Microalgae biomass recovery using organic and inorganic flocculants

Recuperação da biomassa de microalgas utilizando floculantes orgânicos e inorgânicos.

Abstract

The flocculation is associated with low cost and practical for large volumes. This research aimed to select and test a flocculant agent for recovering algal biomass post-cultivation. Ferrous sulfate, ferric chloride, aluminum sulfate, and an organic agent (Tannin-based) were tested. Aluminum Sulfate (100 mg L^-1) was the most effective for C. vulgaris, and Ferric Chloride (50 mg L^-1) for N. oceanica (93% efficiency at pH 7 and 9, respectively). However, cost-benefit analysis identified the organic agent (75 mg L^-1 for both strains) as the best agent option for flocculation. This compound also aligns with the circular economy principles, promoting sustainable resource use by favoring biologically based flocculants.