厌氧氨氧化反应器的启动优化和过程调控研究

发布时间：2018-05-07 19:13

本文选题：厌氧氨氧化 + 零价铁　；参考：《山东大学》2015年硕士论文

【摘要】：厌氧氨氧化工艺可在氮循环中实现“短程”现象,以亚硝态氮作电子受体直接将氨氮氧化成氮气,无需提供有机碳源和氧气,工艺流程短、运行费用低、运行调控简单,同时避免了CO2、N2O等温室气体的产生,实现了高效低耗,在可持续发展及循环经济方面具有广阔前景。但受限于菌种自身一些缺点和问题,该工艺的进一步推广及应用受到了显著影响。一是厌氧氨氧化菌的倍增时间(t1/2=ln 2/μmax)约为11天,最大生长比速率(μmax)也仅为0.065 d-1,启动耗时较长。二是厌氧氨氧化菌需要严格的生长代谢环境,如溶解氧大于0.5 mg/L时即能抑制厌氧氨氧化活性。随着认识的不断深入和研究的不断发展,研究人员已经探索设计出了一系列可用于厌氧氨氧化快速启动的方案,主要思路如下：(1)改进或构建合适的反应器,尽可能减少其中生物量的流失：(2)创造合适的培养环境和培养条件,优化其生长代谢的环境；(3)选取适宜的接种污泥,提高接种污泥的质量。本论文拟从改良培养生境和强化截留污泥能力的角度出发,对厌氧氨氧化工艺的启动优化及过程调控进行研究,以期为该工艺的推广应用提供理论支持及技术参考。一方面,通过向反应器内投加零价铁(ZVI)来强化厌氧氨氧化反应器,零价铁可促进微生物生长增殖,还可通过还原能力消耗溶解氧,创造最适生境,从而缩短厌氧氨氧化的启动用时并提高氮素去除负荷。另一方面,通过采用新型无纺布MBR,减少污泥流失,实现生物量保持,从而加速厌氧氨氧化启动,并通过生物膜的作用提高氮素去除负荷。同时针对二者存在的污泥流失和总氮去除率低问题,构建ZVI组装厌氧氨氧化反应器(下端固定海绵铁,上端固定聚酯海绵),在实现污泥截留的同时,提高总氮去除率。主要结论如下：(1) 投加零价铁(微米级零价铁mZVI、纳米级零价铁nZVI)可显著加速启动厌氧氨氧化工艺,特别是nZVI,可在84天内完成启动,用时缩短约33%。零价铁的投加可显著增加微生物在厌氧氨氧化成熟阶段的胞外聚合物分泌量,其中nZVI效果尤为显著。150天时,投加mZVI和nZVI的反应器内微生物EPS量分别达142.8和149.3 mg/g VSS。零价铁的投加还可显著促进厌氧氨氧化菌的增殖,qPCR结果显示：投加nZVI和nZVI可使厌氧氨氧化片段数由1.82×107增高至1.09×108和1.44×108 copies/ml。(2) 两种MBR均可有效减少生物量流失,运行时间内1tMBR出水SS均小于15 mg/L; nMBR出水SS均小于35 mg/L,形成附着生物膜后,其出水SS可降低至7 mg/L。使用tMBR在56天可实现厌氧氨氧化启动,但其氮素去除效率不稳定；而]MBR44天即可实现启动,随HRT的缩短,在短暂波动后即可稳定脱氮,氮去除负荷最高可达245.4 mgN/L/d。与tMBR相比,使用nMBR可形成明显生物膜,后期几乎不存在悬浮态污泥。(3) 使用新型ZVI组装反应器可在低氮素负荷条件下,16天内两反应器均实现厌氧氨氧化活性恢复。在较高污泥浓度条件下,该新型反应器特别是负载有海绵铁的R1对冬季低温和突变氮负荷均有较强的适应能力,氮素去除负荷可达1100mgN/L/d。综上,本论文的研究将为解决我国水环境中的氮素污染问题提供了新思路和新方法,并为厌氧氨氧化工艺的进一步推广应用提供理论参考和技术支持。
[Abstract]:Anaerobic ammonia oxidation process can realize "short range" phenomenon in nitrogen cycle. It can oxidize ammonia nitrogen into nitrogen directly with nitrite nitrogen as electron acceptor, without providing organic carbon source and oxygen. The process is short, operation cost is low, operation regulation is simple, CO2, N2O and other greenhouse gases are avoided, high efficiency and low consumption are realized, and sustainable development is achieved. The further popularization and application of the process have been greatly influenced by the disadvantages and problems of the bacteria. One is that the multiplication time of the anaerobic ammonia oxidizing bacteria (t1/2=ln 2/ Mu max) is about 11 days, the maximum growth ratio (max) is only 0.065 D-1, and the start time is longer. Two is anaerobic ammonia oxidation. Bacteria need strict growth and metabolic environment, such as dissolved oxygen more than 0.5 mg/L can inhibit the activity of anaerobic ammonia oxidation. With the deepening of understanding and the continuous development of research, researchers have explored a series of schemes which can be used for rapid anaerobic ammonia oxidation. The main ideas are as follows: (1) improve or build appropriate reaction. To minimize the loss of biomass: (2) create a suitable culture environment and culture conditions, optimize the environment for its growth and metabolism, and (3) select the suitable inoculation sludge to improve the quality of the inoculated sludge. This paper is to optimize the start-up of the anaerobic ammonia oxidation process from the angle of improving the cultivation of the habitat and strengthening the energy of the sludge interception. On the one hand, by adding zero valent iron (ZVI) to the reactor to strengthen the anaerobic ammonia oxidation reactor, the zero valent iron can promote the growth and proliferation of microorganism, and can also consume the dissolved oxygen by reducing the energy to create the optimum habitat, thus shortening the anaerobic condition. On the other hand, the new non-woven fabric MBR is used to reduce the sludge loss and maintain the biomass, thus accelerating the anaerobic ammonia oxidation start, and improving the nitrogen removal load through the role of the biofilm. At the same time, the sludge loss and the total nitrogen removal rate in the two cases are low, and the ZVI is constructed. The main conclusions are as follows: (1) the addition of zero valent iron (micron zero valent iron mZVI, nanoscale zero valent iron nZVI) can significantly accelerate the start-up of anammox process, especially nZVI, which can be completed within 84 days. The addition of approximately 33%. zero valent iron can significantly increase the extracellular polymer secretion of microorganism at the stage of anaerobic ammonia oxidation maturation, in which the effect of nZVI is particularly significant at.150 days. The addition of EPS in the reactor of mZVI and nZVI to 142.8 and the addition of 149.3 mg/g VSS. zero valent iron can also significantly promote the anaerobic ammonia oxidizing bacteria. Proliferation, qPCR results show that adding nZVI and nZVI can increase the number of anammox fragments from 1.82 x 107 to 1.09 * 108 and 1.44 x 108 copies/ml. (2) two MBR to reduce the loss of biomass effectively. The 1tMBR effluent SS in operation time is less than 15 mg/L, nMBR effluent SS is less than 35 mg/ L, and after the formation of an attached biofilm, the effluent can be reduced to 7 G/L. can start anaerobic ammonia oxidation at 56 days with tMBR, but its nitrogen removal efficiency is unstable, and]MBR44 days can be realized. With the shortened HRT, the nitrogen removal can be stabilized after a short wave. The maximum nitrogen removal load can reach 245.4 mgN/L/d. compared with tMBR, and nMBR can form a distinct biofilm with nMBR, and there is almost no suspended sludge in the later period. (3) using a new ZVI assembly reactor under low nitrogen load conditions, the activity of anaerobic ammonia oxidation was recovered in the two reactor in 16 days. Under the condition of high sludge concentration, the new reactor, especially the R1 loaded with spongy iron, had strong adaptability to winter low temperature and mutant nitrogen load, and the nitrogen removal load could reach 1100mgN/L/. In D., the research of this paper will provide new ideas and new methods for solving the problem of nitrogen pollution in water environment in China, and provide theoretical reference and technical support for the further popularization and application of anaerobic ammonia oxidation process.

【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

【参考文献】