This study was conducted to evaluate the kinetics of simultaneous removal of COD, NH4+-N and Mn2+ in a biological aerated filter (BAF) system. The evaluation was performed in a BAF system under various conditions of organic loading rates (OLRs) (0.2-1.0 kg COD/m(3) d), aeration rates (ARs) (0-2 L/min) and hydraulic retention times (HRTs) (6-24 h). Increasing the OLR and AR in the BAF system increased simultaneous COD, and Mn2+ removal. Meanwhile, decreasing the HRT resulted in an insignificant impact on COD and NH4+-N removal, but Mn2+ removal was significantly affected. The Monod model was used to estimate the kinetic coefficients of it,,, and K-s for the three substrates, i.e. COD, NH4+-N and Mn2+. The kinetic coefficients were found to be 0.28 d-(1) (mu(max,COD)) and 5.1 mg-COD/L (K-S,K-COD) for COD, 0.17 d(-1) (mu(max,NH4+-N)) and 0.03 mg-N/L (K-S,K-NH4+-N) for NH4+-N, and 0.28 d(-1) (mu(max,M2+)) and 0.03 mg-Mn2+/L (K-S,K-M2+) for Mn2+. From the Monod parameter estimation, the specific growth rate of biomass cells was adequately predicted for high quality effluent of simultaneous COD, NH4+-N and Mn2+ removal. (c) 2014 Elsevier B.V. All rights reserved.