Brewery wastewater treatment and resource recovery through long term continuous-mode operation in pilot photosynthetic bacteria-membrane bioreactor.

Abstract Photosynthetic bacteria (PSB) are considered ideal for high COD wastewater treatment and resource recovery. This work is the first continuous-mode long-term (440 days) pilot study (240 L) by using PSB-membrane (PSB-MBR) system for such purpose. Results showed that the system started-up in 27 days for brewery wastewater and then stably operated under various temperature, initial COD and pH conditions, which showed fast start-up and strong robustness. Comparing with small-batch PSB-MBR system, the capacity of pollutants treatment degradation rate in the pilot-continuous PSB-MBR system was promoted. The operation parameters for pilot-continuous PSB-MBR system were determined as follows: light-micro aerobic, 72 h hydraulic retention time, 1200 mg L−1 inoculum size and 1.0 g L−1 d−1 organic loading rate, 2.5 F/M. Under these conditions, the COD and NH 4 + in effluent were below 80 and 15 mg L−1, respectively. The PSB cell production reached 483.5 mg L−1 d−1 with protein, polysaccharides, carotenoid, bacteriochlorophyll, and coenzyme Q10 of 420.9, 177.6, 2.53, 10.75, 38.6 mg g−1, respectively, showing great potential of resource recovery from organic wastewater. In addition, the collected biomass had no acute toxicity to crucian carps. This work provides a base for the scale-up of this novel technology. Graphical abstract Unlabelled Image Highlights • Continuous pilot PSB-MBR firstly used for brewery wastewater resource recovery. • Operative parameters were determined for long-term pilot-continuous operation. • PSB-MBR system showed strong robustness to water quality and environment changes. • Good effluent quality with PSB cell production of 483.5 g L−1 d−1. • PSB cells were non-toxic, rich in protein and value-added substances. [ABSTRACT FROM AUTHOR]