Effect of salinity on mixed microalgae grown in anaerobic liquid digestate

Abstract

AbstractIn this study, mixed microalgal culture dominated by Chlorella vulgaris and Scenedesmus armatus was grown in Anaerobic Liquid Digestate (ALD) at different NaCl concentrations ranging between 0 and 100 mM. Highest lipid and carbohydrate amounts were observed as 38.4 and 36.2%, respectively, when the salinity was 50 mM NaCl. However, the protein content was drastically decreased to 12.8% with increased NaCl concentration. Furthermore, the algal biomass was subsequently decreased along with the total chlorophyll amount with increased NaCl concentration. Algal species showed diverse response to salinity stress and demonstrated a cost‐effective approach towards the cultivation of mixed microalgae within digestate and provided insight that ALD and/or other wastewaters can be diluted with seawater instead of tap water in the future studies. This study could be further converted into biofuels because of an increase in lipid content along with the digestate treatment, which will help to valorize ALD and bring into economy.