Powder activated carbon/Fe₃O₄ hybrid composite as a highly efficient heterogeneous catalyst for Fenton oxidation of tetracycline: degradation mechanism and kinetic

Abstract

In this work, we prepared and used a composite of powder activate carbon/Fe 3 O 4 magnetic nanoparticles (PAC/Fe 3 O 4 MNPs) as a heterogeneous catalyst to remove tetracycline (TC) from aqueous solution. By using XRD, BET, VSM, SEM, TEM and EDX techniques, also, we tried to characterize the catalyst. The effects of pH, H 2 O 2 , catalyst dosages and also initial TC concentration on the degradation process were assessed. Based on the results, it was indicated that at low pH values and initial TC concentrations, the efficiency of the process is higher than the other values and concentrations studied in this work. Under the ambient conditions and setting the initial pH value and TC concentration at respectively 3.0±0.2 and 10 mg/L, the optimal dosage of reagents were recorded to be 0.3 g/L catalyst and 80.0 mM H 2 O 2 . The values of observed rate constants, k obs , increased by increasing the catalyst loading in the system; however, these values decreases when the initial TC concentration was increased. Our findings indicated that all of TC concentration was nearly degraded during the 180 min reaction. Regarding the reusability of PAC/Fe 3 O 4 MNPs, the results showed that TC and TOC removal efficiencies of 94.5% and 32.3%, respectively, can be achieved after four consecutive runs. By conducting the stability experiments, it was confirmed that PAC/Fe 3 O 4 MNPs is a promising and effective catalyst in Fenton reactions and can be used to treat TCcontaminated water with very low loss of catalytic activity.

Simultaneous adsorption of lead and aniline onto magnetically recoverable carbon: optimization, modeling and mechanism

“…The XRD pattern of Fe 3 O 4 was in a good agreement with the standard Joint Committee for Power Diffraction Studies, (JCPDS No. 19–0629) . The XRD pattern of the synthesized Fe 3 O 4 , which is quite similar to that of pure magnetite, suggests the lack of any impurities in the Fe 3 O 4 structure.…”

Novel highly stable β-cyclodextrin fullerene mixed valent Fe-metal framework for quick Fenton degradation of alizarin

“…11,[13][14][15][16][17][18][19][20] To keep iron in heterogeneous phase, use of carbon based materials are the advantageous due to its unique catalytic properties including the stability in acidic medium and higher temperature. 21 Jaafarzadeh et al reported the Fenton oxidation of tetracycline, catalyzed by powder activated carbon/Fe 3 O 4 hybrid composite with good stability of the catalyst within 4 h. 22 Nidheesh et al found that iron loaded on activated carbon can effectively degrade rhodamin B in aqueous medium by Fenton process. 23 Degradation of phenol by carbon supported Fe catalyst 24 and orange II removal by Fe supported on carbon nanotubes 25 showed good catalytic activities, but with less stability of the catalyst in terms of the high amount of Fe leaching in the former case aer the reaction.…”

Silica-coated magnetite nanoparticles core-shell spheres (Fe3O4@SiO2) for natural organic matter removal

“…In addition, these nanoparticles have enormous specific surface area, large quantity of the reactive surface sites, low toxicity, and excellent magnetic features [18]. Considering mentioned advantages of nano-sized magnetic particles, large adsorption efficiency, significant amount of pollutants adsorption, and quick separation of the adsorbent from the aqueous media through application of an external magnetic field can be expected from applying this method [17, 19, 20]. …”