1s20S1001074217336379main

PreferentialbindingbetweenintracellularorganicmattersandAl13polymertoenhancecoagulationperformanceRuipingLiu1,2,TingtingGuo1,3,MinMa1,4,MingquanYan5,JingQi1,ChengzhiHu1,2,⁎,GangLiu6,HuijuanLiu2,7,JiuhuiQu1,2,WaltervanderMeer81.KeyLaboratoryofDrinkingWaterScienceandTechnology,ResearchCenterforEco-EnvironmentalSciences,ChineseAcademyofSciences,Beijing100085,China2.UniversityofChineseAcademyofSciences,Beijing100049,China3.BeijingUniversityofTechnology,Beijing100124,China4.BeijingWaterworksGroup,Beijing100031,China5.DepartmentofEnvironmentalEngineering,PekingUniversity,Beijing100871,China6.SanitaryEngineering,DepartmentofWaterManagement,FacultyofCivilEngineeringandGeosciences,DelftUniversityofTechnology,2600GADelft,theNetherlands7.StateKeyLaboratoryofEnvironmentalAquaticChemistry,ResearchCenterforEco-EnvironmentalSciences,ChineseAcademyofSciences,Beijing100085,China8.ScienceandTechnology,UniversityofTwente,7500AEEnschede,theNetherlandsARTICLEINFOABSTRACTArticlehistory:Received20December2017Revised12May2018Accepted14May2018AvailableonlinexxxxCoagulationisthebestavailablemethodforremovingintracellularorganicmatter(IOM),whichisreleasedfromalgaecellsandisanimportantprecursortodisinfectionby-productsindrinkingwatertreatment.TogaininsightintothebeststrategytooptimizeIOMremoval,thecoagulationperformanceoftwoAlsalts,i.e.,aluminumchloride(AlCl3)andpolyaluminumchloride(PACl,containing81.2%Al13),wasinvestigatedtoilluminatetheeffectofAlspeciesdistributiononIOMremoval.PAClshowedbetterremovalefficiencythanAlCl3withregardtotheremovalofturbidityanddissolvedorganiccarbon(DOC),owingtothehigherchargeneutralizationeffectandgreaterstabilityofpre-formedAl13species.HighpressuresizeexclusionchromatographyanalysisindicatedthatthesuperiorityofPAClinDOCremovalcouldbeascribedtothehigherbindingaffinitybetweenAl13polymerandthelowandmediummolecularweight(MW)fractionsofIOM.Theresultsofdifferentiallog-transformedabsorbanceat254and350nmindicatedmoresignificantformationofcomplexesbetweenAlCl3andIOM,whichbenefitstheremovaloftryptophan-likeproteinsthereafter.Additionally,PAClshowedmoresignificantsuperioritycomparedtoAlCl3intheremovalof5kDaandhydrophilicfractions,whicharewidelyviewedasthemostdifficulttoremovebycoagulation.ThisstudyprovidesinsightintotheinteractionsbetweenAlspeciesandIOM,andadvancestheoptimizationofcoagulationfortheremovalofIOMineutrophicwater.©2018TheResearchCenterforEco-EnvironmentalSciences,ChineseAcademyofSciences.PublishedbyElsevierB.V.Keywords:IntracellularorganicmatterCoagulationPolyaluminumchlorideMolecularweightdistributionHydrophilicfractionJOURNALOFENVIRONMENTALSCIENCESXX(2018)XXX–XXX⁎Correspondingauthor.E-mail:[e-mail](ChengzhiHu).©2018TheResearchCenterforEco-EnvironmentalSciences,ChineseAcademyofSciences.PublishedbyElsevierB.V.Availableonlineat:Liu,R.,etal.,PreferentialbindingbetweenintracellularorganicmattersandAl13polymertoenhancecoagulationperformance,J.Environ.Sci.(2018),(ChengandChi,2003;Takaaraetal.,2010),sedimentation(Aktasetal.,2013),mediumfiltration(Ewertsetal.,2014),andmembranefiltration(Elciketal.,2016).Additionally,algogenicorganicmatter(AOM)alwaysaccom-paniescyanobacteriacells,andistypicallyrelatedtoproblemswithtoxins(Zamyadietal.,2012),tasteandodor(Watsonetal.,2016),andassimilableorganiccarbon(AOC)(Hammesetal.,2007),andtheformationofdisinfectionby-products(DBPs)(Fangetal.,2010;Songetal.,2016).ThecomponentsandcharacteristicsofAOMarehighlydependentonthealgaespeciesandtheirgrowthstage(Hendersonetal.,2008),andtheirDBPformationisratherdifferentanddependentonmolecularweightandhydrophilicity(Fangetal.,2010).Additionally,AOMisusuallyreferredtoasintracellularorganicmatter(IOM)andextracellularorganicmatter(EOM),withdistinctcomponentsandcharacters.Typically,AOMmainlyincludesbio-chemicalssuchasmetab-olites,nucleicacids(DNAandRNA)(Hammesetal.,2007),proteins,peptides,aminoacids,polysaccharides,oligosaccha-rides,andtracesofotherorganicacidssuchashumic-likesubstances(Pivokonskyetal.,2006;Hendersonetal.,2008).IOMmainlyexistsinalgaecellsandhashigherconcentrationthanEOM,andtheremovalofalgaecellsmayachievepromisingIOMremoval.Onthebasisofthisconsideration,theremovalofIOMmaynotbeproblematicifalgaesuspensionsarewellremoved.However,theinactivationofalgaecellsbypre-oxidationinevitablycausesIOMrelease,whichoccursuponexposureofalgaecellstooxidantssuchaschlorine,ozone,andpermanganate(Hoyeretal.,1987;Hammesetal.,2007;Chenetal.,2009;Maetal.,2012a).IthasbeendemonstratedthatIOMisanimportantprecursortotheformationofdisinfectionby-products.Inconsideringthewidely-usedpreoxidationmethods,thesatisfactory