A prototype IT/BF-MBR (inclined tube/biofilm-membrane bioreactor) for high-rise building wastewater recycling

A novel inclined-tube biofilm-membrane bioreactor (IT/BF-MBR) has been developed in a prototype system for high-rise building wastewater recycling. The prototype IT/BF-MBR system was designed as a single compact reactor with three compartments, starting from first-stage biofilm compartment, second-stage biofilm compartment and aerobic membrane compartment with submerged MF membrane installation. Here, the inclined tube was installed as a prefilter for sieving and filtering the incoming suspended solid and also served as a media to promote biofilm growth in the biofilm compartments to enhance more biomass activity inside the IT/BF-MBR system. The system received raw wastewater from a 20-floor university building at a design flow rate capacity of 4m(3)/day. The IT/BF-MBR could achieve stable treatment performance as above 90% removal efficiencies for organic Chemical oxygen demand, NH4+-N, and total phosphorus. The composition of microbial EPS inside the membrane bioreactor system was found in the following order: lipid>carbohydrate>protein. Furthermore, the quality of treated effluent could comply with the reuse water quality standard for nonpotable uses as toilet flushing and garden watering purposes.