【作者】 高范；

【导师】 张捍民；

【作者基本信息】 大连理工大学 ， 环境工程， 2013， 博士

【摘要】 随着传统的硝化-反硝化生物脱氮工艺已不能满足低C/N比城市污水脱氮处理的要求,近年来以厌氧氨氧化技术为核心的生物脱氮工艺已逐渐成为污水处理领域研究的热点。由于厌氧氨氧化菌对有机物、温度和溶解氧等环境因素非常敏感,并且厌氧氨氧化菌的倍增时间较长,因此探索研究厌氧氨氧化菌应用的有效方式成为了其工业化应用的关键问题。目前,以厌氧氨氧化工艺为核心的组合工艺(SHARON-ANAMMOX工艺、Canon工艺等)已经在污泥消化液、畜禽养殖废水、垃圾渗滤液等高氨氮废水处理中得到广泛应用。本文旨在针对低碳氮比城市污水设计以厌氧处理为核心的低能耗城市污水处理工艺,重点考察基于厌氧水解-硝化-反硝化／厌氧氨氧化技术(Denitrification and Anammox, Den-Anammox)的一体式城市污水脱氮工艺的可行性。并且对Den-Anammox反应的操作条件、碳氮处理性能和微生物菌群变化进行了详细地探索分析。论文取得了一些创新研究成果,主要包括以下几点：(1)厌氧水解反应可以作为以厌氧处理为核心的低能耗城市污水处理工艺的脱碳预处理过程,实现部分COD的脱除同时产生挥发性脂肪酸(VFA),为异养反硝化反应提供有机碳源。厌氧生物反应的反应级数近似为2级,厌氧水解反应的最大COD脱除率为75%,基质的去除主要发生在反应的前3h,并且在第2hVFA积累达到量最大。本实验中厌氧水解反应产生的VFA主要是以乙酸、丙酸和丁酸为主,前两者占VFA总量的95%以上。FISH (fluorescence in situ hybridization)结果显示产酸菌和产甲烷菌的比例分别为39.7%和46.5%。(2)异养反硝化细菌与厌氧氨氧化菌可以实现协同脱氮,Den-Anammox系统的最优氮基质为氨氮和硝酸氮。FISH结果显示基于亚硝酸盐的Den-Anammox系统中的优势菌种为厌氧氨氧化菌,比例为84%,而基于硝酸盐的Den-Anammox系统中优势菌种为异养反硝化细菌和厌氧氨氧化菌,其中厌氧氨氧化菌的比例为65%。与基于亚硝酸盐的Den-Anammox系统相比,基于硝酸盐的Den-Anammox系统具有更好的碳氮综合脱除性能,并且具有更强的有机物耐受能力和低温适应能力。基于亚硝酸盐的Den-Anammox系统的氮去除途径以厌氧氨氧化反应为主,最优COD:NO2--N:NH4+-N为0.6：1.26：1和0.8：1.33：1；基于硝酸盐的Den-Anammox系统的氮去除途径主要为Den-Anammox反应,最优COD:NO3--N:NH4+-N为10：7：6。(3)成功启动了一体式厌氧水解-硝化-反硝化／厌氧氨氧化反应器,室温(25℃)下反应器的总氮和COD平均去除率分别为89.9%和91.5%,并且与传统的硝化-反硝化工艺相比,该工艺节省了能源消耗,减少了温室气体的排放(C02)。当COD/NO3--N为0.94-1.69时,成功实现了短程异养反硝化细菌和厌氧氨氧化菌的协同脱氮,Den-Anammox反应的最大氨氮去除率和总氮去除率分别为97.6%和93.8%。根据生物反应计量学原理分析,Den-Anammox反应对于一体式反应器的氮去除贡献百分比为70%以上。DGGE (denaturing gradient gel electrophoresis)和基因测序结果显示,经过175天后Den-Anammox池中的优势菌群由单一的厌氧氨氧化菌变成了异养反硝化细菌和厌氧氨氧化菌；并且FISH结果显示厌氧氨氧化菌的比例由89%下降到了58%。(4)为了探索厌氧氨氧化技术实际应用的新方式,本实验利用厌氧连续搅拌反应器(CSTR)成功培养了blank-anammox菌颗粒、Fe-anammox菌颗粒和Fe3O4-anammox菌颗粒,三种颗粒的最大特定厌氧氨氧化活性(SAA)值分别为0.205kgN-kgVSS-1d-1、0.24kgN-kgVSS-1d-1和0.239kgN-kgVSS-1d-1,最大颗粒粒径[d(0.5)]分别为602.8μm (第72天)、417.3μm (第39天)和988.5μm(第72天),形成方式分别为ECP-bonding模型、ions-bonding模型和ions-bonding模型。实验得到厌氧氨氧化菌生长的最优ORP为205-209mV,并且其分泌的QS物质为十二酰基高丝胺酸内酯。实验结果表明以Fe3O4为内核的厌氧氨氧化颗粒更稳定,加入Fe3O4可以实现厌氧氨氧化菌的快速稳定颗粒化。更多还原

【Abstract】 Recently, the novel nitrogen reomoval technologies based on anammox reaction have been the research focus in wastewater treatment due to that the tranditional nitrification-denitrification process does not meet the demand of low C/N ratio municipal sewage treatment. However, anammox activity is easlily inhibited by the environmental factors of organics, temperature, DO and etc., and the doulbe time of anammox bacteria is long (11d). Hence, the development of combined process based on anammox reaction is a key problem in the industrial application of anammox reaction. At present, some combined processes based on anammox reaction, such as SHARON-ANAMMOX process and CANON process, have been utilized to treat sludge digestion liquid, aquaculture wastewater and landfill leachate. In this study, a low-energy anaerobic wastewater treatment technology was designed to treat low C/N municipal sewage. We mainly studied the feasibility of the intergated anaerobic hydrolysis (A)-nitrification (O)-Den-Anammox (A) bioreactor. The operation condition, carbon-nitrogen removal performance and microbial community of the A/O/A bioreactor were in detail studied. The main research achievements of this study have been obtained as follows:(1) Anerobic hydrolysis reaction could be utilized as the carbon-removal pretreatment process of low-energy anaerobic sewage treatment combination process, which could remove the most organics of wastewater and produce VFA as the organic carbon source of heterotrophic denitrification. The anaerobic reaction serie was2. The maximum COD removal rate of anaerobic hydrolysis reaction arrived to75%, and the substrate removal was achieved in the initial3hours of reaction. The maximum accumulation of VFA appeared in the2nd h. In this study, the produced VFA mainly included acetic acid, propionic acid and butyric acid. The content of acetic acid and propionic acid in VFA arrived to above95%. FISH (fluorescence in situ hybridization) results showed that the ratios of acid-forming bacteria and methanogens in the reactor were39.7%and46.5%, respectively.(2) The nitrogen removal could be achieved by the synergistic effect of heterotrophic denitrifying bacteria and anammox bacteria. The optimum nitrogen substrate of Den-Anammox system was ammonia and nitrate. FISH results showed that the preponderant bacteria of Den-Anammox system based on nitrite was anammox bacteria and the ratio of anammox bacteria was84%; The preponderant bacteria of Den-Anammox system based on nitrate were heterotrophic denitrifying bacteria and anammox bacteria, and the ratio of anammox bacteria was65%. Compared with Den-Anammox system based on nitrite, the Den-Anammox system based on nitrate had better carbon-nitrogen removal performance and better resistance ability for organics and low temperature. The main nitrogen removal approach of Den-Anammox system based on nitrite was anammox reaction and the optimum influent COD:NO2--N:NH4+-N ratios were0.6:1.26:1and0.8:1.33:1. The main nitrogen removal approach of Den-Anammox based on nitrate was heterotrophic partial denitrification1-anammox reaction and the optimum influent COD:NO3--N:NH4+-N ratio was10:7:6.(3) In this study, an integated anaerobic hydrolysis (A)/nitrification (O)/Den-Anammox (A) bioreactor was successfully started up under room temperature (25℃). The TN (total nitrogen) and COD removal rates of bioreactor were89.9%and91.5%, respectively. Compared with the tranditional nitrification-denitrification process, the integrated A/O/A bioreactor could save energy source consumption and reduce greenhouse gas emission. Under the COD/NO3-N of0.94-1.69, the synergistic effect of heterotrophic denitrifying bacteria and anammox bacteria was achieved in the A/O/A bioreactor. The maximum ammonimum and TN removal rates of Den-Anammox reaction were97.6%and93.8%, respectively. According to biological reaction metrology theory, the nitrogen removal contribution percentage of Den-Anammox reaction was above70%. DGGE (denaturing gradient gel electrophoresis) and gene sequencing results showed that the optimum microbial community of Den-Anammox pool changed from single anammox bacterium to heterotrophic denitrifying bacterium and anammox bacterium through175-day running. And FISH results showed that the ratio of anammox bacteria declined from89%down to58%.(4) In order to explore new application ways of anammox, three different anammox granules including blank-anammox granule, Fe-anammox granule and Fe3O4-anammox granule were successfully obtained by anaerobic continuously stirred tank reactor (CSTR). The maximum SAAs of there anammox granlues were0.205kgN·kgVSS-d-1,0.24kgN·kgVSS-d-1and0.239kgN·kgVSS-1d-1, respectively. The maximum granlue rizes [d(0.5)] of three anammox granules were602.8μm (the72nd day),417.3μm (the39th day) and988.5μm (the72nd day), respectively. The forming models of blank-anammox granule, Fe-anammox granule and Fe304-anammox granule were ECP-bonding model, ions-bonding model and ions-bonding model, respectively. The experimental results showed that the optimum ORP of anammox bacteria was205-209mV and QS matter that was produced by anammox bacteria was N-dodecanoyl homoserine lactone. The experimental results showed that Fe3O4-anammox granule was steadier than blank-anammox granule and Fe-anammox granule. The addition of Fe3O4in the reactor was helpful to achieve the quick and steady granulation of anammox bacteria.更多还原