School of Environment and Safety Engineering, Qingdao University of Science and Technology, Shandong, Qingdao 266042, China.
Water Sci Technol. 2011;63(11):2583-9. doi: 10.2166/wst.2011.567.
The electrochemical degradation of aniline in aqueous electrolyte has been studied by dual-electrode oxidation process using Ti/SnO2-Sb2O5 for anodic oxidation and graphite cathode to produce H2O2 in situ. The linear voltammograms were employed to obtain reasonable anodic and cathodic potential values for the purpose of restraining side reactions. The influence of Fe2+ on aniline degradation was investigated under potentiostatic condition with a three-electrode system. It was found that an anodic potential range of 2.0 +/- 0.1 V and a cathodic potential of -0.65 V could favor anodic oxidation and H2O2 generation. Anodic oxidation was accounted for aniline degradation in the absence of Fe2+, while in the presence of Fe2+ both electro-Fenton oxidation and anodic oxidation (dual-electrode oxidation) could degradate aniline effectively. When cathodic potential values were -0.65 and -0.80 V, the optimum Fe2+ concentration were 0.50 and 0.30 mM, respectively. 77.5% COD removal and 70.4% TOC removal with a current efficiency (CE) of 96-100% were achieved under the optimum conditions. This work indicates that dual-electrode oxidation process characterized by a high CE is feasible for the degradation of organic compounds.
采用 Ti/SnO2-Sb2O5 作为阳极氧化和石墨阴极原位产生 H2O2 的双电极氧化工艺，研究了水溶液中苯胺的电化学降解。线性伏安法用于获得合理的阳极和阴极电位值，以抑制副反应。在三电极系统中，采用恒电位条件研究了 Fe2+ 对苯胺降解的影响。结果发现，阳极电位范围为 2.0 ± 0.1 V，阴极电位为-0.65 V，有利于阳极氧化和 H2O2 的生成。在没有 Fe2+ 的情况下，阳极氧化是苯胺降解的主要途径，而在有 Fe2+ 的情况下，电芬顿氧化和阳极氧化（双电极氧化）都可以有效地降解苯胺。当阴极电位值分别为-0.65 和-0.80 V 时，最佳的 Fe2+浓度分别为 0.50 和 0.30 mM。在最佳条件下，COD 去除率为 77.5%，TOC 去除率为 70.4%，电流效率（CE）为 96-100%。这项工作表明，具有高 CE 的双电极氧化工艺可用于有机化合物的降解。
