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

► When C/N ratios were 5.0 and 3.3, the COD removal efficiencies in the ICS-SBBR reached 92.3% and 97.6%. ► The removal efficiencies of TP reached 95.0%, 97.0% and 97.2% when the C/N ratios were 10.0, 5.0 and 3.3. ► When the C/N ratio was 5.0, the TN removal efficiency was 81.0% under ICS and 65.4% under TCS. ► Compared with TCS-SBBR, reaction and aeration time were shortened by 180 min and 157 min in ICS-SBBR.