Evaluation of flocculation induced by pH increase for harvesting microalgae and reuse of flocculated medium

► A flocculation method by pH increase was found effective for harvesting microalgae. ► Biomass concentration and RPS concentration influenced the flocculation efficiencies. ► Flocculated medium could be reused by neutralizing pH and supplementing nutrients. ► Reused medium maintained an approximate growth yield to that of the fresh medium.