电絮凝法同步去除氨氮和磷的模拟试验

26220132ResearchofEnvironmentalSciencesVol．26No．2Feb．2013．J．2013262181-187．LANGLinZHANGLiuZHUYanetal．SimultaneousremovalofnitrogenandphosphorusbyelectrocoagulationprocessJ．ResearchofEnvironmentalSciences2013262181-187．2012－09－3[e-mail]．*[e-mail]12311111*1．2300092．2300013．200092．Redlich-PetersonGibbs－20～0kJmolR20.98pH．0.15～0.500.02～0.04kW·hg．X788A1001－6929201302－0181－07SimultaneousRemovalofNitrogenandPhosphorusbyElectrocoagulationProcessLANGLin1ZHANGLiu23ZHUYan1CHENPei1ZHUDan1SHIChao1FENGJing-wei11．SchoolofCivilEngineeringHefeiUniversityofTechnologyHefei230009China2．AnhuiInstituteofEnvironmentScienceHefei230001China3．KeyLaboratoryofYangtzeAquaticEnvironmentMinistryofEducationCollegeofEnvironmentalScienceandEngineeringTongjiUniversityShanghai200092ChinaAbstractElectrocoagulationwithstainlesssteelelectrodesandaluminumelectrodeswereadoptedforremovalofammonianitrogenandphosphorus．Thethermodynamicskineticsandtheeffectofdifferentparametersonammonianitrogenandphosphorusremovalwerestudied．Theresultsshowedthatstainlesssteelelectrodeweremoresuitableforremovalofammonianitrogenandphosphorusfromaqueoussolutionscomparedwithaluminumelectrodes．ThephosphorusadsorptionprocesscouldbedepictedprimarilybyRedlich-Petersonfunctionandthehighertemperaturewashelpfulforitsadsorptionwhichwasaspontaneousandendothermalprocess．ThechangesofGibbsfreeenergyrangesfrom－20kJmolto0kJmol．ThecorrelationcoefficientR2wasgreaterthan0.98andthisindicatedthatthekineticdataofphosphorusadsorptionwerebetterfittedwiththepseudo-second-orderkineticmodel．Theremovalefficiencyofammonianitrogenandphosphorusincreasedwithincreasingelectriccurrentdensity．AlowerammonianitrogenremovalrateunderstrongalkalineconditionswasalsoobservedandtheremovalefficiencyofphosphoruswasthebestunderacidconditionswhileitdecreasedwiththeincreasingpH．Thepowervalueswere0.15-0.50and0.02-0.04kW·hgrespectivelywhichwererequiredforammonianitrogenandphosphorusremovalduringelectrochemicalprocesses．Keywordselectrocoagulationnitrogenremovalphosphorusremoval1．DOI10.13198/j.res.2013.02.70.langl.01226、、2-5．pH、6-7．2．8Al→Al3++3e－．3H2O+3e－→32H2+3OH－．Al3+OH－AlOH3．9Fe→Fe2++2e－2Fe2++5H2O+12O2→2FeOH3+4H+Fe2++2OH－→FeOH2．2H2O+2e－→2OH－+H2．．10．．Ikematsu11PtIrFePtIr．FENG12TiRuO2、、CODCr90%．．11.1．．ρρρ－13．0.45μm．pH．1.210cm×10cm×17cm1L．66500cm25mmρ100mgLρ50mgL．ρ253.4mgL．．3.0A1．15minρ．15minρρ．HHρ286、293、303K15min15min0.45μmρ．ρ50mgL0.45μmρ．13.0AFig．1Voltagechangesatconstantcurrent3.0A22.12．2ρ100mgL60min．14．0.8A2812．815．．pHpH．1—2—．2Fig．2Effectofelectrodematerialontheremovalrateofammonianitrogen3．310min295%．1—2—．3Fig．3Effectofelectrodematerialontheremovalrateofphosphorus、、16-17．、．2.2286、293、303K4．4qe．Langmuir、FreundlichRedlich-Peterson1．K1—2862—2933—303．4Fig．4Effectoftemperatureontheadsorptionofphosphorus1Redlich-PetersonLangmuirFreundlich．Langmuir18．Freundlich19．Redlich-Peterson20．2.3GibbsΔG0、ΔS0ΔH021ΔG0=ΔH0－TΔS0lnCe=lnqe－ΔS0R'+ΔH0R'TqemgCemgLR'8.314JK·molTK．381261Table1ParametersofisothermadsorptionequationsatdifferenttemperaturesKLangmuirFreundlichRedlich-Petersonq0mgbR2KFnR2KRαβR2286228.940.0640.948540.462.950.978637.560.550.760.9866293235.370.0850.944448.013.110.990667.140.960.750.9974303240.740.1190.925657.833.350.9935138.461.870.750.9989q0LangmuirmgbLangmuirR2KF、nFreundlichKR、αRedlich-PetersonβRedlich-Peterson．qeRedlich-PetersonCe1T、lnCe．ΔH0R'lnqe－ΔS0R'ΔH0、ΔS0ΔG02．2ΔG0－20～0kJmol|G|ΔH0．2、Table2ThermodynamicparametersevaluatedatdifferentequilibriumadsorptionamountsandtemperaturesqemgΔH0kJmolΔS0〔JK·mol〕ΔG0kJmol286K293K303K10033.8122135.3284－4.8917－5.8390－7.192315027.5676107.2667－3.1107－3.8616－4.934220024.680191.4525－1.4753－2.1155－3.03002.4．22lnqe－qt=lnqe－K1t22tqt=1K2qe2+tqeqttmgK1、K2．3．3R20.98qeqeqeqeR20.97．3Table3ParametersofkineticmodelsforadsorptionofphosphorusρmgLqemgK1R2qemgK2R212.57.80.26740.893614.50.03870.99442521.60.28850.969626.10.01680.99565058.40.37130.939763.30.00500.98372.5．5、60.5A3.0A．5．2.1．6．．23-24．．4minρ4812．、．Am21—0.772—1.543—4.62．5Fig．5EffectofcurrentdensityonammonianitrogenremovalrateAm21—0.772—1.543—3.084—4.62．6Fig．6Effectofcurrentdensityontheremovalrateofphosphorus2.6pHpH．7pH．40min．7pHFig．7EffectofinitialpHontheremovalrateofammonianitrogen7pH．25pH5～9．pH5pH26．HClOClO－27．ClO3－HClOClO－ClO3－28．8pH．8pH．pHFeOH30、FeOH4－、Fe2OH24+FeOH+、29．pH12FeOH4－30-32．pH．pH1—3.02—5.03—7.04—9.05—11.0．8pHFig．8EffectofinitialpHontheremovalrateofphosphoruspH9．9pHpHpH．2.7ρ10ρ．2.1ρρρ．10ρ．ρρρ58126pH1—3.02—5.03—7.04—9.05—11.0．9pHFig．9pHchangesduringelectrolysisρmgL1—253.42—500.03—750.0．1.54Am2．10ρFig．10Effectofchlorineionmassconcentrationontheremovalrateofammonianitrogen．11Fig．11Ammonianitrogenandphosphorusremovalamountvs．powerrequiredduringelectrocoagulation2.8．11．11．29.15gt4.3kW·h37.68gt0.86kW·h0.15～0.500.02～0.04kW·hg．3a、．b286、293、303KRedlich-PetersonLangmuirFreundlichGibbs－20～0kJmol|G|ΔH0．cpHpH．d0.15～0.500.02～0.04kW·hg．References1．M．2001131-202．2AKBALFCAMCS．Copperchromiumandnickelremovalfromme