LAUSR

A novel four-stage pilot-scale anaerobic/anoxic/oxic/oxic (A2/O2) biofilm process was successfully developed to treat coking wastewater with high ammonium loading. In this study, three different dynamical models including first-order substrate removal model, Monod-biological contact oxidation (Monod-BCO) model and modified Stover-Kincannon model were particularly applied to analyze kinetics of ammonium removal in two-step aerobic stage. For O1 reactor, all models were appropriate for describing ammonium removal and the correlation coefficient of first-order substrate removal model, BCO model and modified Stover-Kincannon model were 0.8974, 0.9210 and 0.9726, respectively. The model verification indicated that modified Stover-Kincannon model was slightly more applicable to predict ammonium removal in O1 reactor. And it was demonstrated the maximum removal rate of ammonium was 0.208 kg/(m3 · d) by Stover-Kincannon model. For O2 reactor, modified Stover-Kincannon model turned out to be the best fitting kinetic model for ammonium removal compared to first-order substrate removal model (R2 = 0.1556) and Monod-BCO model (R2 = 0.5022). The maximum ammonium conversion rates (Um2-O2) by the modified Stover-Kincannon model were 1.180 kg/(m3 · d), while saturation rate constant k3-O2 was 1.221 kg/(m3 · d). Furthermore, determination coefficient between measured and predicted values obtained by modified Stover-Kincannon model was quite high (R2 = 0.9788) in O2 process and lower average residual square (6.60 × 10−6) was also obtained. The results of kinetic studies by Stover-Kincannon model can describe well for prediction of ammonia removal efficiency in two-step aerobic biofilm reactors of coking wastewater treatment combined system. This article is protected by copyright. All rights reserved