Performance and hydrodynamic features of a staged up-flow ANAMMOX sludge bed (SUASB) reactor

• The staged ANAMMOX reactor (SUASB) was investigated systematically.
• The application of the kinetic model was validated.
• The robust performance of the SUASB was demonstrated.
• A maximum NRR of 6.04 kg N m−3 d−1 and NLR of 6.88 kg N m−3 d−1 were achieved.
• The hydrodynamic type of the SUASB reactor was investigated.

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 m−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 (KB) and maximum total substrate utilization rate (Umax) were 14.5 and 14.8 kg N m−3 d−1, respectively. Moreover, the C(t)–Θ 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).