acs.est.5b00601

acs.est.5b00601EffectsofIonicStrengthontheChromophoresofDissolvedOrganicMatterYuanGao,*,†MingquanYan,‡andGregoryV.Korshin††DepartmentofCivilandEnvironmentalEngineering,UniversityofWashington,Seattle,Washington98195,UnitedStates‡DepartmentofEnvironmentalEngineering,CollegeofEnvironmentalSciencesandEngineering,PekingUniversity,theKeyLaboratoryofWaterandSedimentSciences,MinistryofEducation,Beijing100871,China*SSupportingInformationABSTRACT:Thisstudyexaminedeffectsofvariationsoftheionicstrength(IS)ontheabsorbanceofdissolvedorganicmatter(DOM).ThemeasurementsperformedforDOMofallochthonous(SuwanneeRiverhumicandfulvicacids,SRHAandSRFA)andautochthonous(PonyLakefulvicacid,PLFA)originshowedthatincreasesofIS(whichwascontrolledbyadditionsofsodiumperchlorate)from0.001to0.3mol/LwereaccompaniedbyincreasesoftheabsorbanceofDOM.TheextentoftheincreaseofDOMabsorbanceobservedatincreasingISwasconsistentlygreaterathigherpHvalues,anditfollowedtheorderofPLFA