Start up partial nitrification at low temperature with a real-time control strategy based on blower frequency and pH

► Partial nitrification can be achieved rapidly at low temperature (11-16 °C) in 40 days. ► Partial nitrification was stably maintained for 140 days by real-time control. ► A novel real-time control strategy based on blower frequency and pH was applied. ► The break point appearing in the BF curve indicated the completion of nitrification. ► FISH analysis showed AOB was the dominant nitrifying bacteria compared with NOB.