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1、生态与农村环境学报2008,24(1):63-67JournalofEcologyandRuralEnvironment太湖不同湖区无机氮转化潜力①曾巾,杨柳燕,肖琳,杜宏伟(污染控制与资源化研究国家重点实验室/南京大学环境学院,江苏南京210093)摘要:采集太湖梅梁湾和东太湖的水样和沉积物,在实验室内模拟研究不同湖区水体中溶解性无机氮(DIN)短期内的转化潜力。研究结果表明,太湖藻型湖区(梅梁湾)和草型湖区(东太湖)水体中存在着强烈的硝化作用,+-+NH42N和NO32N含量之间表现出显著的负相关关系(P<0.05或P<0.01),NH42
2、N质量浓度下降速率为0.08~-1-1+0.19mg·L·d。在同样的试验条件下,藻型湖区硝化速率高于草型湖区。NH42N初始浓度越高则硝化速率也越高,不添加外源氮时硝化速率随着时间的推移而逐渐降低。藻型湖区的反硝化作用强于草型湖区。室内模拟试验20d后,沉积物中TN含量平均下降了3.7%,东太湖水样中平均下降26.7%,梅梁湾平均下降42.2%。湖泊沉积物是进行反硝化作用的重要场所。短期内DIN的转化潜力反映了不同湖区氮素转化速率,也反映了不同生态类型水体对湖泊氮素转化的影响。关键词:梅梁湾;东太湖;DIN;硝化作用;反硝化作用中图分类号:X
3、142;X172文献标识码:A文章编号:1673-4831(2008)01-0063-05ComparativeStudyonTransformationPotentialofDissolvedInorganicNitrogeninDifferentPartsofLakeTaihu.ZENGJin,YANGLiu2yan,XIAOLin,DUHong2wei(StateKeyLaboratoryofPollutionControlandResourceReuse/SchoolofEnvironment,NanjingUniversity,Nan
4、jing210093,China)Abstract:Samplesofwatersanddepositswerecollectedfromalgae2dominatedMeiliangBayandmacrophyte2dominatedEastLakeTaihuforin2labdeterminationofDIN(dissolvedinorganicnitrogen)transformationpotentialswithin20days.Resultsdemonstratethatrapidnitrificationsexistedinth
5、esedimentsandwatersofthetwolakezones,andtherewasre2+-markablenegativecorrelationbetweenNH42NandNO32N(P<0.05orP<0.01).Thenitrificationrateinthealgae2dominatedzonewasalittlehigherthaninthemacrophyte2dominatedzoneinthemicrocosmunderthesamecondition,and+thehighertheinitialNH42Nc
6、oncentration,thehigherthenitrificationrate.Nitrificationratesdecreasedgraduallywithtimewhennoextraneousnitrogenwasadded.DenitrificationwasalsostrongerintheMeiliangBaythanintheEastLake.After20daysinlab,TNdeclinedby3.7%(onaverage)inthesediments,by26.7%inthewaterfromtheEastLake
7、,andby42.2%inthewaterfromtheMeiliangBay,suggestingthatsedimentwasthemostimportantplacefordenitrifica2tion.TransformationpotentialofDINwithinashortperiodoftimereflectsnotonlynitrogentransformationrate,butalsoeffectsofwaterbodiesdifferentineco2typeoncyclingofnitrogeninthelake.
8、Keywords:MeiliangBay;EastLakeTaihu;DIN;nitrification;denitrification[3-4]氮素