Assessment of the Effect of Dielectrophoresis (DEP) on the Viability of Activated Sludge Biomass

Abstract

Effective application of dielectrophoretic forces in membrane bioreactor (MBR) systems has the potential to suppress membrane fouling. Nevertheless, minimizing the impact of the elec. field on biomass suspension is essential to maintain the efficiency of the wastewater treatment process. In this study, interdigitated cylindrical electrodes (IDE), placed inside the membrane module, were used to generate dielectrophoresis (DEP) in an MBR system. The viability of the biomass was determined at different voltages (5-150 V) after 1-h exposure to a pulsed a.c. (AC) elec. field. The results of the behavioral response of the microorganisms revealed that at low voltage applications, the bacteria exhibited good performance and no major impact was found on their viability/metabolism Whereas at high voltage applications (beyond 100 V), the current intensity and medium temperature increased due to the joule heating effect and caused a significant decline in the bacterial activity and pollutant removal efficiency as a result of bacterial lysis.