Synergetic Metronidazole Removal From Aqueous Solutions Using Combination of Electro-Persulfate Process With Magnetic Fe3o4@Ac Nanocomposites: Nonlinear Fitting of Isotherms and Kinetic Models Publisher

Summary: How do we clean antibiotic MNZ from water? Scientists report an electro persulfate system with Fe3O4@AC nanocomposite removed over 90% under optimal conditions. #WaterTreatment #Nanotechnology

Malakootian M^{1, 2} ; Aghasi M² ; Fatehizadeh A^{3, 4} ; Ahmadian M^{1, 2}
Source: Zeitschrift fur Physikalische Chemie Published:2021

Abstract

The removal of metronidazole (MNZ) from aqueous solutions by the electro-persulfate (EC-PS) process was performed in combination with magnetic Fe3O4@activated carbon (AC) nanocomposite. In the first step, the Fe3O4@AC nanocomposites were synthesized and characterized using energy-dispersive X-ray spectroscopy (XRD), vibrating-sample magnetometer (VSM) and field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), mapping, and Fourier-transform infrared spectroscopy (FTIR) analysis. The effect of Fe3O4@AC, PS and EC processes were studied separately and in combination and finally, the appropriate process for MNZ removal was selected. The effect of key parameters on the EC-Fe3O4@AC-PS process including pH, Fe3O4@AC dosage, initial MNZ concentration, and PS concentration were investigated. Based on the results obtained, the Fe3O4@AC had a good structure. The MNZ removal in EC, PS, Fe3O4@AC, EC-Fe3O4@AC, EC-PS, EC-Fe3O4@AC-NaCl, EC-Fe3O4@AC-PS, and EC-Fe3O4@AC-PS-NaCl processes were 0, 0, 59.68, 62, 68.94, 67.71, 87.23 and 88%, respectively. Due to the low effect of NaCl insertion on the EC-Fe3O4@AC-PS process, it was not added into the reactor and optimum conditions for the EC-Fe3O4@AC-PS process were determined. Under ideal conditions, including MNZ = 40 mg/L, Fe3O4@AC dose = 1 g/L, pH = 3, PS concentration = 1.68 mM, current density (CD) = 0.6 mA/cm2 and time = 80 min, the MNZ removal was 92%. Kinetic study showed that the pseudo-second-order model was compatible with the obtained results. In the isotherm studies, the Langmuir model was the most consistent for the data of the present study, and the Q max for Fe3O4@AC dose from 0.25 to 1 g/L was 332 to 125 mg/g, respectively. © 2020 Walter de Gruyter GmbH, Berlin/Boston.