好氧反硝化菌强化生态浮床对水体氮与有机物净化机理

好氧反硝化菌强化生态浮床通过挂膜将异养硝化-好氧反硝化菌与填料结合,并添加曝气强化措施,提高浮床对富营养化水体中氮和有机物的去除效果。结果表明,在7天内,好氧反硝化菌强化生态浮床在COD_(Cr)/TN=1.7~2.9的进水下,对NH_4~+-N、NO_3~--N、TN和COD_(Cr)的去除率分别为54.5%、100%、59.8%和56.3%,对TN和COD_(Cr)的去除率比传统生态浮床分别提高了47.1%和36.3%;在COD_(Cr)/TN=3.3~5.0的进水下,对NH_4~+-N、NO_3~--N、TN和COD_(Cr)的去除率分别为55.4%、100%、48.9%和65.6%,对TN和COD_(Cr)的去除率比传统生态浮床分别提高了21.0%和20.0%。好氧反硝化菌强化生态浮床中,曝气和异养硝化-好氧反硝化菌的添加提高了浮床对有机物的降解,增强了其在高溶解氧水平下的反硝化作用,克服了曝气生态浮床对NO_3~--N降解效果差的缺点。利用Monod动力学方程对好氧反硝化菌强化生态浮床初期降解氮素和有机物过程进行描述,相关系数为0.9,说明Monod动力学方程适用于描述好氧反硝化菌强化生态浮床的反应动力学。     

反硝化除磷戈登氏菌属的富集及其菌剂制备

【背景】投加微生物菌剂是强化生物处理效能的重要手段,反硝化是污水脱氮除磷的关键步骤,但目前对于反硝化微生物菌剂相关的研究报道较少。【目的】驯化高效反硝化聚磷菌菌剂,并对系统进行生物强化。【方法】采用两阶段法快速富集反硝化聚磷菌,筛选高效脱氮除磷功能菌株NC1-1并进行鉴定,以NC1-1为菌种来源制备干粉菌剂,研究菌剂强化A²SBR系统污水处理效果。【结果】历经36 d后反硝化聚磷菌富集成功,菌株NC1-1经鉴定属于戈登氏菌属,其脱氮除磷率分别为89.46%和91.68%。麦麸、玉米粉配比为85%:15%、NC1-1投菌量为20 mL、发酵液用量20 mL的条件下成功制得干粉菌剂,干粉菌剂最佳投加量为10%的A²SBR系统总磷（total phosphorus,TP）和NO₃^--N去除率比未投加菌剂的A²SBR系统提高12.06%和11.52%。【结论】菌剂NC1-1的投加使A²SBR系统的污染物去除效能进一步提高,研究结果为进一步研究反硝化聚磷菌菌剂提供了...     

一株好氧反硝化菌的分离鉴定及其除氮特性

【目的】生物除氮中反硝化菌具有重要的作用,需氧反硝化菌研究较少,有着很好的应用潜力,本研究主要从环境样品中分离具有高效去除铵氮和亚硝酸盐氮活性的好氧反硝化菌,并对其分类及除氮特性进行研究。【方法】以高效去除铵氮、除亚硝酸盐氮和好氧反硝化能力为主要指标,从富营养化的池塘淤泥水和工厂污泥样品中进行菌株分离筛选。通过生理生化特点以及16S rRNA序列分析对活性最好的菌株进行初步鉴定。在好氧条件下,分别以NO-3-N、NH+4-N和NO-2-N作为唯一氮源,考察菌株的好氧反硝化特性、去除铵氮和亚硝酸盐氮特性,以及不同初始pH值、温度、碳源、摇床转速对该菌去除铵氮和亚硝酸盐氮特性的影响。【结果】得到的细菌中,以菌株C-4的活性最好,其16S rRNA序列与不动杆菌的同源性达99%,结合生理生化特点,初步确定菌株C-4属于不动杆菌属(Acinetobacter sp.)。以柠檬酸钠作为碳源,30℃、120 r/min振荡培养,种龄为18 h,用初始pH为8.5的200 mg/L NH +4-N培养基和初始pH为7.5的100 mg/L NO -2-N培养基进行测定,分别培养15 h与12 h,净除氮率分别达到65.8%和47.8%。【结论】从鱼塘水样中分离到一株好氧反硝化菌C-4,初步鉴定为不动杆菌属的一个种(Acinetobacter sp.),具有较高的反硝化特性和高效去除铵氮与亚硝酸盐氮的能力,在处理实际池塘污水时中,净除氮率可达73.04%以上。     

基于响应面法对一株好氧反硝化菌脱氮效能优化

【目的】水体富营养化是当今我国水环境面临的重大水域环境问题,氮素超标排放是主要的引发因素之一。好氧反硝化菌构建同步硝化反硝化工艺比传统脱氮工艺优势更大。获得高效的好氧反硝化菌株并通过生长因子优化使脱氮效率达到最高。【方法】经过序批式生物反应器(Sequencing batch reactor,SBR)的定向驯化,筛选获得高效好氧反硝化菌株,采用响应面法优化好氧反硝化过程影响总氮去除效率的关键因子(碳氮、溶解氧、pH、温度)。【结果】从运行稳定的SBR反应器中定向筛选高效好氧反硝化菌株Pseudomonas T13,采用响应面法对碳氮比、pH和溶解氧关键因子综合优化获得在18 h内最高硝酸盐去除率95%,总氮去除率90%。该菌株的高效反硝化效果的适宜温度范围为25?30 °C;最适pH为中性偏碱;适宜的COD/NO3?-N为4:1以上;最佳溶解氧浓度在2.5 mg/L。【结论】从长期稳定运行的SBR反应器中筛选获得一株高效好氧反硝化菌Pseudomonas T13,硝酸盐还原酶比例占脱氮酶基因的30%以上,通过运行条件优化获得硝氮去除率达到90%以上,对强化废水脱氮工艺具有良好应用价值。     

一株海水异养硝化-好氧反硝化菌系统发育及脱氮特性

【目的】确定一株分离自海水的异养硝化-好氧反硝化菌的系统发育地位并探索其脱氮特性和机理,以期为解释异养硝化-好氧反硝化机理以及改进海水养殖及废水的生物脱氮工艺提供理论依据。【方法】通过形态观察、生理生化实验和16S rRNA基因序列分析,鉴定该菌株;通过测定菌株在不同无机氮源降解测试液中的生长和脱氮效率,分析其异养硝化和好氧反硝化性能。【结果】经鉴定该菌株属于盐单胞菌属(Halomonas);最适生长条件为盐度3%、pH 8.5、温度28℃、碳氮比10:1,在盐度为15%的培养液中仍能生长;可以同时去除氨氮、亚硝酸氮和硝酸氮,24 h时对NH4+-N、NO2--N、和NO3--N的去除率可分别达到98.29%、99.07%、96.48%,3种形态无机氮同时存在时,会优先利用NH4+-N,且总无机氮去除率较单一存在时更高,说明该菌株可实现同步硝化反硝化。【结论】该分离自海水的异养硝化-好氧反硝化菌属于盐单胞菌属(Halomonas),在高盐环境中仍能生长,同时具有高效的异养硝化和好氧反硝化能力,能够独立完成脱氮的全部过程。     

好氧反硝化聚磷菌的筛选及菌群构建优化

【背景】近年来,随着海水养殖规模的扩大,养殖产品产生的排泄物与残留的饲料大量积累,导致养殖水域的氮磷元素含量上升,水体富营养化加剧并对环境造成危害。【目的】从红树林人工湿地中筛选出好氧反硝化聚磷菌株并研究各菌株的最佳除氮除磷效率,随后通过响应面法构建菌群,进一步强化菌株去除污染物的能力。【方法】将前期筛选出的5株耐盐异养硝化-好氧反硝化菌通过异染颗粒染色和聚-β-羟基丁酸(poly-β-hydroxybutyricacid,PHB)染色进行好氧反硝化聚磷菌的筛选,通过单因素试验明确各菌株的最佳除氮除磷条件,并利用Design-Expert软件和Box-Benhnken响应面法进行配比试验。【结果】经过筛选获得3株耐盐好氧反硝化聚磷菌,分别为肺无色杆菌(Achromobacter pulmonis) strain E43、氧化木糖无色杆菌(Achromobacterxylosoxidans)strainJ1和食油假单胞菌(Pseudomonasoleovorans)strain F2,发现菌株E43具有聚磷功能,确定了耐盐好氧反硝化聚磷菌群的最优降解投加比例为E43:J1:F2=1:1:...     

极端条件下异养硝化-好氧反硝化菌脱氮的研究进展

异养硝化-好氧反硝化(HN-AD)是对传统自养硝化异养反硝化理论的丰富与突破。HN-AD菌在好氧条件下可快速实现氨氮、硝态氮(NO_3~–-N)、亚硝态氮(NO_2~–-N)三氮同步脱除。它们不仅具有分布范围广、适应能力强、代谢通路特殊等特点,而且还具有世代时间短、脱氮速率快、高活性持久等独特优势,在高盐、低温、高氨氮等极端条件表现出了巨大的脱氮潜力,因此在废水生物脱氮领域受到广泛关注。文中在介绍HN-AD菌属类别及代谢机理的基础上,重点总结了在高盐、低温、高氨氮等极端条件下进行氨氮脱除的HN-AD种属,系统分析了它们在极端条件下的脱氮特性及潜力,并简述了HN-AD菌在极端条件下的工艺应用研究进展,最后展望了HN-AD脱氮技术的应用前景和研究方向。     

一个氨氧化菌群的筛选及除氮特性

摘要:【目的】筛选耐受低C/N比、高氨氮环境的高效氨氧化菌群,为开发新型氨氮去除菌剂奠定基础。【方法】采用多点取样、低C/N比、高浓度氨氮废水强行驯化、驯化液连续梯度稀释等步骤,筛选具有高效去除铵氮能力的氨氧化菌群,并考察不同C/N比、摇床转速和铵氮浓度下目的菌群去除铵氮的特性;分离培养目的菌群中的优势菌株,经形态学观察、生理生化特性测定和16S rRNA序列分析对菌株进行鉴定。【结果】筛选到了3个具有较强去除铵氮能力的氨氧化菌群,其中以JQ8活性最好,对初始NH4+ -N 17.86 mmol/L、C/N比为4的合成废水处理6 d后,NH4+-N去除率达到97.01%;在C/N≥4、NH4+-N≤28.57 mmol/L环境下,菌群JQ8对溶液中NH4+-N的6 d去除率均可达95%,净除氮率接近80%。实验室模拟好氧活性污泥处理系统处理线路板工业废水,用菌群JQ8对系统强化处理7 d后NH4+-N和TN去除率分别达到87.8%和67.9%。分析菌群JQ8组成发现,Defluvibacter sp.、Paracoccus sp．和Aquamicrobium sp．细菌为其主要优势菌株。【结论】从垃圾渗滤液中筛选到一个具有较强铵氮去除能力的氨氧化菌群JQ8,可耐受较低C/N比和高氨氮环境,在强化污水处理系统对工业废水氨氮处理中,表现出良好的效果。     

反硝化基因工程菌株YP4S的构建及对污水除氮特性研究

从养殖场污泥中筛选出菌株YP4,经16S rDNA分子发育树的同源序列比对,确定为克雷伯什菌属(Klebsiella sp.)。由NCBI数据库查编码亚硝酸还原酶(Nir)的基因nirS序列,设计引物,以铜绿假单胞菌PAOI基因组DNA为模板,应用PCR技术扩增目的片段nirS,经过双酶切、克隆和转化,得到重组质粒pYP4S,然后转化野生菌株YP4,构建反硝化基因工程菌YP4S。菌株生长曲线测定表明,工程菌株YP4S与YP4的生长特性基本一致。工程菌株YP4S对模拟污水COD、TN、NH_4^+-N和NO_3^--N具有较高的去除率,YP4S与YP4相比,对NO_2^--N积累的减少量为(32.44±3.96)%,明显减少了NO_2^--N的积累。通过正交试验获得工程菌株YP4S在C/N=10、T=30℃、r=200 r/min和pH=7.0的最佳组合条件下,对模拟污水TN去除率较高。应用工程菌株YP4S处理猪场沉淀池的实际污水,COD、TN、TP、NH_4^+-N和NO_3^--N去除率分别为(95.87±0.82)%、(76.38±3.84)%、(97.13±0.54)%和(75.35±2.57)%,NO_2^--N积累量为(3.31±1.24) mg/L,表明工程菌株YP4S具有较好反硝化作用,对含氮量高的实际污水修复具有潜在的应用前景。     

分离于河口区芦苇湿地1株好氧反硝化菌的鉴定及其反硝化特性

【目的】筛选高效脱氮且N_2O释放量少的好氧反硝化细菌,并对菌株的反硝化特性进行研究,可为河口湿地富营养化水体的生物修复提供技术支撑。【方法】经BTB培养基初筛和反硝化能力测定,从辽河河口区芦苇湿地土壤中分离得到1株具有较高反硝化能力的好氧反硝化菌C3。经形态观察、生理生化鉴定和16S rRNA序列分析,对菌株进行鉴定。研究温度、碳源、pH及C/N对其生长量、反硝化能力及N2O释放的影响。【结果】筛选得到的高效好氧反硝化细菌C3,经鉴定属于假单胞菌属(Pseudomonas sp.)。反硝化特性研究结果表明,该菌最适碳源为柠檬酸三钠,在温度为30°C、pH为7.0、C/N为10时生长速率和脱氮效率最高且N_2O释放量较少。在此条件下,该菌在36 h内使NO_3~–由179.55 mg/L降至5.08 mg/L,脱氮率高达97.17%。该菌株在整个反硝化过程中中间产物N_2O的最大累积量较低,为0.22 mg/L。【结论】从湿地土壤中分离所得好氧反硝化菌C3为假单胞菌属的1个种(Pseudomonas sp.),该菌株在高效除氮和低N_2O累积方面均具有明显优势,对后续河口湿地富营养化水体治理具有重要意义。     

Assessing the feasibility of achieving biological nutrient removal from wastewater at an Irish food processing factory

In Ireland, wastewaters emanating from the food industry typically contain elevated levels of nitrogen and phosphorus before treatment. Two pilot scale studies were performed to determine the feasibility of achieving biological N and P removal on-site at a food ingredients plant. The wastewater treated by the pilot reactors was that which resulted from the day-to-day production in the full-scale food ingredients plant. Both reactors were of the anaerobic/anoxic/oxic (A/A/O) design, however the sizing of the zones was varied in this study. In the first pilot study, while treating a wastewater of the following strength: 1008 mg COD/l; 30.1 mg NH4-N/l and 26.7 mg P/l, removal efficiencies of 93%, 99% and 98% were obtained for COD, NH4-N and P, respectively. In the second study, while operating at reduced hydraulic retention times and lower recycle rates, the pilot plant treated a wastewater of the following strength: 1757 mg COD/l; 62 mg NH4-N/l and 57 mg P/l, with removal efficiencies of 94%, 97% and 75% obtained for COD, NH4-N and P, respectively. This work showed that biological nutrient removal could be successfully applied to treatment of food industry wastewaters.     

石灰石滤柱出水回流曝气生物滤池系统的处理效能及微生物群落多样性

【背景】曝气生物滤池(Biological Aerated Filter,BAF)对有机物和氨氮的处理效果较好,但除磷效果不佳。【目的】提高BAF系统的除磷效能。【方法】在缺氧/好氧滤柱后设置了部分采用石灰石滤料的滤柱(未添加石灰石滤料的系统作为对照组),对比分析了使用石灰石滤柱出水回流BAF系统的处理效能,通过最大或然法(Most Probable Number,MPN)和高通量测序技术考察了石灰石滤柱出水回流对好氧柱中硝化细菌的数量和微生物群落结构的影响。【结果】对比试验表明,有回流的BAF系统对化学需氧量、NH_4~+-N、总氮和总磷的去除率比无回流时分别提高了3.16%、41.21%、40.62%和18.93%;采用石灰石滤料的系统对化学需氧量、NH_4~+-N、总氮和总磷的去除率比对照组分别提高了1.75%、2.3%、2.2%和23.1%;由高通量测序结果可知,试验组的好氧柱中变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)、α-变形杆菌纲(Alphaproteobacteria)、β-变形菌纲(Betaproteobacteria)、γ-变形菌纲(Gammaproteobacteria)和黄单胞菌科(Xanthomonadaceae)的丰度比对照组分别提高了25.2%、4.8%、5.5%、7.4%、7.3%、12.0%和6.6%,属分类水平下两者不同物种数量为170种。【结论】石灰石滤柱出水回流能显著提高总氮和总磷的去除效果,回流液中的Ca2+具有化学除磷的作用,同时也能改善好氧柱内的菌群结构,强化生物除磷效果。     

Enhanced denitrifying phosphorous removal in a novel anaerobic/aerobic/anoxic (AOA) process with the diversion of internal carbon source

A novel anaerobic/aerobic/anoxic (AOA) process is proposed to realize denitrifying phosphorous removal in this study, and the characteristic of the AOA process is transferring part of the anaerobic mixed liquor to the post-anoxic zone for providing the carbon source needed for denitrification. The AOA process was operated for 3 months, and the average removal efficiencies of NH4+-N, TN and PO4(3-)-P were 93.0±3.1%, 70.3±2.9% and 87.3±11.8%, respectively. A mass balance analysis indicated that 0.49±0.02 g VSS(-1) d(-1) of PO4(3-)-P and 0.23±0.04 g VSS(-1) d(-1) of NO3--N were simultaneously removed in the anoxic zone, and it is speculated that denitrifying phosphorous removal occurred in the AOA process. Furthermore, 0.24±0.06 g VSS(-1) d(-1) of TN was removed in the aerobic zone via simultaneous nitrification and denitrification (SND). The results demonstrate that the multi-zone structure of the AOA process favors the enhancement of denitrifying phosphorous removal and SND for municipal wastewater treatment.     

Pseudomonas alcaliphila AD-28的脱氮性能及其关键酶活性

【背景】异养硝化-好氧反硝化菌由于能够同时实现硝化反硝化作用而备受关注,但由于菌的种类不同,其脱氮途径不尽相同,研究菌株脱氮关键酶的种类及其活性可以推测菌株的脱氮途径,从而为菌株在生产上的应用提供技术支撑。【目的】研究Pseudomonas alcaliphila AD-28的脱氮性能及其关键酶的活性,为菌株脱氮分子机理研究奠定基础。【方法】以柠檬酸钠为碳源,以硫酸铵、亚硝酸钠、硝酸钾为氮源,研究菌株AD-28的脱氮性能并检测其关键酶氨单加氧酶(AMO)、羟胺氧化还原酶(HAO)、亚硝酸盐还原酶(NIR)、硝酸盐还原酶(NAR)的酶活性。【结果】菌株AD-28培养24h的菌密度(OD600)可达1.971,对初始浓度为18.85mg/L的氨氮、26.13mg/L的硝酸盐氮、19.47mg/L的亚硝酸盐氮、66.11 mg/L的总氮去除率均达到96%以上;关键酶AMO、HAO、NIR和NAR的比活力分别为0.028、0.003、0.011、0.027 U/mg。【结论】Pseudomonas alcaliphila AD-28能同时进行异养硝化-好养反硝化作用,该菌在AMO作用下将NH4+-N氧化为羟胺,然后由HAO氧化为NO2--N,NO2--N和NO3--N在NIR、NAR等酶的催化作用下脱氮。     

Simultaneous removal of phosphorus and nitrogen in a sequencing batch biofilm reactor with transgenic bacteria expressing polyphosphate kinase

To improve phosphorus removal from wastewater, we constructed a high-phosphate-accumulating microorganism, KTPPK, using Pseudomonas putida KT2440 as a host. The expression plasmid was constructed by inserting and expressing polyphosphate kinase gene (ppk) from Microcystis aeruginosa NIES-843 into broad-host-range plasmid, pBBR1MCS-2. KTPPK was then added to a sequencing batch biofilm reactor (SBBFR) using lava as a biological carrier. The results showed that SBBFR with KTPPK not only efficiently removed COD, NH(3)-N, and NO(3)(-)-N but also had a high removal capacity for PO(4)(3-)-P, resulting in a low phosphorus concentration remaining in the outflow of the SBBFR. The biofilm increased by 30-53% on the lava in the SBBFR that contained KTPPK after 11 days when compared with the reactor that contained P. putida KT2440. Real-time quantitative polymerase chain reaction confirmed that the copy of ppk was maintained at about 3.5 × 10(10) copies per μL general DNA in the biofilm after 20 days. Thus, the transgenic bacteria KTPPK could maintain a high density and promote phosphorus removal in the SBBFR. In summary, this study indicates that the use of SBBFR with transgenic bacteria has the potential to remove phosphorus and nitrogen from wastewater.     

Effect of carbon source on biological nutrient removal in a sequencing batch reactor

Sequencing batch operation was used for nutrient (COD, NH4-N, NO3-N, PO4-P) removal from synthetic wastewater by using different carbon sources. Operation consisted of anaerobic, anoxic, oxic, anoxic and oxic (An/Ax/Ox/Ax/Ox) phases with durations of 2/1/4.5/1.5/1.5 h. Glucose, acetate and a mixture of glucose/acetate were used as carbon source to yield a COD/N/P ratio of 100/5/1.5 in the feed. Sludge age was kept constant at 10 days. COD, NH4-N, NO3-N and PO4-P removal efficiencies were maximum at the levels of 96%, 87%, 81% and 90% respectively, when a mixture (50/50) of glucose and acetate was used.     

In situ simultaneous organics and nitrogen removal from recycled landfill leachate using an anaerobic-aerobic process

An anaerobic-aerobic process including a fresh refuse landfill reactor as denitrifying reactor, a well-decomposed refuse reactor as methanogenesis reactor and an aerobic activated sludge reactor as nitrifying reactor was operated by leachate recirculation to remove organic and nitrogen simultaneously. The results indicated that denitrification and methanogenesis were carried out successfully in the fresh refuse and well-decomposed landfill reactors, respectively, while the nitrification of NH(4)(+)-N was performed in the aerobic reactor. The maximum organic removal rate was 1.78 kg COD/m(3)d in the well-decomposed refuse landfill reactor while the NH(4)(+)-N removal rate was 0.18 kg NH(4)(+)-N/m(3)d in the aerobic reactor. The biogas from fresh refuse reactors and well-decomposed refuse landfill reactors were consisted of mainly carbon dioxide and methane, respectively. The volume fraction of N(2) increased with the increase of NO(3)(-)-N concentration and decreased with the drop of NO(3)(-)-N concentration. The denitrifying bacteria mustered mainly in middle layer and the denitrifying bacteria population had a good correlation with NO(3)(-)-N concentration.     

利用啤酒废水小球藻异养培养

摘要：【目的】利用小球藻异养培养技术处理啤酒废水,旨在为啤酒废水资源化利用和降低小球藻生产成本提供一个途径。【方法】在含有10 g/L葡萄糖的基本培养基进行异养小球藻高效藻株的筛选,并用于啤酒废水的资源化处理。【结果】从5株小球藻中得到2株适合高密度异养培养的藻株（Chlorella pyrenoidosa 15-2070 和 Chlorella vulgaris 15-2075）,在啤酒废水的资源化处理过程中这2株小球藻得到非常接近的试验结果。利用由废水配制含10 g/L葡萄糖的基本培养液培养Chlorella pyrenoidosa 15-2070获得了5.3 g/L藻细胞;并且在此过程中,啤酒废水得到有效利用,几种主要污染物最高去除率为：CODcr,92.2 %;BOD5,95.1 %;NO3--N,98.5 %;NH4+-N,92.3 %。【结论】啤酒废水中的重要环境污染物在培养小球藻的过程中可以得到有效地清除,并从中可以获得具有商业价值的小球藻细胞。     

Denitrifying phosphorus removal and impact of nitrite accumulation on phosphorus removal in a continuous anaerobic-anoxic-aerobic (A2O) process treating domestic wastewater

A lab-scale anaerobic-anoxic-aerobic (A(2)O) process was operated to investigate denitrifying phosphorus removal and nitritation-denitritation from domestic wastewater, especially regarding the impact of nitrite accumulation caused by nitritation on phosphorus removal. The results showed that mean total nitrogen (TN) removal was only about 47% and phosphorus removal was almost zero without the pre-anoxic zone and additional carbon source. Contrastively, with configuration of pre-anoxic zone, TN and phosphorus removal was increased to 75% and 98%, respectively, as well as denitrifying phosphorus removal of 66-91% occurred in the anoxic zone. Nitritation-denitritation was achieved through a combination of short aerobic actual hydraulic retention time and low dissolved oxygen levels (0.3-0.5 mg/L); however, phosphorus removal deteriorated with increase of nitrite accumulation rates. The free nitrous acid (FNA) concentration of 0.002-0.003 mg HNO(2)-N/L in the aerobic zone inhibited phosphorus uptake, which was major cause of phosphorus removal deterioration. Through supplying the carbon sources to enhance denitrification and anaerobic phosphorus release, nitrite and FNA concentrations in the aerobic zone were reduced, and phosphorus removal was improved. Compared with nitrification-denitrification, nitritation-denitritation reduced the carbon requirement by 30% and performed biological nutrients removal well with mean TN and phosphorus removal of 85% and 96%, respectively.