TheapplicationofMonodequationtodenitrificati

Vol.:(0123456789)13InternationalJournalofEnvironmentalScienceandTechnology Monodequationto denitrificationkineticsdescriptionin the movingbedbiofilmreactor(MBBR)L. Kopec1 ·A. Kopec2 ·J. Drewnowski3Received:11July2017/Revised:5March2018/Accepted:11May2018©TheAuthor(s)2018AbstractInthispaper,thekineticconstantsVmaxandKCODoccurringintheMonodequation,whichdescribethedenitrificationprocessinthemovingbed,aredetermined.Forthispurpose,alaboratorymovingbedbiofilmreactor(MBBR)wasused.ThefillingofthereactorconsistedofEvUPerlcarriers.Theexperimentwascarriedoutwithanexcessofnitrate,anddenitrificationratewasdependentontheconcentrationofexternalorganiccarbon,whichconstitutedtheBrenntaPluspreparation.Deter-minationofconstantswasmadebyHofstee–Eadiemethod,wherebytherewasobtained:Vmax=0.78 gNO3−–N/g D.M./dayandKCOD=16.97 g O2/m3.ThenewMonodequationwasverifiedusingMBBRconstructedonanindustrialscaleinwastewatertreatmentplantinGronowoGórne(Poland).AfterjoiningtheMBBRtothetechnologicalsystemandafteraperiodofbiomassadaptation,totalnitrogenremovalefficiencyincreasedfrom53.5to86.0%.Theresultsoftheresearchhavebeendiscussedwithseveralsimilarresearches.KeywordsMBBR ·Movingbedbiofilmreactor ·Denitrification ·Nitrogenremoval ·Wastewatertreatment ·Monodequation ·KineticsofdenitrificationIntroductionInPoland,insmallbiologicaltreatmentplantsdesignedforlessthan2000people(usingusuallyactivatedsludgeorbiofilters)theremovalofammonianitrogen,duetoitstoxiceffect,wastheoneofthemostimportantissuessofar.Thematterofremovingoxygenformsofnitrogen—nitriteandnitrate(denitrificationprocess),isusuallysecondaryimportanceandoftenremainsunresolved.ItcontributestothecontaminationofsurfacewaterinPoland,whichisexposedtoeutrophicationprocess(Obarska-Pempkowiaket al.2015;JucherskiandNastawny2012;Sytek-Szmeichelet al.2016).Toprotectthesurfacewater-efficientdevicesforthecom-pleteremovalofcontaminantsfromwastewater,resistanttovariablerateandtheleachingofbiomassshouldbesought.Thisisespeciallyimportantfornon-urbanizedareas,whereprocesscontrolishindered(Gajewskaet al.2011).Ammoniumremoval(moreaccuratelynitrite/nitrateremoval)isreallyabigchallengefacedbybothlarge-scaleandsmall-scaleWWTPs,mainlyduetotheinsuf-ficientcarbonsourcesinwastewater.Moreover,therearesignificantdifferencesbetweencentralizedwaste-waters(i.e.,largescale)anddecentralizedwastewaters(i.e.,smallscale)accordingtoChenet al.2016.Full-scaleevaluationofaerobic/extended-idleAEIzonewasaffectedbyseasonalvariation,andtheefficienciesofcontaminantremovalwerestableandexcellent(totalnitrogen86%,others92%)intheintegratedsystem.Thisstudyoffersanattractiveoptionforbiologicalnutri-entremoval(BNR)fromcarbohydrate-richwastewatersandalsoprovidesaprototypeforwastewatertreatmentinremoteareas.Forsmalltreatmentplantsrelationshipbetweentherateofnitratesremovalandavailablesub-stratecanbedescribedbyMonodequation.ThereisnoEditorialresponsibility:BinbinHuang.*[e-mail]1Ekofinn-PolLtd,ul.Lesna12,80-297 Banino,Poland2Departmentof MechanicalEngineering,KoszalinUniversityof Technology,ul.Raclawicka15-17,75-620 Koszalin,Poland3Facultyof Civiland EnvironmentalEngineering,GdanskUniversityof Technology,ul.Narutowicza11/12,80-233 Gdańsk,PolandInternationalJournalofEnvironmentalScienceandTechnology13needtoapplyanyadvancedequation,butsimpleonewithtwoconstants:Vmax—describingthemaximumrateofdenitrificationandKCOD—characterizingthesubstrateconcentrationatwhichhalfthemaximumrateisreached.Theaimofthisstudywastodeterminethekineticcon-stantsVmaxandKCODoccurringintheMonodequation.Theconstantsdescribedenitrificationprocessinamovingbed.Thelaboratorymovingbedbiofilmreactor(MBBR)wasusedtodetermination.Thefillingofthereactorcon-sistedofEvUPerlcarriers.Designatedequationwasveri-fiedusingaMBBRconstructedonanindustrialscaleinWWTPinGronowoGórne(Poland).Thestudywhichwasconductedduringasummerperiod(August–September2015)hasalsodeterminedtheefficiencyofdenitrifica-tionbeforeandafterjoiningtheMBBRdevicetothetechnologicalsysteminordertoenhancebiochemicalprocessesefficiencyofwastewater.Materialsand methodsAteststandsimulatingtheoperationofasmallMBBRwasconstructedinthelaboratory.Itwasassumedthattheopera-tionofthelaboratoryreactorissimilartoMBBRunderdeni-trificationprocessintherealconditions.Theconstructionofthesetworeactors(inthelaboratoryandthepilotscale)isshowninFig. 1a,b.Duringtheconstructingofthereac-tors,thedescriptionofMBBRgivenbyRustenet al.(2006)wasused.ThelaboratoryMBBR(Fig. 1a)consistedofcontainerwithacapacityof28 L,anditwasmadeoftransparentplastic(Plexiglas).Aworkingvolumeofdevicewas24 L.Movingbed—EvuPerlcarrierstook25%oftheworkingvolume(6 L).Centrallyinthereactorastirrerwithtwobladesof8 cmlengthwasplaced.Stirrershaftwasdrivenbyamotorwithspeedcontrol.Frequencyofmixingwas100 rpm(becauseatthisvaluedidnotoccuroxygenationandallmovingcarriersoffillingweretouched).MoredetailsoftheconstructionandoperationofalaboratoryMBBRhasbeenshowninstudiesbyKopećet al.(2016).Thereactorwasfilledw