible by NPRP award (NPRP7-089-2-044) from Qatar National Research Fund (QNRF) (grant ID NPRP7-089-2-044 ). The statements made herein are solely the responsibility of the authors. The authors would also like to acknowledge the help provided by Qatar Works Authority (Ashghal) for providing the wastewater and sludge samples. Scopus