面向生物电化学-厌氧耦合工艺放大的电极载体构型优化与流态模拟

Bioelectrochemical system could greatly enhance the refractory pollutants removal from wastewater by microbial catalysis and direct potential control. Introducing bioelectrochemical system as a kind of bio-carrier to the anaerobic process is considered an effective way to scale it up and enable application. This program bases on the electrode bio-carrier anaerobic coupling process and focuses on the two key points of its amplification: the resistance of conductive material and the 3-dimentional configuration of electrochemical bio-carrier. In this program, we propose to modify the material according to its different physicochemical properties, and optimize the 3-dimentianal configuration of electrochemical bio-carrier via fluid simulation. The research is going on to reduce the resistance and voltage loss of electrode bio-carrier and avoid the problems, such as short current, low efficiency of mass transfer, and low rate of bio-electrochemical reaction, when the electrode bio-carrier is amplified and coupled in anaerobic reactor. This research will build a real platform of bioelectrochemical anaerobic coupling process to verify the simulated results of fluid, as well as establish a hydrodynamical model to describe the flow characteristics of electrode bio-carrier anaerobic coupling reactor and understand the effect mechanism of the configuration of electrode bio-carrier on the performance of the coupled system. This research will provide theoretical and technical basis for the scaling-up of bioelectrochemical and anaerobic coupling process.

生物电化学技术利用电极微生物催化和定向电位调控，可以实现水中难降解污染物的高效去除，将生物电化学体系与厌氧工艺耦合被认为是实现该技术规模化应用的有效途径。本研究基于生物电化学-厌氧耦合工艺，围绕生物电化学系统在放大过程中的两个关键问题：电极材料导电性和电极载体空间构型，提出针对电极载体材料的不同物化性质进行改性处理的研究方法，以及基于流态模拟，优化电极载体空间构型的研究思路。解决生物电化学系统放大过程中电压降损耗大、及其与厌氧耦合时流体短流、传质效率低、生物电化学反应受限等问题。并搭建生物电化学-厌氧耦合工艺平台，对流态模拟结果进行验证，建立适用于本工艺特征的流体力学模型，解析电极载体构型对耦合装置流态及效能的影响机制，为生物电化学-厌氧耦合工艺的放大化提供理论和技术基础。

本项目面向工业废水中难降解污染物深度去除的工艺需求，建立了高效的生物电化学-厌氧耦合水处理工艺，该工艺基于电活性微生物具有的电极呼吸特性，通过电压或电势定向调控电子转移路径，激活了微生物-污染物之间的代谢通路，降低了难降解污染物的复杂度或氧化性，阻断了毒害污染物抑制，强化了厌氧工艺的脱色、脱毒、脱卤等功能，大大改善了废水的可生化性。本项目围绕生物电化学-厌氧耦合工艺的构建与调控、电极材料改性及电极载体构型优化展开，取得的创新性成果包括：【1】构建了生物电化学系统主导的复合型厌氧工艺新模式，揭示了电极生物载体空间位置对耦合工艺效能的影响机制，通过电子补偿机制分析，证明了该耦合工艺具有低电子供体需求的优势；【2】建立了石墨烯原位修饰三维碳纤维电极的方法，突破了传统碳基材料高电阻率的限制因素，加速了电极表面电子传递，增大了电极电活性表面积，显著提高了电极材料的导电性，实现了系统快速启动和污染物高速降解；【3】构筑了新型三维电极生物载体模块，提出了基于流态模拟优化载体空间构型的研究思路，从水力学角度解析了电极载体空间构型对工艺效能的影响机制，获得了褶皱层叠状电极载体和套筒型电极载体的优化运行方案，在此基础上，通过流态模拟，考察了生物电化学-厌氧耦合装置的流态特征，建立了流体力学模型，为实现该工艺的规模化应用提供了理论指导和技术基础，推进了电极生物载体的工程化应用进程。在本项目资助下，发表SCI收录论文8篇，申请发明专利4项。