Long term assessment of factors affecting nitrifying bacteria communities and N-removal in a full-scale biological process treating high strength hazardous wastewater

► We characterized the dynamics of nitrifying bacterial communities in a full-scale WWTP. ► Full nitrification led to good performance in TN removal and a higher nitrification rate. ► Amounts of AOB were positively linked to influent SCN− concentration. ► Nitrobacter and nitrite concentrations were closely associated. ► COD and phenol concentrations seemed the primary reason for deteriorated nitrification.