短程硝化-反硝化除磷工艺调控和功能菌生态位机制解析

Short-cut nitrification and denitrifying are two unconventional technology for biological denitrification and phosphorus removal with relatively various research carried on currently. However, systematical research on the coupling mechanism of these technologes in continuous flow-single sludge system, the variation of the microbial population and the action mecahnism of functional genes are far from enough. In this research, denitrifying phosphate-accumulating organisms(DPAO) which took NO2 as electron acceptor was domasticated on the platform of an annular flow oxidation ditch reactor regarding sewage in daily life as the study object for the exploration of system quick start and stability maintenance strategy. Simultaneously, combining sequencing batch test, the study on growth kinetic parameters of nitrosomas and denitrifying phosphorus removing bacteria(DPB) which could utilize NO2 as its electron acceptor were also conducted. Properties on microbial community structure of the system and attenuation law were studied on the basis of molecular biology method as LIVE/DEAD Baclight、PCR-TGGE、FISH. The theory of ecological niche was fairly considered with the help of gene chip technology in the study on collaboration law between microbial species carrying the key functional genes. The studies above all, as a result, devote themselves in better understanding of short-cut nitrification, denitrification and the coupling mechanism of their phosphorus removal from the whole system, microbial communities and gene as three different dimensions, aiming at mitigating the contradiction in conventional nitrogen and phosphorus removal technologies and improving their theory basis.

短程硝化和反硝化除磷技术是目前研究较多的非传统生物脱氮除磷技术，但系统地对连续流单污泥系统中两种技术的耦合机制、微生物种群变化情况、各功能基因作用机制的研究较少。本项目以环形推流氧化沟反应器为平台，以实际生活污水为研究对象，驯化以NO2-为电子受体的反硝化聚磷菌，对系统快速启动和稳定维持策略进行研究，同时，结合序批试验，研究亚硝酸菌和可利用NO2-作为电子受体的反硝化除磷菌的生长动力学参数；采用LIVE/DEAD Baclight、PCR-TGGE、FISH等分子生物学手段，对系统微生物群落结构和衰减规律等特性进行深入研究；结合生态位理论，利用基因芯片技术，研究携有关键功能基因的微生物种间协作规律。通过以上研究，可从系统、微生物种群和基因三个不同层面进一步认识短程硝化、反硝化以及除磷的耦合作用机理，缓解传统生物脱氮除磷工艺矛盾，完善脱氮除磷理论。

在氮磷排放标准日益严格日益严格的环境下，同时实现污水处理的高效脱氮除磷是一必然趋势。反硝化脱氮除磷理论的提出为污水同步脱氮除磷提供了新的思路和视角。本研究搭建了一套采用环形推流氧化沟工艺的一体化污水处理反应器，对反应器的运行效能及工艺优化进行了研究；利用传统微生物技术，从污水处理系统活性污泥中分离、筛选及纯化出具有同步脱氮除磷效应的反硝化聚磷菌，通过传统鉴定法法和及 16S rDNA 序列测定，对筛选出的菌株进行了鉴定；从不同初始 pH 值（pH =3、5、7、9、11）、不同电子受体类型（硝酸盐和亚硝酸盐）、不同电子受体浓度（硝酸盐浓度从 10mg/L 到 40mg/L，亚硝酸盐浓度从 1mg/L到 4mg/L）以及不同初始接种比（0%、1%、2%、5%、10%、15%）等关键因子进行其对该菌属脱氮除磷性能的影响研究。针对目前关于反硝化除磷的研究多关注于有机物和氮磷去除效果和反硝化除磷微生物的研究，本研究以59种不同磷源模拟单一磷污染物，探讨不同形态磷对常规活性污泥（O-S活性污泥）、以硝酸盐为电子受体驯化后的活性污泥（N-S活性污泥）和以亚硝酸盐为电子受体驯化后的活性污泥（No-S活性污泥）的影响，研究几种活性污泥对不同磷源利用途径的差异、生长情况的变化、群落结构的演化、功能基因丰度的变化、酶活性影响等等，为活性污泥微生物利用NO3-、NO2-作为电子受体，提高同时脱氮除磷效果提供理论依据。