Performance of sequencing batch biofilm reactors with different control systems in treating synthetic municipal wastewater

This study aimed to evaluate the performances of sequencing batch biofilm reactors (SBBRs) in removing nitrogen and phosphorus from synthetic municipal wastewater with different carbon to total nitrogen (C/N) ratios. The effect of control systems, including an intelligent control system (ICS) and conventional timer control system (TCS) on the performance of SBBRs was also investigated. When C/N ratios were 10.0, 5.0 and 3.3, the average COD removal efficiencies in the ICS-SBBR reached 87.7%, 92.3% and 97.6%, while total phosphorous (TP) removals reached 95.0%, 97.0% and 97.2%. When the C/N ratio was 5.0, the TN removal efficiency was 81.0% under ICS and 65.4% under TCS. Moreover, compared with TCS-SBBR, both reaction time and aeration time were shortened by 180 min and 157 min, respectively, in the ICS-SBBR. Therefore, the ICS-SBBR has potential in practical applications for significant nitrogen and phosphorus removal and energy savings.