State Key Laboratory of Hydraulics and Mountain River Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China; Sino-German Centre for Water and Health Research, Sichuan University, Chengdu 610065, China.
National Engineering Research Center of Clean Technology in Leather Industry, College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China.
J Hazard Mater. 2021 Mar 15;406:124725. doi: 10.1016/j.jhazmat.2020.124725. Epub 2020 Nov 30.
The generation of sludge is the main issue in iron-based electrochemical techniques. Interestingly, in this study, the effluent was totally limpid and iron sludge did not generate when dissolved silicate (NaSiO) was used as the electrolyte in an electrolysis catalyzed ozone (ECO-NaSiO) system. More importantly, the pseudo-first-order rate constants (0.112 min) for DMAC degradation in ECO-NaSiO process was much higher than those of ECO systems using other electrolytes. An inhibition film formed on the iron electrode surface was identified to inhibit excess corrosion of iron electrodes and efficiently catalyze decomposition of ozone simultaneously. It was confirmed that hydroxyl radical (OH) played a dominant role for the degradation of DMAC, and O and HO were also contained in ECO-NaSiO system. The contributions of contained oxidative reactions in ECO-NaSiO system were quantitatively evaluated. Finally, the degradation pathway of DMAC was proposed. This work provides an effective way for protecting electrode from corrosion in electrochemical process.
污泥的产生是铁基电化学技术的主要问题。有趣的是，在这项研究中，当溶解的硅酸钠（NaSiO）用作电催化臭氧（ECO-NaSiO）系统的电解质时，流出物完全清澈，并且没有产生铁污泥。更重要的是，在 ECO-NaSiO 工艺中，DMAC 的降解伪一级速率常数（0.112 min）比使用其他电解质的 ECO 系统高得多。确定在铁电极表面形成的抑制膜同时抑制铁电极的过度腐蚀并有效地催化臭氧分解。已证实，羟基自由基（OH）在 DMAC 的降解中起主导作用，并且 ECO-NaSiO 系统中还包含 O 和 HO。定量评估了 ECO-NaSiO 系统中包含的氧化反应的贡献。最后，提出了 DMAC 的降解途径。这项工作为保护电极免受电化学过程中的腐蚀提供了一种有效方法。
