基于微生物群体感应的好氧颗粒污泥稳定性调控机制

Aerobic granular sludge has advantages over conventional flocs, e.g., excellent biological activity and settling performance, high organic loading rate and ability of simultaneous nitrogen and phosphorus removal. Although aerobic granular sludge is regarded as one of the promising biotechnologies in wastewater treatment, instability limit its application. This proposal aims to reveal the regulation mechanism of microbial quorum sensing on aerobic granules stability by adjusting its agglomeration performance. First, the quorum sensing mode of aerobic granular sludge were investigated by ascertaining the species and spatial distribution of key signal molecules released from stable aerobic granules based on HPLC-MS and high-throughput sequencing techniques .Second, the relationship between the process conditions and signal molecules released from stable aerobic granules were explored so as to set up the quorum sensing regulation mechanism of long-term stability. Finally, the coagulation ability of aerobic granules were strengthened by adding corresponding signal molecules, and then the mechanism of directional control on granules stability was achieved, which could lay the ground for putting aerobic granules technique into practice.

好氧颗粒污泥具有良好的生物活性，沉降性能好，有机负荷率高，能同步脱氮除磷，在污水处理中显示出广阔的应用前景，但好氧颗粒污泥稳定性差，严重制约了其推广和应用。本项目基于微生物群体感应原理，系统探讨群体感应系统对好氧颗粒污泥稳定性的调控机制。采用高效液相色谱-质谱技术和高通量测序技术，分析鉴定好氧颗粒污泥群体感应信号分子种类及其空间分布规律，解析稳定好氧颗粒污泥的群体感应模式；探究不同工艺条件下群体感应信号分子对颗粒污泥稳定性的作用规律，构建好氧颗粒污泥稳定运行群体感应调节机制；探讨外源投加群体感应信号分子对促进微生物凝聚性能的影响，揭示好氧颗粒污泥稳定运行定向调控策略，为好氧颗粒污泥技术的实际应用奠定基础。

好氧颗粒污泥具有沉降性能好、容积负荷高、有机物去除率高等优点，但由于启动时间长，运行稳定性差等因素，在污水处理领域的应用与推广受到了制约。本项目利用分子生物学原理，研究基于群体感应的好氧颗粒污泥稳定运行调控机制。. 探讨稳定好氧颗粒污泥群体感应运行模式，采用高效液相色谱-质谱技术和高通量测序技术等，研究了好氧颗粒污泥粒化的动态变化过程中所分泌和释放的关键群体感应信号分子种类及分布规律，发现主要分布在泥相中的短链信号分子C6-HSL有利于能促好氧颗粒污泥生长，加速硝化污泥生物量累积；主要分布在水相中的长链信号分子3-oxo-C12-HSL可以通过参与胞外聚合物（EPS）的形成促进好氧颗粒污泥粒化。在稳定的群落结构下，信号分子C6-HSL起到群体感应调控的主要作用；Kineosphaera菌属是分泌3-oxo-C12-HSL信号分子的主要菌属。. 探讨工艺条件对稳定性的群体感应规律，发现进水的碳氮比对信号分子以及好氧颗粒污泥群体感应规律有较大影响，在碳氮比为15的条件下，好氧颗粒污泥生长期的信号分子为 C14-HSL，其浓度为1.04 μg/L；成熟期的信号分子为 C12-HSL，浓度为1.70 μg/L；稳定期的信号分子为 C10-HSL，浓度为1 μg/L；处于稳定期的颗粒污泥中微生物优势种群Norank_p_Saccharibacteria 有助于维持好氧颗粒污泥的稳定；接种污泥对群体感应和好氧颗粒污泥稳定性的研究结果表明，稳定期主要信号分子有C10-HSL和C14-HSL，能促进微生物聚集生长，加速颗粒形成并维持颗粒污泥的稳定性；解体期信号分子为3-oxo-C14-HSL，有加速颗粒解体的作用。. 探讨好氧颗粒污泥稳定运行定向调控，向处于解体期的污泥系统中投加外源信号分子C10-HSL，有助于颗粒污泥重新凝聚恢复到稳定状态，表明可通过投加外源信号分子C10-HSL定向调控颗粒污泥的稳定性。. 本研究结果可实现利用群体感应的好氧颗粒污泥稳定运行调控，对提高好氧颗粒污泥稳定性具有重要意义。.