Manometric method for evaluation of anammox activity in mainstream anammox at Sjölunda WWTP

Abstract: Implementing anammox based processes in the mainstream at municipal wastewater treatment plants is challenging and requires carefully constructed control strategies in order to be successful. A method to measure the specific anammox activity (SAA) was further developed and implemented in the mainstream anammox pilot plant at Sjölunda Wastewater Treatment Plant. The developed method was found to be reliable and reproducible. The influence of initial nitrite and ammonium concentrations on the SAA as well as temperature dependency were analysed. The tests, based on continuously monitored manometric batch tests, were performed on MBBR carriers type K1®. The SAA showed a dependency of initial nitrite concentrations below 75 mg N L-1 whereas the activity was independent of initial concentrations in the interval of 75–125 mg N L-1. Temperature dependency of the specific anammox activity as expressed in Ea increased at lower temperatures (10–20°C) compared to higher temperatures (20–30°C). Decreasing temperature from 30°C to 10°C resulted in 95-98% loss of the anammox activity.