Coupling of Nutrient Removal and Biodiesel Production By Asterarcys quadricellulare Microalga Grown in Municipal Wastewater

Abstract The present study focused on the feasibility of using municipal wastewater (WW) as culture medium for cultivation of microalgae. The study aimed to assess the efficiency of microalgae in nutrients removing capacity from wastewater and its biomass and lipid productivity for using as biodiesel feedstock. Based on that, the green microalga Asterarcys quadricellulare was isolated and grown for 24 days in Bold’s Basal Medium as a control and at different concentration of secondary treated municipal wastewater (WW) diluted with distilled water (25%, 50%, 75% and 100%WW). Results of 75%WW treatment recorded 96.6%, 98.4%, and 89.9% removal efficiency for, nitrate, ammonia and total phosphorus, respectively. Also, it revealed high biomass productivity and biomass content, where it recorded 69.0 mgL-1 day-1, and 1.44 g/L, respectively. Likewise, high lipid productivity 17.2 mg L−1 day−1 and 360.6 mg/L lipid content. Consequently, Asterarcys quadricellulare fatty acids profile estimation revealed an increase in Oleic, Palmitic and Linoleic acids levels. Most properties of biodiesel derived from the studied microalga meet with values established by the ASTM D6751 and EN 14214 biodiesel standards. According to this analysis, A. quadricellulare microalga could be used for wastewater bioremediation and biomass production with a suitable content of lipids proper as biodiesel feedstock. The predictive biodiesel properties pointed that it has a good quality compared with international standards.