厌氧处理系统微生物群落结构与生态网络研究

发布时间：2018-06-29 16:46

本文选题：厌氧氨氧化 + 厌氧消化　；参考：《哈尔滨工业大学》2015年博士论文

【摘要】：污染物处理与资源化是当今环境工程领域的热点研究之一,它符合可持续发展的要求。厌氧氨氧化和厌氧消化是该领域重要且典型的两个厌氧微生物过程,基于这两个过程而开发的处理系统广泛应用于处理含氮废水和有机废物处理。长期以来,厌氧氨氧化处理系统存在启动缓慢这一技术瓶颈,特别是当缺乏成熟的厌氧氨氧化接种污泥时,启动过程可能长达1年以上。对于厌氧消化,传统的反应器类型(如厌氧发酵罐)虽然结构简单、工艺成本低,但是受污泥截留效率的限制,往往只能在较低有机负荷(5kg-COD/(m3?d))条件下运行。近年来,生活污水初滤过程逐渐受到重视,被认为可以替代污水厂中的初沉池并减轻后续工艺(如膜处理工艺)的压力。目前尚无生活污水初滤产物的厌氧消化方面的研究报道。为了解决厌氧氨氧化反应器启动缓慢和传统厌氧消化反应器无法在高有机负荷条件下运行的问题,论文通过运行不同类型的厌氧处理系统并借助分子生物学分析方法,研究了厌氧氨氧化处理系统的启动策略和生活污水初滤产物的高负荷条件厌氧消化效能,通过构建厌氧氨氧化以及厌氧消化的微生物生态网络,分析了上述两个典型厌氧处理系统中微生物群落的演替规律。研究发现,反应器类型和接种污泥类型均对厌氧氨氧化的启动有重要影响。对比了利用序批式反应器(SBR)和厌氧膜生物反应器(An MBR)启动厌氧氨氧化的速度。SBR反应器接种好氧颗粒污泥,在147天内使总氮负荷从0.03kg-N/(m3?d)提升到0.4 kg-N/(m3?d),但是总氮去除率较低(~50%),启动效果不理想。通过连接外置式微滤膜组件形成An MBR,总氮负荷在6个月内可被提升到0.8 kg-N/(m3?d)且总氮去除率维持在70%~80%,启动成功。另一个An MBR接种污水厂缺氧段活性污泥,在8个月内实现总氮负荷0.7 kg-N/(m3?d),总氮去除率为30%~40%。此外,研究了接种污泥对厌氧氨氧化反应器启动效率的影响。结果表明,接种污泥的群落越均匀、初始厌氧氨氧化菌的含量越高(106基因拷贝数/m L)越有利于反应器快速启动。分子生物学分析结果表明,反应器中厌氧氨氧化菌Kuenenia stuttgartiensis是优势菌种,其在启动最快的反应器中的数量在6个月内提高了3个数量级(109基因拷贝数/m L)。生活污水初滤产物的主要成分是纤维素。在55oC和35oC条件下分别运行厌氧发酵罐长达656天,研究发现在35oC条件下反应器可以在有机负荷为14kg-COD/(m3?d)的范围内稳定运行,甲烷产率达到150Nm L/g COD,但是进一步提升有机负荷导致甲烷产率大幅降低至50Nm L/g COD,且反应器严重酸化。在55oC条件下反应器可在有机负荷高达22kg-COD/(m3?d)的条件下稳定运行,甲烷产率达120NmL/g COD且反应器未酸化。基于16S r DNA的454测序结果表明,55oC条件下反应器的最优势细菌菌属是OP9菌门下的Caldatribacterium saccharofermentans菌属,古细菌为Methanothermobacter菌属;35oC条件下的最优势细菌是Bacteroides菌属,古细菌为Methanosaeta菌属。β-多样性结果表明,在55oC条件下反应器的菌群对有机负荷的提升比在35oC条件下更敏感。为了更直观的表现厌氧菌群的组成特点,构建了厌氧氨氧化以及厌氧消化的微生物生态网络。结果表明,Kuenenia stuttgartiensis菌在厌氧氨氧化微生物网络中占据最重要的位置。而对于厌氧消化系统而言,55oC条件下的微生物生态网络遗传稳定性高于35oC条件下的微生物生态网络。这一现象说明,当有机负荷逐渐提升时,55oC反应器群落中关键功能菌群演替的同步性优于35oC反应器群落,因此,前者在面对不断提高的有机负荷时仍表现出较强的稳定性。此外,为了考察微生物生态网络在空间维度上的演变规律,以相同接种污泥在35oC条件下运行另外两个厌氧处理系统:厌氧动态膜生物反应器(An DMBR)和升流式厌氧污泥床(UASB)。研究发现,网络在空间维度上的演变受空间范围的影响,同一空间内的网络均匀度高于不同空间的网络均匀度。从整体上看,微生物生态网络在空间维度上的变化比在短时间维度上的变化更明显。
[Abstract]:Treatment and resource utilization of pollutants is one of the hot topics in the field of environmental engineering today. It is in line with the requirements of sustainable development. Anaerobic ammonia oxidation and anaerobic digestion are two important and typical anaerobic microbial processes in this field. The treatment systems developed based on these two processes are widely used in the treatment of nitrogen and organic waste. For a long time, the anaerobic ammonia oxidation treatment system has a bottleneck to start slowly. Especially when the anaerobic ammonia oxidation is lacking, the start-up process may be over 1 years. For anaerobic digestion, the traditional reactor type, such as anaerobic fermentation tank, is simple and low in process cost, but the efficiency of sludge interception is low. Limited, usually only under the condition of low organic load (5kg-COD/ (M3? D)). In recent years, the initial filtration process of domestic sewage has been paid more and more attention. It is considered to be able to replace the initial sedimentation tank in the sewage plant and reduce the pressure of the subsequent process (such as membrane treatment). In order to understand the slow start of anaerobic ammonia oxidation reactor and the problem that the traditional anaerobic digestion reactor can not operate under the high organic load condition, the starting strategy of the anaerobic ammonia oxidation treatment system and the high negative effect of the sewage initial filtration product are studied by running different types of anaerobic treatment system and using the molecular biological analysis method. Under the condition of anaerobic digestion, the succession law of microbial communities in the two typical anaerobic treatment systems was analyzed by constructing an anaerobic ammonia oxidation and anaerobic digestion microbial ecological network. The study found that the type of reactor and the type of inoculated sludge all had important effects on the start-up of anammox. The SBR and the anaerobic membrane bioreactor (An MBR) started the anaerobic ammonia oxidation speed.SBR reactor to inoculate aerobic granular sludge, and increased the total nitrogen load from 0.03kg-N/ (M3? D) to 0.4 kg-N/ (M3? D) in 147 days, but the total nitrogen removal rate was low (~50%), and the effect was not ideal. The total nitrogen was negative by connecting the external microfiltration membrane module. The charge could be raised to 0.8 kg-N/ (M3? D) within 6 months and the total nitrogen removal rate was maintained at 70%~80%, and the other An MBR was inoculated with the activated sludge from the anoxic section of the sewage plant. The total nitrogen load was 0.7 kg-N/ (M3 d) and the total nitrogen removal rate was 30%~40%. in 8 months. The effect of the inoculation sludge on the start-up efficiency of the anaerobic ammonia oxidation reactor was studied. The results showed that the more homogeneous the inoculated sludge community was, the higher the initial anammox content (106 gene copy number /m L) was, the more conducive to the quick start of the reactor. The results of molecular biological analysis showed that the anaerobic ammonia oxidizing bacteria Kuenenia stuttgartiensis was the dominant strain in the reactor, and its number in the fastest starting reactor was within 6 months. 3 orders of magnitude (109 gene copy number /m L) were improved. Cellulose was the main component of the initial filtration product of domestic sewage. The anaerobic fermentation tank was run for 656 days under the conditions of 55oC and 35oC. It was found that the reactor could operate steadily in the range of 14kg-COD/ (M3? D) under the condition of 35oC, and the methane yield reached 150Nm L/g COD. It is to further increase the organic load to reduce the methane yield to 50Nm L/g COD, and the reactor is seriously acidified. Under the condition of 55oC, the reactor can operate stably under the condition of organic load up to 22kg-COD/ (M3? D), the methane yield is 120NmL/g COD and the reactor is not acidified. The 454 sequencing results based on 16S R DNA show that the reaction is under the condition of reaction. The most dominant bacteria genus of the apparatus is Caldatribacterium saccharofermentans under the gate of OP9 bacteria, and the palaeobacteria belong to the genus Methanothermobacter; the most dominant bacteria under the 35oC condition are Bacteroides bacteria, and the palaeobacteria are Methanosaeta bacteria. The results of beta diversity indicate that the increase of organic load in the reactor under 55oC conditions is 3. 5oC is more sensitive. In order to show the composition of anaerobes more intuitively, a microbial ecological network for anaerobic ammonia oxidation and anaerobic digestion is constructed. The results show that Kuenenia stuttgartiensis bacteria occupy the most important position in the anaerobic ammonia oxidation microbial network. For anaerobic digestion system, the microorganism under the condition of 55oC is microbiological. The genetic stability of the ecological network is higher than the microbial ecological network under the 35oC condition. This phenomenon shows that when the organic load is gradually increased, the synchronization of the key functional groups in the 55oC reactor community is better than that of the 35oC reactor community. Therefore, the former still exhibits strong stability in the face of the increasing organic load. In order to investigate the evolution of microbial ecological network in the spatial dimension, two other anaerobic treatment systems were operated under the same inoculation sludge under 35oC conditions: anaerobic dynamic membrane bioreactor (An DMBR) and upflow anaerobic sludge bed (UASB). The study found that the evolution of the network in the space dimension was influenced by the space range, the same space. The network uniformity in the network is higher than the network uniformity in different spaces. As a whole, the changes in the spatial dimension of the microbial ecological network are more obvious than that in the short time dimension.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：X703.1

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