低氧条件下A_2_O工艺对城市污水脱氮处理的中试研究_李炳荣

中国环境科学2019,39(1)：134~140ChinaEnvironmentalScience低氧条件下A2/O工艺对城市污水脱氮处理的中试研究李炳荣,曹特特,王林,李咏梅*(同济大学环境科学与工程学院,污染控制与资源化研究国家重点实验室,上海200092)摘要：以巢湖市某污水处理厂实际污水为处理对象,基于节能降耗的需求开展A2O工艺中试研究.研究结果表明:当溶解氧从2mg/L降至0.5mg/L时,COD和氨氮的去除率分别为80%和90%,去除性能并未受到影响,没有出现亚硝酸积累,而TN的去除率有较大幅度的提升,从15%提升至44%.低溶解氧条件下,温度降低主要对TN去除率产生影响,从夏季的44%下降至冬季的29%,而氨氮的去除率仍维持在90%以上.由于进水碳源不足,出水主要以硝酸盐氮为主,低温脱氮率仅为29%.长期低氧条件下运行,AOB和NOB的优势种属为Nitrosomonadaceae和Nitrospira,相对丰度分别为2.33%和6.40%.系统NOB在数量和动力学性能上均优于AOB,同时发现存在Denitratisoma好氧反硝化菌,其相对丰度为1.59%.研究结果为低氧条件下实现城市污水脱氮提供了理论和实践依据.关键词：A2O工艺；低溶解氧；脱氮处理；氨氧化菌；亚硝酸盐氧化菌中图分类号：X703.5文献标识码：A文章编号：1000-6923(2019)01-0134-07Apilot-scalestudyonnitrogenremovalofmunicipalwastewaterbyA2/Oprocessunderlowdissolvedoxygencondition.LIBing-rong,CAOTe-te,WANGLin,LIYong-mei*(StateKeyLaboratoryofPollutionControlandResourcesReuse,CollegeofEnvironmentalScienceandEngineering,TongjiUniversity,Shanghai200092,China).ChinaEnvironmentalScience,2019,39(1)：134~140Abstract：Apilot-scaleA2OprocesswascarriedouttotreatsewageinawastewatertreatmentplantinChaohuCity,aimingtosaveenergy.Theresultsshowedthatwhenthedissolvedoxygen(DO)decreasedfrom2mg/Lto0.5mg/L,theremovalratesofCODandammoniawere80%and90%,respectively,meaningtheremovalperformancewasnotaffected,andnonitriteaccumulationoccurred,inthemeantime,theremovalrateofTNincreasedsignificantly,from15%to44%.UnderlowDOcondition,thedecreaseoftemperaturemainlyaffectedtheTNremovalrate,from44%insummerto29%inwinter,whereastheremovalrateofammoniawasstillabove90%.Duetotheshortageofcarbonsource,thenitrogenremovalratewasonly29%underlowtemperature,resultinginahighnitrateconcentrationintheeffluent.Underlong-termlowDOconditions,thedominantmicrobialspeciesofAOBandNOBwereNitrosomonadaceaeandNitrospira,withrelativeabundanceof2.33%and6.40%respectively.NOBissuperiortoAOBinbothquantityandkineticperformance.Atthesametime,Denitratisomawasfoundwiththerelativeabundanceof1.59%,whichwasconsideredasaerobicdenitrifyingbacteria.Thesefindingsprovidetheoreticalandpracticalsupportfornitrogenremovalfrommunic