The performance and hydrodynamic features of a staged up-flow ANAMMOX (anaerobic ammonium oxidation) sludge bed (SUASB) reactor was evaluated. When the reactor was at steady-state conditions, the nitrogen loading rate (NLR) and nitrogen removal rate (NRR) were 5.63 and 4.82 kg N 111(-3) d(-1), respectively. The reactor could withstand a 1.5-fold substrate or hydraulic shock. The modified Stover-Kincannon model was used for the kinetic analysis, and the saturation value (K-B) and maximum total substrate utilization rate (U-max) were 14.5 and 14.8 kg N m(-3) d(-1), respectively. Moreover, the c(t)-Theta curve showed the existence of dead zones in the SUASB at the hydraulic retention times (HRTs) of 3 and 12 h, and the flow pattern performance of the SUASB fell between those of a continuous stirred tank reactor (CSTR) and a plug flow reactor (PFR). (C) 2014 Elsevier B.V. All rights reserved.