Highly efficient heterogeneous electro-Fenton reaction for tetracycline degradation by Fe–Ni LDH@ZIF-67 modified carbon cloth cathode: Mechanism and toxicity assessment

• Published in: Journal of environmental management Vol. 354; p. 120336
• Main Authors: Cheng, Shuting, Wu, Bingqing, Pang, Yuehong, Shen, Xiaofang
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2024
• Subjects: Carbon cloth; Degradation; Heterogeneous electro-Fenton; Hydrogen peroxide; Tetracycline; Degradation; Heterogeneous electro-Fenton; Carbon cloth; Hydrogen peroxide; Tetracycline
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2024.120336

In this work, a novel and efficient Fe–Ni LDH@ZIF-67 catalyst modified carbon cloth (CC) cathode was developed for tetracycline (TC) degradation in heterogeneous electro-Fenton (Hetero-EF) process. Compared to Fe–Ni LDH/CC (75.7%), TC degradation rate of Fe–Ni LDH@ZIF-67/CC cathode increased to 95.6% within 60 min. The synergistic effect of hetero-EF and anodic oxidation process accelerated electron transfer, the maximum H2O2 production of Fe–Ni LDH@ZIF-67/CC electrode reached 264 mg/L, improving utilization efficiency of H2O2. The cathode possessing a satisfied TC degradation performance over a wide pH (3–9). Free radical capture experiment revealed the collaboration of ·O2−, ·OH, and 1O2 play a significant role in TC degradation. The 5 cycles experiment and metal ion leaching experiment showed that the proposed Fe–Ni LDH@ZIF-67/CC has good recyclability and stability. In addition, the proposed Fe–Ni LDH@ZIF-67/CC cathode achieved satisfying performance in real water (tap water: 97.3%, lake water: 97.7%), demonstrating the possibility for practical application. TC degradation pathways were proposed by theory analysis and experimental results. The toxicity of TC intermediates was reduced by Hetero-EF degradation according to Toxicity Estimation Software Tool and Escherichia coli growth inhibition experiments. This work provides a novel modified cathode to improve removal efficiency of antibiotics in wastewater. [Display omitted] •Fe–Ni LDH@ZIF-67/CC cathode was developed for tetracycline degradation.•The cathode possessed high catalytic performance over a wide pH range from 3 to 9.•The cathode solved the recovery problem and saved the amount of used catalyst.•The toxicity of tetracycline was effectively reduced by Hetero-EF degradation.