生物电化学系统矿化减毒偶氮染料调控策略与机理研究

Bioelectrochemical system (BES) is an emerging technique to achieve the reductive decolorization of azo dye. However, the low decolorization efficiency and high toxicity of the intermediates are the principal limiting factors of the application of BES. Electrode modification and sequential regulation strategy are proposed to improve the decolorization efficiency and mineralization by BES. The cathode is modified with redox mediator to improve its surface structure and electrochemical characteristics, and then the mechanism of dye degradation and the electron shuttle between the cathode and the substrate (azo dye) are revealed. A system coupling cathodic reduction and anodic oxidation, and system with sequential reduction and in situ oxidation at the biocathode are established to realize pollutant mineralization in a single BES. Afterwards, the regulation strategy and key factors of dye mineralization are studied, and the electron shuttle mechanism is subsequently revealed. Finally, the bioelectrochemical reactor for azo dye wastewater treatment is developed based on the above theoretical study. With the regulation of the reactor, the stable operation is achieved to mineralize and detoxify azo dye. The subject is undoubted of having significant research value and application prospect, and it would provide some innovative ideas and reference for the treatment of the dyeing wastewater.

生物电化学系统是实现偶氮染料还原脱色的新兴技术，而脱色效率低和中间产物毒性高一直是其应用的限制性因素。拟采用电极修饰改性和电极序列调控，以提高生物电化学系统对染料的脱色效率和矿化程度。通过电极改性及氧化还原介体修饰，改善其表面结构和电化学特性，揭示染料及电极之间电子传递过程和降解机理。构建阴极还原-阳极氧化、阴极还原-原位氧化耦合体系，探索其优化设计策略，识别偶氮染料矿化减毒的关键因子，揭示染料矿化全过程电子转移途径和机制。基于以上理论研究，建立生物电化学处理染料废水反应器，通过参数调控，实现反应器优化稳定运行和染料矿化减毒，为染料废水的高效低耗深度矿化提供新的思路与借鉴，极具理论研究价值与实际应用前景。

发展新型高效的染料废水处理技术是水污染控制领域的一个重要任务。生物电化学系统是实现偶氮染料还原脱色的新兴技术，而脱色效率低和中间产物毒性高一直是其应用的限制性因素。为探究影响生物电化学系统转化污染物关键因子，本研究通过不同方法改性修饰电极，检测对不同偶氮染料脱色效率和毒性变化，构建阴极还原-阳极氧化体系提高污染物的转化效率。首先通过原位利用阳极的有机物厌氧转化产生的电子还原阴极处的染料，并通过检测电化学阻抗谱得出，阴极的高阻抗限制了电子转移速率进而抑制了转化污染物的性能；然后通过系列改性方法（过渡金属和石墨烯复合、氧化钌与碳纳米管复合、藻渣不同预处理方式）得到系列不同性能的电极材料，与普通碳毡相比，产电能力提高3倍，最大功率密度提高4倍，欧姆内阻和电荷传递内阻分别降低至未改性的一半，转化污染物的速率提高2-5倍；通过大型蚤毒性实验、LIVE/DEAD法检测不同体系产物的毒性，得出强化电极在提高污染物转化的同时，降低了产物的毒性；最后探索了阴极还原-阳极氧化耦合矿化污染物的可行性，污染物先在阴极被还原，然后被阳极微生物进一步氧化，氧化过程中产生的电子用于阴极还原污染物，实现污染物电子的充分利用而无需额外提供电能或者有机碳源。通过本研究的开展，为有机污染物废水的高效、低能耗的处理提供了一个有潜力的方法。