基于微生物群落结构解析不同C/N对雌激素去除的影响研究

Steroid estrogen, existed in ng/L levels in water environment, is the main substance causing the feminization of aquatic organisms. In the sewage treatment plant, whether the estrogen could be effectively removed is becoming a scientific problem to be resolved urgently. In the actual process of sewage treatment, the C/N of wastewater could not only influence the removal of COD、N、P and other nutrients, but also affect the removal of estrogen through changing the microbial community structure of heterotrophic and AOB in the activated sludge. Therefore, this study deals with different C/N artificial wastewater by SBR system, and determines the removal efficiency of COD and N, then analyzes the microbial community structure of heterotrophic and AOB in the activated sludge using molecular ecology technology, such as ARISA、TRFLP、FISH and clone library. After the SBR system runs stably, add the E2 and EE2, and examine their removal efficiency by GC-MS. Furthermore, we take the activated sludge after the system runs stably, and conduct static experiments. On the one hand, adsorption performance of different SBR activated sludge system will be discussed. On the other hand, what role of heterotrophic bacteria and AOB paly in the degradation of estrogen will be further studied through adding ATU to inhibit the nitrification. The results will provide the theory guide to improve the removal efficiency of estrogen for sewage treatment plant when deepen the removal of nitrogen and phosphorus.

水环境中以ng/L水平存在的雌激素，是引起水生生物雌性化的主要原因物质，污水处理厂中的雌激素能否被有效降解成为亟需解决的科学问题。在实际污水处理过程中，进水水质的C/N不仅会影响COD、N、P的去除，而且会通过影响活性污泥中异养菌和AOB的群落结构而影响雌激素的去除。因此，本项目通过SBR系统处理不同C/N人工配水，测定对COD和N的去除率，并利用ARISA、TRFLP、FISH和克隆文库等分子生态学技术解析活性污泥系统中异养菌和AOB的群落结构变化。待SBR系统运行稳定后，分别投加E2和EE2，利用GC-MS方法测定两种雌激素的去除率。此外，取SBR系统运行稳定后的活性污泥，进行静态实验，探讨不同SBR活性污泥系统对雌激素吸附性能差异；并通过添加ATU抑制硝化作用，进而确定异养菌和AOB在降解雌激素上各自的作用。研究结果为污水处理厂深化脱氮除磷的同时，提高雌激素的去除效率提供理论指导。

水环境中以ng/L水平存在的雌激素，是引起水生生物雌性化的主要原因物质，污水处理厂中的雌激素能否被有效降解成为亟需解决的科学问题。实际污水处理过程中，进水水质的C/N不仅会影响COD、N、P的去除，而且会通过影响微生物群落结构而影响雌激素去除。本项目通过SBR系统处理不同C/N人工配水，测定对COD和N的去除率，并利用Miseq高通量测序技术解析活性污泥系统中异养菌和AOB的群落结构变化。待SBR系统运行稳定后，分别投加E1、E2、EE2，利用SPE-HPLC-MS方法测定雌激素去除率。此外，取SBR系统运行稳定后的活性污泥，进行静态实验，明确吸附在不同雌激素去除上的作用；并通过添加ATU抑制硝化作用，进而确定AOB在降解不同雌激素上的作用。. 结果表明，COD去除率随着C/N不断升高而升高，出水NH3-N和NO2-N随着C/N不断升高而升高，而出水NO3-N随着C/N不断升高而降低。当C/N为5和8时，微生物丰富度高于2和11时，而C/N为2和11时，微生物种群多样性高于5和8时。从门或纲的分类来看，4个SBR系统中丰度较高的均为变形菌门、拟杆菌门和放线菌门；从属的水平看，差异较大，与硝化相关的Nitrospira、Nitrosomonas、Nitrosomonadaceae等3个属的数量均随着C/N的升高而不断降低，而Tetrasphaera、Comamonadacea等异养菌的数量则随着C/N的升高而显著升高；AOB、NOB均是在C/N为2时最多，随着C/N的升高，其数量呈现下降趋势。活性污泥对EE2的吸附能力最强，对E1的吸附能力次之，对E2的吸附能力最弱，低温下活性污泥对雌激素的吸附效果比高温下更好。三种雌激素的吸附等温线均符合Freundlic吸附等温线，吸附常数KF值随着温度的增加而降低。AOB的共代谢对E1和E2的生物降解起了重要作用， 而对EE2的生物降解作用微乎其微。C/N值对雌激素E1和E2的去除率影响不大，均比较高，但对E2的平均去除率明显高于E1，而对雌激素EE2去除的影响较大，当C/N为8时EE2去除率较高，达到了75.69%，而C/N为2时EE2去除率最低，仅为59.42%。. 本项目从微生物生态学的角度逐步深层次揭示雌激素去除的机制，研究结果为污水处理厂深化脱氮除磷的同时，提高雌激素的去除效率提供理论指导。