Schroeder Chelsea M, Koehler Taylor M, Leadbeater Nicholas E
Department of Chemistry, University of Connecticut 55 North Eagleville Road Storrs Connecticut 06269 USA
RSC Adv. 2024 Dec 4;14(52):38385-38390. doi: 10.1039/d4ra07657e. eCollection 2024 Dec 3.
The widespread use of synthetic dyes has led to the release of substantial amounts of dye-contaminated wastewater, posing significant environmental and health concerns. This study focuses on the use of anodic and electrochemically activated persulfate oxidation for the degradation of organic contaminants. Specifically, the structural variations of nine dyes in the indigoid and azo families, and their impact on the efficiency of electrochemical oxidation were analysed. An continuous monitoring apparatus with a UV-visible detector was employed to collect data in real-time. The electrochemically activated persulfate system demonstrated higher efficiency compared to the anodic oxidation approach. In both systems the efficiency of decolourisation was highly dependent on the structure of the pollutant. Electron-withdrawing substituents in direct conjugation with the chromophore, bulky auxochromes, and extended aromatic systems significantly decreased the decolourisation efficiency. Conversely, changing the location of electron-withdrawing groups and adding electron-donating substituents increased the decolourisation efficiency, even overcoming the detrimental effects of bulky groups and extended conjugation. This type of systematic structural comparison study is essential for highlighting the interconnected nature of pollutant structure and degradation speed so that efficient electrochemical oxidation systems can be designed for the treatment of genuine wastewater effluent containing more than one pollutant.
合成染料的广泛使用导致大量受染料污染的废水排放，引发了重大的环境和健康问题。本研究聚焦于利用阳极和电化学活化过硫酸盐氧化法降解有机污染物。具体而言，分析了靛族和偶氮族中九种染料的结构变化及其对电化学氧化效率的影响。采用配备紫外可见检测器的连续监测装置实时收集数据。与阳极氧化法相比，电化学活化过硫酸盐系统表现出更高的效率。在这两种系统中，脱色效率高度依赖于污染物的结构。与发色团直接共轭的吸电子取代基、庞大的助色团和扩展的芳香体系显著降低了脱色效率。相反，改变吸电子基团的位置并添加供电子取代基可提高脱色效率，甚至克服庞大基团和扩展共轭的不利影响。这种系统性的结构比较研究对于突出污染物结构与降解速度之间的内在联系至关重要，以便能够设计出高效的电化学氧化系统来处理含有多种污染物的实际废水排放。
