The characteristics of the anaerobic sludges in Anammox-EGSB bioreactors started up with anaerobic methanogenic sludge(AMS)

fresh Anammox sludge(FAS)and stored Anammox sludge(SAS)were investigated respectively.It was found that Anammox-EGSB bioreactors could be started up successfully with these three kinds of seeding sludges.The performance of the bioreactor inoculated with SAS was better than that inoculated with AMS

but worse than that inoculated with FAS.After the start-up

the VSS/SS ratio

granular diameter

settling velocity and SAA of these three seeding sludges were superior to those of the initial state.The color of three seeding sludges tended to be bright red.Besides

the cell suspension showed the characteristic absorption peaks between 400 nm and 420 nm.The changes on color and the absorption spectrum of the sludges were correlated with the changes of numbers and the activity of microorganisms during the start-up.The color and absorption spectrum could be used as an indicator in the start-up of Anammox reactors.