High specific activity for anammox bacteria enriched from activated sludge at 10°C

[Display omitted] •Anammox bacteria enriched at 10°C from waste water treatment plant sludge.•Enriched Candidatus Brocadia fulgida appeared to have an activity optimum at 20–30°C.•Biomass yield of 0.046gbiomass/gN converted, similar to that at high temperature.•Anammox activity of 39mgN/gVSS/d, a factor 2 higher than previously reported.•Cold adapted anammox species beneficial for nitrogen removal in water line of WWTPs. Anammox in the water line of a waste water treatment plant (WWTP) saves energy for aeration and allows for recovering biogas from organic material. Main challenges for applying the anammox process in the water line are related to the low temperature of