Removal of phosphorus from a municipal wastewater by simultaneous precipitation of ironhydroxy-phosphate (IHP) was investigated. The addition of Fe3+ was performed to supplement biological excess phosphorus removal by a completely mixed alternating aerobic-anoxic (AAA) activated sludge process. The cycles of 3-h anoxic time and 3-h aerobic digestion were set to controlling a single-sludge nitrification-denitrification. In this study, attempt has been made to analyse the effects of initial dissolved Fe/P molar ratio and pH on IHP precipitation. The AAA treatment process to remove soluble reactive and total phosphorus from domestic wastewater had a moderate efficiency. The empirical formula of IHP that differs from different pH ranges was verified. Two types of Fe-4(OH)(9)PO4 and Fe-5(OH)(6)(PO4)(3) precipitate may occur in different conditions of the AAA process. The efficiency of phosphorus removal from domestic wastewater by an AAA process was verified to contribute to a working methodology for the application of technologies in the field of domestic wastewater treatment. (C) 2014 Elsevier B.V. All rights reserved.