Programa Institucional de Fomento a la I+D+i, Universidad Tecnológica Metropolitana, Ignacio Valdivieso 2409, P.O. Box 8940577 San Joaquín, Santiago, Chile.
Laboratorio de Electroquímica del Medio Ambiente, LEQMA, Facultad de Química y Biología, Universidad de Santiago de Chile, USACh, Casilla 40, Correo 33, Santiago, Chile.
Sci Total Environ. 2020 Oct 20;740:140154. doi: 10.1016/j.scitotenv.2020.140154. Epub 2020 Jun 11.
The development of heterogeneous Fenton-based electrochemical advanced oxidation processes is important for the removal of organic pollutants at industrial level in the near future. This work reports the application of heterogeneous photoelectro-Fenton (HPEF) with UVA light as an enhanced alternative to the more widespread heterogeneous electro-Fenton (HEF) process. The treatment of the antibiotic cephalexin using chalcopyrite as a sustainable catalyst was studied using an undivided IrO/air-diffusion cell. XPS analysis showed the presence of Fe(III), Cu(I) and Cu(II) species on the surface. The amount of Fe ions dissolved upon chalcopyrite exposure to continuous stirring and air bubbling was proportional to chalcopyrite content. In all cases, the occurrence of pH self-regulation to an optimum value near 3 was observed. The HEF and HPEF treatments of 100 mL of 50 mg L cephalexin solutions with 0.050 M NaSO have been studied with 1.0 g L chalcopyrite at 50 mA cm. Comparative homogeneous EF and PEF with dissolved Fe and Cu catalysts were also performed. HPEF was the most effective process, which can be mainly explained by the larger production of homogeneous and heterogeneous OH and the photodegradation of the complexes formed between iron and organics. The effect of applied current and catalyst concentration on HPEF performance was assessed. Recycling experiments showed a long-term stability of chalcopyrite. Seven initial aromatics and six cyclic by-products of cephalexin were identified, and a plausible degradation route that also includes five final carboxylic acids is proposed.
开发异质芬顿基电化学高级氧化工艺对于未来在工业规模上去除有机污染物非常重要。本工作报道了以 UVA 光为增强手段的异质光电芬顿（HPEF）在抗生素头孢氨苄处理中的应用，作为更为广泛应用的异质电芬顿（HEF）工艺的增强替代方法。使用未分隔的 IrO/空气扩散池研究了使用黄铜矿作为可持续催化剂的头孢氨苄的处理。XPS 分析表明表面存在 Fe(III)、Cu(I)和 Cu(II)物种。在连续搅拌和空气鼓泡暴露于黄铜矿的情况下，溶解的 Fe 离子量与黄铜矿含量成正比。在所有情况下，均观察到 pH 自我调节到接近 3 的最佳值。用 1.0 g/L 黄铜矿在 50 mA/cm 下处理 100 mL 50 mg/L 头孢氨苄溶液的 HEF 和 HPEF 以及具有 0.050 M NaSO 的连续搅拌和空气鼓泡的处理，进行了研究。还进行了具有溶解 Fe 和 Cu 催化剂的均相 EF 和 PEF 的比较。HPEF 是最有效的工艺，这主要可以解释为产生了更大的均相和异相 OH 以及铁与有机物之间形成的复合物的光降解。评估了施加电流和催化剂浓度对 HPEF 性能的影响。回收实验表明黄铜矿具有长期稳定性。鉴定出头孢氨苄的七种初始芳族化合物和六种环状副产物，并提出了一条可能的降解途径，其中还包括五种最终羧酸。
