HARVESTING OF CHLORELLA SP. MICROALGAE BY DIELECTROPHORETIC FORCE USING TITANIUM DIOXIDE (TiO2) INSULATED ELECTRODES

Abstract

The harvesting of microalgae using conventional technologies suffers from biomass contamination, high energy consumption and long processing time. In this study, titanium dioxide (TiO2) insulated stainless steel electrodes were used for the harvesting of Chlorella sp. microalgae by dielectrophoretic force. The new electrode configuration is expected to achieve high harvesting efficiency with zero contamination for the harvested biomass. The effect of various experimental parameters on the harvesting efficiency were evaluated using a bench scale setup. This includes settling time, applied voltage, interelectrode distance, application of pulsed electric field, and applied current frequency. The maximum harvesting efficiency of 76.6% was obtained at 4 mm interelectrode distance, 200 V applied voltage, 250 kHz frequency, and application of pulsed electric field for 30 minutes. Under these conditions, the energy consumption was 7.76 kWh/kg. The most significant impact of using the new electrode configuration is achieving high harvesting efficiency with no contamination for the biomass.