pH对沟渠沉积物截留农田排水沟渠中氮磷的影响研究席北斗

:,,1969,,,、。＊“973”(No.2005CB724203、No.2002CB410800-07、No.2002CB412300)。pH对沟渠沉积物截留农田排水沟渠中氮、磷的影响研究＊席北斗1徐红灯1,2翟丽华3王京刚2(1.,100012;2.,100029;3.,100084)　　,pH、,pH、。:pH,NH+4-NNO-2-NTNpH;(TDP)pH,TP5dpH,;pH,,pH-。pH、、,。　　pHEffectofpHonretentionofNandPinditchsediments　XiBeidou1,XuHongdeng1,2,ZhaiLihua3,WangJing-gang2.(1.ChineseResearchAcademyofEnvironmentalScience,Beijing100012;2.DepartmentofEnvironmentalEngineering,BeijingUniversityofChemicalTechnology,Beijing100029;3.DepartmentofEnvironmentalSci-enceandEngineering,TsinghuaUniversity,Beijing100084)Abstract:　SeriesofdynamicandstaticexperimentswereperformedtostudytheeffectsofditchsedimentsonthefateofNandPatacidic,basicandneutralpH(5,7and9),thepHeffectontheNandPretentioninthesediments,andthemasstransferatthesediment-waterinterface.TheadsorptivecapacityofthesedimentsforNH+4-N,nitrifica-tiontoproduceNO-2-NandretentionofTNallincreasedwithincreasingpH,whichalsoenhancedthesediments'ad-sorptivecapacityforTDPandincreasedtheretentionofTPduringthefirst5days.ThetransferofNspeciesatthesediment-waterinterfacewasaffectedduetothepH'seffectonthemicrobialactivitiesandthatthetransferofPspe-ciesattheinterfacewasaffectedduetopH'seffectonabsorptionandionicexclusion.KnowingtheeffectsofpHonNandPretentioninditchsedimentswillhelptounderstandthetransferandtransformationofNandPspeciesinag-riculturedrainageditch,whichisimportantforeffectivecontrolofagriculturalnon-pointsourcepollution.Keywords:　N　P　Interception　Ditchsediment　Agriculturedrainageditch　pH　　、,,[1]。,、。,、。,[2]。,、,、,。,、,、;,,、。,,,[3]。、,、pH、DO、。pH,,pH、、,pH、。·490·　　29　7　20077DOI:10.15985/j.cnki.1001-3865.2007.07.0041　Table1　PhysicalandchemicalcharacteristicoftheditchsedimentspH/(g·kg-1)/(cmol·kg-1)CEC1)/(cmol·kg-1)Fe/(g·kg-1)Ca/(g·kg-1)/%/%0.020～2.000mm0.002～0.020mm0.002mm5.6～6.534.980.3213.4521.9715.4897.610.055.634.4　　:1)CEC。1　　　,,,1。pH6～9,pH5.6～6.5,pH5～9。1.1实验方法1.1.1　　　(22)300mL,15g200mL(0.2g0.12g),30min,NaOHHClpH5、7、9,(30±0.5)℃,150～160r/min,pH,pH5、7、9,,1,50mL。0.45μm,NH+4-N、NO-3-N、NO-2-N(TDP),pHNH+4-N、NO-3-NNO-2-NTDP。。1.1.2　　　3PVC(××=35cm×35cm×40cm),,15cm,20cm。15g,200mL。,。,NaOHHClpH5、7、9,pH,30min1,pH,50mL1。11pH5、7、9,20。。6000r/min15min,。0.45μm,TNTP,pH。1.2分析方法　　pH、NH+4-N、NO-3-N、NO-2-N、TN、TPTDP,《》。2　2.1pH对截留氮的影响2.1.1　NH+4-N　　NH+4-N(0.0001～0.0030mg/L),。12,3pH,NH+4-NpH。pH57,NH+4-N,pH9,。pHNH+4-N,。NH+4-N,(NH+4)(NH3),[4]:NH+4=NH3+H+(1)　　KT:pK=0.09018+2729.92/(273.2+T)(2)　　(2):fNH+4=1/(1+10pH-pK)(3):fNH+4NH+4-NNH+4-N。　　(3),pH,NH+4-NNH+4-N,pH8,。pHNH+4,NH+4-N,NH+4-N。1　NH+4-NFig.1　EffectofpHontheNH+4-Nconcentrationprofile·491·　pH、2　NH+4-NFig.2　EffectofpHontheprofileofadsorptivecapacityofsedimentsforNH+4-N2.1.2　NH+4-N　　NO-2-NNO-3-N,。3pHNO-2-N。pHNO-2-N,pH[5],NO-3-N,。3,NO-2-NpH,pH。pHTN,,。pH,pH7～9[6],pH6,pH10,pHOH-[7]。,pH(5～9)pH,pHNH+4-N。,3NO-2-NpH,DO(1.5～2.3mg/L),,,DO,pHNH+4-N。3　NO-2-NFig.3　EffectofpHontheNO-2-Nconcentrationprofile2.1.3　TN　　TN(0.005～0.010mg/L),。4pHTN。4,TN5,5d。pH,TN,pHTN。pHTN,NH+4-N,pHOH-,NH+4OH-:NH+4+OH-=NH3+H2O。TNNH+4NH3。OH-,NH+4NH3,TN。,,N2N2O,TN。,pH7～8,pH7.5。pH6.59.0,[8]。pH5～9,DO1.5～2.3mg/L,5,NH+4,TNpH;pH,,5dpHTN。4　TNFig.4　EffectofpHontheretentionofTNinditchsediments2.2pH对截留磷的影响2.2.1　TDP　　TDP,(0.007mg/L),。56,(30℃),pH5、7、9,TDPpH,TDPpH。pH,pH[9]:H3PO4+H2OH2PO-4+H3O+(pKa1=1.96)(4)H2PO-4+H2OHPO2-4+H3O+(pKa2=6.92)(5)HPO2-4+H2OPO3-4+H3O+(pKa3=11.74)(6)　　pH4～7,H2PO-4,·492·　　29　7　200775　TDPFig.5　EffectofpHontheTDPconcentrationprofile6　TDPFig.6　EffectofpHontheprofileofadsorptivecapacityofsedimentsforTDPH2PO-4[10];pH7～10,,HPO2-4PO3-4,H2PO-4,TDPpH,TDP。　　6,TDPpH,,pH(5、79)TDP,pH,。2.2.2　TP　　TDP,TP,0.014mg/L,。7pHTP。7,TP,5dTPpH。,、、、,pHTP。,pH。、CEC(1),,[11],pH。,,,4～10kg/hm2[12]。pH,。7,(5d)TPpH,,、,,pHTP。,pHTP、。7　TPFig.7　EffectofpHontheprofileoftheretentionofTPinditchsediments2.3pH对氮、磷界面交换的影响2.3.1　pH　　NO-2-N,NH+4-N。pH。,、,pH,,、,NH+4-N。,pH,,DO,DO,,,,NO-3-N,NH+4-NNO-3-N[13]。-,-。,,,NO-3-N、NH+4-N;,,,NH+4-N、NO-3-N。,。、,。,-,pH,pH。2.3.2　pH　　-·493·　pH、,。,,;pH,,,,。56,pH,TDPTDP,pH,。,pH5～7,HPO2-4、H2PO-4,;pH,,,,Al(Ⅲ)-,:　　(x-1)AlHPO4++AlOH2+=AlxOH(PO4)2+x-1+(x-1)H+(7):x2、34。　　pH,,OH-Fe-PAl-P,:FePO4+3OH-※Fe(OH)3+PO3-4(8)AlPO4+3OH-※Al(OH)3+PO3-4(9)　　,pH5,,pH。,pH9TDP,。3　　　　(1)pH,NH+4-N、NO-2-NTNpH,pH。　　(2)pHTDPpH;pHTP,pHTP5d,pH。　　(3),pH、;,pH,。[1]　,,.[J].:,2004,32(6):618.[2]　,,,.-[J].,2004,23(4):272.[3]　TANNERCC,SUKIASJPS,UPSDELLMP.Relationshipsbetweenloadingratesandpollutantremovalduringmaturationofgravel-bedconstructedwetland[J].J.Environ.Qual.,1998,27:448-458.[4]　EMERSONK,RUSSORC,LUNDRE,etal.Aqueousammo-niaequilibriumcalculations:effectofpHandtemperature[J].J.Fish.Res.Bd.Can.,1975,32:2379-2383.[5]　,,,.[M].2.:,1996.[6]　,,,.[J].,2001,20(6):390-393.[7]　,.、[J].,1999,10(5):630-634.[8]　.pH、[J].,1994,14(4):308-313.[9]　.[J].,1997,18(3):45-48.[10]　.[J].,1991,13(5):31-34.[11]　LYAMUREMYEF,DICKRP,BAHAMJ.Organicamend-mentsandphosphorusdynamicsI:phosphoruschemistryandsorption[J].SoilSci.,1996,161(7):426-435.[12]　,,,.[J].,2006,25():353-355.[13]　NEDWELLDB,TRIMMERM.NitrogenfluxesthroughtheupperestuaryoftheGreatOuse,England:theroleofthebot-tomsediment[J].MarineEcologyProgressSeries,1996