Wastewater treatment and simultaneous production of algal lipids in sequencing batch reactors containing a microalgal-bacterial consortium

Abstract

The use of microalgal-bacterial consortiums has attracted interest owing to their potential in sewage treatment. However, the performance of sequencing batch reactor (SBR) coupled with microalgal-bacterial consortiums has not been investigated extensively. The present study investigates two SBRs namely R1 and R2, operated for 60 d; R1 was supplemented with microalgal-bacterial consortium, while R2 contained conventional activated sludge. The average removal efficiency for chemical oxygen demand, ammonia nitrogen, total nitrogen, and total phosphorus in R1 were 91.7%, 98.8%, 69.9%, and 64.3%, which improved by 4.9%, 3.4%, 10.1%, and 8.6% compared to R2, respectively. The maximum chlorophyll content was 345.77 mg L−1 and the maximum lipid content was 340 mg L−1 in R1 which indicates the potential of algal biomass production. Microbial analysis showed the community characteristics and the population dynamics in R1 and R2 at different stages, and revealed the influence of the microalgal-bacterial consortium on microbial community evolution. These results suggest that microalgal-bacterial consortium-based systems can be used to treat wastewater and efficiently utilize sewage as a source of high-value compounds.