浮水植物型人工湿地对水稻田排水中氮磷污染的控制效果英文方荣杰

ControlEffectofFloatingPlantsConstructedWetlandtoNitrogenandPhosphorusPollutionfromRiceFieldDrainageFANGRong-jie12*TANMao-lan11．CollegeofEnvironmentalScienceandEngineeringGuilinUniversityofTechnologyGuilin541004China2．GuangxiKeyLaboratoryofEn-vironmentalEngineeringandProtectionAssessmentGuilinUniversityofTechnologyGuilin541004ChinaAbstractObjectiveThecontroleffectoffloatingplantsconstructedwetlandtonitrogenandphosphoruspollutionfromricefielddrainagewasstudied．MethodFirstlythecharacteristicoffloatingplantsandthepurificationprincipleofpollutantswereintroducedandthenpurificationeffectwasanalyzedthroughcontrollingnitrogenandphosphoruspollutionfromricefielddrainagebyfloatingplantsconstructedwetland．ResultBymeansoffloatingplantsconstructedwetlandtheaverageremovalrateoftotalnitrogenTNfromdouble-seasonearlyandlatericefielddrainagereached52．17%and62．23%respectivelywhilethatoftotalphosphorusTPwas45．69%and74．37%respectivelywithbetterremovaleffect．Meanwhilefloatingplantshaveecologicalandornamentalvaluetosomeextent．ConclusionFloatingplantsconstructedwetlandcouldnotonlycontrolnitrogenandphosphoruspollutioninfielddrainageeffectivelybutalsokeepfarmlandecosysteminhealthystate．KeywordsFloatingplantsConstructedwetlandTNTPPurificationeffectChinaReceivedNovember82010AcceptedNovember232010SupportedbyNaturalScienceFoundationofGuangxiProvince0991026FoundationofGuangxiKeyLaboratoryofEnvironmentalEngineeringandProtectionAssessment0701K019ProjectofEn-vironmentalEngineeringInnovationTeamofTalentSmallUplandCon-structioninUniversitiesinGuangxi2007Number71InnovationProgramProjectofPostgraduateEducationinGuangxiProvince2009105960815M25．*[e-mail]uiltbytheoptimizingsimulationofnaturalwetlandsystemandisaecosystemwhichdisposessewagethroughphysicalchemicalandbiologicaleffectandmedium-plant-microorganismisasecologicalenvironment1－5．Since1970sconstructedwetlandtechnologyhasdevelopedrapidlyandhasbeenwidelyusedintheremovalofnitrogenandphosphorusduetotheadvantagesoflessinvestmentgoodeffectandconvenientoperationmaintenance6－7．Amongdif-ferenttypesofconstructedwetlandsurfaceflowwetlandhastheadvantagesofshortmaturitylowoperationcostofcapitalconstructionandsimilartonaturalwetland8－9andissuitableforthecontrolofnon-pointsourcepollutionfromfarmlanddrain-age．Comparedwithemergentandsubmergedplantfloatingplantcanadaptwiderangeofwaterdepthduetofloatingonwaterandhasstrongreproductivecapacityremovingnitrogenandphosphoruseffectively8whileitiseasytoplantharvestandmanageasanimportantplantusedinsurfaceflowwet-land．Astypicalfloatingplantslotusandwaterlilycanpurifywatereffectivelyandhavecertainornamentalandecologicalvalue．FloatingplantsconstructedwetlandstudiedinourpaperislocatedinQingshitanirrigationdistrictinGuilinCityinGuan-gxianddouble-seasonricewasplantedintheirrigationdis-trictwhilethegrowthperiodofearlyriceisfromMaytoJulyandthatoflatericeisfromJulytoSeptember．1Characteristicandpurificationprincipleoffloatingplant1．1CharacteristicoffloatingplantWiththecharacteristicofstrongreproductivecapacityfloatingplantcanreleaseoxy-gentowaterfromrootsbymeansofphotosynthesisandcanabsorbnutrientgreatlysoNPandheavymetalcanbere-movedeffectivelybymeansofplantuptake．Commonfloatingplantsincludelotuswaterlilywaterhyacinthduckweedandsoon．Lotusandwaterlilywerestudiedinourpaper．1．2PurificationprincipleoffloatingplantWetlandcanpurifypollutantsinwaterthroughadsorptionandinterceptionofsedimentplantuptakeroot-zonereactionandmicrobialdeg-radation．Plantplaysanimportantroleinwetlandpurificationontheonehandplantrootswithlargesurfacecanadherelotsofmicroorganismsandrhizospherecancreatemicroenviron-mentwhichisbeneficialtothegrowthofvariousmicroorgan-ismsontheotherhandplantcantransportoxygenfromstemsandleavestorootsformingaerobicmicro-zonenearrootswhichcanpromotetheconversionoforganicmatterNandPinadditionplantuptakefornutrientisthemainwaytopurifywater．Withlargeareaofleaveslotuscanresistsolarradiationandreducethematerialexchangebetweenatmos-phereandwatersurfaceofwetlandandoxygeninatmospherecannotbesupplementedinwetlandinstantlyforminganaero-bicenvironment．Meanwhileanaerobicenvironmentoflotusandwaterlilycanspeedupdenitrificationandpromotethede-compositionofNandP．Inadditionlotusandwaterlilycanflowerandhaveappreciationvalue．EditorYANGYingyingProofreaderWANGNanlingMeteorologicalandEnvironmentalResearch201011170－722Purificationeffectoffloatingplantscon-structedwetlandFloatingplantswereplantedinconstructedwetlandandmeasuringweirwassetatinletandoutletofconstructedwet-landwhilepollutantinfielddrainageflowedintoconstructedwetlandthroughinletanddischargedthroughoutletafterpurifi-cation．Thepurificationeffectwasanalyzedaftertestingwaterqualityatinletandoutlet．2．1RemovaleffectofTNinearlyandlatericefielddrain-ageFromFig．1theremovalrateofconstructedwetlandtoTNwasonly16．45%atreturninggreenstageofearlyrice．Af-fectedbyfieldfertilizationbeforesowingNconcentrationinfielddrainagewashigheratreturninggreenstageofearlyricewhilericewaslittlewithpoorfertilizerabsorptionabi