简介：Theadsorptiveremovalofarsenicbysynthetically-preparednanoFe-Mnbinaryoxides（FM）wasinvestigated.AnovelmethodusingpotassiumpermanganateandferricchlorideasrawmaterialswasusedtosynthesiseFM.ThemolarratioofFeandMninthesyntheticFe-Mnbinaryoxideswas4:3.TheFM-1andFM-2（preparedatdifferentactivationtemperatures）havinghighspecificsurfaceareas（358.87and128.58m2/g,respectively）wereamorphousandofnanoparticletypes.TheamountofarsenicadsorbedonFM-1washigherthanthatadsorbedonFM-2particles.AfteradsorptionbyFM-1,residualarsenicconcentrationdecreasedtolessthan10μg/L.Theadsorptionkineticsdatawereanalyzedusingdifferentkineticmodelsincludingpseudofirst-ordermodel,pseudosecond-ordermodel,Elovichmodelandintraparticlediffusionmodel.Pseudosecond-orderkineticmodelwasthemostappropriatemodeltodescribetheadsorptionkinetics.TheadsorptionpercentageofAs（Ⅲ）increasedinthepHrangeof2–3whileitdecreasedwiththeincreaseofpH（3

简介：Understandingtheeffectsoforganicacids（OA）onthetransformationofFeandMntosurfacewaterfromtheweatheringcoalgangueisofgreatbene?ttoriskassessmentandremediationstrategiesforcontaminatedwaterandsoil.BasedontheinvestigationonsurfacewaterinthecentralcoaldistrictsoftheGuizhouProvince,18watersampleswerecollectedforheavymetalanalysis.TheresultsindicatedthatthepHvalueofsurfacewaterislow（3.11–4.92）,andFeconcentration(1.31–5.55mgL-1)andMnconcentration(1.90–5.71mgL-1)were,onaverage,10.86and34.33timesthelimitofSurfaceWaterQualityStandards,respectively.InordertoevaluatetheeffectsoftheOAonthedissolutionofFeandMnfromtheweatheringcoalgangue,columnelutionandbatchleachingexperimentswereconducted.Theresultsshowthatthelowmolecularweightoforganicacids（LMWOAs,i.e.,oxalic,tartaric,malicandcitricacids）andfulvicacidssigni?-cantlyacceleratedthedissolutionofFeandMn;inaddition,whentheconcentrationofOAreached25mmolL-1,theconcentrationsofFe,andMnwere1.14–67.08and1.11–2.32timesashighasthosein0.5mmolL-1OA,respectively.Furthermore,themigrationofFeandMnwassigni?cantlyin?uencedbythepHandEh,especiallyforFe;theionMnwasdissolvedfromtheganguemoreeasilythantheionFeinthecolumnleaching,whichwascontrarytotheresultsofbatchleaching.

简介：ThestrongadaptabilityofBroussonetiapapyrifera(L.)Vent.tolowphosphorus(P)conditionscanbeattributedtothelargeamountofroot-exudedorganicacidsandthehighef?ciencyofPextraction.However,microelementcontentsarein?uencedbylow-Pstress,andtheireffectsonthephotosyntheticcapabilityofB.papyriferaremainunknown.Inthisstudy,weinvestigatedtheeffectsoflow-Ptreatmentonnetphotosyntheticrate(P_N);chlorophylla?uorescence(ChlF)characteristics;andFe,Mn,Cu,andZncontentsofB.papyriferaandMorusalbaL.seedlings.ResultsshowthatB.papyriferaexhibitedbetterphotosyntheticcapabilityundermoderatePde?-ciency(0.125,0.063,and0.031mmol/LPtreatments),whereasthephotosyntheticcapabilityofM.albadecreasedundermoderateandseverePde?ciency(0.016and0mmol/LPtreatments).UndermoderatePde?ciency,thedecreaseinCuandZncontentsinB.papyriferawaslowerthanthatinM.alba.UnderseverePde?ciency,aconsiderabledecreaseofphotosyntheticcapabilityinB.papyriferaandM.albawasassociatedwithlowCuandZncontents.ThePNofthetwoMoraceaespeciesexhibitedabettercorrelationwithCuandZncontentsthanwithFeorMncontent.Pde?ciencycouldnotonlydecreasecyclicphotophorylationandphotosyntheticef?ciency,butcouldalsoaffectthestabilityofthylakoidmembranestructureandelectrontransportef?ciencybyin?uencingthecontentsofCuorZn,therebyaffectingphotosynthesis.

简介：WeperformedasystematictraceandrareearthelementanalysisforthebeddedFe-MncarbonaterocksrelatedtothestratiformAg-Pb-ZnmineralizationintheLengshuikengoredistrict,JiangxiProvince,SouthChina.ThreetypesofFe-Mncarbonatesaredistinguished,namely,themassive,breccia,andveintypes.Bothcarbonateandsilicatefractionsinthesamplesareanalyzedfortheirtraceandrareearthelementconcentrationsusingastepacid-leachingtechnique.OurresultsshowthatthecarbonatefractionsinthemassivetypesampleshavethelowestREEconcentrationsbutpronouncedpositiveEuandYanomalieswithEu/Eu*valuefrom1.3to6.2andY/Hovaluefrom40.1to59.5,andsimilarcharacteristicsarealsoshownforthesilicatefractionsinthemassivetypesamples(Eu/Eu*=1.0–6.7,Y/Ho=20.7–55.1).TheseREEcharacteristicsaresimilartothoseofSedextypemassivesulfidedepositsworldwide,andwesuggestthatthemassivetypeFe-Mncarbonaterockswerelikelyformedfromanexhalativevolcanic-hydrothermalfluidfeedingthedepressionbasinofavolcaniclake.Thehighconcentrationsofredox-sensitiveelementsandratiossuchasU/Th,V/CrandV/(V+Ni)indicateadysoxicenvironmentfortheFe-Mncarbonatedeposition.Incontrast,thebrecciatypeandveintypeFe-Mncarbonatesamplesshowdifferenttraceandrareearthelementfeaturesfromthoseofmassivetypesamples,andtheyaremoresimilartothevolcanicrocksandmagmatic-hydrothermalfluidsintheLengshuikengoredistrictandmayreflectstrongoverprintingfromvolcanicandsub-volcanicmagmatismrelatedtotheporphyrytypemineralizationinthedistrict.