Membrane bioreactor (MBR) technology has been commonly employed in the treatment of domestic wastewater. However, total phosphorus (TP) removal performance and membrane fouling are two major challenges for MBR application. In this study, FeCl ₃ $\cdot$ 6H₂O was added to the membrane tank (MT) to improve the overall performance of University of Cape Town (UCT)-MBR. When the Fe(III) dosing concentration was increased from 0 to 1.8 mmol/L, the concentration of TP in the effluents was declined from 3.0 to 0.1 mg/L, and the high transmembrane pressure was reduced by 21.9%. The total nitrogen (TN) removal efficiency remained similar. However, when the Fe(III) dosing concentration was increased to 2.2 and 2.6 mmol/L, the phosphorus accumulating organisms (PAOs) and ammonia oxidizing bacteria (AOB) activities were greatly inhibited. Based on the overall nutrient removal and membrane fouling mitigation performances, the optimal Fe(III) dosing concentration was determined to be 1.8 mmol/L

膜生物反应器 (MBR) 技术已普遍用于处理生活废水。然而，总磷 (TP) 去除性能和膜污染是 MBR 应用的两大挑战。在本研究中，FeCl ₃ $\cdot$6H ₂ O被添加到膜罐（MT）中以提高开普敦大学（UCT）-MBR的整体性能。当Fe(III)投加浓度从0增加到1.8 mmol/L时，出水中TP浓度从3.0下降到0.1 mg/L，高跨膜压降低21.9%。总氮 (TN) 去除效率保持相似。然而，当Fe(III)的投加浓度增加到2.2和2.6 mmol/L时，聚磷菌(PAOs)和氨氧化菌(AOB)活性受到极大抑制。基于整体营养物去除和膜污染缓解性能，最佳 Fe(III) 投加浓度确定为 1.8 mmol/L