College of Water Conservancy and Civil Engineering, Shandong Agricultural University, Tai'an, Shandong, 271018, China; College of City and Architecture Engineering, Zaozhuang University, Zaozhuang, Shandong, 277160, China.
College of Resources and Environment, Shandong Agricultural University, Tai'an, Shandong, 271018, China.
J Environ Manage. 2024 Jun;360:121111. doi: 10.1016/j.jenvman.2024.121111. Epub 2024 May 17.
The widespread use of antibiotics and the inefficiency of traditional degradation treatments pose threats to the environment and human health. Previous studies have reported the potential of bio-electro-Fenton (BEF) processes for antibiotic removal. However, some drawbacks, such as a strict pH range of 2-3 and iron sludge generation, limit their large-scale application. Thus, to overcome the narrow pH range of traditional BEF processes, a photo-BEF (PBEF) system was established using a novel FeMn-layered double hydroxide (LDH)/graphitic carbon nitride (g-CN) (FM/CN) composite cathode. The performance of the PBEF system was investigated by degrading tetracycline (TC) under low-power LED lamp irradiation. The results indicated that the pH range of the PBEF system could be expanded to 3-11 using an FM/CN cathode, which exhibited a TC removal efficiency of 63.0%-75.9%. The highest TC removal efficiency was achieved at pH 7. The efficient mineralization of TC by the PBEF system can be high, up to 67.6%. In addition, the TC removal mechanism was discussed in terms of reactive oxygen species, TC degradation intermediate analyses, and density functional theory (DFT) calculations. Strong oxidative hydroxyl radicals (·OH) were the dominant reactive oxidizing species in the PBEF system, followed by ·O and h. Three pathways of TC degradation were proposed based on the analysis of intermediates, and the reactive sites attacked by electrophilic reagents were explored using DFT modeling. In addition, the overall toxicity of TC degradation intermediates effectively decreased in the PBEF system. This work offers deep insights into the TC removal mechanisms and performance of the PBEF system over a wide pH range of 3-11.
抗生素的广泛使用和传统降解处理的低效性对环境和人类健康构成了威胁。先前的研究已经报道了生物电化学-Fenton（BEF）工艺在抗生素去除方面的潜力。然而，一些缺点，如严格的 2-3 的 pH 范围和铁污泥的产生，限制了它们的大规模应用。因此，为了克服传统 BEF 工艺的狭窄 pH 范围，使用新型 FeMn 层状双氢氧化物（LDH）/石墨相氮化碳（g-CN）（FM/CN）复合材料阴极建立了光-BEF（PBEF）系统。通过在低功率 LED 灯照射下降解四环素（TC）来研究 PBEF 系统的性能。结果表明，使用 FM/CN 阴极可以将 PBEF 系统的 pH 范围扩展到 3-11，TC 的去除效率为 63.0%-75.9%。在 pH 7 时达到最高 TC 去除效率。PBEF 系统对 TC 的有效矿化作用很高，可达 67.6%。此外，还从活性氧物种、TC 降解中间产物分析和密度泛函理论（DFT）计算等方面讨论了 TC 的去除机制。强氧化性的羟基自由基（·OH）是 PBEF 系统中的主要活性氧化物质，其次是·O 和 h。基于中间产物分析提出了三种 TC 降解途径，并通过 DFT 建模探讨了亲电试剂攻击的反应活性点。此外，在 PBEF 系统中，TC 降解中间产物的整体毒性有效降低。这项工作深入了解了 TC 去除机制和 PBEF 系统在 3-11 宽 pH 范围内的性能。
