回流对城镇污水处理厂A^(2)O-MBR工艺除磷效果影响及机制-工程化规模研究  

Mechanism and effect of reflux ratio of A^(2)O-MBR process on phosphorus removal:A full-scale study

作　　者：董君兰 楼菊青[1] 王如意[1] 刘春晓[2] DONG Junlan;LOU Juqing;WANG Ruyi;LIU Chunxiao(School of Environmental Science and Engineering,Zhejiang Gongshang University,Hangzhou 310012;School of Computer Science and Technology,Zhejiang Gongshang University,Hangzhou 310012)

机构地区：[1]浙江工商大学环境科学与工程学院,杭州310012 [2]浙江工商大学计算机科学与技术学院,杭州310012

出　　处：《环境科学学报》2025年第2期31-44,共14页Acta Scientiae Circumstantiae

基　　金：浙江省‘尖兵’‘领雁’研发攻关计划(No.2023C03149);浙江工商大学“数字+”学科建设项目(No.SZJ2022B016)。

摘　　要：本研究对两个同样采用A^(2)O-MBR工艺的城镇污水处理厂在不同回流条件下的运行监测数据进行了深入分析.检测分析了沿程水相和泥相中磷浓度、胞外聚合物(EPS)含量及微生物群落结构,并开展了非原位批次实验,深入分析了释磷/吸磷、挥发性脂肪酸(VFA)以及聚羟基烷酸酯(PHA)、糖原(Glyc)的变化情况,揭示了不同回流条件下不同形态磷浓度的变化及机制.结果发现,在较低内回流比(缺氧池回流至厌氧池R1=100%、好氧池回流至缺氧池R2=200%)和较高外回流比(MBR回流至好氧池R3=500%)时,系统中溶解性总磷(DTP)浓度先上升后下降,且出水磷浓度较低,各单元贡献率计算发现好氧吸磷量显著高于厌氧释磷量.同时,微生物群落的丰富度和多样性显著较高,典型聚磷菌(PAOs)Candidatus Accumulibacter、Dechloromonas相对丰度较高,除磷性能较好.然而,在较高内回流比(R_(1)=200%、R_(2)=300%)和较低外回流比(R_(3)=400%)时,DTP浓度持续下降,未观察到明显的释磷现象,主要的吸磷过程发生在缺氧阶段.厌氧、缺氧段硝态氮(NO_(3)^(-)-N)、溶解氧(DO)和氧化还原电位(ORP)较高,不利于生物除磷性能的发挥.此外,EPS含量及PN/PS比值较低,表明微生物活性受到抑制.非原位释磷/吸磷批次实验进一步验证了这一点,单位释磷速率低,且糖原分解量和PHA产生量均较小.微生物群落分析显示,Nitrospira、Ferruginibacter和IMCC26207为代表性分类菌群.研究结果可为A^(2)O-MBR工艺的污水处理厂的优化运行提供理论依据.In this study,the long-term operational monitoring data of two municipal wastewater treatment plants,also using the A2O-MBR process,were analyzed in depth under different reflux conditions.The phosphorus concentration in the liquid and sediment,the extracellular polymeric substances(EPS)content,and the microbial community structure along the process were analyzed.The non-in-situ batch experiments were carried out by testing the variations of phosphorus release/uptake,volatile fatty acids(VFA)concentration,and the content of Polyhydroxyalkanoate.Consequently,the changes of the concentrations of different phosphorus species under different reflux conditions and their mechanisms were revealed.Compared with L plant,the total dissolved phosphorus(DTP)concentration in the system first increased and then decreased and the phosphorus concentration in the effluent was lower in Y plant,running at lower internal reflux ratios(anoxic tank refluxed to anaerobic tank R1=100%,aerobic tank refluxed to anoxic tank R2=200%)and higher external reflux ratios(MBR refluxed to aerobic tank R3=500%).Furthermore,the phosphorus uptaken in the aerobic tank was significantly higher than that released in the anaerobic tank according to the calculated contribution ratio of each unit in Y plant.At the same time,the richness and diversity of microbial community were significantly higher in Y plant,and the relative abundance of typical phosphorus-aggregating organisms(PAOs)Candidatus Accumulibacter,Dechloromonas,was higher,resulting in better phosphorus removal performance.However,the DTP concentration kept decreasing along the process,with no obvious phosphorus release observed,and the main phosphorus uptake process was found to be in the anoxic stage in L plant,running at higher internal reflux ratios(R_(1)=200%,R_(2)=300%)and lower external reflux ratios(R_(3)=400%).In the anaerobic and anoxic tanks in L plant,the nitrate nitrogen(NO_(3)^(-)-N),dissolved oxygen(DO),and oxidation-reduction potential(ORP)were higher,which was unfavorable to the

关 键 词：回流比 生物除磷 A2O工艺 微生物群落 

分 类 号：X703[环境科学与工程—环境工程]