Department of Civil & Environmental Engineering, Imperial College London, London SW7 2AZ, UK.
Department of Civil & Environmental Engineering, Imperial College London, London SW7 2AZ, UK.
J Hazard Mater. 2021 Jun 5;411:125167. doi: 10.1016/j.jhazmat.2021.125167. Epub 2021 Jan 16.
A novel process involving the simultaneous electrochemical-oxidation (EO) and electrosynthesis of ferrate has been investigated for the treatment of the commonly detected and recalcitrant pesticide, atrazine. The present study considered the electrosynthesis of ferrate, in neutral pH, using low concentration iron (Fe) representative of raw water levels and its subsequent effect on atrazine degradation. Ferrate synthesis was unaffected by current density (10-80 mA cm), indicating mass transport limitations. Synthesis was affected by the initial iron concentration, whereby 0.051, 0.108 and 0.332 mg L was generated with an Fe concentration of 0.5, 1.0 and 3.0 mg L, respectively. When operating under simultaneous EO and ferrate oxidation, atrazine degradation exceeded that of a solely EO process. From an initial concentration of 2.00 mg L, atrazine was degraded to 1.34, 1.05 and 0.51 mg L during 10, 40 and 80 mA cm, characterised by pseudo-first-order kinetics. Degradation with electrochemically-generated ferrate could be described by second-order kinetics, and yielded a degradation rate constant of 23.5 M s. The effect of natural organic matter (NOM) on atrazine degradation was also investigated. Ferrate was observed to be mostly scavenged by resorcinol, a representative NOM compound, having a second-order reaction rate constant of 9.71 × 102 M s.
一种新的过程，涉及电化学氧化（EO）和高铁酸盐的电合成，已被研究用于处理通常检测到的和顽固的农药，莠去津。本研究考虑了在中性 pH 下，使用低浓度的铁（Fe）来合成高铁酸盐，代表原水的水平，以及它对莠去津降解的后续影响。高铁酸盐的合成不受电流密度（10-80 mA cm）的影响，表明传质限制。合成受初始铁浓度的影响，当铁浓度分别为 0.5、1.0 和 3.0 mg L 时，分别生成 0.051、0.108 和 0.332 mg L 的高铁酸盐。当在同时进行 EO 和高铁酸盐氧化的情况下操作时，莠去津的降解超过了单纯的 EO 过程。从初始浓度 2.00 mg L 开始，莠去津在 10、40 和 80 mA cm 下分别降解至 1.34、1.05 和 0.51 mg L，符合准一级动力学。电化学生成的高铁酸盐的降解可以用二级动力学来描述，并且得到 23.5 M s 的降解速率常数。天然有机物（NOM）对莠去津降解的影响也进行了研究。高铁酸盐被间苯二酚（一种代表性的 NOM 化合物）主要猝灭，其二级反应速率常数为 9.71×102 M s。
