CAST工艺处理低C_N生活污水的强化脱氮性能_马娟

第3卷第2期环境工程学报Vol.3,No.22009年2月ChineseJournalofEnvironmentalEngineeringFeb.2009CAST工艺处理低C/N生活污水的强化脱氮性能马娟1,2彭永臻1＊王淑莹1王丽1王少坡1,3(1.北京工业大学北京市水质科学与水环境恢复重点实验室,北京100022;2.兰州交通大学环境与市政工程学院,兰州730070;3.天津城市建设学院环境与市政工程系,天津300384)摘要研究了不同运行条件对CAST工艺处理低C/N实际生活污水脱氮性能的影响,并对pH值和ORP的变化规律进行了分析。结果表明,传统4h运行模式下,提高原水C/N比,TN去除效果并无显著提高;对于低C/N生活污水,降低充水比有利于提高出水TN去除率,然而,充水比降至16%时,系统因低负荷运行发生污泥膨胀。在不投加外碳源的情况下,采用分段进水交替A/O运行模式可大幅改善系统脱氮性能,且TN去除率随着交替次数的增多而提高,交替4次平均去除率达87.23%。系统采用实时控制方式运行时,可根据有机物降解、氨氧化及反硝化时pH值和ORP曲线上是否出现拐点,来判断反应系统的曝气以及搅拌时间是否过长、适当或不足。关键词生物脱氮生活污水CAST中图分类号X703.1文献标识码A文章编号1673-9108(2009)02-0234-05EnhancingnitrogenremovalperformanceofCASTforlowratioofC/NmunicipalwastewatertreatmentMaJuan1,2PengYongzhen1WangShuying1WangLi1WangShaopo1,3(1.KeyLaboratoryofBeijingforWaterQualityScienceandWaterEnvironmentRecoveryEngineering,BeijingUniversityofTechnology,Beijing100022;2.InstituteofEnvironmentalandMunicipalEngineering,LanzhouJiaotongUniversity,Lanzhou730070;3.DepartmentofEnvironmentalandMunicipalEngineering,TianjinInstituteofUrbanConstruction,Tianjin300384)AbstractThenitrogenremovalperformanceofCASTtreatinglowC/NwastewaterunderdifferentoperationconditionswasinvestigatedandtheprofilesofpHandORPwereanalyzed.TheresultsshowedthatTNremovalratecouldn'tbeimprovedbyincreasingtheC/Nratioofwastewaterwhenthesystemoperatedintraditionalmold.DecreasingthefillingratioofwastewaterwashelpfulforincreasingTNremovalrate,whilesludgebulkingandnitrateaccumulationhappenedbecauseoftheoperationunderlong-termconditionoflowcarbonsourceandincompletedenitrificationwhenthefillingratiowas16%.Nitrogenremovalefficiencycouldbegreatlyenhancedbyalternatinganoxic-aerobicprocesswithstepfeedingwithoutaddingexternalcarbonsource,anditwasin-creasedbyincreasingfeedfrequencywiththemaximumvalueof87.23%.Whenreal-timecontrolstrategywasemployed,thejudgmentontheendingofnitrificationanddenitrificationcouldbebasedontheinflectionpointonthevariedcurveofORPandpHduringorganicdegradation,ammoniaoxidationandnitratereduction,andthusreducingaerationandmixingt