Cultivation of microalgae on liquid anaerobic digestate for depollution, biofuels and cosmetics: a review

Abstract

AbstractSolid wastes from domestic, industrial and agricultural sectors cause acute economic and environmental problems. These issues can be partly solved by anaerobic digestion of wastes, yet this process is incomplete and generates abundant byproducts as digestate. Therefore, cultivating mixotrophic algae on anaerobic digestate appears as a promising solution for nutrient recovery, pollutant removal and biofuel production. Here we review mixotrophic algal cultivation on anaerobic waste digestate with focus on digestate types and characterization, issues of recycling digestate in agriculture, removal of contaminants, and production of biofuels such as biogas, bioethanol, biodiesel and dihydrogen. We also discuss applications in cosmetics and economical aspects. Mixotrophic algal cultivation completely removes ammonium, phosphorus, 17β-estradiol from diluted digestate, and removes 62% of zinc, 84% of manganese, 74% of cadmium and 99% of copper.