潜流人工湿地脱氮效率影响因素及沿程去除特性研究_杨新萍

第二届全国农业环境科学学术研讨会论文集2007年7月570潜流人工湿地脱氮效率影响因素及沿程去除特性研究杨新萍，周立祥，戴媛媛（南京农业大学资源与环境学院环境工程系，南京210095）摘要：人工湿地主要的脱氮途径有氨的挥发、氨化、微生物硝化/反硝化、植物吸收和基质吸附，其中微生物的生物转化作用是人工湿地主要的脱氮方式。以野外水平潜流芦苇砾石床人工湿地研究了湿地对微污染河道水的长期动态去除特性，运行结果表明：潜流湿地稳定运行期的脱氮性能略低于启动期，整个运行期间湿地TN去除率不足40%。模拟水平潜流湿地微区试验表明，其对有机物降解、硝化与反硝化反应、TN去除具有同步性；稳定运行期间潜流湿地的后部下层有明显硝化反应发生，试验结果与传统湿地脱氮理论不相一致。人工湿地脱氮机理有待进一步明晰。关键词：潜流人工湿地；脱氮；去除率；硝化；反硝化NitrogenRemovalinDifferentDistancesandEffectFactorsofHorizontalSubsurfaceFlowConstructedWetlandsYANGXin-ping，ZHOULi-xiang，DAIYuang-yuang(CollegeofResourcesandEnvironmentalSciences,NanjingAgriculturalUniversity,Nanjing210095,China)Abstract：Thenitrogenremovalmechanismintheconstructedwetlandsconsistsofvolatilization,ammonification,nitrification/denitrification,plantuptakeandmatrixadsorption.Generally,nitrification/denitrificationisthemajornitrogenremovalmechanisminconstructedwetlands.Takenthemicro-pollutedpoolwaterasinfluent,thepollutantlong-termremovalefficiencyanddynamicfeatureofthehorizontalsubsurfaceflowgravel-bedconstructedwetlandswithreedwasinvestigated.Theresultsofapproximatetwo-yearoperationshowedthatperformanceofsubsurfaceconstructedwetlands(SSCWs)wasprocessoffluctuationandsubsequentstabilization.COD,nitrogenreductionsdisplayedseasonalvariationsandcorrelationwithplantbiomassincrement.Nitrogenreductionefficiencydecreasedalittleinthesecond-year.Theremovalefficiencyoftotalnitrogenwasbelow40%duringoperationperiod.Takenthelow-strengthasinfluent,thepollutantremovalefficiencyofmicro-SSCWswithreedwasalsoinvestigated.Nitrification/denitrificationoccurredconcurrentlywithCOD,TNremoval.Therewasobviousnitrificationevenindeepsoillayeroftheendofmicro-SSCWs.Resultsshowedthattheresomedifferencesinthemechanismsofnitrogenremoval.Thesubsurfacewetlandspossessedsoundperformanceofnitrogenremoval,butitsmechanismofnitrogenremovaliswaitingtobestudiedforward.Keywords：horizontalflow;subsurfaceconstructedwetlands(SSCWs);nitrogenremoval;removalefficiency;nitrification;denitrification在德国Kickuth（1972）提出的“根区法”[1]理论基础上发展起来的人工湿地污水处