THE HARVESTING OF HIGH LIPID CONTENT MICROALGAE BIOMASS THROUGH A FLOCCULATION STRATEGY

Abstract

Different flocculants were evaluated for the flocculation of microalgae biomass of Acutodesmus obliquus. Flocculation was tested with FeCl₃ and NaOH at different concentrations and compared to a sample centrifuged at 7000 rpm. The evaluated parameters were absorbance (540 nm) in the clarified medium, and lipids concentration. For FeCl₃ (0.2 mmol L^-1) as flocculant, efficiency was 96.8%, and with NaOH (8 mmol L^-1) 93.5%. Centrifugation efficiency was lower than with either flocculants: 91.7%. However, NaOH flocculation reduced lipid content, which did not occur with FeCl₃. Flocculation efficiency was affected by salt concentration, reducing efficiency by 79% due to increased nutrient concentration (9 mL L^-1).