Performance and Modeling of Moving Bed Biofilm Process for Nutrient Removal from Wastewater

In this study, experiments have been conducted to evaluate the removal of nutrients from synthetic wastewater using a moving bed biofilm process. For this purpose, the process was applied in series with anaerobic, anoxic, and aerobic units in four separate reactors. Moving bed biofilm reactors were operated continuously at different loading rates of nitrogen and phosphorus and different hydraulic retention times. In addition, for kinetic analysis,first-order substrate removal, Grau, and Stover-Kincannon models were tested with the experimental data. Based on the results obtained, a close to complete nitrification with an average Total Kjeldahl Nitrogen (TKN) removal efficiency of 99.72% was obtained in the aerobic reactor under optimum conditions. In this reactor, the average specific nitrification rate was 1.92 g NOx-N/kg VSS.h. During the study, statistically significant correlation was observed between the aerobic phosphorus removal rate and the anaerobic phosphorus release rate. Under optimum conditions, the average total nitrogen and phosphorus removal efficiencies were 80.9% and 95.8%, respectively. Finally, based on the kinetic analysis and with regard to nitrogen and phosphorus removals, the Stover-Kincannon model was selected as suitable for analyzing the experimental data and modelling of the moving bed biofilm process.