An integrated approach for microalgae cultivation using raw and anaerobic digested wastewaters from food processing industry

Abstract An integrated approach has been proposed to produce microalgal biodiesel using both raw wastewater (RW) and anaerobically digested wastewater (ADW) of food processing industry without addition of extra nutrients or carbon source for cultivation besides obtaining effluent discharge permissible limits of TN, TP, and COD. Three microalgae species cultivated with following different combinations: RW, ADW, RW + ADW, and glucose + ADW. Results indicated that the addition of RW as a carbon source in ADW significantly enhanced BP, LP, and TN removal as compared to the ADW alone. The runs with RW + ADW removed COD, TN, and TP by 89%, 84%, and 70%, respectively. Sc. obliquus showed highest biomass and lipid productivities (211 and 27.5 mg L −1  d −1 ) for RW + ADW. The addition of RW or glucose in ADW significantly lowered PUFA contents to 5–15% CDW (as against 35–50% with ADW) for Chl. sorokiniana and Sc. obliquus .