Based on Vacuum UV (VUV) in situ cracking water to generate reactive oxygen species (ROS) and promote Fe²⁺/Fe³⁺ redox cycle, a novel oxidant-free VUV/Fe²⁺/oxalate (Ox) homogeneous oxidation process was built to efficiently degrade norfloxacin (NOR). The performance and synergistic mechanism of VUV/Fe²⁺/Ox for NOR degradation under near-neutral conditions were investigated. Compared with sub-processes, VUV/Fe²⁺/Ox obviously accelerated NOR oxidation and reduced energy consumption, and its synergistic factor of NOR removal was 2.32. Effects of operating parameters Fe²⁺, Ox dose and solution pH on VUV/Fe²⁺/Ox and their mechanisms were analyzed. Synergistic mechanisms of NOR degradation via VUV/Fe²⁺/Ox, such as in situ generation of H₂O₂, Fe²⁺/Fe³⁺ redox cycle, ROS characterization and contribution analysis, NOR degradation pathways and its toxicity changes were also investigated. Through the use of ROS fluorescence characterizations and quenching experiments, hydroxyl radical and superoxide radical were identified as primary ROS in VUV/Fe²⁺/Ox, and their contributions to NOR degradation were 73.17 % and 20.91 %, respectively. Besides, synergistic mechanisms of VUV/Fe²⁺/Ox process, which mainly included the respective roles of VUV irradiation, Fe²⁺ and Ox, were also recommended. Furthermore, effects of chelators and water matrices on NOR degradation via VUV/Fe²⁺/Ox were also researched. VUV/Fe²⁺/Ox process showed satisfactory NOR degradation effects in actual waters, indicating its practical application potential. The degradation of NOR by novel VUV/Fe²⁺/Ox process significantly reduced its environmental and health hazards.

中文翻译：

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用于高效去除诺氟沙星的新型无氧化剂 VUV/Fe2+/草酸盐工艺：氧化性能和协同机制


基于真空紫外 （VUV） 原位裂解水生成活性氧 （ROS） 并促进 Fe²⁺/Fe³⁺ 氧化还原循环，构建了一种新型无氧化剂 VUV/Fe²⁺/草酸盐 （Ox） 均相氧化工艺，以高效降解诺氟沙星 （NOR）。研究了 VUV/Fe²⁺/Ox 在近中性条件下 NOR 降解的性能和协同机制。与子工艺相比，VUV/Fe²⁺/Ox 明显加速了 NOR 氧化并降低了能耗，其去除 NOR 的协同因子为 2.32。分析操作参数 Fe²⁺ 、 Ox 剂量和溶液 pH 对 VUV/Fe²⁺/Ox 的影响及其机制。还研究了通过 VUV/Fe²⁺/Ox 降解 NOR 的协同机制，如原位生成 H₂O₂、Fe²⁺/Fe³⁺ 氧化还原循环、ROS 表征和贡献分析、NOR 降解途径及其毒性变化。通过使用 ROS 荧光表征和猝灭实验，羟基自由基和超氧自由基被鉴定为 VUV/Fe²⁺/Ox 中的初级 ROS，它们对 NOR 降解的贡献分别为 73.17 % 和 20.91 %。此外，还推荐了 VUV/Fe²⁺/Ox 过程的协同机制，主要包括 VUV 照射、Fe²⁺ 和 Ox 的各自作用。此外，还研究了螯合剂和水基质对通过 VUV/Fe²⁺/Ox 降解 NOR 的影响。VUV/Fe²⁺/Ox 工艺在实际水域中表现出令人满意的 NOR 降解效果，表明其实际应用潜力。 新型 VUV/Fe²⁺/Ox 工艺降解 NOR 显著降低了其对环境和健康的危害。