多点进水潜流湿地的水力效率及氮浓度空间变化_张涛

多点进水潜流湿地的水力效率及氮浓度空间变化＊张涛宋新山＊＊(东华大学环境科学与工程学院,上海201620)摘要通过脉冲示踪实验比较了3种多点进水方式和一般推流式的水力效率,通过脱氮实验获得不同水力效率下总氮和铵态氮浓度的空间分布,并对水力效率和脱氮效率进行了相关性分析。结果表明:4种布水方式中,阶梯进水方式的有效体积比和水力效率均最高,此时潜流湿地系统内部水流停留时间分散程度较低,水流混合流动程度较弱,更接近于推流;不同布水方式下总氮在潜流湿地中的空间分布差异比铵态氮明显,阶梯进水方式有利于湿地后段的反硝化脱氮作用;水力效率与总氮去除率存在极显著的相关性,而与铵态氮的去除相关性不显著。关键词潜流人工湿地;多点进水;示踪实验;水力效率;脱氮中图分类号X703文献标识码A文章编号1000-4890(2010)11-2210-06Hydraulicefficiencyandspatialvariationofnitrogenconcentrationinsubsurfaceflowcon-structedwetlandswithdifferentmulti-inflows.ZHANGTao,SONGXin-shan(CollegeofEnvironmentalScienceandEngineering,DonghuaUniversity,Shanghai201620,China).ChineseJournalofEcology,2010,29(11):2210-2215.Abstract:Throughtracertests,thehydraulicefficiencyoffourkindssubsurfaceflowconstructedwetlandswithdifferentinflowconfigurations(i.e.,commonhorizontalflowand3kindsofmulti-inflow)wasexamined,withthespatialvariationoftotalnitrogen(TN)andammoniumnitrogen(NH+4-N)inthewetlandsandthecorrelationbetweenthehydraulicefficiencyandthenitrogenremovalefficiencystudied.Amongthefourinflowconfigurations,step-inflowhadthehighesthy-draulicefficiency,becauseithadalongmeanresidenttimeandlowresidencetimedistribution(RTD),revealingthattheflowpatternwasmuchclosertoaplugflowwithweakerverticalmix-ture.Underthefourinflowconfigurations,theTNandNH+4-Nshowedstratifieddistribution,andTNvariedobviouslyasaresultofdifferentinflowconfigurations.Thestep-inflowwasinfavorofthedenitrificationinthebackendofthewetlandbed.Thereweresignificantrelationshipsbe-tweenhydraulicefficiencyandTNremovalefficiency,whilehydraulicefficiencydidnotaffecttheremovalofNH+4-Nsignificantly.Keywords:subsurfaceflowconstructedwetland;multi-inflow;tracertest;hydraulicefficiency;denitrification.＊上海市自然科学基金项目(10ZR1400300)、国家水专项(2008ZX07207-006-04)、国家自然科学基金创新群体基金项目(50721006)和国家重点基础研究发展计划资助项目(2006CB403402-3)。＊＊通讯作者E-mail:newmountain@dhu.edu.cn收稿日期:2010-05-27接受日期:2010-08-03水体氮污染形势日趋严峻,人工湿地因比传统的污水处理技术具有更高的脱氮效率、更低的运行维护成本、更好的生态属性而倍受青睐(周琪,2009)。基于建造成本、运行管理、异味控制等的考虑,潜流人工湿地(SSFCWs)是目前国际上较多研究和应用的一种湿地处理系统。人工湿地去除水中污