以胞内储存物驱动的短程同时硝化/反硝化除磷调控机理研究

The optimal process control mode and the balanced collaborative mechanism in a variety of biochemical reactions of intracellular storage polymer (PHB) driven simultaneous nitrification/ denitrification phosphorus removal (SNDPR) via to nitrite treating low carbon municipal wastewater in the A/OLASBR (anaerobic/ oxygen limited aeration sequence biaoractor) were investigated. The good coexistence of denitrifying phosphorus accumulating organisms (DNPAOs) emploied nitrite to electron acceptor and nitrosomonus was explored also. In the process of SNDPR via to nitrite wiche PHB was as carbon source-driven power, the coupling correlation of PHB and electrochemical parameters was resolved. In order to solve the carbon source and energy consumption problems of N and P removle, the research parameters and control mode of SNDPR via to nitrite were verified in the stable operation treating low carbon municipal wastewater. In this research, it will improve the utilization rate of carbon source and ensure the high efficiency of simultaneous N and P removal under the conditions of priority for obtaining carbon in wastewater stored in the intracellular and PHB used the carbon source-driven power. Simultaneously, adopted DNPAOs emploied nitrite to electron acceptor with the meeting point of coupling nitrosation and denitrification phosphours removal, it can shorten the reaction process, simplify the reacting conditions and sequence of the nitrogen and phosphorus removal, reduce energy consumption of municipal wastewater treatment, achieve the aim of simultaneous N and P removal , save carbon and energy consumption.

构建厌氧/限氧曝气的序批式生物系统(A/OLASBR)，以碳、氮、磷比例失调的城市污水为对象，研究以胞内储存物（PHB）驱动的短程同时硝化/反硝化除磷（SNDPR）过程优化控制模式和各种生化进程平衡协同的调控机理，探索在同一反应器中以亚硝酸盐为电子受体的反硝化聚磷菌（DNPAOs）和亚硝化菌共存的适宜条件，解析以PHB为碳源驱动力的短程SNDPR过程中PHB与电化学参数之间的耦合关联性。经实际碳源偏低城市污水的稳定运行，验证研究参数和控制模式，以期解决脱氮除磷的碳源和能耗难题。申请项目拟通过优先获取污水中碳源储存于胞内，以PHB为碳源驱动力来提高碳源利用率，保证同步脱氮除磷的高去除率，同时采用以亚硝酸盐为电子受体的DNPAOs作为亚硝化和反硝化除磷耦合的契合点，简化生物脱氮除磷反应发生的条件和顺序、进一步缩短反应的途径和进程、降低城市污水处理的能耗，达到同步脱氮除磷和节省碳源及能耗的目的。

项目针对传统脱氮除磷工艺存在的缺陷、污水排放标准提高和处理工艺所需低碳可持续发展的要求，以模拟的碳源偏低城市污水为处理对象，构建厌氧/限氧曝气的序批式生物系统(A/OLASBR)，研究的以胞内储存物驱动的短程同时硝化/反硝化除磷技术（短程SNDPR），能使亚硝化和反硝化除磷过程在同一空间和时间发生，可解决传统脱氮除磷工艺中碳源争夺、污泥龄、能耗高等问题，实现“一碳两用”，适合于碳源偏低的城市污水处理。. 采用分步培养法，分别驯化亚硝化菌和以亚硝化菌为电子受体的反硝化除磷菌，然后混合于同一系统，进行两种功能菌群共存的驯化培养。在培养驯化成熟后的系统内，研究了厌氧段进水碳源和总磷浓度对PHB积累的影响，并在此基础上，提出前置曝气方式促进PHB最大化积累，来解决外碳源最大化积累为碳源驱动力PHB的问题。在后续低氧段，通过考察不同供气模式（连续曝气和间歇曝气）下，短程SNDPR过程中TP、TN、NH4+、NO2-、NO3-和PHB的变化规律，来解析厌氧段最大化积累的PHB驱动亚硝化和短程反硝化除磷过程速率平衡的有效操控条件。. 试验结果表明，分步驯化优势菌种后混合共存培养的方式，能有效实现同时亚硝化和反硝化除磷过程，成熟系统内TN去除率为83.1%，TP去除率为90.2%。进水碳源和总磷浓度与PHB的最大积累量呈正相关，且碳源浓度对PHB积累量的影响比总磷浓度的影响大。比较无前曝气时厌氧PHB最大积累量，增设前曝气运行方式可促进PHB的最大化积累。连续曝气模式下，气量为30L/h有利于短程SNDPR的稳定持续发生，其TN去除率为93.7%，TP去除率为96.4%；间歇曝气模式下，低AF值和低fIA值能为系统提供利于短程SNDPR发生的微氧环境，并均化氧化还原反应，PHB降解速率更为平稳，恒定气量为40L/h时，AF值为0.5与fIA值为24工况下短程SNDPR稳定性和效果最佳，TN去除率为91.1%，TP去除率为92.9%。. 由上述研究结果可知，厌氧段前设置前曝气的运行方式可强化PHB的最大化积累，以此段最大化积累的PHB为后续低氧段的唯一碳源驱动力，并控制其在低氧阶段均衡有效降解，可为平衡亚硝化与反硝化除磷速率创造有利条件，是实现短程硝化/反硝化除磷的关键。