The Importance of Aerobic Mixing, Biofilm Thicknes

The Importance of Aerobic Mixing, Biofilm Thickness Control and Modeling on the Success or Failure of IFASWaterPractice™•Vol.1•No.5©2007WaterEnvironmentFederation•doi:10.2175/193317707X256991TheImportanceofAerobicMixing,BiofilmThicknessControlandModelingontheSuccessorFailureofIFASSystemsforBiologicalNutrientRemovalDipankarSen1*,CliffordW.Randall2,RhodesR.Copithorn3,MarkkuHuhtamäki4,GregFarren5,WayneFlournoy61SantaClaraValleyWaterDistrict,5750AlmadenExpressway,SanJose,CA95118,USA.2DepartmentofCivilEngineering,VirginiaTech,Blacksburg,VA,USA.3Stearns&Wheler,Cazenovia,NY,USA.4JuuroconOy,Naantali,Finland.5AnneArundelCountyDPW,MD,USA.6EntexInc,NC,USA.*Towhomcorrespondenceshouldbeaddressed.Email:DSen@valleywater.org.ABSTRACTResearchonfullscaleIntegratedFixedFilmActivatedSludge(IFAS)andMobileBedBiofilmReactor(MBBR)systemsshowedthatproblemsdevelopedwithexcessivebiofilmthicknesswhenthemixingandrollpatternsdecreased.Evaluatedmediaincludedfixedbedcordmedia,movingbedspongemediaandmovingbedplasticme