Removal of Methyl Orange from water under visible light using Perovskite catalyst

Lin, Kyaw (2019) Removal of Methyl Orange from water under visible light using Perovskite catalyst. Honours thesis, Murdoch University.

Abstract

Organic dyes are a group of major pollutants found in the wastewater which is discharged from many textile industries. They raised a growing public concern in terms of their environmental impact. Several treatment methods have been trialled, especially advanced oxidation processes (AOPs), e.g. photolysis and Fenton process, ozonation, sonolysis and electrochemical oxidation. Currently, extensive research has been done using TiO2 as the photocatalyst under UV light to degrade organic dyes in water. However, the process using TiO2 was found to be economically unviable because of high maintenance cost and energy consumption of UV lamp. The heterogeneous photo-Fenton process utilizing visible light has a great potential to overcome these challenges. It can treat dye-containing wastewater at room temperature by using hydroxyl radicals which are generated during the process.

This project focused on the photo-Fenton degradation of Methyl Orange (MO) using LaFeO3 (LFO) perovskites. The catalytic properties of LFO, 10 % Ag-doped LFO (10AgLFO) and 10 % Ca-doped LFO (10CaLFO) were tested in the photo-Fenton reaction under the visible light illumination at atmospheric pressure and controlled temperature.

All LFO, 10AgLFO and 10CaLFO were synthesized by a facile hydrothermal reaction. Their structural, morphological and optical properties were characterized using XRD, SEM, EDS, and UV-vis spectroscopy. The sample LFO, which was prepared using the hydrothermal method with 800 °C calcination, showed good crystallinity, small pore size and pore volume, good surface area and low band gap energy. It was proven to be the better photocatalyst as compared to 10AgLFO and 10CaLFO. Therefore, LFO was selected over 10AgLFO and 10CaLFO to investigate the effect of operation parameters, e.g. MO concentration, light source and presence of co-existing ions, on the photo-Fenton catalytic degradation of MO. Under the initial conditions: pH = 6, 10 mg /L MO concentration (no co-existing ion), 0.3 g/L H2O2, and 0.1 g/L LFO, ~70% of MO degradation rate was achieved after 120-min photo-Fenton reaction under visible light illumination.

Item Type:	Thesis (Honours)
Murdoch Affiliation(s):	Chemistry and Physics
Supervisor(s):	Li, Linda
URI:	http://researchrepository.murdoch.edu.au/id/eprint/44800

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