Optimizing MABR operation for efficient tetracycline and nutrient removal in wastewater

The escalating pollution from pharmaceutical wastewater, notably tetracycline (TC), demands innovative treatment solutions. This study explores a membrane aerated biofilm reactor (MABR) for TC biodegradation and simultaneous removal of total nitrogen (TN), ammonia nitrogen (NH4+-N), and total phosphorus (TP). The MABR employed polypropylene hollow fiber membranes (0.2μm pore size) to develop stratified biofilms enabling microbial synergy: aerobic nitrifiers degraded NH4+-N while anoxic denitrifiers reduced TN. Optimal conditions (0.122 MPa aeration, 16-h HRT, 0.4 mg/L TC) achieved 70% TC degradation, 90% NH4+-N removal, 88% TN removal, 75% TP removal, and 93% COD removal. Microbial analysis confirmed TC mineralization via synergistic biofilm communities, minimizing toxic byproducts. The system's energy-efficient oxygen diffusion (direct membrane aeration) and high contaminant-removal efficiency underscore its cost-effectiveness. These findings position MABR as a sustainable, non-toxic solution for complex wastewater treatment.