Treatment of the micropollutants over monolith structured perovskite catalysts by innovative methods

In the context of this thesis, methylparaben which is originated from personal care products and classified as micropollutant is degraded in the presence of perovskite type catalysts synthesized on monolithic structure by innovative processes which are photocatalytic and photo-Fenton-like oxidation. Four different perovskite type catalysts (LaFeO3, BiFeO3, LaTi0.15Fe0.85O3 and BiTi0.15Fe0.85O3 on monolithic structure) were prepared by sol-gel method and characterized by BET, SEM, XRD and FT-IR analysis. A catalyst screening study was carried out with these catalysts and tested for the degradation of methylparaben and the highest degradation was observed in the presence of BiFeO3 on monolithic structure. Then, a parametric study was carried out in order to investigate the optimum conditions for the degradation of methylparaben. In accordance with the parametric study, the effect of pH (3, 5 and 7), initial hydrogen peroxide concentration (no, 0.5 mM, 1 mM and 1.5 mM), catalyst loading (no, 0.1 g/L and 0.2 g/L) and the temperature (30 °C, 50 °C and 60 °C) were investigated. According to the results of parametric study, the optimum conditions for the degradation of methylparaben were determined as pH=7, [H2O2]0=0.5 mM, 0.1 g/L catalyst loading and the degradation of methylparaben was evaluated as 82.8 % under the optimum conditions. The iron leaching amount was tested by Atomic Absorption Spectrometer (AAS) and it was 0.06 ppm for the treated water under optimum conditions. A toxicity test was carried out and 1.09 % inhibition was observed for the treated water under optimum conditions. According to the kinetic study, degradation of methylparaben was described by the second order reaction kinetic model and reaction rate constant was 0.0383, 0.1767, 0.2448 L/mg.min for 30, 50 and 60 °C, respectively. Additionally, the activation energy was calculated as approximately 54 kJ/mol.