【作者】 戴兴春；

【导师】 黄民生；

【作者基本信息】 华东师范大学 ， 环境科学， 2008， 博士

【摘要】 A²／O工艺兼具脱氮和除磷功能，在水污染控制工程中发挥着巨大作用。但A²／O工艺由于自身多种因素的相互制衡，其脱氮除磷功能难以进一步提升，并影响到其应用范围和效益；城市合流污水C／N较低、难降解成份多和水质变化大的特点，对A²／O工艺的稳定运行也提出了新的问题。本论文依托上海市建委2007年重大科技攻关项目《污水处理升级改造工艺技术》（建科2007-007）开展研究，通过模拟上海市白龙港污水处理厂二期升级改造工程A²／O工艺，以城市合流污水为对象，重点研究：①外源条件（温度和F／M）对A²／O系统处理功能的影响；②强化ANAMMOX（Anaerobic AmmoniumOxidation）技术对A²／O系统处理功能的提升效果；③耦合生物指标（DHA、PHB、OUR、ATP和DNA分子标记）的监控体系及其在A²／O系统中应用可行性；④极端低C／N对A²／O系统处理功能的冲击效应及适宜的修复方法。本论文的目标是通过工艺调控、监控体系优化、异常修复研究，为城市合流污水A²／O处理系统的稳定、高效运行提供相关的技术依据。主要得出如下结论：（1）温度和F／M对A²／O系统处理功能的影响温度与A²／O工艺处理功能密切相关，季节更替对处理效果有一定影响。COD去除率在15℃～25℃范围内，由70％上升至85％，25℃以上可保证COD稳定和高效的去除效果。最佳脱氮温度范围约为25℃～30℃之间，TN去除率约70％，硝化率达95％，过高或过低的温度条件对脱氮功能均有抑制作用；温度变化对系统除磷效果影响较小，但是除磷功能易受到系统运行条件的影响，波动较大，平均去除率约50％。COD降解最佳F／M范围0．14～0．22gBOD₅／gMLSS．d；反硝化最佳F／M范围0．125～0．23gBOD₅／gMLSS．d；硝化最佳F／M范围0．14～0．28gBOD₅／gMLSS．d；除磷最佳F／M范围是0．14～0．23gBOD₅／gMLSS．d。综合COD去除、反硝化、硝化和除磷要求，实验最佳F／M介于0．14～0．22gBOD₅／gM LSS．d之间，高于A²／O的常规设计标准0．10～0．15gBOD₅／gMLSS．d。因此，对处理低C／N废水的装置而言，适度提高系统的F／M可提升其处理效能。（2）A²／O系统监控体系优化及其应用DHA、PHB、OUR、ATP和DNA分子标记分析技术优化了A²／O工艺传统监控体系，有利于从微生物生理生化活性和群落结构演替角度解析A²／O系统功能变化的过程机制，并准确和灵敏地评价A²／O系统的即时运行状态。稳定高效的A²／O系统其对应的DHA介于30,4a^lTF／gTSS．h之间，DHA含量过高和过低时出水水质恶化，DHA上限值约为60mgTF／gTSS·h左右。稳定高效的A²／O系统中厌氧池RHB含量介于23～28mg／gMLSS之间，提高温度和F／M对RIB合成有促进作用，平均约消耗140mgPHB去除1mg磷。A²／O实验系统的OUR值介于7．1～13．3mgO₂／gMLSS·h，硝化OUR介于0．88～2．95mgO₂／gMLSS·h之间。温度与OUR及硝化OUR成正相关，高F／M可增加OUR，但同时会降低系统的硝化OUR，导致硝化功能恶化。ATP可表征活性污泥中活体微生物数量的增减，A²／O实验系统的ATP含量介于1．14～1．86mg／gMLSS，上限约为2．08mg／gMLSS，温度和F／M对ATP的影响与微生物的生长繁殖有关。PCR-DGGE可有效分析A²／O系统中氨氧化细菌AOB（Ammonia-OxidizingBacteria）和硝化细菌NOB（Nitrite-Oxidizing Bacteria）群落结构的动态变化。温度的变化对硝化菌群落结构影响较大，低温时多样性相对丰富，高温时群落结构相对稳定，其中AOB₂、AOB₄和AOB₆在AOB菌群中占优势种，NOB菌群以Nitrobacter为主，优势种为Nb₇、Nb₈和Nb₉，Nitrospira优势种主要为Np2；F／M<0．15 BOD₅／gMLSS·d时有利于硝化菌群的生长，F／M>0．32BOD₅／gMLSS·d时适生种较少。不同F／M条件下AOB优势种为AOB₂、AOB₄和AOB₆，Nitrobacter优势种为Nb₁、Nb₂、Nb₄和Nb₇，Nitrospira菌群优势种主要为Np₆。（3）A2^／O系统强化ANAMMOX的效能在A²／O系统曝气池中通过限制DO的方式可形成NO₂^--N积累，强化ANAMMOX反应，提高系统脱氮能力。强化ANAMMOX反应的兼氧池NH₄⁺-N和TN去除率分别提高15个百分点和9个百分点，而系统TN的去除率提高约7个百分点。但采用限制DO的运行方式对COD和TP的去除有一定影响，同比条件下，COD去除率下降5个百分点，TP去除率下降1．4个百分点。ANAMMOX脱氮率约占A²／O系统TN去除率的21．9％，反应基质以NH₄⁺-N和NO₂^--N为主，在反应过程中生成少量NO₃^--N，3者的比例约为1：1．256：0．155；最佳反应pH约为7．8～8．0；DO对ANAMMOX有抑制作用；温度对其反应速率影响较大，从30．6℃至24．6℃变化过程中，ANAMMOX反应速率由1．47mg／L·h降低至1．175mg／L·h。（4）低C／N冲击效应及修复技术C／N=3．5时可明显降低系统的硝化功能，C／N=1．2可使反硝化功能完全停止，同时降低COD和TP的去除功能，并导致污泥膨胀和产生“漂泥”。而采用加大回流比的方法可有效缩短修复时间，相同条件下NH₄⁺-N去除率平均可提高20个百分点，TN去除率提高约7．4个百分点，COD去除率提高约5．4个百分点，但是该方法对修复系统除磷功能的作用不明显；提高F／M和降低SRT的修复方法可有效提高系统的处理功能，同比条件下NH₄⁺-N去除率平均提高约5个百分点，硝化OUR提高7％，亚硝化OUR提高4．2％，TN去除率提高约4．7个百分点，COD去除率提高约7．4个百分点，TP的去除率提高约4．5个百分点。本论文通过对A²／O工艺的技术参数选择、监控方法优化和异常问题修复等方面的研究，为保障A²／O工艺处理低C／N城市合流污水的稳定和高效运行提供了可靠的科学依据，具有良好的应用前景。更多还原

【Abstract】 Based on the functions of nitrogen and phosphorus removal, the A²/O process is playing an important role in water pollution control. But the function of nitrogen and phosphorus removal can’t be further improved, because of restricting by its multiple self-factor. So, improving the function and extending application of A²/O process has become the new subject in wastewater treatment field. Furthermore, the wastewater of combined sewage system has special characteristics of low C/N and high content of N and P.These problems have greatly hindered the efficant and stable operation of sewage treatment equipment. Therefore, it is very important to timely and accurately evaluate the operation status of system, diagnosis the abnormal conditions, puts forward solving countermeasure, and improve process function by enhancing ANAMMOX technology. The study has great significance in the water pollution controll domain, especially in Waterbody Eutrophi cation control field.This thesis is based on the project of process technology upgrade and transform in wastewater treatment plant supported by Shanghai Committee for Urban Construction and Transportaion. By simulating real system of Bailonggan wastewater treatment plant, the research investigated the effect of temperature and F/M on system, and study treatment efficiency after enhancing ANAMMOX technology. The purpose of experiment was to explore the impact effect of low C/N, put forward solving technique, attempt to establish the monitoring and evaluating system of biochemistry indexes and further improve the nitrogen and phosphorus removal function.The results showed that the temperature and the processing functions of A²/O process were closely related. And the seasonal change had some negative effect on treatment efficiency. COD removal rate was rising from 70% to 85% when temperature changed from 15℃to 25℃, and removal rate was stable when the temperature was up to 25℃. The temperature range of 25℃-30℃was the best for denitrification, and too high or too low temperature could inhibit function of nitrogen removal. In this temperature range, the removal rate of TN was about 70%; nitrification could reach to 95%. The influence of temperature variation on the phosphorus removal was limited, but the phosphorus removal could easily be affected by operation condition. So, the fluctuation of phosphorus removal was large, and average removal rate was 50%.The best range of F/M for COD remove was 0.14-0.22gBOD₅/gMLSS·d. The best range of F/M for denitrification was 0.125-0.23gBOD₅/gMLSS·d. The best range of F/M for nitrification was 0.14-0.28gBOD-5/gMLSS·d, and best range of F/M for phosphorus remove was 0.14-0.23gBOD₅/gMLSS·d. In summar, the best range of F/M for the A²/O system was 0.14-0.22gBOD₅/gMLSS·d. It was slightly higher than the design standard of A²/O. It was show that increasing F/M was an effective solution to the problems encountered in low C/N wastewater treatment system.Biochemical index of DHA、PHB、OUR and ATP could not only reflect the organic matter degradation efficency of microbe, but also could judge the organic matter degradation velocity and operation conditions of the treatment equipments The suitable range of DHA was 30-40mgTF/gTSS·h, upper limit value was 60mgTF/gTSS·h, too high or too low concentration of DHA could lower effluent quality. Temperature and routine F/M had distinct influence on the synthesis of PHB, the concentration of PHB in anaerobic tank is between 23mg/gMLSS-28mg/gMLSS, mean consumption 140mg PHB could uptake 1mg phosphorus. Normal OUR was between 7.1-13.3mgQ₂/gMLSS·h, conventional value of nitration OUR was between 0.88-2.95mgO₂/gMLSS·h, the value of OUR was correspondingly adjusted by temperature. Increase the F/M was benefit to the OUR, but high F/M would inhibit nitrification and negatively affect the function of nitrogen removal. ATP could characterize the quantity of living microbe of activated sludge, the range of ATP was between 1.14-1.86mg/gMLSS, the influence of temperature and F/M on ATP was related to growth and reproduction of microbe, the upper limit value of ATP was about 2.08mg/gMLSS. PCR-DGGE could effectively analyze the community structure variation of AOB and NOB which was the man parts of Nitrobacteria The variation of temperature could easily make the successions of Nitrobacteria The species of community was relatively abundant when the temperature was low, but the community structure was stable when the temperature was high. The dominant bacteria of AOB were AOB₂, AOB₄ and AOB₆. The chief NOB of microflora was Nitrobacter of which dominant bacteria was Nb₇, Nb₈, Nbg. And the NP₂ was the mainly of Nitrospira. Just like the effect of temperature, the man microbes of AOB were AOB₂, AOB₄ and AOB₆ when the F/M changed. But the main species of Nitrobacter were Nb₁, Nb₂, Nb₄ and Nb₇, and the Np₆ of Nitrospira, which was different with the temperature On the other hand, the results showed that F/M <0.15 BODs/gM LSS·2d was beneficial to the growth of nitrification floraEnhancing the nitrogen and phosphorus removal function of A²/O process by ANAMMOX technology was an effective way. The results showed that lowering DO in aeration tank cloud result in effective accumulation of NO₂^--N, enhance ANAMMOX function, and strengthen nitrogen removal in the system. More 15% NH₄⁺-N and more 9% TN could be removed respectively in the anoxic tank. More 7% TN could be removed in the whole system. But lowering DO had negative influence on the function of COD and TP removal, and the removal rate of COD and TP decreased 5% and 1.4% respectively.TN removal by ANAMMOX is account for 21.9% of TN removal rate in system, the reaction medium was NH₄⁺-N and NO₂^--N, and generated small amount of NO₃^--N in reaction process. The proportion of those factors was 1:1.256:0.155; the best range of pH for ANAMMOX reaction was 7.8-8.0. DO could restrict ANAMMOX, and temperature had great influence to the reaction rate The reaction rate decreased from 1.47mg/L·h to 1.175mg/L·h when temperature changed form 30.6℃to 24.6℃.The results of shocking and restoring experiment showed that the nitration function could be greatly limited by wastewater of which C/N was 3.5. The denitrification function could completely stop when C/N was 1.2, meanwhile it could result in the fast decrease of COD and TP removal, and in sludge bulking and floating sludge. Increasing reflux ratio could effectively shorten restoration time, and the removal rate of NH₄⁺-N, TN and COD could be improved 20%,7.4% and 5.4% respectively. But this method had no effect on phosphorus removal. Increasing F/M and lowering SRT could also improve the processing function of system, the removal rate of NH₄⁺-N, TN, COD and TP could be improved about 5%, 4.7%, 7.4% and 4.5% respectively. The method could also improve the bioactivities of sludge, and the nitrification OUR and nitrosification OUR could be improved about 7% and 5.7% respectively.更多还原