Effect of the induced dielectrophoretic force on harvesting of marine microalgae (Tetraselmis sp.) in electrocoagulation

In this study, a new electrocoagulation electrode configuration has been investigated in order to induce dielectrophoretic (DEP) force for the enhanced harvesting of marine microalgae (Tetraselmis sp.). Asymmetrical aluminum electrodes with an alternative current power supply were used. The impact of electrode configuration, current density and electrolysis time were evaluated. A maximum algal harvesting efficiency of 90.9% was achieved using 7.1 mA/cm2 current density and 10 min electrolysis time. The energy consumption was found to be 4.62 kWh/kg of microalgae. The major significance of using the new electrode configuration was found in the aluminum content in the harvested biomass which decreased by 52% compared to the conventional symmetrical electrocoagulation electrodes. [Display omitted] •AC & AC-DEP module was tested for harvesting microalgae.•Optimum conditions were 10 min electrolysis time and 7.1 mA/cm2 current density.•At optimum conditions, both modules showed similar algal harvesting efficiency.•However, AC-DEP module showed 52% reduction in aluminum content in biomass.