EPS结构特征对吸附污水中有机物界面过程的影响及定向调控机制

Presently, the secondary biological treatment process is widely and primarily adopted in municipal wastewater treatment plants. However, the process focuses on the removal of wastewater pollutants to satisfy the stringent discharge standards, causing high energy consumption and low organic matter content of sludge, which limits the resource-oriented potential of sludge. Therefore, based on a novel concept of transfer of organic pollutants by utilizing activated sludge flocs, while the target of the directional control of the process was enhanced with the application of extracellular polymeric substances (EPS), the starting points of this project are the resource recovery of organic matter from wastewater and the resource-oriented potential enhancement of sludge. In-depth analysis of the trait transition of different EPS and their composition and spatial distribution in activated sludge flocs, the influence of the structural characteristics of different EPS on the interface process of adsorption of organic pollutants in wastewater can be revealed. In view of the mechanism in promoting EPS secretion of microbial with suitable control strategies including intermittent starvation and micro-electric field, as well as the behavior characteristics in regulating highly aggregated EPS with feasible hydraulic shear methods including mixing and aeration, the regulated mechanism of the EPS-enhanced adsorption process for organic matter can be illuminated. The successful implementation of this project can not only change the migration and transformation pathways of organic matter in conventional wastewater treatment process but also provide a new insight for the resource recovery of wastewater.

目前，城市污水处理厂普遍采用以二级生物处理为主的污水处理工艺。然而，仅以去除污水中污染物为目的追求高出水水质标准的污水处理工艺，不仅会大大提高污水处理厂能耗，同时由于剩余污泥有机质含量过低而影响其资源化潜质。因此，本项目以污水中有机物资源化回收和剩余污泥资源化潜质提高为出发点，提出活性污泥絮体转移污水中有机物的理念，以强化EPS吸附污水中有机物效能的定向调控为目标，在深入分析活性污泥絮体中不同EPS性状变迁过程及其组成与空间分布特征的基础上，揭示不同EPS结构特征对吸附污水中有机物的界面过程的影响，明晰间歇式饥饿和微电场刺激等调控策略促进活性污泥絮体中微生物分泌更多EPS的机理，明确搅拌和曝气等水力剪切手段调控聚集性能更强的EPS类型暴露的行为特征，阐明强化EPS吸附污水中有机物效能的调控机制，同时为改变传统污水处理工艺中有机物的迁移转化途径以及污水资源化利用新思路提供科学依据。

城市污水处理厂普遍采用以二级生物处理为主的污水处理工艺，但仅以去除污水中污染物为目的追求高出水水质标准的污水处理工艺，不仅会大大提高污水处理厂能耗，同时由于剩余污泥有机质含量过低而影响其资源化潜质。研究以强化EPS吸附污水中有机物效能的定向调控为目标，在解析S-EPS、LB-EPS和TB-EPS等不同类型EPS性状变迁过程及其组成与分布特征的基础上，明确了不同时期EPS的表面性质、分子量分布及酶活结构特征，阐明了不同时期不同EPS之间（TB-EPS之间，LB-EPS之间以及TB-EPS与LB-EPS之间）的作用力，解析了TB-EPS引发的界面作用力及其与二氧化硅胶体、高岭土、大肠杆菌、牛血清蛋白、纤维素、腐殖酸不同污染物胶体探针之间的相互作用，阐明了间歇式饥饿调控策略下促进活性污泥絮体中微生物分泌EPS的作用机制，同时明确了搅拌、曝气等不同水力剪切条件下调控聚集性能更强的TB-EPS暴露的行为特征，为改变传统污水处理工艺中有机物的迁移转化途径以及污水资源化利用新思路提供了科学依据。