High pH-induced flocculation-sedimentation and effect of supernatant reuse on growth rate and lipid productivity of Scenedesmus obliquus and Chlorella vulgaris

- Ca(OH)2 showed higher recovery efficiency but CaCO3 appeared in the pellet.
- Mg2+ is not the sole factor affecting high pH induced flocculation with Na(OH).
- Medium reuse after centrifugation and flocculation is a viable way to save water.
- Biomass and lipid productivity were higher in reused media than in fresh media.
- Lipids from microalgae grown in reused media were rich in unsaturated fatty acids.