A_2_O工艺中二沉池污泥上浮的原因与对策_王社平

技术总结A2/O工艺中二沉池污泥上浮的原因与对策王社平1,2,邵军峰1,万琼1,3,安少锋1,贺亮1,申建荣4(1.西安建筑科技大学环境与市政工程学院,陕西西安710055;2.西安市市政设计研究院,陕西西安710068;3.西安科技大学建筑与土木工程学院,陕西西安710054;4.西安高科园林景观工程有限责任公司,陕西西安710075)摘要:针对A2/O工艺处理城市污水时出现的二沉池污泥上浮现象,探讨分析了其主要原因及对策。分析结果表明,丝状菌过度繁殖引起的污泥膨胀和二沉池底部污泥发生的反硝化作用是二沉池污泥上浮的主要原因。其中,丝状菌性污泥膨胀主要是由水温太低引起的,而进入二沉池的硝态氮浓度过高导致了底部污泥的反硝化作用。在好氧池的DO>2mg/L、pH处于适宜范围内的条件下,通过强化缺氧池的反硝化作用、调整污泥回流比、减少污泥在二沉池中的停留时间等措施,有效抑制了二沉池中污泥的上浮。关键词:A2/O工艺;二沉池污泥上浮;丝状菌;污泥膨胀;反硝化中图分类号:X703文献标识码:C文章编号:1000-4602(2010)13-0043-04CausesandCountermeasuresonSludgeFloatinginSecondarySedimentationTankinA2/OProcessWANGShe-ping1,2,SHAOJun-feng1,WANQiong1,3,ANShao-feng1,HELiang1,SHENJian-rong4(1.SchoolofEnvironmentalandMunicipalEngineering,Xi'anUniversityofArchitectureandTechnology,Xi'an710055,China;2.Xi'anMunicipalEngineeringDesignandResearchInstitute,Xi'an710068,China;3.SchoolofArchitectureandCivilEngineering,Xi'anUniversityofScienceandTechnology,Xi'an710054,China;4.Xi'anGaokeGardenLandscapeEngineeringCo.Ltd.,Xi'an710075,China)Abstract:ForsludgefloatingphenomenoninthesecondarysedimentationtankinwhichA2/Oprocessisusedtotreatmunicipalsewage,thecausesandcountermeasureswereanalyzed.Theresultsshowthatthesludgefloatingismainlyduetothesludgebulkingcausedbyexcessivegrowthoffilamen-tousbacteriaandthesludgedenitrificationoccurredatthetankbottom.Thefilamentoussludgebulkingismainlycausedbytoolowtemperature,andthedenitrificationofsludgeatthebottomiscausedbyexces-sivenitratenitrogenenteringintosecondarysedimentationtank.WhenDOismorethan2mg/LandpHisinanappropriaterangeinaerobictank,thesludgefloatinginthesecondarysedimentationtankcanbeeffectivelyinhibitedbyenhancingthedenitrificationinanoxictank,regulatingthesludgereturnratio,re-ducingthesludgeretentiontimeandsoon.Keywords:A2/Oprocess;sludgefloatinginsecondarysedimentationtank;filamentousbac-teria;sludgebulking;denitrification·43·第26卷第13期2010年7月中国给水排水CHINAWATER＆WASTEWATERVol.26No.13Jul.2010目前许多城市污水处理厂采用厌氧/缺氧/好氧工艺(简称A2/O工艺),但是在实际运行中,常出现二沉池中污泥上浮而导致出水水质不达标的问题,其原因与污水厂进水水质的波动、生物反应池缺氧段反硝化过程不完全、二沉池中排