Comparative Study of Various Preparation Methods of MnFe2O4 Nanoparticles for the Degradation of Phenol

  • Noor Nader Ibrahim Albadawi

Student thesis: Master's Thesis

Abstract

In this study, a catalytic system for water treatment has been developed and employed for phenol degradation that includes manganese ferrite nanoparticles (MnFe2O4) as a heterogeneous catalyst, peroxymonosulfate (PMS) as an oxidant, and ultraviolet (UV) radiation as an energy source (MnFe2O4/PMS/UV). Manganese ferrite nanoparticles were synthesized using three different preparation methods, including sol-gel, hydrothermal, and co-precipitation. The structure, phase-purity, morphology, crystallinity, elemental composition, and thermal stability were determined and compared using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Thermogravimetric Analysis (TGA). The influence of the various preparation methods on the catalytic activity of synthesized catalysts for phenol degradation was investigated. HPLC results revealed that the sol-gel MnFe2O4 exhibited the highest catalytic activity towards phenol degradation in the presence and absence of UV radiation. Under UV irradiation, the MnFe2O4 exhibited a maximum phenol removal efficiency of 100% in 25 minutes with an initial phenol concentration of 60 mg/L, 1.2 g/L PMS dosage, and 0.4 g/L catalyst loading. Whereas in dark reaction conditions, it had a 100% degradation in 60 minutes, with the same concentrations. Furthermore, the catalytic degradation processes were found to be dependent on numerous operating parameters, including the initial concentration of phenol, catalyst loading, PMS dosage, initial pH, and calcination temperatures. The degradation rate was enhanced by increasing the PMS dosage, increasing the MnFe2O4 catalyst loading, or decreasing the phenol concentration. Moreover, the activity of the as-prepared sol-gel MnFe2O4 was higher than the annealed ones (200°C, 400°C, and 600°C). Additionally, MnFe2O4 was successfully regenerated and reused for five degradation cycles. The kinetic studies revealed that the phenol catalytic degradation followed pseudo-first-order kinetics.
Date of AwardDec 2021
Original languageAmerican English

Keywords

  • MnFe2O4; PMS; UV; Phenol degradation.

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