Environmental and Water Resources Division, Department of Civil Engineering, Indian Institute of Technology Madras, Chennai, 600036, India.
Environmental and Water Resources Division, Department of Civil Engineering, Indian Institute of Technology Madras, Chennai, 600036, India.
Chemosphere. 2018 Oct;209:113-123. doi: 10.1016/j.chemosphere.2018.05.148. Epub 2018 May 26.
Ferrocene functionalized graphene based graphite felt electrode was firstly investigated for heterogeneous electro-Fenton oxidation of ciprofloxacin in neutral pH condition. Electrochemical reduction of Ferrocene functionalized graphene oxide (Fc-ErGO) was performed by cyclic voltammetry technique. At neutral pH condition, Fc-ErGO electrode (0.035 min) exhibited ∼3 times and ∼9 times higher removal rates in comparison with plane ErGO (0.010 min) and plane graphite felt (0.004 min) electrodes respectively. The effect of pH and applied potential were studied for the degradation of ciprofloxacin in Fc-ErGO based electrode. Higher removal rate was observed at acidic pH (0.222 min), whereas alkaline pH showed lower removal efficiency (0.014 min). > 99% removal of ciprofloxacin was achieved with in 15 min and 120 min of reactions period at pH 3.0 and pH 7.0, respectively. HO generation was found to be high in plane ErGO electrode system in all of the pH conditions. Owing to the high redox ability of ferrocene, Fc-ErGO electrode generated high concentration of OH radicals (426 μM pH 3.0; 247 μM pH 7.0; 210 μM pH 9.0) than ErGO and plane graphite felt electrodes; The electrode reusability study was performed to understand the electrode stability. There was no significant change in removal efficiency even after the 5th cycle of reusability study at both acidic and neutral conditions. The possible mechanism of oxidation in Fc-ErGO based electro-Fenton process was also proposed based on the continuous monitoring of HO and OH radicals generated in the system.
铁氰化功能化石墨烯基石墨毡电极首次被用于研究中性 pH 条件下异相电芬顿氧化环丙沙星。通过循环伏安技术对铁氰化功能化氧化石墨烯（Fc-ErGO）进行电化学还原。在中性 pH 条件下，Fc-ErGO 电极（0.035 min）的去除率分别比平面 ErGO 电极（0.010 min）和平面石墨毡电极（0.004 min）高约 3 倍和 9 倍。研究了 pH 值和施加电位对 Fc-ErGO 基电极中环丙沙星降解的影响。在酸性 pH（0.222 min）下观察到更高的去除率，而碱性 pH 则表现出较低的去除效率（0.014 min）。在 pH 3.0 和 pH 7.0 下，分别在 15 min 和 120 min 的反应周期内实现了环丙沙星>99%的去除。在所有 pH 条件下，平面 ErGO 电极体系中均发现 HO 生成量较高。由于铁氰化铁的高氧化还原能力，Fc-ErGO 电极产生的 OH 自由基浓度较高（pH 3.0 时为 426 μM；pH 7.0 时为 247 μM；pH 9.0 时为 210 μM），高于 ErGO 和平面石墨毡电极；为了了解电极稳定性，进行了电极重复使用性研究。在酸性和中性条件下进行第 5 次重复使用性研究后，去除效率均无明显变化。还根据系统中生成的 HO 和 OH 自由基的连续监测，提出了 Fc-ErGO 基电芬顿过程中氧化的可能机制。
