In this study, nanoscale zero-valent iron (nZVI) was synthesized and used to activate persulfate (PS) for the degradation of norfloxacin (NOR). The nZVI/PS system exhibited a high reactivity towards NOR, and the degradation efficiency of NOR (100 mg/L) reached 93.8% with 0.1 g/L nZVI, 12 mM PS, and an initial pH of 7.0 within 7 min. The NOR degradation followed a pseudo-first-order kinetic model, and the effects of parameters such as nZVI dosage, PS concentration, initial pH, and temperature were investigated systematically. Overloading of nZVI lowered the degradation efficiency owing to the quenching effect of excessive Fe²⁺. The higher PS concentration and temperature favored the degradation of NOR. The influence of pH was not obvious, and the degradation was effective in a wide pH range. In addition, the radical quenching experiments and electron paramagnetic resonance (EPR) indicated that both sulfate radical (SO₄^⋅-) and hydroxyl radical (OH^⋅) were the dominant radicals in the degradation process, in which the latter played a more important role. Finally, three degradation pathways were proposed based on the result of intermediates identified by liquid chromatography-mass spectrometry. Overall, this study indicated that the nZVI/PS system could provide a promising alternative for NOR wastewater treatment.

中文翻译：

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纳米级零价铁活化过硫酸盐工艺降解诺氟沙星的水溶液

在这项研究中，合成了纳米级零价铁（nZVI），并用于活化过硫酸盐（PS）来降解诺氟沙星（NOR）。nZVI / PS系统显示出对NOR的高反应性，在0.1 g / L nZVI，12 mM PS和7分钟内初始pH值为7.0的情况下，NOR的降解效率（100 mg / L）达到93.8％。NOR降解遵循伪一级动力学模型，并系统研究了nZVI剂量，PS浓度，初始pH和温度等参数的影响。由于过量的Fe ²⁺的淬灭作用，nZVI的超载降低了降解效率。较高的PS浓度和温度有利于NOR的降解。pH的影响不明显，并且在宽的pH范围内降解均有效。此外，自由基猝灭实验和电子顺磁共振（EPR）表明，这两种硫酸根（SO ₄ ^⋅-）和羟基自由基（OH ^⋅）为在降解过程中占主导地位的基团，其中后者起到更重要的作用。最后，根据液相色谱-质谱法鉴定中间体的结果，提出了三种降解途径。总体而言，这项研究表明，nZVI / PS系统可以为NOR废水处理提供有希望的替代方案。