| 题名 | 典型A2/O工艺污泥膨胀的微生态效应与调控研究 |
| 作者 | 王娟 |
| 学位类别 | 博士 |
| 答辩日期 | 2014-11 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 杨敏 |
| 关键词 | 丝状菌污泥膨胀 Candidatus Microthrix parvicella 种群动态 功能群落结构 污泥膨胀控制技术，Filamentous sludge bulking, Candidatus Microthrix parvicella, Bacterial community dynamics, Microbial functional structure,bulking control technique |
| 其他题名 | Study on the impact of sludge bulking on bacterial population in typical A2/O system and the control technique |
| 学位专业 | 环境工程 |
| 中文摘要 |
生物脱氮除磷工艺是消除水体富营养化的有效方法，广泛应用于城市污水处理系统中。然而由于丝状菌过量繁殖所引起的膨胀问题成为了影响生物脱氮 除磷工艺正常运行最为普遍且最为棘手的难题，一旦发生系统难以恢复且恢复时间较长。保障活性污泥体系的稳定运行一直是污水处理努力的主要方向之一。因此， 开展典型污水处理系统生物脱氮除磷工艺污泥膨胀的微生物生态机制与调控技术研究对于提高污水处理运行管理水平，减少污染物排放有着十分重要的现实意义。 本研究以常年发生污泥膨胀问题的北方典型生物脱氮除磷A2/O工艺和倒置A2/O工艺为研究对象，进行了长达四年的跟踪调查研究。包括导致污泥膨胀的优势 丝状菌特征和演替规律以及整体微生物群落结构的动态变化规律，特别是掌握污泥膨胀对重要功能种群的影响。深入理解污泥膨胀系统中微生态平衡与失衡的原因， 及对工艺运行效果的影响。并针对两个工艺的污泥膨胀问题，建立污泥膨胀的调控机制。 主要研究成果归纳如下: 本文首先分析了四年间污泥膨胀体积指数（SVI）的变化情况，发现温度与SVI的变化呈现明显的负相关，并总结出了污泥膨胀的周期性变化。通过对污染物去 除情况的整体分析，发现污泥膨胀对化学需氧量（COD）、磷的去除效果并没有明显的影响，而出水中NH4+-N、NO2-N和NO3-N的浓度则出现了较 大的波动。 为了了解丝状菌的动态变化规律及对污泥性状的影响，对完整膨胀周期丝状菌丰度和优势丝状菌种类的交替变化规律进行了研究。显微镜镜检的结果表明污泥膨胀期 间大量丝状菌从污泥絮体中伸出，使得污泥絮体结构被破坏。在非膨胀期，丝状菌的主要类型为Type 0092和Type 0041。随着SVI的升高，丝状菌的丰度从1级（few）上升到5级（abundant） ， Candidatus Microthrix parvicella成为了优势的丝状菌。并且丝状菌的形态的不同对污泥沉降性的影响也不同。 丝状菌的大量繁殖可能会对功能种群的存在造成影响，从而引起处理系统对污染物的去除效果产生变化。 通过利用细菌16s rRNA克隆文库的方法对膨胀周期的种群结构的分析结果表明，丝状菌“Candidatus Microthrix parvicella”的大量繁殖导致污泥中的优势种群从变形菌门转变为了放线菌门，并且伴随着其中主要细菌β-变形菌门数量的显著降低。非膨胀期重要聚 磷菌“Candidatus Accumulibacter phosphatis”种群出现了大量的流失，然而除磷的效果并未受到影响,奈瑟氏染色结果表明大量的聚磷颗粒可以在Candidatus Microthrix parvicella中发现，因此其可能在污泥膨胀期对除磷做出了贡献。其他重要的功能菌AOB (Nitrosomonas), NOB (Nitrospira)和反硝化菌 (Thauera)也已经无法在污泥膨胀最为严重的时期检测到。出水中NH4-N和NO2-N的含量出现了显著的积累。 通过取消厌氧区，将倒置A2/O工艺改为A/O即缺氧区/好氧区；将A2/O工艺的污泥负荷控制在0.1 kg BOD5/kg MLSS/d以上，均可有效的抑制Candidatus Microthrix parvicella的过度繁殖，将丝状菌的丰度控制在3级以下。并且重要的功能细菌都可以再次被检测到。 |
| 英文摘要 | Biological nitrogen and phosphorus removal process is an effective method to eliminate the water eutrophication and is widely used for wastewater treatment. Sludge bulking, with the overgrowth of filamentous bacteria as the main reason, is a frequently encountered problem in waste water treatment plants. The recovery of the treatment system to the normal state was always difficult and requires a long period. More efforts were made in order to secure the stability of activated sludge processes. Therefore, study on the microbial ecosystem in activated sludge and control strategy has great significant in operational management of wastewater treatment plants and pollution reduction. In this study, the two parallel biological nitrogen and phosphorus removal processes (conventional and inverted A2/O processes) in a plant, which have been experiencing serious sludge bulking, was continuously monitored over four years to tracked the filament levels and determine the potential impacts of sludge bulking on the bacterial community structures as well as the relevant bacteria. These results could provide useful information for further analysis on the ecological balance or unbalance and understand the influence on the performance of two processes. The control strategies have been found and establish finally. The main results are summarized as follows: The changes of SVI values in four years indicated that SVI has a significant negative correlation with temperature. The cyclical variation of sludge bulking has also been found. The functions of phosphorus removal as well as COD removal were not decrease. However, the effluent concentrations of NH4+-N、NO2-N and NO3-N fluctuated during sludge bulking period. To better understand the dynamic changes of filamentous bacteria and bacterial community structures under different sludge conditions, we tracked the filament levels as well as the dominant filamentous bacteria over the period covering a whole cycle of the sludge bulking event. The microscopic examination of sludge samples showed that a large number of extended filaments stretching out from the flocs. A low level of filament abundant was observed during non-bulking period, with type 0092 and 0042 as the dominant filamentous bacteria. With the increase of the SVI, the filament abundance increased from 1 (few) to 5 (abundant), with Candidatus Microthrix parvicella becoming the dominant filamentous bacteria. The overgrowth of filamentous bacteria may lead to the exclusion of functional of functional bacteria and thus influence on the nutrient removal performance. Sludge bulking resulted in significant shift in bacterial compositions from Proteobacteria dominant to Actinobacteria dominant, characterized by the significant present of filamentous “Candidatus Microthrix parvicella” and decrease of the dominant Betaproteobacterial population.The phosphorus removal efficiency was not adversely affected by the significant loss of the “Candidatus Accumulibacter phosphatis”, which should have played a key role in phosphorus removal. Neisser staining revealed the presence of large polyphosphate granules in “Candidatus Microthrix parvicella”, suggesting that this microbial group might have been responsible for phosphorus removal during sludge bulking period when “Candidatus Accumulibacter phosphatis” was excluded from the systems. The other important relevant bacterial population including AOB (Nitrosomonas), NOB (Nitrospira) and denitrifying bacteria (Thauera) were obsent under serious bulking. Accumulation of nitrite and ammonia was observed during serious bulking. The excessive proliferation of Candidatus Microthrix parvicella could be controlled after the inverted A2/O process was changed to A/O and the sludge loading of A2/O process was increased to 0.1 kg BOD5/kg MLSS/d. The filament abundance kept lower than 3 (common). The relevant bacteria could be detected in two processes. |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/34514]  |
| 专题 | 生态环境研究中心_环境水质学国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 王娟. 典型A2/O工艺污泥膨胀的微生态效应与调控研究[D]. 北京. 中国科学院研究生院. 2014. |
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