纳米粒子存在下活性污泥胞外聚合物的产生特性及对微生物细胞的保护作用机制研究

Adverse effects of nanoparticles on biological wastewater treatment have raised widespread concerns. Extracellular polymeric substances (EPS), major components of activated sludge flocs, have important physiological functions and may play an important role in protecting the microbial cells. This research focuses on the production characteristics of EPS in the presence of nanoparticles and the protective mechanisms of EPS to microbial cells. In this study, typical metal and metal oxide nanoparticles are selected. First, the formation and characteristics of EPS in the presence of nanoparticles will be studied to reveal the influence mechanism of nanoparticles on the characteristics (surface properties, flocculation and sedimentation) of activated sludge and on the physicochemical stability of the reactor. Then, the adsorption of nanoparticles on EPS and the antioxidation of EPS will also be studied to demonstrate the protection mechanisms of EPS. At Last, the composition and content of EPS will be regulated and optimized through process parameters to reduce the adverse effects of nanoparticles on the activated sludge system and to ensure the stablility of the reactor. The implementation of this research will provide scientific basis and theoretical support for better understanding the impact of nanoparticles on biological wastewater treatment systems and the operation optimization of biological wastewater treatment processes.

纳米粒子对废水生物处理系统的不利影响已得到广泛关注。胞外聚合物（Extracellular polymeric substances，EPS）是活性污泥絮体的主要组成部分，具有重要的生理功能，可能在保护微生物细胞中发挥着重要作用。本申请项目围绕着纳米粒子存在下EPS的产生特性及对微生物细胞的保护作用机制开展研究。选取典型金属及金属氧化物纳米粒子，研究纳米粒子存在下EPS的形成规律及性质，揭示其对污泥特性（表面特性、絮凝性和沉降性能）及系统物化稳定性的影响机制；系统的研究EPS对纳米粒子的吸附截留作用及EPS的抗氧化作用，探讨EPS对活性污泥微生物的保护机制。在此基础上，通过工艺参数的优化调控EPS的组成及含量，减轻纳米粒子对活性污泥系统的不利影响，保证反应器的稳定运行。本项目的实施将为认识纳米粒子对废水生物处理系统的影响及优化废水生物处理工艺的运行提供科学依据和理论支持。

纳米粒子对废水生物处理系统的不利影响已得到广泛关注。胞外聚合物（Extracellular polymeric substances，EPS）是活性污泥絮体的主要组成部分，具有重要的生理功能，可能在保护微生物细胞中发挥着重要作用。本研究合成了纳米银并对其进行了物化性质的表征，研究了纳米粒子存在下微生物产物包括胞外聚合物EPS和溶解性微生物产物SMP的形成规律及性质，揭示纳米粒子对活性污泥有机物降解、硝化过程及对污泥特性的影响；研究EPS对纳米粒子的吸附截留作用；通过离体实验，借助光谱法和等温滴定微量热研究分析EPS与纳米粒子的相互作用，探讨对活性污泥微生物的保护机制。通过化学分析、染色和超薄切片等手段研究了纳米银对活性污泥微生物的细胞毒性作用。该研究为认识纳米粒子对废水生物处理系统的影响提供了理论依据。