Enhanced activation of persulfate by CuCoFe2O4@MC/AC as a novel nanomagnetic heterogeneous catalyst with ultrasonic for metronidazole degradation. (January 2022)

• Record Type: Journal Article
• Authors: Rajabi, Saeed; Nasiri, Alireza; Hashemi, Majid
• Is Part Of: Chemosphere. Volume 286:Part 3(2022)
• Publication Date: 2022-01
• Subjects: Advanced oxidation processes -- Metronidazole -- Magnetic nanocatalyst -- Persulfate -- Ultrasonic; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.131872
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: In this study, the degradation of Metronidazole (MNZ) using CuCoFe2 O4 @MC/AC catalyst synthesized by microwave-assisted method, as an efficient activator for persulfate (PS) in the presence of ultrasonic (US: 60 kHz) was investigated. X-ray powder diffraction (XRD), Field emission scanning electron microscope (FESEM), Energy dispersive spectroscopy (EDS)-Mapping and Line scan, Fourier transform infrared spectroscopy (FTIR), Vibrating-sample magnetometer (VSM), and Thermal gravimetric analysis (TGA) were conducted to characterize the structure of CuCoFe2 O4 @MC/AC catalyst and then the catalyst dose, PS dose, MNZ concentration, and pH parameters were optimized. The maximum MNZ degradation of 93.78 % was achieved after 15 min reaction at the optimized operation conditions: 0.4 g L −1 of catalyst, 6 mM of PS, 5 mg L −1 of MNZ, and pH of 3. The removal efficiency of Total Organic Carbon (TOC) was 87.5 % under optimal conditions. According to kinetic equations, it was found that the MNZ degradation followed both kinetics ( pseudo -first-order and Langmuir-Hinshelwood) based on the coefficient of determination (R 2 ) of 0.949, 0.9716, 0.9073, 0.9721, and 0.9662 at concentrations of 5, 10, 15, 20, and 30, respectively. The surface reaction rate constant (Kc ) and the adsorption equilibrium constant (KL-H ) of the Langmuir-Hinshelwood model were 0.81 (mg L −1 min −1 ) and 2.184 (L mg −1 ), respectively. The free radical scavenging experiments were conducted to illustration the proposed mechanism, which shown that the SO4 − was the predominant radicals involved in MNZ degradation. Finally, the regeneration of the catalyst was investigated and showed that after five cycles of use and regeneration by chemical and thermal methods, this catalyst has acceptable chemical stability. Graphical abstract: Image 1 Highlights: A novel nanomagnetic heterogeneous catalyst of CuCoFe2 O4 @MC/AC was Synthesized with microwave assisted method. Catalyst was characterized by FESEM-EDS, Mapping, line scan, FTIR, XRD, TGA, and VSM. CuCoFe2 O4 @MC/AC was used as an efficient sonocatalyst for the degradation of metronidazole in the presence of persulfate (PS). The effect of radical scavengers and mineralization of MNZ by TOC measuring were investigated. CuCoFe2 O4 @MC/AC sonocatalyst could be magnetically recovered and it presented high activity stability for five repetitive runs.