UVA/TiO2–ZnO–NiO Photocatalytic Oxidation Process of Dye: Optimization and CFD Simulation

Abstract Heterogeneous photocatalysts was a promising material for removing organic pollutants. Titanium dioxide (TiO2) was a suitable photocatalyst for its cost efficiency and high stability to reduce various pollutants. Enhancing TiO2 photocatalyst performance by doping with changed metals or non-metal ions and organic compounds have been reviewed. These methods could enhance photoelectrochemical activity via: (i) by a donor of electrons via electron-donor agents that would produce particular defects in TiO2 structure and capture transporters of charge; (ii) by reducing recombination rate of the charge transporters and increasing degradation of pollutants. This study investigates the modification approaches of TiO2 that comprise methods for overcoming the essential TiO2 restrictions and enhancing the photocatalytic degradation of organic pollutants. Consequently, it emphasized on the current progress of modified-TiO2 used for different pollutants in ambient conditions. Amendment techniques, such as inorganic and organic parts as doping, are studied. The reported experimental results obtained with the photocatalytic oxidation process for degrading organic pollutants were also collected and assessed.

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Photocatalytic Oxidation Process (UV/H2O2/ZnO) in the treatment and sterilization of dairy wastewater

Acta Scientiarum Technology ◽

10.4025/actascitechnol.v35i1.11132 ◽

2013 ◽

Vol 35 (1) ◽

Cited By ~ 5

Author(s):

Priscila De Abreu ◽

Erlon Lopes Pereira ◽

Cláudio Milton Montenegro Campos ◽

Fabiano Luiz Naves

Keyword(s):

Photocatalytic Oxidation ◽

Oxidation Process ◽

Dairy Wastewater

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Experimental and Computational Analysis of NOx Photocatalytic Abatement Using Carbon-Modified TiO2 Materials

Catalysts ◽

10.3390/catal10121366 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1366

Author(s):

Tatiana Zhiltsova. ◽

Nelson Martins ◽

Mariana R. F. Silva ◽

Carla F. Da Silva ◽

Mirtha A. O. Lourenço ◽

...

Keyword(s):

Fluid Dynamics ◽

Kinetic Model ◽

Photocatalytic Oxidation ◽

Cfd Simulation ◽

Emission Spectra ◽

Chemical Kinetic ◽

Solar Light ◽

Model Parameters ◽

Chemical Kinetic Model ◽

Simulated Solar Light

In the present study, two photocatalytic graphene oxide (GO) and carbon nanotubes (CNT) modified TiO2 materials thermally treated at 300 °C (T300_GO and T300_CNT, respectively) were tested and revealed their conversion efficiency of nitrogen oxides (NOx) under simulated solar light, showing slightly better results when compared with the commercial Degussa P25 material at the initial concentration of NOx of 200 ppb. A chemical kinetic model based on the Langmuir–Hinshelwood (L-H) mechanism was employed to simulate micropollutant abatement. Modeling of the fluid dynamics and photocatalytic oxidation (PCO) kinetics was accomplished with computational fluid dynamics (CFD) approach for modeling single-phase liquid fluid flow (air/NOx mixture) with an isothermal heterogeneous surface reaction. A tuning methodology based on an extensive CFD simulation procedure was applied to adjust the kinetic model parameters toward a better correspondence between simulated and experimentally obtained data. The kinetic simulations of heterogeneous photo-oxidation of NOx carried out with the optimized parameters demonstrated a high degree of matching with the experimentally obtained NOx conversion. T300_CNT is the most active photolytic material with a degradation rate of 62.1%, followed by P25-61.4% and T300_GO-60.4%, when irradiated, for 30 min, with emission spectra similar to solar light.

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Performance of Nonconcentrating Solar Photocatalytic Oxidation Reactors: Part II—Shallow Pond Configuration

Journal of Solar Energy Engineering ◽

10.1115/1.2930069 ◽

1994 ◽

Vol 116 (1) ◽

pp. 8-13 ◽

Cited By ~ 26

Author(s):

P. Wyness ◽

J. F. Klausner ◽

D. Y. Goswami ◽

K. S. Schanze

Keyword(s):

Photocatalytic Oxidation ◽

Direct Evidence ◽

Oxidation Process ◽

Volume Ratio ◽

Order Rate Constant ◽

Solute Concentration ◽

Catalyst Loading ◽

Photocatalytic Process ◽

Initial Concentration ◽

First Order

A solar photocatalytic oxidation facility has been fabricated in which the destruction of 4-chlorophenol (4CP) is tested in three adjacent shallow pond reactors. Each of the reactors has depths of 5.1, 10.2, and 15.3 cm (2, 4, and 6 in.), respectively. It is found that 4CP is successfully oxidized with the photocatalyst, titanium dioxide (TiO2), suspended in a slurry or adhered to a fiberglass mesh. The pond reactors, however, perform better with the slurry. It has also been found that the first-order rate constant for oxidation of 4CP increases with decreasing initial concentration. For the same incident ultraviolet (UV) intensity, catalyst loading, and initial solute concentration, the oxidation rate of 4CP is invariant provided the aperture to volume ratio is fixed. It has been determined that the 4CP solution contains sufficient dissolved oxygen to support the photocatalytic oxidation process. Direct evidence is provided to demonstrate that the utilization of photons in the photocatalytic process becomes less efficient as the number of incident photons on the catalyst increases.

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Influence of Operating Parameters on Photocatalytic Oxidation of 2,4-Dichlorofenol in Aqueous Solution by TiO2/Stainless Steel Photocatalytic Membrane

Applied Sciences ◽

10.3390/app112411664 ◽

2021 ◽

Vol 11 (24) ◽

pp. 11664

Author(s):

Liliana Bobirică ◽

Constantin Bobirică ◽

Giovanina Iuliana Lupu ◽

Cristina Orbeci

Keyword(s):

Stainless Steel ◽

Photocatalytic Degradation ◽

Photocatalytic Oxidation ◽

Oxidation Process ◽

Organic Substrate ◽

Molar Ratio ◽

Operating Parameters ◽

Photocatalytic Reactor ◽

Initial Concentration ◽

Working Solution

The influence of some operating parameters of an UV photocatalytic reactor with TiO2/stainless steel photocatalytic membrane on the photocatalytic oxidation of 2,4-dichlorophenol from aqueous solutions was studied in this paper. It was shown that the pH of the working solution substantially influences the photocatalytic degradation of the organic substrate, with the degradation efficiency increasing with decreasing the pH of the working solution by a maximum corresponding to pH 3. The rate constant of the photocatalytic oxidation process is about twice as high at pH 3 comparative with pH 7 for the same initial concentration of the organic substrate. The molar ratio of hydrogen peroxide/organic substrate also influences the photocatalytic oxidation process of the organic substrate. The results obtained in this paper highlight the fact that a stoichiometric molar ratio is favorable for the photocatalytic degradation of 2,4-dichlorophenol. It has also been shown that the initial concentration of the organic substrate influences the rate of photocatalytic degradation. It appears that the rate of photocatalytic degradation decreases with the increasing of initial concentration of 2,4-dichlorophenol.

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