This work examines the photocatalytic capacity of Fe2O3-TiO2 catalysts for inactivating Enterococcus faecalis in water and compares it to a peroxide-assisted process. The influence of H2O2, PMS, pH, and temperature is assessed. Material stability and free radical species involved in disinfection are also evaluated. The main findings indicate that Fe2O3-TiO2 photocatalysts do not improve disinfection results compared to mesoporous TiO2, achieving total disinfection after 90 min. Using PMS and H2O2 as oxidants in Catalytic Wet Peroxide Oxidation, system 0.15 mM PMS/0.5 g/L mTiO(2) under solar radiation reduced the required time to 10 min for total bacterial inactivation (extended to 30 min with diclofenac present due to competition for radicals), whereas H2O2 took approximately 70 min. The Fe2O3-TiO2 heterojunction catalysts (Cat2 – Cat5) showed no improvement, likely due to bacteria-photocatalyst interactions preventing oxidants from reacting with Fe on the catalyst surface. EPR analyses revealed hydroxyl radicals as the predominant oxidizing species (over 90% abundance). Additionally, higher pH values (>6) decreased inactivation kinetics, while increasing the temperature to 40 degrees C improved it by up to 120%. The photocatalyst showed low stability from the fourth use, with a 40% decrease in bacterial inactivation kinetics.
This work examines the photocatalytic capacity of Fe2O3-TiO2 catalysts for inactivating Enterococcus faecalis in water and compares it to a peroxide-assisted process. The influence of H2O2, PMS, pH, and temperature is assessed. Material stability and free radical species involved in disinfection are also evaluated. The main findings indicate that Fe2O3-TiO2 photocatalysts do not improve disinfection results compared to mesoporous TiO2, achieving total disinfection after 90 min. Using PMS and H2O2 as oxidants in Catalytic Wet Peroxide Oxidation, system 0.15 mM PMS/0.5 g/L mTiO(2) under solar radiation reduced the required time to 10 min for total bacterial inactivation (extended to 30 min with diclofenac present due to competition for radicals), whereas H2O2 took approximately 70 min. The Fe2O3-TiO2 heterojunction catalysts (Cat2 – Cat5) showed no improvement, likely due to bacteria-photocatalyst interactions preventing oxidants from reacting with Fe on the catalyst surface. EPR analyses revealed hydroxyl radicals as the predominant oxidizing species (over 90% abundance). Additionally, higher pH values (>6) decreased inactivation kinetics, while increasing the temperature to 40 degrees C improved it by up to 120%. The photocatalyst showed low stability from the fourth use, with a 40% decrease in bacterial inactivation kinetics. Read More
Related posts:
A comprehensive review on ultraviolet disinfection of spices and culinary seeds and its effect on quality
Penconazole and potassium upregulate antioxidant defense to conferring simulated drought tolerance in wheat plants
Neuroprotective Effect of Fructus Ligustri Lucidi in Spinal Cord Neuron Injury during H2O2‐Mediated Oxidative Stress
Biochemical responses of sorghum and maize to the impacts of different levels of water deficit and nitrogen supply
Electron Beam Irradiation Inhibited Potato Sprouting by Regulating the Metabolism of Membrane Lipid Peroxidation and Antioxidant
Effects of tree species composition on the CO2 and N2O efflux of a Mediterranean mountain forest soil