Comprehensive investigation of pollutant removal and microbial community in University of Cape Town membrane bioreactors by aluminum sulfate addition

• Published in: Journal of water process engineering 2025-01, Vol.69, p.106834, Article 106834
• Main Authors: Sun, Guangrong, Cong, Haibing, Zhang, Chuanyi
• Format: Article
• Language: English
• Subjects: Aluminum sulfate; Microbial community; Phosphate removal; UCT-MBR
• ISSN: 2214-7144; 2214-7144
• DOI: 10.1016/j.jwpe.2024.106834

In this study, two enduringly stable University of Cape Town membrane bioreactors (UCT-MBR) by varying influent C/N ratios (7.3/5.3, reactor A/B) and aluminum sulfate addition (0.03 mM/0.15 mM, reactor A/B) were investigated to explore the correlation of pollutant removal, microbial community, influent quality and chemical dosage. The findings indicated that the mean removal efficiencies of COD, TN were 93.1 %, 75.1 % (Reactor A) and 92.32 %,76.4 % (Reactor B) without chemical addition. The removal efficiency of NH4+-N was approximately 100 % and the effluent concentrations of total phosphorus (TP) were 0.72 mg/L and 1.45 mg/L. The addition of aluminum sulfate further enhanced the TP removal with the effluent concentration of 0.40 mg/L and 0.47 mg/L, without negative impact on the removal of COD, NH4+-N and TN. 0.03 mM addition could enhance anaerobic phosphorus release capacity, whereas 0.15 mM addition suppressed the release of phosphorus under anaerobic conditions and its uptake during aerobic phase. At the genus level, the bacterial distributions associated with phosphorus removal without chemical addition in reactor A and B were 22.5 % and 22.0 %. After the chemical addition, the proportions were changed to be 27.8 % and 15.2 %. It was evident that the 0.03 mM aluminum sulfate addition could stimulate the proliferation of phosphorus removal microorganisms, whereas 0.15 mM would have an inhibitory effect. •COD and NH4+-N removal was not influenced by aluminum sulfate addition.•0.03 mM aluminum sulfate addition promoted phosphorus removal.•0.15 mM aluminum sulfate inhibited microorganism proportion for phosphate removal.