Pulsed Electric Field Treatment of Microalgae: Inactivation Tendencies and Energy Consumption

Abstract

Pulsed electric field (PEF) treatment can be used to facilitate microbial cell lysis. The aim of this paper is to investigate this effect of PEF treatment on microalgae. The PEF system used in this paper consists of a pulse generator and treatment cell with parallel-plane metallic electrodes. The PEF treatment of microalgae, Spirulina, was conducted using 33.3 and 66.7-kV/cm electric field impulses. The efficiency of the PEF treatment for inactivation of microalgae was assessed by comparison of the growth curves of PEF-treated and untreated samples. Results showed that growth of microalgae can be stopped by the application between 100 and 500 high-field impulses with field magnitude 33.3 kV/cm. When the field is increased to a magnitude of 66.7 kV/cm, the growth of microalgae can be stopped by application of 50 impulses. Overall, this paper confirms that PEF treatments can be used for the inactivation of algae and the energy consumption of the PEF process can be reduced using suspensions with lower electrical conductivity.