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,　FeCl3　center　dot　6H(2)O　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　(C)　2021　Elsevier　B.V.　All　rights　reserved.