Degradation of Mefenamic Acid Using Magnetic Multi-Walled Carbon Nanotube As a Novel Particle Electrode in a Three-Dimensional Electro-Fenton Process Publisher



Zare MR¹ ; Mengelizadeh N¹ ; Pourzamani H^{2, 3} ; Hajizadeh Y^{2, 3} ; Mohammadi H⁴ ; Saloot MK⁵ Show Affiliations
Source: Desalination and Water Treatment Published:2020

Abstract

Electrocatalytic degradation of mefenamic acid (MFA) by magnetic multi-walled carbon nanotubes (MMWCNTs), as a novel particle electrode, was studied in a three-dimensional electro-Fenton (3DEF) reactor. The physicochemical properties of MMWCNTs were determined by field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction (XRD) techniques. The effect of variables and their interaction during the oxidative degradation of MFA was evaluated using response surface methodology (RSM) based on 5 levels of 5 factorials central composite design (CCD). The RSM results showed a suitable quadratic polynomial model for explaining the relationship between electrocatalytic activity and operational parameters (R2 = 99.6). The optimization results indicated that maximum MFA degradation efficiency (98.36%) could be obtained at pH of 6.2, MFA concentration of 6.19 mg/L, the current density of 19.94 mA/cm2, MMWCNTs dosage of 69.13 mg/L, and reaction time of 82.95 min. Comparative experiments showed further production of hydroxyl radical (•OH) and higher electrocatalytic activity of the 3DEF system. The MMWCNTs particle electrode showed excellent stability and reusability for MFA oxidation. 3,4-dimethyl benzaldehyde and 3-methylbut-2-enoic acid were identified as MFA degradation intermediates using dispersive liquid–liquid microextraction combined with gas chromatography-mass spectrometry (GC-MS). © 2020 Desalination Publications. All rights reserved.