污泥回流比对分段进水A_O生物脱氮工艺的影响_王伟

中国环境科学2008,28(2)：116~120ChinaEnvironmentalScience污泥回流比对分段进水A/O生物脱氮工艺的影响王伟,彭永臻*,孙亚男(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)摘要：采用连续流分段进水缺氧/好氧(A/O)中试系统处理生活污水,研究污泥回流比(R)对系统性能的影响.结果表明,当R值高于1.0时,尽管第一段缺氧区的硝酸盐氮去除量明显增加,而系统硝化、反硝化效果均明显降低.当R为0.75时,系统总氮去除率最高,为92%;而当R值为1.5时,总氮去除率最低,为72%.当系统污泥沉降性能较好时,R值对二沉池泥泥位和泥水分离效果影响不大;而当污泥沉降性能较差时,二沉池泥位随R值增大而呈线性增加,此时提高R值会加剧污泥膨胀.此外,高R值使得系统各段悬浮固体浓度呈梯度分布的规律变得不再明显,降低系统污泥储量.同时,提高R值会降低系统固体停留时间,进而影响系统的污泥种群分布.关键词：生活污水；生物脱氮；分段进水；污泥回流比中图分类号：X703文献标识码：A文章编号：1000-6923(2008)02-0116-05Theinfluenceofsludgerecycleratioonthestep-feedA/Obiologicalnitrogenremovalprocess.WANGWei,PENGYong-zhen*,SUNYa-nan(KeyLaboratoryofBeijingforWaterQualityScienceandWaterEnvironmentalRecoveryEngineering,BeijingUniversityofTechnology,Beijing100022,China).ChinaEnvironmentalScience,2008,28(2)：116~120Abstract：Theeffectofsludgerecycleratio(R)ontheperformanceofthesystemwasinvestigatedinapilot-scalestep-feedanoxic/oxic(A/O)nitrogenremovalprocessfordomesticwastewatertreatment.Boththenitrificationanddenitrificationperformancedecreasedobviously,althoughthenitrateremovalinthefirstanoxiczonewasincreasedwhenthevalueofRwashigherthan1.0.ThehighestandthelowesttotalnitrogenremovalefficiencywereachievedwhentheRwere0.75and1.5respectivelywiththeremovalefficiencywere92%and72%accordingly.Whenthesettleabilityofthesludgewaswell,theRhadnosignificanteffectonthesludgelevelofclarifieranditsseparation,however,whenthesettleabilityofthesludgewasnotfavored,withtheincreaseofR,thelevelofsludgeinclarifierwasincreasedlinearlyandtheproblemofbulkingsludgewasexacerbated.Inaddition,theregulationofgradientdistributionthatthemixedliquidsuspendedsludgeconcentrationateachstagehasbeennotclearwhentheRwasathigherlevelandthesludgereserveswasdecreasedaccordingly.Meanwhile,whentheRwasincreased,theSRTwasdecreasedaccordingly,andthesludgepopulationcanbechangedfurthermore.Keywords：domesticwastewater；biologicalnitrogenremoval；step-feed；sludgerecycleratio连续流分段进水缺氧/好氧(A/O)工艺是一项高效污水生物脱氮工艺,其具有所需池容较小、脱氮效率高、抗冲击负荷能力强等优点[1-3].为取得良好脱氮效果,必须对进水流量比、曝气量