外加磁场对模拟SBR处理系统微生物群落影响的研究

发布时间：2018-09-08 10:10

【摘要】：SBR反应系统的应用越来越普遍,为进一步提高其处理效率,本文提出在SBR反应体系再外加一个磁场来提高其运行性能。研究了不同磁场强度对SBR反应系统污染物降解效率的影响,采用MiSeq高通量测序技术解析了磁场条件下活性污泥微生物群落多样性变化,并运用宏基因组测序技术深入解析活性污泥微生物群落及功能变化。主要研究结果如下:(1)磁场的加入在一定程度上提高了SBR系统的运行性能,且在700GS磁场强度下效果最明显。其中,外加磁场对SBR反应系统中总氮去除效果的影响显著,在700GS时脱氮率从无磁场的65.69%提高到85.98%。外加磁场显著提高了污泥脱氢酶活性,因而也会对各种污染物的去除产生积极作用。通过对不同磁场强度下活性污泥微生物群落多样性的比较发现,700GS磁场下活性污泥微生物丰度及多样性最高。(2)实验SBR反应器中的细菌域共鉴定出14个门,主要以变形菌门(25.3%~61.5%)、拟杆菌门(18.6%~46.2%)、放线菌门(5.3%~47.2%)、酸杆菌门(0.4%~4.0%)为主。活性污泥中细菌群落结构变化与污水处理效率存在一定相关性,重要的脱氮细菌,如?-Proteobacteria的Rhodoblastus、Paracoccus,?-Proteobacteria的Alicycliphilus、Comamonas、Xenophilus、Acidovorax、Dechloromonas、Thauera,?-Proteobacteria的Desulfovibrio,以及Planctomycetes门等,在中等磁场强度尤其是700GS时,丰度最高,与脱氮效率增加有内在的联系。典型的PAOs如Acinetobacter、Pseudomonas、Propionicimonas等,在中等磁场条件下含量较高,与除磷率变化趋势相同。活性污泥中污染物降解菌含量与污染物去除率成正相关关系,外加磁场通过改变微生物群落结构影响污水处理效果。(3)选取多样性变化最显著的700GS磁场条件下的活性污泥以及对照组活性污泥进行宏基因组测序,共检测到68个门类、1773个属和3523个物种。其中,大多数属于细菌域(95.93%~95.88%),古细菌域含量0.089%~0.154%,真核域含量在3.2155%~3.3800%,病毒含量0.0158%~0.0169%。在700GS磁场下,可有效促进活性污泥宏基因组中Microgenomates、Fusobacteria、Parcubacteria、Tenericutes、Chlamydiae、Chrysiogenetes、Cyanobacteria、Planctomycete、Chordata、Microsporidia、Phaeophyceae、Glomeromycota、Blastocladiomycota、Euryarchaeota等门的生长,但会对部分门类产生抑制作用。通过分析两种活性污泥宏基因组中细菌域25个优势属丰度变化情况发现,700GS磁场可以有效促进活性污泥中Thioalkalivibrio、Azoarcus、Thaueratao、Cellulomonas、Dermacoccus、Luteipulveratus、Arsenicicoccus、Kocuria、Mycobacterium、Propionibacterium、Streptomyces、Candidatus Saccharimonas等优势属的增长。相反,也会在一定程度上抑制活性污泥中部分优势菌属的生长。(4)700GS磁场作用活性污泥并未改变宏基因组中主要KEGG功能基因的排序。两种活性污泥宏基因组中检测到的KEGG的6大类功能相关基因含量以及Carbohydrate metabolism、Overview、Amino acid metabolism、Energy metabolism、Signal transduction五个含量相对较高的子类功能基因含量排序均未变。(5)系统的脱氮率,与活性污泥宏基因组中参与氮代谢的功能基因密切相关。700GS磁场可有效促进脱氮过程相关功能基因增长,从而提高污水处理中氮的去除率。通过对活性污泥宏基因组中氮代谢相关的功能基因及其代谢通路的分析发现,反硝化相关功能基因占据优势地位。参与反硝化反应的nitrate reductase、nitrite reductase、nitric oxide reductase、nitrous-oxide reductase酶含量相关基因在700GS磁场下活性污泥宏基因组中含量高于未加磁场,参与硝化反应的ammonia monooxygenase、hydroxylamine dehydrogenase,以及参与氨化反应的nitrite reductas、ferredoxin-nitrite reductase、ferredoxin-nitrate reductase、hydroxylamine reductase相关基因含量在700GS磁场下受到不同程度的抑制作用。检测到的700GS下活性污泥宏基因组厌氧氨氧化反应的hydrazine synthase、hydrazine dehydrogenase有关基因的含量高于未加磁场,且执行厌氧氨氧化过程的浮霉菌门含量在700GS下含量是未加磁场的1.8倍,说明700GS磁场条件可以有效促进浮霉菌门的生长。
[Abstract]:The application of SBR reaction system is becoming more and more popular. In order to further improve its treatment efficiency, a magnetic field is added to SBR reaction system to improve its performance. The effect of different magnetic field intensity on the degradation efficiency of pollutants in SBR reaction system is studied. The microorganisms of activated sludge under magnetic field are analyzed by MiSeq high-throughput sequencing technology. The main results are as follows: (1) The operation performance of SBR system was improved to a certain extent by adding magnetic field, and the effect was most obvious under 700GS magnetic field. Among them, total nitrogen in SBR reaction system was affected by applied magnetic field. The removal efficiency of activated sludge increased from 65.69% without magnetic field to 85.98% at 700GS. External magnetic field significantly increased the activity of sludge dehydrogenase and therefore had a positive effect on the removal of various pollutants. Mud microbial abundance and diversity were the highest. (2) In the SBR reactor, 14 phyla were identified, mainly Proteus (25.3% ~ 61.5%), Bacteroides (18.6% ~ 46.2%), Actinomycetes (5.3% ~ 47.2%) and Acidobacterium (0.4% ~ 4.0%). Denitrifying bacteria such as?-Proteobacteria's Rodoblastus, Paracoccus,?-Proteobacteria's Alycliphilus, Comamonas, Xenophilus, Acidovorax, Dechloromonas, Thauera,?-Proteobacteria's Desulfovibrio, and Planctomycetes gates have the highest abundance at medium magnetic field strength, especially at 700GS, and are intrinsically associated with increased nitrogen removal efficiency. Typical PAOs such as Acinetobacter, Pseudomonas, Propionicimonas, etc. have higher content in medium magnetic field, and the trend of phosphorus removal rate is the same. The content of pollutant degrading bacteria in activated sludge is positively correlated with the removal rate of pollutants, and the effect of magnetic field on wastewater treatment is affected by changing the structure of microbial community. A total of 68 classes, 1773 genera and 3523 species were detected in activated sludge and control sludge under 700 GS magnetic field. Most of them belong to bacterial domain (95.93%~95.88%), Archaea domain (0.089%~0.154%), eukaryotic domain (3.2155%~3.3800%) and virus (0.0158%~0.0169%). At 700GS magnetic field, it can effectively promote the growth of microgenomes, Fusobacteria, Parcubacteria, Tenericutes, Chlamydiae, Chrysiogenetes, Cyanobacteria, Planctomycete, Chordata, Microsporidia, Phaeophyceae, Glomeromycota, Blastocladiomycota, Euryarchaeota, but inhibit the growth of some phyla. The results showed that 700GS magnetic field could effectively promote Thioalkalivibrio, Azoarcus, Thaueratao, Cellulomonas, Dermacoccus, Luteipulveratus, Arsenicicoccus, Kocuria, Mycobacterium, Propionibacterium, Streptomyces, Candid. On the contrary, the growth of some dominant bacteria in activated sludge was inhibited to some extent. (4) Activated sludge treated with 700 GS magnetic field did not change the sequence of the major KEGG functional genes in the macrogenome. (5) The denitrification rate of the system is closely related to the functional genes involved in nitrogen metabolism in the macrogenome of activated sludge. 700GS magnetic field can effectively promote the denitrification process. Through the analysis of functional genes related to nitrogen metabolism and their metabolic pathways in activated sludge macrogenome, it was found that denitrification-related functional genes occupied a dominant position. Us-oxide reductase content-related genes in the macrogenome of activated sludge under 700 GS magnetic field were higher than those without magnetic field, ammonia monooxygenase, hydroxylamine dehydrogenase, nitrite reductase, ferredoxin-nitrate reductase, hydroxylamine redu involved in nitrification Ctase-related gene content was inhibited in different degrees under 700 GS magnetic field. hydrazine synthase and hydrazine dehydrogenase-related gene content in anaerobic ammonia oxidation of activated sludge under 700 GS was higher than that without magnetic field, and the content of Phytophthora in anaerobic ammonia oxidation process was not under 700 GS. Adding 1.8 times the magnetic field indicates that 700GS magnetic field conditions can effectively promote the growth of floating mold doors.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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