School of Environmental Science and Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India.
Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India.
Environ Pollut. 2023 Apr 1;322:121242. doi: 10.1016/j.envpol.2023.121242. Epub 2023 Feb 7.
The current research demonstrates the efficiency of a low-cost MIL-53(Fe)-metal-organic framework (MOF) derived FeO@C (MIL-53(Fe)@FeO@C) electrocatalyst in a batch-scale electro-Fenton (EF) process for the degradation of salicylic acid (SA) from wastewater. The electrocatalyst was prepared from the combination of polyethylene terephthalate (PET) and iron scrap wastes. The result showed 91.68 ± 3.61% degradation of 50 mg L of SA under optimum current density of 5.2 mA cm, and pH of 7.0 during 180 min of electrolysis time. The degradation of SA from waste catalyst was similar to the chemical-based MIL-53(Fe)-derived FeO@C (cFe) cathode catalyst. The presence of chloride ions (Cl) in the water matrix has shown a strong inhibitory effect on the elimination of SA, followed by nitrate (NO), and bicarbonate (HCO) ions. The multiple cyclic voltammetry (CV) analysis and reusability test of waste cathode catalyst showed only 8.03% drop of current density at the end of the 20th cycle and 5% drop of degradation efficiency after 6th cycle with low leaching of iron. The radical scavenging experiment revealed that the HO generated via electrochemical generation of HO had a prominent contribution in the removal of SA compared to HO/O. Besides, possible catalysis mechanism and degradation pathways were deduced. Furthermore, a satisfactory performance in the treatment of SA spiked in real water matrices was also observed by waste-derived FeO@C cathode catalyst (wFe). Additionally, the total operating cost and toxicity analysis showed that the as-synthesized wFe cathode catalyst could be appropriate for removing organic pollutants from wastewater in the large-scale application.
当前的研究表明，一种低成本的 MIL-53(Fe)-金属有机骨架（MOF）衍生的 FeO@C（MIL-53(Fe)@FeO@C）电催化剂在批处理电芬顿（EF）过程中用于降解废水中的水杨酸（SA）的效率。该电催化剂由聚对苯二甲酸乙二醇酯（PET）和废铁屑的组合制备而成。结果表明，在电流密度为 5.2 mA cm、pH 值为 7.0 的最佳条件下，50 mg L 的 SA 降解率为 91.68 ± 3.61%，180 min 的电解时间。废催化剂对 SA 的降解与基于化学的 MIL-53(Fe)衍生的 FeO@C（cFe）阴极催化剂相似。水中氯离子（Cl）的存在对 SA 的消除表现出强烈的抑制作用，其次是硝酸盐（NO）和碳酸氢根（HCO）离子。废阴极催化剂的多次循环伏安（CV）分析和可重复使用性测试表明，在第 20 次循环结束时电流密度仅下降 8.03%，第 6 次循环后降解效率下降 5%，铁浸出率低。自由基捕获实验表明，电化学产生的 HO 比 HO/O 更有助于去除 SA。此外，还推导出了可能的催化机制和降解途径。此外，废衍生的 FeO@C 阴极催化剂（wFe）在处理实际水基质中添加的 SA 时也表现出令人满意的性能。此外，总运行成本和毒性分析表明，合成的 wFe 阴极催化剂可适用于大规模应用中从废水中去除有机污染物。
