双龙湖综合整治后的水环境状况研究

重庆大学硕士学位论文双龙湖综合整治后的水环境状况研究姓名：刘亚丽申请学位级别：硕士专业：市政工程指导教师：张智20051001中文摘要I摘要湖泊水库是人类最重要的淡水资源之一，为人们提供水利防洪、用水供水、供应能源、水产养殖、游览观赏、改善航运、接纳排污以及气候调节等多种功能，对社会和经济发展起到不可估量的作用，是人们生活不可缺少的宝贵资源。保护湖泊环境对国民经济与社会的持续稳定快速发展至关重要。水体富营养化问题是当今世界水污染治理难题。我国湖泊由水质污染引起的富营养化问题十分突出，是困扰中国经济发展的主要环境问题之一。双龙湖位于重庆市北郊渝北两路城区，渝北区水资源丰富，开发潜力大，是重庆市北面一个新建卫星城市。双龙湖作为城市内湖，丰富城市景观，为人们提供舒适的休闲场所。由于开发过程中未实行有效保护，水体污染严重，并造成其有限的集雨面积逐渐减少。渝北政府于2003－2004年对双龙湖进行综合治理：设环湖污水截流管；截流雨水净化入湖；整治湖湾、种植岸坡护土植物；湖底清障、底泥疏浚；布置深水曝气循环活水设备；人工放养鱼苗净化水体等。本研究就双龙湖综合治理工程实施后，根据2004－2005年连续监测数据，对双龙湖不同点位、水深水环境变化规律进行分析预测；用综合营养状态指数法TLI评价其富营养化状况；分析预测双龙湖内源营养盐污染，就控制污染提出合理化建议；测定双龙湖初级生产力，并对其进行预测研究。(1)双龙湖总体水质基本符合地面水环境质量Ⅳ类水质标准。由于循环水量变化和环境因素的影响，双龙湖丰、平水期水质优于枯水期，垂直方向表层、中层水质优于底层水。(2)根据综合营养状态指数法TLI评价双龙湖水体得出：双龙湖丰、平水期处于中营养水平；枯水期水质较差，处于轻富营养水平。(3)内源污染对双龙湖水环境影响不容忽视。温度、pH值、溶解氧和水动力对底泥氮磷释放强度影响显著，影响因素的水平间有显著差异。底泥氮磷营养盐释放强度随温度升高、溶解氧降低和水动力增强而增大；磷释放随pH值升高而增加，氮反之。浸泡水草氮磷营养盐释放强度随温度升高、溶解氧降低和光照减弱而增大。定期收获水草，清理湖面死亡水生植物减轻内源污染。根据底泥营养盐释放模型的计算，合理调解深水曝气设备运行工况，增加底质上层水溶解氧，减少底泥氮、磷释放量，改善双龙湖水环境。(4)根据双龙湖浮游植物水柱日净产量时空分析测定，认为双龙湖初级生产同水温、透明度、溶解氧、溶解性总磷呈显著正相关，以7、8月最高，最低值出现在1月。根据模型计算双龙湖全年浮游植物净产量为1815033kg。理论产鱼潜力重庆大学硕士学位论文II9075.2kg。定期收获鱼产品可以从湖泊生态系统中移出氮、磷等营养元素，从而减轻双龙湖富营养化。(5)今后应当加强对双龙湖水体外源性营养盐负荷量及时空分布规律、湖泊湖流规律、湖泊生态系统结构及湖泊综合开发与利用等方面的研究，组建机理性的双龙湖预测预报模型，指导整个湖泊的综合利用和水污染防治。关健词：双龙湖，水环境，富营养化，限制性因素，内源污染，初级生产力英文摘要IIIABSRACTLakesandreservoirsareoneofthemostimportamtwaterresouse,provideforpeoplewaterconservancyandfloodcontrol,waterusingandwatersupply,energysupply,marineproducts,sceneryappreciate,shippingimprove,accepttherowdirtywaterandweatherregulateetc,andalsocaninterferentthesocietyandeconomyuneveluablely,theyareindispensabilitypricelessresource.Asforthis,itisverynecessarytoprotecetwater-enviromenttokeepondevelopingquicklyofsocietyandeconomy.Eutrophicationofwaterbodieshasbecomeaglobalanddifficultproblemincontrollingwaterpollutionandisoneofthemostimportantenvironmentalproblems.Atpresent,eutrophicationofwaterbodiesisveryseriousinChina,whichisthemainenvironmentalproblemoflimitingeconomicdevelopment.ShuangLong-lakeislocatedinthenorthernpartofChongQing,YuBeidistrit,whichhasrichwaterresouseandisasatellitecity.Asalakeinurbancity,ShuangLong-lakeimprovethecity’scenery,providepeopleacomfortareaforentertainment.Butbecauseofuncautionousdevelopment,ShuangLong-lakewaspollutedseariously,anddecreasethelimitedrainGatheringareagradually.YuBeidistrithaveasyntheticallytreatmentengineeringonthelake:Establishethesewagesystemalongtheshoretocollectethewastewater;Arrangeplantdecontaminationbedtomaketherainwaterclean;Wholecurethelakegulfandplanttheshoretoprotectthewaterbody;purethelake’sbottom,implementdredgingengineering;Arrangedeepwateraerateandcirculationequipmentswhichcanmakethewaterflow;Putthefishfryintothelaketoprotectewaterbody.ThisresearchanalysisandpredictwaterqualityandvarietyregulationofShuanglong-lakeindifferentpositionfomeflatsurfaceandvirticaldirectionaccordingtothecontinuouswatermonitordataof2004.2005aftersynthesizingtreatment;UsetheTLIevaluationmethodtocarryoneutricationassessmentindifferentpositionandwaterseason;Analyzetopredictthesourcenutritionalpollute&putforwardtherationalizationsuggestiontocontrolthepollution;StudytomeasureShuangLong-lake’sprimaryproductionandcarryontheestimatingandverifying.(1)ShuangLong-lake’swaterqualitysatisfywaterstandardof.BecausetheⅣwatercirculationandvariouskindsofenvironmentalfactorsinfluenceoverallwaterenvironment,waterqualityinperiodofnormallevelbetterthanthatofdryseason,it重庆大学硕士学位论文IVindicatesthatbyanalyzingwaterbodysurfacestorey,middlelevelwateraresuperiortothewaterqualityofgroundfloor.(2)Inthehighandaveragewaterseasonwaterqualityisatitsnormallevel,muchbetterthanthatofdryseason,whichisinthelightrichnutritionlevel.(3)Theendogenesispollutecan'tbeignoredwhichcanpollutwaterenvironment.Temperature,pH,dissolvingoxygenandwatermotiveforceinterferesendimentreleasingintensityofnitrogen&phosphorusremarkably.Phosphorus&nutritionreleaseingintensityrisesastemperaturerises、dissolvesoxygenreduces、watermotiveforcestrengthen,phosphorusrisesaspHrises,whilenutritiondrops.Theintensityofsoakedpasturenutritionreleasingriseswithtemperature,dissolvesoxygenreducingandilluminationweaken.Bycalculationinmodelsaccordingtothenutritionreleaseingofsendiment,mediatingthedeepwaterequipmenttoimprovedissolveoxygen,canmakewaterqualitybetterandreduceamountofreleasingphosphorus,improvetheoverallwaterenvironment.(4)Primaryproductionisinfluencedbytemperature,transparency,dissolveoxygen,dissolvedtotalphosphorus,whichisthehighestinAugust,theminimumvalueappearsinJanuary.Itis1815033kgtocalculateoutthenetproductionofphytoplanktonofthewholeyearaccordingtothemodelofnetproductionofprimaryproduction.Thetheoryfishpotentialityis9075.2kg.Reapfish'sproductscanshiftoutsuchnutritionelementsasthenitrogen,phosphorus,etc.fromthelakeecosystemregularly,thuslighteneutrophicationofShuangLong-lake.(5)Researchshouldbestrengthened,includingstudiesdoneontheentirewaterlayer-fromthewatersurfacetothebottomofthelake;monitoringthechemicalelementloadingsandtheirtemporalandspatialdistributing,studytheprinciple