膜生物反应器中膜污染的界面热力学机制及其调控研究

Membrane fouling is a key scientific problem in the field of membrane separation technology, which highly limits the widespread applications of membrane and membrane bioreactor (MBR) technology. Supported by the just finished Youth Project of National Natural Science Foundation, we find that the adhesion behavior of foulants under curved surface conditions were significantly different from that under planar surface conditions, and there existed significant osmotic pressure effect during cake layer filtration process, which was the main source of filtration resistance. The underlying mechanisms of these results and their control methods deserve further study. Based on these findings, this proposal provides new ideas regarding quantitative calculation of interfacial interactions between membrane and foulants with curved surfaces, and designing anti-fouling ultrafiltration membranes based on the calculation results. The surface properties and structure will be characterized by using various technologies such as AFM and CLSM observation. The obtained data will serve for modeling of surface morphologies and quantitative calculation of interfacial interactions under curved surface conditions by using mathematical methods and supercomputer calculation technology. Meanwhile, the osmotic pressure mechanism during cake layer filtration will be investigated. And then, the methods to control interfacial interactions and osmotic pressure effects will be provided. This proposal will not only provide a new way to reveal the membrane fouling mechanisms and develop efficient membrane fouling control methods in MBR, but also propel the technology for wastewater treatment and reuse forward, demonstrating the great scientific significance.

膜污染问题是膜分离技术领域急待解决的关键科学问题，极大制约了膜及膜生物反应器技术的广泛应用。在刚结题的国家自然科学基金青年项目的资助下，发现曲面条件下的污染物粘附行为与平面条件下的行为明显不同；同时膜面污泥层过滤存在显著的渗透压效应，是过滤阻力的主要来源。这些发现的内在机制和调控方法急待进一步研究。基于这些发现，课题组提出对曲面条件下膜与污染物之间的界面作用力进行定量计算，并以之指导抗污染超滤膜的设计的新思路。课题组拟采用AFM、CLSM等技术对膜、污染物和污泥层的表面性质及结构进行表征，采用数理计算方法结合超级计算机技术对表面形态进行建模并实现曲面条件下热力学的定量计算，同时深入揭示渗透压效应机制，最后提出界面作用力和渗透压效应的调控方法。本项目的研究不仅是揭示MBR中的膜污染机理和构建高效膜污染控制方法的一条新途径，也是对高效污水处理和回用技术的进一步发展，具有重要的科学意义。

膜污染问题是膜分离技术领域急待解决的关键科学问题，极大制约了膜及膜生物反应器技术的广泛应用。本项目在前期发现独特的曲面条件下污染物粘附行为和渗透压效应的基础上，提出揭示这些污染行为的界面热力学机制，并以之指导膜制备及膜污染控制的新思路。在项目执行期间，课题组建立了和验证了一整套膜污染界面作用力定量计算方法体系，研究了系列因子通过影响界面作用力而影响膜污染的机制。同时将高分子体系的热力学机制引入到膜污染研究领域，较完整阐述了膜面污染层过滤过程中的热力学机制，建立了数学模型，并揭示了相关影响因子的影响途径。最后提出了基于界面热力学的膜污染控制策略。本项目在膜污染基础理论方面取得了一定的突破。基于这些工作，本项目科研成效较突出，共发表SCI论文37篇和申报专利7项，其中SCI一区论文19篇，二区论文18篇，总影响因子超过240，单篇平均影响因子超过6.0。