基于生物相分离与循环相结合的ABR-MBR一体化工艺反硝化除磷耦合调控机制研究

A combined process of high efficient Anaerobic Baffled Reactor(ABR) with Membrane biological Reactor(MBR) which is of high efficient biomass retention ability as a new multi-functional coupling integrated process is proposed here for denitrifying phosphorus removal based on the microbial phase seperation and circulation and as a way of inner carbon supply and Nitrosation. A series conventional and advanced microbiologial analytical methods such as the Denaturing Gradient Gel Electrophoresis ( PCR-DGGE ) and Fluorescence In Situ Hybridization ( FISH ) will be applied for the following study, including: (1)the mechanism of high quality C-source supply and its effective utilization, (2) synergu mechanism of biomass phase separation and circulation, the dynamic profile of dominant biomass population, and (3) the key coupling mechanism of between Nitrosation in MBR and denitrifying phosphorus removal in ABR, in order to reveal the biological synergy mechanism between bio-phase separation, Nitrosation and utilization of denitrifying phosphorus removal bacteria(DPB) for obtaining high efficient and stable denitrifying phosphorus removal, and finally, the key operational tactics and dynamic control model for coupling high quality C-source supply, Nitrosation and denitrifying phosphorus removal is aimed to be proposed.

本研究将高效ABR与具有高截留分离效能的MBR工艺的有机组合，构建基于生物相分离和循环的、以优质内碳源提供和亚硝化为途径的多功能耦合联动的反硝化除磷一体化新工艺。研究中充分利用常规和聚合酶链式反应-变性梯度凝胶电泳（PCR-DGGE）和荧光原位杂交（FISH）等技术深入开展：（1）优质碳源提供及其有效利用的机制研究、生物相分离与循环微生物种群生物协同机制研究；（2）优势微生物菌群数量动态变化规律研究；（3）MBR亚硝化和ABR反硝化除磷耦合联动的关键机制研究，以获得实现稳定高效亚硝化和反硝化除磷的运行机制、系统中生物相分离与反硝化除磷菌对底物利用的生物协同机制，并建立优质碳源提供、亚硝化和反硝化除磷等过程的耦合联动机制，构建基于生物相分离条件下动态循环耦合系统运行的关键技术条件。

本项目将高效ABR与具有高生物截留功能的MBR进行有机组合，构建了基于优质内碳源提供和亚硝化为途径的多功能耦合联动反硝化除磷一体化新工艺。通过批次实验、连续流小试实验，同时借助高通量测序等分子生物学手段，按照项目既定的研究计划和研究内容，逐步完成了新工艺中反硝化除磷优质碳源供给及其有效利用实现机制、MBR中短程硝化实现及混合液回流循环至ABR点位优化控制、耦合工艺实现短程硝化和反硝化除磷联动机制和转化机理等研究内容，确立了基于微生物相分离条件下实现低耗高效短程硝化和反硝化除耦合运行的关键运行参数和控制策略。主要研究结果有：优质碳源在ABR中的浓度变化规律受进水容积负荷影响显著，乙酸是优质碳源的主要组成（占51-60%）；长期的低DO（＜0.5 mg·L-1）运行使得Nitrospira类NOB富集，不利于MBR中亚硝酸盐的积累，而高DO浓度（2.5~3.5 mg·L-1）并逐渐缩短SRT是MBR中实现良好亚硝化的关键；硝化液回流比是实现ABR-MBR耦合工艺脱氮除磷联动运行的关键参数；在进水容积负荷为0.9kg/（m3·d）、回流比为200%的条件下，ABR-MBR耦合工艺对COD、TN和TP的平均去除率分别为92%、63%和65%；基于高通量测序结果发现，Thauera菌属的成功富集（从2%提升至47.5%）亦是实现反硝化除磷的关键。本项目为氮磷去除新途径的探索、低耗高效处理污水处理新工艺的开发提供了支撑。