生物硅藻土动态膜双层膜污染机理研究

Bio-diatomite dynamic membrane (BDDM) is a very promising advanced municipal wastewater treatment technology due to its high pollutants removal efficiency, high filtration flux, excellent solid-liquid separation capacity and low membrane module cost. However, the researches of fouling mechanism of the BDDM have not been studied yet, which is the most important factor influencing its operation process. This research investigated the fouling mechanism of the BDDM, such as morphological structure, compressibility, and interface mutual adhesive effect, with a BDDM reactor at lab-scale in continuous-flow mode. The morphological structure of the BDDM will be analyzed according to the results of the components and hierarchical structure of the cake layer. Porosity, particle deformation and anti-compressibility of the cake layer are selected as the essential factors for interpretation of the special compressibility of the BDDM. The interface mutual adhesive effect between the BDDM cake layer and the underlying stainless steel support mesh is very important for analysis of the BDDM fouling mechanism, which will be focused on the macro adhesive force between the cake layer and the underlying support mesh, and the micro adhesive force between the residual matters and the underlying support mesh. Combined with the aforementioned research results, the double membrane fouling mechanism of the BDDM cake layer and the underlying support mesh will be analyzed systematically. This research has very important academic value and realistic significance for the analysis of the double membrane fouling mechanism of the BDDM and the promotion of the advanced municipal wastewater treatment technology development.

生物硅藻土动态膜技术污染物处理效率高、过滤通量大、固液分离效果好、膜组件造价低，是一项很有应用前景的城镇污水深度处理技术，但目前国内外还没有对其膜污染机理进行系统的研究。本课题在自主研发的生物硅藻土动态膜反应装置基础上对生物硅藻土动态膜结构、压缩特性、交界面相互粘附作用等膜污染机理进行深入研究。通过对泥饼组分、分层形成结构等进行研究，明确生物硅藻土动态膜形态和结构特征；通过对泥饼孔隙率、颗粒变形、抗压缩能力等进行研究，解析生物硅藻土动态膜独特的压缩变形特性及其对膜污染的影响；通过分析动态膜和支撑基网的宏观粘附力及残留物质与基网之间的微观粘附力，阐释生物硅藻土动态膜-基网交界面相互粘附作用。结合以上研究结果，综合分析动态膜泥饼（第一层膜）与不锈钢基网（第二层膜）的双层膜污染机制。课题对揭示生物硅藻土动态膜双层膜污染机理、促进城镇污水深度处理技术发展等方面具有重要的学术价值和现实意义。

动态膜过滤技术过滤通量大、固液分离效果好、膜组件造价低，是一项很有应用前景的污水深度处理技术。动态膜运行特性及大孔支撑基网表面沉积泥饼层的膜污染特性是动态膜技术研究的关键问题。本项目在自主研发的动态膜装置基础上，对活性污泥动态膜（可以添加硅藻土、活性炭等提高污染物去除及过滤性能）结构、压缩特性、交界面相互粘附作用等膜污染机理进行深入研究。形成的动态膜泥饼分层结构明显，从外到内组成颗粒粒径逐渐增大，有利于提高膜通量和泥饼的动态剥离；同时，胶体、溶解性有机物及微生物等与基网表面存在界面作用力，混合液中金属离子与膜表面沉积凝胶层存在离子架桥作用。本研究研究论文9篇，其中SCI收录8篇，申请中国发明专利2项，撰写《动态膜水处理新技术》专著由科学出版社于2014年正式出版，该书为国内第一本专门介绍动态膜水处理技术的专业著作。