污泥发酵产酸自生动态膜反应器中膜过滤机理与污染调控策略

By the application of self-forming dynamic membrane technology on the process of sludge fermentation and acid-producing, those problems of sludge fermentation, namely long hydraulic retention time, large volume of the fermentation tank and high investment and operation costs, could be resolved, and the inhibitory effects of produced acid and added flocculants could be reduced, resulting in enhanced acid-producing rate.However, membrane fouling is the bottleneck limiting the large-scale application of the self-forming dynamic membrane bioreactor for sludge fermentation and acid-producing.. The purpose of this research is to investigate the membrane filtration mechanism and fouling control strategy in the self-forming dynamic membrane bioreactor for sludge fermentation and acid-producing. By analyzing the mechanisms of dynamic membrane formation and filtration under the condition of high viscosity, the theoretical system and kinetic models would be established. By investigating the changes of structure and composition of dynamic membrane during the different stages of filtration process, the characteristics of membrane fouling could be understood and the boundary between effective separation layer and pollution layer could be determined, based on which, therefore, the kinetic models depicting the changing trends of membrane fouling could be established. Moreover, fouling control strategy of dynamic membrane under the condition of high viscosity could be introduced based on the fluid mechanics and biological control theory, respectively.. The results obtained in this research could provide theoretical references for the establishment of dynamic membrane system in filtrating mixtures with high concentration and high viscosity, extend recent theory of dynamic membrane formation and filtration and describe the fouling mechanism of self-forming dynamic membrane in non-Newtonian fluid environment, as well as introduce corresponding control strategy.

将自生动态膜分离技术应用到污泥发酵产酸过程中,可以解决污泥发酵产酸过程中水力停留时间长、发酵罐体积大、投资和运行成本高等问题, 以及减轻产物酸和絮凝剂对发酵产酸的抑制作用, 提高产酸率。然而，膜污染是限制污泥发酵产酸自生动态膜反应器推广应用的瓶颈问题。. 本项目旨在研究污泥发酵产酸动态膜反应器中膜过滤机理与污染调控策略。分析高粘度环境下自生动态膜的形成与过滤机理，建立相应的理论体系和动力学模型；通过检测不同过滤阶段，动态膜的结构和组成成分的变化，分析自生动态膜污染特征，确定动态膜有效分离层与污染层的界定标准，建立描叙动态膜污染变化趋势的动力学模型；分别从流体力学和生物控制理论的角度，提出适合高粘度环境下自生动态膜的污染控制策略。. 该研究将为建立高粘度混合物的动态膜过滤系统提供理论参考；扩展现有的动态膜理论知识；阐述动态膜在非牛顿流体环境下的污染机制，并提出相应的控制策略。

污泥厌氧发酵产酸是一种有机固废减量化和资源化处理处置新技术；将自生动态膜分离技术应用到污泥发酵产酸过程中,可以解决传统发酵过程所存在的水力停留时间长、发酵罐体积大、投资和运行成本高等问题, 以及减轻产物酸和絮凝剂对发酵产酸的抑制作用, 提高产酸率；然而，膜污染是限制污泥发酵产酸自生动态膜反应器推广应用的瓶颈问题。本研究旨在考察污泥发酵产酸自生动态膜反应器中膜过滤机理与污染调控策略。通过分析高粘度环境下自生动态膜的形成与过滤机理，建立相应的理论体系和动力学模型；通过检测不同过滤阶段，动态膜的结构和组成成分的变化，弄清自生动态膜污染特征，确定动态膜有效分离层与污染层的界定标准，建立描叙动态膜污染变化趋势的动力学模型；同时，分别从过滤物组成和生物控制理论的角度，提出适合高粘度环境下自生动态膜的污染控制策略。. 通过项目的实施，（1）设计和制作了一套新型的污泥发酵产酸自生动态膜反应器系统，包括污泥发酵产酸罐的建立与自旋转式动态膜组件的建立。考察了高粘度条件下，主要运行参数对动态膜的影响特征，并筛选出了最佳的运行条件。实现了反应器系统的长期稳定运行，提高了污泥发酵产酸效果和污泥转化率。（2）通过对产酸过程中污泥粘度、过滤阻力、流动性和粒径分析，确定了污泥厌氧发酵过程中污泥理化性质的变化，阐述了污泥发酵产酸过程中污泥过滤性能变化的基本原理；为研究自生动态膜在高粘度污泥条件下的过滤机理提供依据，确定了最佳污泥发酵浓度。（3）弄清了高粘度条件下自生生物动态的形成规律和主要运行参数的影响特征，实现了自生生物动态膜良好的截留和有机酸选择性转移效果。详细考察了污泥预处理和厌氧发酵产酸过程对污泥过滤特性的影响，系统地分析了动态形成机制，建立了数学模型；研究了动态膜污染特征，并提出了膜污染的控制策略。（4）考察了污泥发酵产酸过程中有机物的转化规律，特别是蛋白质的转移与降解规律，开发了污泥碱性发酵定向产酸技术，提高了有机酸品质；并利用动态膜对蛋白质的截留特征，通过添加蛋白水解酶，提高了污泥有机物转化率。