Systematic formulation of brewery effluent for high-efficiency epuration and food-grade microalgae production
Résumé
Actual (vs. synthetic) effluents were recovered, costeffectively settled, augmented, and inoculated with Chlorella vulgaris. These minimal modifications ensure ease of process scale-up and economical viability while preserving the foodgrade status of the stream. After successful shake flask runs, the process was transferred to 100 and then 500-ml working volume photobioreactors. The achieved performances (biomass production from 0.29 to 0.49 g/L/d-light dose dependent-and removal rates, 24.5 ± 4.3 mg/L/d for PO 3-4 , 6.8 ± 1.6 mg/L/d for SO 2-4 , 107 ± 32 mg/L/d for Total Nitrogen, and 1.30 ± 0.32 mg/L/d for Total Organic Content) are twice as high as the ones reported by other scholars. Cell productivity and illumination were almost perfectly correlated, demonstrating that the process can be easily controlled via adjustment of the illumination. Finally, the produced microalgae exhibit a balanced macronutrient profile and can be deemed food-grade, opening the way to biomass valorization as feed.