BOD and COD removal in vinasses from sugarcane alcoholic distillation by Chlorella vulgaris: Environmental evaluation

Abstract

Fermentation of sugarcane-derived liquors for ethanol production produces a liquid waste called vinasse, which is highly contaminant and constitutes a serious ecological problem. Therefore, to reduce this liquid waste’s contamination potential, vinasses from the alcoholic distillation were used as a growth medium for microalgae species like Chlorella vulgaris, evaluating their possible environmental advantages and industrial uses. Reductions in COD and BOD of up to 49% and 70% respectively, were observed, coupled with a maximum algal biomass production of 10.50 ± 0.92 g/L. Also, after fermentation, the human ingestion toxicity potential, terrestrial toxicity potential, and photochemical oxidation potential were reduced by 85%, 83%, and 93% respectively. These results contribute to the understanding of C. vulgaris growth using vinasses as a culture medium under strict heterotrophic conditions and the use of microalgal biomass to reduce the environmental burden caused by vinasses.