电催化膜-微生物燃料电池耦合技术去除难降解有机物及作用机制

Treatment of high concentration refractory organic wastewater is facing big challenges. One effective and economical solution is to develop chemical detoxification-biodegradation coupled technologies. The electrocatalytic membrane reactor (ECMR) and microbial fuel cell (MFC) technologies, both of which are electrochemical systems, show advantages in removing refractory organic pollutants. In this study, the bio-cathode reducing O2 was used to replace the chemical cathode reducing H2O in ECMR. By sharing the O2-reduction bio-cathode, ECMR was coupled with MFC to form the electrocatalytic membrane-microbial fuel cell coupled process, which can effectively and economically remove the refractory organic pollutants by chemical detoxification-biodegradation. .First, we will study the electrocatalytically oxidizing reaction characteristics of the electrocatalytic membranes when using O2-reduction bio-cathode as the counter-electrode. The electrocatalytic membrane-microbial fuel cell coupled process will then be established. We will investigate and optimize the treatment efficiency of high concentration refractory organic wastewater by the coupled process. The reaction dynamics of refractory organic pollutants and their reaction paths will be elucidated to reveal the synergistic mechanisms of electrocatalytic oxidation and biodegradation on the removal of refractory organic pollutants, supporting the coupled process optimization. This study is of great significance to provide a new way to effectively and economically treat the high concentration refractory organic wastewater.

高浓度难降解有机废水的处理面临着重大挑战，开发化学脱毒-生物矿化耦合技术是实现其高效经济处理的有效途径。结合电催化膜反应器与微生物燃料电池对难降解有机物去除效率高的优势及同为电化学系统的特点，本项目采用O2还原生物阴极代替一般电催化膜反应器的H2O还原化学阴极，通过共用O2还原生物阴极来耦合电催化膜反应器与微生物燃料电池，形成集化学脱毒-生物矿化为一体的电催化膜-微生物燃料电池耦合工艺，实现对高浓度难降解有机废水的高效经济处理。.首先研究O2还原生物阴极作为对电极时电催化膜的电催化氧化反应特性，进而建立电催化膜-微生物燃料电池耦合工艺，考察高浓度难降解有机废水的处理效果并优化工艺条件，剖析难降解有机物的反应动力学及降解途径，揭示电催化氧化-生物降解对难降解有机物的协同去除机制，为耦合工艺优化提供理论支持。本项目将为高浓度难降解有机废水的高效经济处理提供一条新途径，具有重要的研究意义。

电催化氧化技术近年来在难降解废水处理领域受到了广泛关注。如何同时提高其去除效果并降低能耗，是目前面临的重大挑战。研究提出将生物电化学技术与电催化氧化技术相耦合，构建生物阴极-电催化膜耦合反应器的解决思路。.首先以溶胶-凝胶法制备了高性能电催化膜阳极材料，在苯酚及垃圾渗滤液等废水中验证了其去除难降解有机物的高效性。进而采用三种形式，将电催化膜与生物阴极进行耦合：.第一，构建O2还原生物阴极-电催化膜耦合反应器（Biocathode-Electrocatalytic Membrane Reactor, BECMR）：以MnOx/Ti电催化膜为阳极，采用石墨毡作为阴极填料并接种，利用电压调控手段实现了BECMR的启动。与电催化膜反应器（Electrocatalytic Membrane Reactor, ECMR）相比，BECMR能够在更低的电压下进行启动，且对亚甲基蓝废水的TOC去除效果约由20%提高到40%，能耗约降低一半。.第二，构建反硝化生物阴极-电催化膜耦合反应器（Denitrifying Biocathode-Electrocatalytic Membrane Reactor, DBECMR）：利用电压调控手段实现了DBECMR的启动。与ECMR相比，DBECMR不仅能够实现阴极脱氮（95%以上），还能使阳极TOC去除率提高了约20%。.第三，建立好氧生物阴极-电催化膜耦合反应器串联工艺（Electrocatalytic membrane-bio sequential reactor, ECM-BR）：利用电流调控手段实现了ECM-BR的启动，通过阳极、阴极的化学脱毒-生物矿化协同作用提高了染料的去除效果。与单纯采用电催化氧化相比，COD去除率提高了20-60%，尤其在高浓度进水下好氧生物阴极对COD去除的贡献更加显著。.最后，对难降解有机物的去除机理及反应动力学进行了分析。发现耦合生物阴极后，改变了阴极反应，使得阴极电势提高，不仅降低了启动电压（根据热力学理论），而且能够提高阳极电势，促进MnOx/Ti电催化膜阳极生成ˑOH，因此提高了其对亚甲基蓝的去除效果。难降解有机物在MnOx/Ti电催化膜中的降解符合一级反应动力学。电催化膜的氧化作用可使亚甲基蓝的可生化性（BOD5/COD）由0.295提高到0.65，有助于后续好氧生物阴极处理。