人工纳米材料胁迫下的好氧颗粒污泥微生物特性和强化反硝化除磷机理

Manufactured nanomaterials (MNMs) with unique physical and chemical characteristics, namely, quantum surface effect, small dimension effect, quantum tunnel effect, interface and surface effect, etc., are widely applied in commercial and industrial fields. The frequent emergency of the MNMs in wastewater treatment plants will inhibit microbes’ growth and its metabolic activities, which could greatly reduce the stability of the biological wastewater treatment system. . We will choose CuO NPs and CeO2 NPs as the two typical MNMs in this study. The removal mechanisms of CuO NPs、CeO2 NPs by aerobic granular sludge (AGS) will be investigated，and the influence mechanism of MNMs on the cultivation, the steady operation and the basic characteristics of the aerobic granular sludge-denitrifying phosphorus removal (AGS-DPR) will be trace analyzed. The stress mechanism of CuO NPs、CeO2 NPs on the microorganisms of the AGS-DPR can be illustrated, which is dependent on the analysis of the biological activity, microbial community diversity, and denitrifying phosphorus accumulating organisms (DPAOs). Through the research on the phosphorus removal process, phosphorus removal pattern and its principles of the AGS-DPR at different concentrations of CuO NPs、CeO2 NPs, the response relationships between the enhanced denitrifying phosphorus removal mechanism with its microorganisms of the AGS-DPR on the MNMs stress can be established. Based on that, the denitrifying phosphorus removal control and optimization strategy of AGS will be put forward. The study results can further elucidate the environmental influence of MNMs and provide the scientific basis for the application of AGS technology.. This candidate project has the feasible academic thinking, reasonable technical solutions, well-knit research foundations, dependent researcher team and perfect study conditions. Those all provide the complete technical support and guarantee for the research with the high quality accomplishment.

针对人工纳米材料（MNMs）应用日益广泛并在污水中频繁出现进而影响污泥稳定性及微生物活性等问题，选择CuO NPs、CeO2 NPs作为典型MNMs，研究好氧颗粒污泥对其去除机制；以基于MNMs胁迫的好氧颗粒污泥强化反硝化除磷机理为目标，从微生物发展变化规律入手，采用动态和静态试验并结合分子生物学方法，探讨典型MNMs对反硝化除磷好氧颗粒污泥培养及其稳定运行的影响机制，分析颗粒污泥基本性质变化规律，研究MNMs作用下的微生物活性与群落组成的发展变化规律，揭示MNMs对反硝化除磷好氧颗粒污泥微生物的胁迫机理；进一步跟踪好氧颗粒污泥的脱氮除磷过程、除磷途径、物料平衡及其相关动力学参数，形成MNMs胁迫下的好氧颗粒污泥反硝化除磷与微生物的响应机制，提出好氧颗粒污泥反硝化除磷的调控与优化措施。通过本项目研究，为进一步阐明MNMs的环境效应和推动好氧颗粒污泥技术应用提供科学依据。

人工纳米材料（MNMs）具有一定生物毒性，被认为是新型污染物，其进入污水后可团聚、溶解或氧化，并被有机质、生物质和/或EPS吸附，与其他混合物或微生物转化物反应，从而影响污水处理系统稳定性。本课题选择CuO NPs、CeO2 NPs两种典型MNMs，研究了MNMs胁迫下的好氧颗粒污泥微生物特性及其强化反硝化除磷机理，为阐明MNMs的环境效应和好氧颗粒污泥的工程应用提供理论依据。.依托本项目发表学术论文10篇，其中SCI检索5篇；培养硕士研究生3人。主要研究成果如下：.（1）进水中CuO NPs浓度为0~2mg/L时，普通活性污泥均可被实现好氧颗粒化，但随进水中CuO NPs浓度升高，越不利于好氧颗粒污泥的形成。进水中CuO NPs的对污泥COD和TN去除性能影响较小，但较高浓度的CuO NPs （2mg/L）长期存在对好氧颗粒污泥中聚磷菌群的富集存在抑制作用。.（2）好氧颗粒污泥对CuO NPs的去除效果随温度升高先升高再降低，随pH和初始CuO NPs浓度升高而升高。温度从10℃升高到40℃时，CuO NPs的去除量增加约10mg/g，温度超过40℃，去除量下降。CuO NPs初始浓度为100mg/L时，好氧颗粒污泥对CuO NPs的吸附能力仍未达到饱和；通过拟合，Frundlich吸附等温线的1/n为0.54，表明好氧颗粒污泥对CuO NPs的吸附性较好。.（3）10 mg/L CeO2 NPs长期毒性超过好氧颗粒污泥的自我调控能力，TN和TP去除率与空白组相比分别下降了10%和21%；磷吸收量在好氧和缺氧阶段较空白组分别降低了15.32%和66.31%。研究结果表明厌氧-缺氧反硝化除磷菌对CeO2 NPs的敏感程度较传统厌氧-好氧除磷菌大；同时CeO2 NPs浓度为10 mg/L时，聚磷菌代谢方式已由聚磷代谢（PAM）转变为聚糖代谢（GAM）。.（4）CeO2 NPs暴露浓度越高、时间越久，污泥胞内ROS含量越多，胞外LDH释放量越大，PPX和PPK酶活性越受抑制。10 mg/L CeO2 NPs暴露下系统内微生物多样性最高，以Pseudomonas和 Accumulibacter 为代表的好氧聚磷菌相对丰度较空白组分别下降2.97%和 12.77%，聚糖菌丰度显著增加；进一步证明高浓度CeO2 NPs会严重抑制颗粒污泥内聚磷菌活性，改变颗粒污泥代谢方式。