【作者】 路青；

【导师】 华兆哲；

【作者基本信息】 江南大学 ， 环境工程， 2009， 硕士

【摘要】 对于生化性较差的或高浓度含氮废水,传统生物脱氮工艺处理成本较高。目前国内外对低碳氮比(C/N)废水处理技术的发展趋势是采用厌氧氨氧化(Anaerobic ammonium oxidation,Anammox)技术。但要将这项技术推向应用,必须要解决Anammox菌的菌种来源和菌体持留等问题。本论文在总结前人对Anammox研究成果的基础上,首先比较了不同普通污泥源对Anammox反应器启动效能,选出最佳污泥源。在此基础上,在膜生物反应器(Membrane Bioreactor,MBR)中,研究了其运行特性及运行过程中微生物群落结构及相对数量的变化,并研究了Anammox过程中MBR的最佳工况条件。主要研究内容如下:(1) R1、R2、R3三个反应器中分别接种好氧污泥、厌氧颗粒污泥、厌氧消化污泥,经过2-3个月的运行,均获得了具有Anammox活性的富集培养物。其中R1、R2、R3中总氮去除率分别达到76 %、82 %和80 %;出水污泥浓度分别为1.34 gSS/d、0.42 gSS/d、0.95gSS/d;污泥体积指数则分别为23.23 ml/gSS、11.11 ml/gSS和19.38 ml/gSS;三个反应器稳定运行所消耗的时间关系为R3<R2<R1。就总体而言,厌氧颗粒污泥是富集Anammmox菌的最适污泥源。(2) MBR运行过程中,污泥VS/TS由初始的0.66提高到0.77,说明体系中出现了适应环境的菌群;MBR稳定运行后,Anammox颗粒污泥粒径主要集中在0.2-1mm,实验证明了颗粒污泥是Anammox功能的重要承载者;总氮容积负荷达0.245 g/(L.d),总氮去除率约80 %,NH4+-N和NO-2-N去除率分别为81 %、91 %。MBR运行初期,由异养菌等菌体自溶造成膜污染严重,当Anammox成为主导反应时,由Anammox微生物生长造成的膜污染远远小于MBR运行初期。(3) MBR抗水力负荷实验表明,水力停留时间(HRT)由14 h缩短至7.9 h时, MBR能稳定运行,NH4+-N、NO2--N去除率分别保持在75 %、85 %;温度在30-35℃、pH值为7-8,Anammox活性较高;上升流速在1.8-2.3 m/h时,MBR运行状况良好;从氮素去除情况、运行成本、操作的简便性综合来看,较为合适的操作方式为:进水0.55 h,循环5 h,沉降0.3 h,出水0.15 h。(4)扫描电镜(SEM)实验发现,接种污泥以杆状菌为主,有少量的丝状菌和球菌;Anammox污泥主要是由球菌和杆菌组成。T-RFLP实验证实,Anammox菌富集前后微生物群落结构和相对数量发生了明显变化,运行后整个反应器中适应Anammox运行方式的菌种增殖较多,种类丰富,包括planctomyce、pirellula、gemmata、pseudomonas。更多还原

【Abstract】 For the traditional biological nitrogen removal technology, it results expensive in those wastewaters with low biodegradable matter and high nitrogen concentrations. Nowadays the trend in development of treating wastewater with lower ratio of carbon to nitrogen is anaerobic ammonium oxidation(Anammox) process. In order to put it into practical use, Anammox inocula must be achieved and the biomass must be hold inside the reactor. Based on the summarizing the results of previous studies on Anammox, the influence of different sludges on the efficiency of Anammox process was studied in this paper. On the basis of those study, the operation characterictics and microbial community distribution of Anammox in a membrane bioreactor was analysed. The best operation of MBR in the Anammox process was also studied in this studied. The main results were as follows:(1) After 2-3 months of incubation, The enrichment of Anammox strains from the conventional sludge such as aerobic sludge, anaerobic granular sludge and anaerobic digestion sludge are observed in the R1, R2, R3; The removal rate of ammonium, nitrite and total nitrogen were 82 %, 92 %, 91 %; The concentration of effluent sludge were 1.34 gSS/d, 0.42 gSS/d, 0.95gSS/d; The volume index of sludge were 23.23 ml/gSS, 11.11 ml /gSS and 19.38 ml/gSS; Judged by the start-up time, R1was the shortest, followed by R2 and R3.(2) The VS/TS was changed from 0.67 to 0.77 during the Anammox process in MBR; At the end of the anammox reactor operation, the size of Anammox granular sludge was mainly concentrated in 0.2-1mm, experiment demonstrated that granular sludge played an important role in the Anammox process; and the nitrogen-loading rate amounted to 0.245 kgTN/(m3.d), and the removal efficiency of total nitrogen, ammonia and nitrite was 80%, 81%, 91 %, respectively. Cell lysis from heterotrophs was proposed to be one key factor influencing the membrane fouling in the first days, and the first days was remarkably higher than that the period of Anammox bacteria dominated the microbial community in the reactor.(3) During the hydraulic shock text, the HRT of MBR was gradually shorted from 14 to 7.9 h, the NH4+-N and NO2--N removal efficiencies were stable at about 75% and 85%, respectively. Anammox activities were good when temperature was 30-35℃and pH was 7-8. The optimal ascend velocity of flow is 1.8-2.3 m/h in this study. Consideration of nitrogen removal, operating costs, the simplicity of operation, the optimal operation mode was that the reactor was operated in cycles of 6 h , fed for 0.55 h, mixed for 5 h, settlement for 0.3 h, draw for 0.15 h.(4) The photographs showed that the seeding sludge were mostly rod bacteria while Anammox sludge was mostly spherical and rod in shape. Based on terminal restriction fragment length polymorphism (T-RFLP) analysis, the composition and relative populations of the microbial community changed obviously in association with the enrich of Anammmox. The enrichment of Anammox strains such as planctomyce, pirellula, gemmata, pseudomonas were found after enrichment in MBR.更多还原