Laboratori d'Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain.
Laboratori d'Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain.
Water Res. 2018 Jan 1;128:71-81. doi: 10.1016/j.watres.2017.10.048. Epub 2017 Oct 23.
The electrochemical degradation of tetracaine hydrochloride has been studied in urban wastewater. Treatments in simulated matrix with similar ionic composition as well as in 0.050 M NaSO were comparatively performed. The cell contained an air-diffusion cathode for HO electrogeneration and an anode selected among active Pt, IrO-based and RuO-based materials and non-active boron-doped diamond (BDD). Electrochemical oxidation with electrogenerated HO (EO-HO), electro-Fenton (EF) and photoelectro-Fenton (PEF) were comparatively assessed at pH 3.0 and constant current density. The pharmaceutical and its byproducts were oxidized by OH formed from water oxidation at the anode surface and in the bulk from Fenton's reaction, which occurred upon addition of 0.50 mM Fe in all media, along with active chlorine originated from the anodic oxidation of Cl contained in the simulated matrix and urban wastewater. The PEF process was the most powerful treatment regardless of the electrolyte composition, owing to the additional photolysis of intermediates by UVA radiation. The use of BDD led to greater mineralization compared to other anodes, being feasible the total removal of all organics from urban wastewater by PEF at long electrolysis time. Chlorinated products were largely recalcitrant when Pt, IrO-based or RuO-based anodes were used, whereas they were effectively destroyed by BDD(OH). Tetracaine decay always obeyed a pseudo-first-order kinetics, being slightly faster with the RuO-based anode in Cl media because of the higher amounts of active chlorine produced. Total nitrogen and concentrations of NH, NO, ClO, ClO and active chlorine were determined to clarify the behavior of the different electrodes in PEF. Eight intermediates were identified by GC-MS and fumaric and oxalic acids were quantified as final carboxylic acids by ion-exclusion HPLC, allowing the proposal of a plausible reaction sequence for tetracaine mineralization by PEF in Cl-containing medium.
盐酸丁卡因在城市废水中的电化学降解研究。在模拟基质中进行了与类似离子组成的处理，以及在 0.050 M NaSO 中进行了处理。该电池包含一个用于 HO 电生成的空气扩散阴极和一个在活性 Pt、基于 IrO 和基于 RuO 的材料以及非活性掺硼金刚石（BDD）之间选择的阳极。在 pH 3.0 和恒定电流密度下，比较了电化学氧化（EO-HO）、电芬顿（EF）和光电芬顿（PEF）的效果。药物及其副产物通过阳极表面水氧化和 Fenton 反应在本体中形成的 OH 氧化，在所有介质中加入 0.50 mM Fe 后发生 Fenton 反应，以及模拟基质和城市废水中所含 Cl 的阳极氧化产生的活性氯。无论电解质组成如何，PEF 过程都是最有效的处理方法，这是因为 UVA 辐射对中间体的额外光解。与其他阳极相比，BDD 的使用导致更大的矿化，通过 PEF 在长时间电解时可以从城市废水中完全去除所有有机物。当使用 Pt、基于 IrO 或基于 RuO 的阳极时，氯化产物大多难以降解，而 BDD(OH) 可有效地将其破坏。丁卡因的降解总是遵循伪一级动力学，在 Cl 介质中使用 RuO 基阳极时略快，因为产生的活性氯较多。总氮和 NH、NO、ClO、ClO 和活性氯的浓度被确定，以阐明不同电极在 PEF 中的行为。通过 GC-MS 鉴定了 8 种中间体，并通过离子排斥 HPLC 定量了富马酸和草酸作为最终羧酸，从而提出了在含 Cl 介质中通过 PEF 矿化丁卡因的合理反应序列。
