Research on Harvesting of Microalgae Chlorella Sp. By Electrochemical Flotation Method Using Corrosive Electrodes

Abstract

Microalgae are a promising feedstock for biodiesel production. Harvesting of microalgal biomass is still a bottleneck to its commercial scale application, due to small cell size, low culture densities, colloidal stability and thus economic disadvantage. The aim of this study was to evaluate the biomass separation of the small size microalgae Chlorella sp. by electrochemical flotation process with rectangle electrodes using aluminum or iron plates. The most effective conditions for this experiment involved the use of an aluminum electrode for 30 min with a current density of 1.5 mA/cm 2 , whereas the iron electrode has been used ineffectively with the same of conditions. The effect of current density (0.5-3 mA/cm 2 ), concentration of microalgae biomass (0.29-1.5 g/L), and electrolyte (0-2 g/L) for aluminum electrode were analyzed. The highest recovery efficiency of 90 % was obtained for Chlorella sp. at 1.5 mA/cm 2 in 30 min and concentration of microalgae biomass of 0.74 -1.5 g/L with power consumption of 1.36 kWh/kg. The electrochemical flotation process with aluminum electrodes could be a possible harvesting step at commercial scale for microalgal biomass production.

Microalgal Biomass Generation via Electroflotation: A Cost-Effective Dewatering Technology

“…The study demonstrated that by utilizing a current density of 1.5 mA/cm 2 for 30 min, Al was more beneficial to the electroflotation process than Fe as 90% of microalgae was harvested with the former. Additionally, 0.74-1.5 g/L concentration of microalgal biomass was harvested in this study with a power consumption of 1.36 kWh/kg [92]. Further, Estupinan et al (2018) designed a unique electroflotation system for the effective harvesting of freshwater microalgae as well as to increase the biomass concentration.…”