MBR强化脱氮除磷工艺处理城市污水的中试

针对城市污水处理,提出了膜-生物反应器(MBR)强化脱氮除磷工艺,并开展了近3个月的中试。试验结果表明,COD、总氮、氨氮及总磷去除率分别达到86.5%、69.3%、98.0%及81.0%,平均出水COD、总氮、氨氮及总磷质量浓度分别为26、9.3、0.44、0.44 mg.L-1,达到国家一级A排放标准;内源反硝化、反硝化除磷及同步硝化反硝化现象的共同存在使工艺的脱氮除磷性能得到整体强化;蛋白质和多糖是膜污染的主要有机成分,采用次氯酸钠溶液定期清洗可维持MBR强化脱氮除磷工艺的稳定运行。     

两种回流方式倒置A~2O-MBR工艺处理城市污水中试研究

考察了两种回流方式下倒置A2O-膜生物反应器(MBR)去除污染物的效果。试验结果表明,采用工艺2的回流方式,COD、NH3-N、TN及TP去除率分别达到84.7%、99.2%、62.2%及73.3%,平均出水COD、NH3-N、TN及TP质量浓度分别为42.5、0.25、14.4、0.56 mg/L,基本满足国家一级A排放标准,脱氮除磷效果优于工艺1(TN、TP去除率分别为52.5%、49.5%),而COD和NH3-N的去除率基本不受回流方式影响;膜组件高效截留作用使出水浊度维持在1.0 NTU以下;系统存在同步硝化反硝化、反硝化除磷作用,有利于强化系统脱氮除磷的性能。     

水解反硝化工艺强化脱氮处理

碳源对脱氮除磷都具有重要的作用,碳源不足会导致脱氮效果降低,出水TN水质不达标。为解决碳源不足造成的脱氮能力差的问题,本试验采用水解反硝化脱氮工艺,将水解酸化与反硝化脱氮过程相结合,取代缺氧反硝化,有效地解决了碳源不足所导致的脱氮效果差的问题。利用水解反硝化脱氮工艺处理城市污水,出水NH₄⁺-N、TN和COD都满足一级A标准,去除率分别为98.0%、69.4%和82.7%,比同期污水处理厂AAO工艺的TN去除率高出17.5%。在BOD₅/TN为3～5的条件下,水解池中污泥的比反硝化速率为缺氧池污泥的1.2～1.7倍,并且去除相同的N所需要的碳源较少,在碳氮比为3:1、3.5:1、4:1和5:1时去除单位N水解池可分别节省59.5%、52.2%、19.9%和23.1%的COD,有效地解决了脱氮过程中碳源不足问题。     

改良多级A/O对低C/N生活污水强化除磷效果研究

针对传统多级A/O工艺处理低碳氮比生活污水除磷效果差的问题，通过增设前置厌氧段改良多级A/O工艺，重点研究了除磷效果的可行性。结果表明：在温度为17℃±3℃、流量分配比为100%∶0∶0、水力停留时间为10h、污泥回流比为50%、污泥龄为14天的条件下，系统总体除磷效果较好。其中COD、TP平均去除率分别为89.81%、90.35%，出水平均浓度分别为32.65mg/L、0.49mg/L，均优于GB 18918—2002《城镇污水处理厂污染物排放标准》一级A排放标准。由于受到硝化反硝化的综合影响，对污水中含有的氮素去除效果一般，其中NH₃-N、TN去除率均为50%左右，出水平均浓度为30.32mg/L、30.41mg/L，可通过外加碳源的方式增强反硝化能力，进一步提高系统脱氮效果，出水有望达到一级B标准。改良工艺在保证有机物去除效果的基础上基本实现了脱氮除磷，可为实际生活中处理低C/N生活污水提供参考。     

A~2/O工艺强化反硝化除磷控制策略研究

在传统A2/O工艺的基础上,通过设立预缺氧区(即建立A-A2/O工艺)、外加碳源等手段,强化A2/O工艺处理低C/N生活污水的脱氮除磷能力。试验结果表明,经过强化后的A2/O反应器对COD、TN及TP去除效果良好,COD、TN及TP的去除率分别为92%、98%、85%。系统表现出明显的反硝化除磷现象,缺氧区除磷量占总除磷量的17.18%。反硝化除磷现象的产生降低了碳源缺乏对A2/O工艺脱氮除磷性能的影响,提高碳源的利用效率。为采用A2/O工艺处理低C/N生活污水的污水处理厂提供理论依据。     

AOA工艺内源反硝化强化深度脱氮除磷

以实际低C/N生活污水为处理对象,考察了AOA（厌氧/好氧/缺氧）工艺内源反硝化脱氮除磷性能。实验重点研究了生物填料的快速挂膜情况、微生物种群结构变化和系统脱氮除磷效率。结果表明,接种污泥后系统污染物去除性能迅速提高,阶段Ⅲ出水COD、NH₄+^-N、TIN、TP平均浓度分别为33.36 mg/L、1.80 mg/L、5.27 mg/L和0.23 mg/L,相应的去除率分别77.4%、94.6%、84.3%和94.2%。FISH实验结果表明,活性污泥中功能菌聚糖菌GAOs占比13.5%,聚磷菌PAOs占比11.1%,生物膜上硝化菌AOB占比18.3%,NOB占比9.2%。在无外加碳源条件下,系统利用原水内碳源通过后置内源反硝化和反硝化除磷实现深度脱氮除磷,同时AOA工艺只有污泥回流,较传统A²O工艺节省了硝化液回流能耗,运维管理方便。     

连续流砂过滤器处理城市二级出水中试研究

采用连续流砂反硝化过滤工艺对无锡芦村城市污水处理厂二级出水进行脱氮除磷中试研究,以达到出水水质满足GB 18918-2002<城镇污水处理厂污染物排放标准>一级A的排放标准.试验选用聚合氯化铝(PAC)为强化连续流砂反硝化过滤工艺除磷的混凝剂,选用醋酸钠作为碳源补充剂,研究了连续流砂反硝化过滤工艺对污染物的去除效果.结...     

溶解氧对污泥转移SBR工艺除污性能的影响

污泥转移SBR工艺通过并联运行SBR反应器之间以污泥回流方式相互转移,增加反应阶段污泥量而提高系统的除污性能,并减少沉淀阶段污泥量而提高系统的容积利用率。以实际生活污水为处理对象,研究了该新工艺在不同溶解氧水平下对系统除污性能的影响。结果表明,溶解氧对于COD的去除影响不明显,而对TN和TP的去除影响显著。当溶解氧质量浓度控制在1.0～1.5 mg/L时,系统对于COD的去除率为83.8%,出水COD均小于60mg/L;系统对于TN和TP的去除率分别为79.7%和93%,平均出水TN和TP的质量浓度分别为5.9、0.19 mg/L。通过物料衡算发现,系统中TN的去除主要是依靠同步硝化反硝化完成的,占系统TN去除量的55.6%。     

A~2/O-BAF组合工艺对生活污水脱氮除磷的影响研究

以生活污水为研究对象,重点考察了A2/O-BAF组合工艺的脱氮除磷特性。试验结果表明,该工艺可以实现有机物、氮、磷的同步深度去除,出水水质满足《城镇污水处理厂污染物排放标准》(GB18918-2002)一级标准中A标准;COD、NH4+-N和TP的去除率与内循环回流比之间没有明显的相关性;曝气生物滤池对氨氮的硝化效率接近100%;在4种不同的内循环回流比条件下,出水TN分别为20.6、14.5、8.2和7.8 mg.L-1,TN的去除率分别为66.1%、76.0%、86.5%和87.1%,TN的去除率随着内循环回流比的增大呈增大趋势;当内循环回流比为200%、300%和400%时,TN去除率的增大幅度呈递减规律;系统中存在着明显的反硝化除磷现象,且内循环回流比增大有利于反硝化除磷。     

长泥龄改良A2/O工艺的短程硝化反硝化除磷

为解决传统A²/O工艺硝化与除磷泥龄(SRT)之间的矛盾,进一步提高低C/N(P)比生活污水同步脱氮除磷效率,采用一种改良A²/O工艺在长SRT条件下处理生活污水.试验结果表明,该工艺可有效筛选和强化反应器内活性污泥,并大量富集长SRT的反硝化除磷菌(DPAO).通过亚硝酸盐氧化菌(NOB)淘洗阶段后,反应器在SRT=19.6d、A²O段污泥浓度(MLSS)=5.5 g·L^-1、水力停留时间(HRT)=8.2 h、污泥回流比(R)=90%、硝化液回流比(r)=250%、溶解氧(DO)=1.5～0.3 mg·L^-1,间歇曝气段HRT=4 h、曝气周期1 h曝气1 min(DO=0.3～0.5 mg·L^-1)、沉淀59 min条件下长期运行,COD、NH₄⁺-N、TP和TN的平均去除率分别为88.71%、99.2%、93.77%和89.52%,出水亚硝化率(NO₂^--N/NO_x^--N)可达97.2%,DPAO占聚磷菌(PAO)比为95.5%.污水中约72.96%的COD被DPAO合成PHA除磷,15.75%的COD由异养反硝化消耗,约41.96%和31.31%的N分别通过反硝化除磷和异养反硝化去除.剩余污泥主要由DPAO和反硝化菌增殖产生,分别占82.74%和17.24%,较传统脱氮除磷途径减少了58.76%的碳源消耗和44.6%的污泥排放.     

混合型城市污水强化脱氮除磷工艺试验研究

采用膜膜强化集成工艺,对混合型城市污水进行脱氮除磷效果试验研究。试验结果表明,COD、NH3-N、TN及TP去除率分别达到80%、96%、60%及88%,系统平均出水COD为25 mg/L,NH3-N、TN及TP的质量浓度分别为0.9、13、0.44 mg/L。系统运行稳定,各项指标均可达到国家一级A标准(GB 18918-2002)。     

曝气生物滤池后置反硝化效能研究

以甲醇为外碳源,对生活污水进行两级串联O-A曝气生物滤池脱氮及去除COD的试验研究。采用陶粒为填料,向二级滤柱中投加甲醇,确定甲醇的最佳投量,考查该种形式的曝气生物滤池脱氮效果及出水COD浓度是否达标。试验表明,甲醇投量为20mg/L时,曝气生物滤池二级出水COD﹑NH3-N﹑NO3--N﹑TN平均质量浓度分别为49.3﹑3.3﹑1.6﹑5.5mg/L,其去除率分别为85.3%﹑85.7%﹑77.1%﹑82.0%。达到很好的脱氮及去除COD效果。出水水质达到了《城镇污水处理厂污染物排放标准》一级标准中的B级标准。     

微电解—水解酸化-硝化反硝化工艺处理假发生产废水

采用微电解—水解酸化-硝化反硝化工艺处理假发生产废水,微电解去除废水中的色度和其他污染物,并提高废水的可生化性,以利于后续生化处理;水解酸化提高后续处理的容积负荷,提高去除效率,对进水中有机氮的氨化作用明显,硝化反硝化可将水解产生的NH3-N全部转化。运行结果表明,进水COD为1 100 mg/L、氨氮为120 mg/L的情况下,该工艺降解COD及脱氮效果良好;处理工艺保证系统出水COD〈40 mg/L,氨氮〈5 mg/L,达到了《污水综合排放标准》一级标准。     

基于MABR的市政污水处理强化脱氮中试研究

建立了A²/O-MABR耦合的中试系统，在不改变污水处理厂原有A²/O工艺以及不外加碳源的条件下，利用MABR丰富的微生物群落强化碳和氮的去除。该系统在最适宜参数下运行，COD、NH₄⁺-N和TN的出水水质满足市政污水处理厂一级A排放标准。微生物分析表明MABR生物膜上富集了丰富的脱氮功能菌群，例如Proteobacteria和Bacteroidetes等常规反硝化菌群，以及Thauera和Paracoccus等好氧反硝化菌群。MABR生物膜上丰富的脱氮功能菌群强化了系统对TN的去除。实验结果表明MABR在市政污水处理厂提标改造和强化脱氮方面拥有很大的应用潜力。     

BDP工艺应用于华中某污水厂体表改造工程中试实验

采用生物倍增+赛莱默深床反硝化滤池工艺应用于华中地区某污水厂中试系统,其COD去除率达到90.2%、氨氮去除率均值达到94.2%、TP去除率为93.52%,出水效果稳定。该结果表明,采用生物倍增+反硝化滤池工艺能够有效提升污水厂出水水质,为污水厂进行提标改造工程提供理论依据。     

A~2/O淹没式生物膜工艺处理城镇污水的研究

山东省东阿县污水处理厂一期工程采用厌氧-缺氧-淹没式生物膜法(A2/O)工艺处理城镇污水。COD平均去除率为93.8%,出水平均COD为22.7 mg.L-1;NH3-N和PO43--P平均去除率为97.6%和76.0%,出水平均质量浓度为0.87、0.78 mg.L-1,出水满足城镇污水处理厂污染物排放标准(GB 18918-2002)一级A标准。研究还发现厌氧池中存在厌氧氨氧化反硝化协同反应,NH3-N、NO3--N平均去除量分别为2.43、4.11 mg.L-1。     

Comparison of a sMBR and a CASP system for wastewater reclamation and re-use

The performance of a submerged membrane bioreactor (sMBR) for municipal wastewater reclamation and re-use was compared with that of a current classic activated sludge process (CASP). The average chemical oxygen demand (COD) of CASP effluent was 75 mg/l, while the average COD of sMBR filtrate was 15 mg/l. In general, COD removal was above 98%. However, the best results were obtained at a sludge rentention time (SRT) of 50 days. The total phosphorus (TP) content of the filtrate decreased to a level <1 mg/l under aerobic conditions in which aeration occurred continuously. It was shown that the filtrate TP and orthoposphate (Orto-P) concentrations increased dramatically during the periods of intermittent aeration because phosphorus is released under anoxic conditions. In the CASP effluent, the average TP and Orto-P were 7.9 mg/l and 7.1 mg/l, respectively. The filtrate was free of suspended solids (SS) and total coliform bacteria. The effluent SS in the CASP was 40 mg/l. The turbidity removal in the sMBR reached almost 99%, i.e. generally less than 1 NTU, while the average turbidity of the CASP effluent was almost 15 NTU. The removal of ammonium nitrogen (NH₄⁺-N) in the sMBR was almost 99.8%. In addition, the nitrate concentration in the filtrate decreased to 2.4 mg/l under both aerobic & anoxic conditions. It was shown that both nitrification and denitrification could be successfully reduced through intermittent aeration. Average total Kjeldehl nitrogen (TKN) and NH₄⁺-N in the CASP effluent were 30.2 mg/l and 20 mg/l, respectively, i.e. the nitrification efficiency was 42.9%, and the denitrification value was not available. When these results are compared with those in the CASP, it indicated that the sMBR could be successfully used for reclamation and re-use of municipal wastewater.     

污泥双回流-厌氧/好氧/缺氧强化内源反硝化深度脱氮

目前,如何经济有效地实现低C/N生活污水深度脱氮仍是污水处理厂面临的一个重大挑战。理论上后置反硝化可以实现深度脱氮效果,但往往由于缺乏外碳源难以同时满足经济高效脱氮。本研究建立的新型污泥双回流-厌氧/好氧/缺氧(AOA)工艺有利于富集培养以Candidatus Competibacter为主的反硝化聚糖菌(DGAOs),能够开发与利用内碳源脱氮。该系统长期处理低C/N (3.2)实际城市生活污水,TIN去除率达91.81%,出水TIN浓度为4.36 mg·L^-1。此外,提高第二污泥回流量增加了缺氧区的MLSS同时提升了比内源反硝化速率,是深度氮去除的主要原因。随着去除效果的提升,充分的厌氧环境使得内碳源贮存量升高,脱氮效果呈现正向循环。二沉池底部产生的额外碳源随第二回流引入系统进一步强化脱氮。本研究阐明了污泥双回流-AOA系统节碳脱氮的原理与关键,为低C/N城市污水的脱氮效率提供了一种可行性。     

Comparison of COD, nitrogen and phosphorus removal between anaerobic/anoxic/aerobic and anoxic/aerobic fixed biofilm reactor using SAC (Synthetic Activated Ceramic) media

In order to remove nitrogen and phosphorus simultaneously and to develop a compact process for retrofitting a conventional activated sludge system, a new fixed-biofilm reactor was designed and tested employing an operation strategy with three and two reaction phases : anaerobic/anoxic/aerobic (Run-1) and anoxic/aerobic (Run-2). Four kinds of HRT (4, 6, 8 and 10 h) were varied to investigate the effect of nitrification and denitrification in each reactor. The results of the experiments are summarized as follows. All removal rates of COD, T-N and T-P in the water treated in Run-1 were higher than those of Run-2. The average values of COD, T-N and T-P in the treated water were reduced to 5.0 mg/L, 5.6 mg/L and 3.1 mg/L in case of Run-1. The COD and T-N removal efficiencies of Run-1 were higher than that of Run-2, but the difference between Run 1 and Run 2 was almost negligible. More than 60 % T-P removal efficiency could be achieved when the HRT was above 8 hour, but the efficiency was sharply decreased to 36% as the HRT was decreased to 4 hour in case of Run-1. Although the removal efficiency of T-P in Run-2 decreased by 56 % compared with that of Run-1, the fixed biofilm reactor using SAC media reduced the volume of reactor, and high-level COD and T-N removal from domestic wastewater was performed ; stable effluent quality was thereby achieved. The performance of Run 2 with no anaerobic reactor was mostly similar to that of Run 1 with an anaerobic reactor, except for T-P removal. Hence, according to these results, anoxic and aerobic processes using SAC media could be possible for removing organics and nutrients from municipal wastewater, in case phosphorus removal is not considered for municipal wastewater with low concentration of phosphorus.