Development of the anaerobic baffled reactor-membrane bioreactor (ABR-MBR) as a biological nutrient removal system for high-rise building wastewater recycling

Abstract

A novel anaerobic baffled reactor-membrane bioreactor (ABR-MBR) system has been developed as a compact combined biological treatment system and membrane separation unit for wastewater recycling from high-rise buildings. Here, the anaerobic baffled reactor (ABR) compartment had five baffles and served as anaerobic degradation zone, followed by the aerobic membrane bioreactor (MBR) compartment for further aerobic degradation of organic residues. The total operating hydraulic retention time (HRT) of the ABR-MBR system was 3 h (2 h for ABR compartment and 1 h for aerobic MBR compartment). The wastewater used in the study came from Charoen Wisawakam Building, Faculty of Engineering, Chulalongkorn University, located in Bangkok city, Thailand. The results showed that treated effluent quality was quite good and highly promising for water reuse purposes. The average permeate flux of the membrane was kept at 30 L/m2-h. The ABR-MBR system could remove more than 90% COD, total nitrogen, and total phosphorus from building wastewater at total operating HRT of only 3 h. Specific phosphorus uptake rate obtained in the aerobic MBR compartment is calculated to be 4.82 mgP/gMLSS h. Moreover, a rapid phosphorus uptake phenomenon in the MBR compartment implies that PAOs biomass seems to respond for biological phosphorus removal by the ABR-MBR system. The research suggests that the ABR-MBR system can be a promising system for water reuse and reclamation for high-rise buildings in the near future.