Biological sulfamethoxazole degradation along with anaerobically digested centrate treatment by immobilized microalgal-bacterial consortium: Performance, mechanism and shifts in bacterial and microalgal communities

Abstract Though microalgal-bacterial consortium in photobioreactor (PBR) has been investigated to the anaerobically digested centrate (ADC) treatment, the impact and degradation of micropollutant sulfamethoxazole (SMX) in this system has never been reported. In this research, three microalgal-bacterial consortiums were parallel operated with suspended Chlorella vulgaris (C. vulgaris), immobilized C. vulgaris and immobilized C. vulgaris-powdered activated carbon (PAC), namely PBR (SCV), PBR (ICV) and PBR (ICV+PAC), respectively. The impact of SMX on the ADC treatment performance, C. vulgaris growth and microbial community shifts were investigated. The performance of SMX removal and potential SMX degradation mechanism by the microalgal-bacterial consortium were explored. The results showed that SMX significantly inhibited PBR (SCV) with unsatisfactory C. vulgaris growth, ADC treatment and SMX removal. Comparatively, immobilized microalgae beads protected microalgae in PBR (ICV) and PBR (ICV+PAC) obtaining higher proportion of living C. vulgaris of 85.1% and 86.2%, respectively, comparing to that of 74.6% in PBR (SCV) (p