Kinetic model basis of ozone/light-based advanced oxidation processes: a pseudoempirical approach

2020 ◽  
Vol 6 (4) ◽  
pp. 1176-1185 ◽  
Author(s):  
Manuel Figueredo ◽  
Eva M. Rodríguez ◽  
Javier Rivas ◽  
Fernando J. Beltrán
Keyword(s):  
Kinetic Model ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Oxidation Processes ◽  
Photocatalytic Ozonation ◽  
Ozonation Process

Pseudoempirical modeling of the complex photocatalytic ozonation process.

scholarly journals Catalytic Advanced Oxidation Processes for Sulfamethoxazole Degradation

2019 ◽  
Vol 9 (13) ◽  
pp. 2652 ◽  
Author(s):  
Jéssica Martini ◽  
Carla A. Orge ◽  
Joaquim L. Faria ◽  
M. Fernando R. Pereira ◽  
O. Salomé G. P. Soares
Keyword(s):  
Carbon Nanotubes ◽  
Titanium Dioxide ◽  
Reaction Time ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Catalytic Ozonation ◽  
Ion Concentrations ◽  
Oxidation Processes ◽  
Photocatalytic Ozonation ◽  
Mineralization Degree

The degradation of sulfamethoxazole (SMX) by several advanced oxidation processes (AOPs) is carried out in the presence of different catalysts. The catalysts used consisted of carbon nanotubes (CNT), titanium dioxide (TiO2), a composite of carbon nanotubes and titanium dioxide (TiO2/CNT), and iron supported on carbon nanotubes (Fe/CNT). SMX removal was evaluated by catalytic ozonation, photocatalysis, catalytic oxidation with hydrogen peroxide, and combinations of these processes. The evolution of the SMX concentration during reaction time, the mineralization degree, the toxicity of the treated solution, and the formation of organic intermediates and ions were monitored. Ozonation catalyzed by Fe/CNT and CNT and photocatalytic ozonation in the presence of CNT presented the fastest degradation of SMX, whereas photocatalytic ozonation with CNT showed the best results in terms of organic matter removal (92% of total organic carbon (TOC) depletion). Total mineralization of the solution and almost complete reduction of toxicity was only achieved in the photocatalytic ozonation with H2O2 and Fe/CNT catalysts. The compound 3-amino-5-methylisoxazole was one of the first intermediates formed during SMX degradation. p-Benzoquinone was only formed in photocatalysis. Oxalic and oxamic acids were also detected and in most of the catalytic processes they appeared in small amounts. Ion concentrations increased with the reaction time.

scholarly journals Degradation Efficiency and Kinetics Analysis of an Advanced Oxidation Process Utilizing Ozone, Hydrogen Peroxide and Persulfate to Degrade the Dye Rhodamine B

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 974
Author(s):  
Piotr Zawadzki ◽  
Małgorzata Deska
Keyword(s):  
Hydrogen Peroxide ◽  
Rhodamine B ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation Process ◽  
Dye Degradation ◽  
Advanced Oxidation ◽  
Degradation Process ◽  
Oxidation Processes ◽  
First Order Kinetics ◽  
Ozonation Process

In this study, the effectiveness of a rhodamine B (RhB) dye degradation process at a concentration of 20 mg/L in different advanced oxidation processes—H2O2/UV, O3/UV and PDS/UV—has been studied. The use of UV in a photo-assisted ozonation process (O3/UV) proved to be the most effective method of RhB decolorization (90% after 30 min at dye concentration of 100 mg/L). The addition of sulfate radical precursors (sodium persulfate, PDS) to the reaction environment did not give satisfactory effects (17% after 30 min), compared to the PDS/UV system (70% after 30 min). No rhodamine B decolorization was observed using hydrogen peroxide as a sole reagent, whereas an effect on the degree of RhB degradation was observed when UV rays strike the sample with H2O2 (33% after 30 min). The rhodamine B degradation process followed the pseudo-first-order kinetics model. The combined PDS/O3/UV process has shown 60% color removal after 30 min of reaction time at an initial dye concentration of 100 mg/L. A similar effectiveness was obtained by only applying ozone or UV-activated persulfate, but at a concentration 2–5 times lower (20 mg/L). The results indicated that the combined PDS/O3/UV process is a promising method for high RhB concentrations (50–100 mg/L) comparing to other alternative advanced oxidation processes.

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