scholarly journals Heterogeneous Catalytic Ozonation of Aniline-Contaminated Waters: A Three-Phase Modelling Approach Using TiO2/GAC

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3448
Author(s):  
Cristian Ferreiro ◽  
Natalia Villota ◽  
José Ignacio Lombraña ◽  
María J. Rivero
Keyword(s):  
Reaction System ◽  
Catalytic Ozonation ◽  
Kinetic Constants ◽  
Catalyst Loading ◽  
Solid Catalyst ◽  
Order Kinetic ◽  
Phase Reaction ◽  
Reaction Products ◽  
Heterogeneous Catalytic ◽  
Three Phase

This work aims to study the sustainable catalytic ozonation of aniline promoted by granular active carbon (GAC) doped with TiO2. Aniline was selected as a model compound for the accelerator manufacturing industries used in the manufacture of rubber due to its environmental impact, low biodegradability, and harmful genotoxic effects on human health. Based on the evolution of total organic carbon (TOC), aniline concentration measured using high performance liquid chromatography (HPLC), pH and ozone concentration in liquid and gas phase, and catalyst loading, a three-phase reaction system has been modelled. The proposed three-phase model related the ozone transfer parameters and the pseudo-first order kinetic constants through three coefficients that involve the adsorption process, oxidation in the liquid, and the solid catalyst. The interpretation of the kinetic constants of the process allowed the predominance of the mechanism of Langmuir–Hinshelwood or modified Eley–Rideal to be elucidated. Seven intermediate aromatic reaction products, representative of the direct action of ozone and the radical pathway, were identified and quantified, as well as precursors of the appearance of turbidity, with which two possible routes of degradation of aniline being proposed.

scholarly journals Pilot scale experiments of magnesia hydration under gas-liquid-solid (three-phase) reaction system

2017 ◽  
Author(s):  
Xiaojia Tang ◽  
Qiwei Lv ◽  
Lin Yin ◽  
Yixing Nie ◽  
Qi Jin ◽  
...  
Keyword(s):  
Reaction System ◽  
Pilot Scale ◽  
Phase Reaction ◽  
Three Phase

The analysis of magnesium oxide hydration in three-phase reaction system

2014 ◽  
Vol 213 ◽  
pp. 32-37 ◽  
Author(s):  
Xiaojia Tang ◽  
Lin Guo ◽  
Chen Chen ◽  
Quan Liu ◽  
Tie Li ◽  
...  
Keyword(s):  
Magnesium Oxide ◽  
Reaction System ◽  
Phase Reaction ◽  
Three Phase

Overall Effectiveness Factor for Slab Geometry in a Three-Phase Reaction System

2014 ◽  
Vol 12 (1) ◽  
pp. 417-427 ◽  
Author(s):  
Diego E. Boldrini ◽  
Gabriela M. Tonetto ◽  
Daniel E. Damiani
Keyword(s):  
Reaction System ◽  
Effectiveness Factor ◽  
Phase Reaction ◽  
Slab Geometry ◽  
Reaction Systems ◽  
Mixed Control ◽  
Three Phase ◽  
Power Law Kinetics ◽  
Theoretical Results ◽  
Overall Effectiveness

Abstract The overall effectiveness factor for slab geometry applicable to uniform washcoats on a monolith surface for three-phase reaction systems was studied in the present work. Analytical solutions for zero-order reactions and Langmuir–Hinshelwood and power law kinetics were reported. The analysis of the theoretical results showed that not considering the geometry of the monolithic system in a proper way lead to 14% errors in reactions parameters when operating under mixed control (kinetic-internal diffusion) and negligible external mass-transfer resistances.

scholarly journals Heterogeneous Catalytic Ozonation of Phenol over Iron-based Catalysts in a Trickle Bed Reactor

2020 ◽  
Vol 30 (2) ◽  
pp. 1-13
Author(s):  
Luis Briceño Mena ◽  
Esteban Durán Herrera
Keyword(s):  
Mass Transfer ◽  
Reaction System ◽  
System Optimization ◽  
Catalytic Ozonation ◽  
Glass Beads ◽  
Axial Dispersion ◽  
Trickle Bed Reactor ◽  
Coated Glass ◽  
Heterogeneous Catalytic ◽  
Trickle Bed

The use of continuous reactors for heterogeneous catalytic ozonation is yet to be investigated in order to develop a viable technology for industrial applications. This paper presents hydrodynamic and degradation studies on the use of a co-current down flow trickle bed reactor for heterogeneous catalytic ozonation of phenol (as model pollutant) over Fe-Diatomite pellets and Fe-coated glass beads. It was found that the reactor can operate under trickle or pulsing flow regimes, promoting mass transfer augmentation. Residence time distribution data, fitted with n-CSTR and axial dispersion (ADM) models, showed low axial dispersion and high flow distribution. Just the Fe-diatomite pellets showed important phenol adsorption (16 %). Degradation experiments demonstrated that phenol conversion was substantial when using both catalysts, up to 19,7 % pollutant conversion with liquid-phase space times of just 6 s. Compared to direct ozonation, the use of the Fe-diatomite pellets and Fe-coated glass beads enhanced the reactor performance by 48 % and 23 %, respectively. It was confirmed that mass transfer is an important factor that restricts this reaction system performance; consequently, further improvement in mass transport rate is necessary for system optimization.

scholarly journals Minerals as Potential Catalysts in Heterogeneous Catalytic Ozonation: A Kinetic Study of p-CBA Degradation in Aqueous Solutions at pH 7

2021 ◽  
Vol 5 (1) ◽  
pp. 5
Author(s):  
Savvina Psaltou ◽  
Efthimia Kaprara ◽  
Manassis Mitrakas ◽  
Anastasios Zouboulis
Keyword(s):  
Kinetic Model ◽  
Kinetic Study ◽  
Raw Materials ◽  
Catalytic Ozonation ◽  
Second Order ◽  
Order Kinetic ◽  
First Order ◽  
Heterogeneous Catalytic ◽  
Order Kinetic Model ◽  
Pseudo Second Order

This study examines the removal of p-CBA via the application of heterogeneous catalytic ozonation in the presence of 13 minerals. The solids were used as raw materials or after hydrophilic/hydrophobic modification. The optimal minerals were zeolite, calcite, dolomite, and thermally treated talc. The kinetic study showed that the decomposition of ozone followed a first-order kinetic model for all ozonation systems, whereas the kinetic model of p-CBA removal depended on the materials that were applied. The catalytic degradation of p-CBA followed a second-order kinetic model, while in the presence of non-catalytic materials; the p-CBA abatement was in best agreement with the pseudo-second-order kinetic model, as single ozonation.

scholarly journals Removal of Formaldehyde by CWO

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1471
Author(s):  
Estefania Rodríguez-Carrasco ◽  
Mirella Gutiérrez-Arzaluz ◽  
Violeta Mugica-Álvarez ◽  
Miguel Torres-Rodríguez
Keyword(s):  
Oxidation Reaction ◽  
Mixed Oxides ◽  
Reaction System ◽  
Alpha Phase ◽  
Phase Reaction ◽  
Tertiary Treatment ◽  
Catalytic Wet Oxidation ◽  
Three Phase ◽  
Aqueous Effluents

A large part of the wastewater generated by the Chemical and Transformation Industries are discharged with the presence of organic pollutants, in many cases they contain refractory organic compounds such as formaldehyde in a very low concentration for their recovery to be profitable, but it is high enough for to constitute a source of important pollution, which causes a loss of biodiversity and retards sustainable development. In the present work, the elimination of formaldehyde by the catalytic wet oxidation reaction is evaluated as part of the tertiary treatment of aqueous effluents in a three-phase reaction system, using copper and cobalt mixed oxides catalysts supported in alumina (alpha phase), the results of the characterization of the catalyst used are also shown, by conventional techniques.

Heterogeneous catalytic ozonation of 2-chlorophenol queous solution with alumina as a catalyst

2001 ◽  
Vol 43 (2) ◽  
pp. 213-220 ◽  
Author(s):  
C.H. Ni ◽  
J.N. Chen
Keyword(s):  
Catalytic Ozonation ◽  
Solid Catalyst ◽  
Heterogeneous Catalytic ◽  
Ph Values ◽  
Catalyst Dosage ◽  
Reaction Constants ◽  
Kinetics Of

Heterogenous catalytic ozonation of 2-chlorophenol (2-CP) in the presence of γ-alumina as a solid catalyst has been investigated in this research. It showed that the rate for degradation of TOC could increase from 21% to 43%. The pseudo-first reaction constants of 2-CP could increase from 0.8688 min-1 to 0.1270, increasing by approximately 40%. At the same time, the consumption of ozone was only half that of ozone alone. This research also explored the effects of the catalyst dosage, pH values and removal kinetics of 2-CP. In addition, three consecutive running with the same catalyst revealed insignificant reduction of the activity. Furthermore, the elimination of toxicity was evaluated by Microtox® analysis. The detoxification was more stable and with good results.

scholarly journals Mathematical Modelling of Photocatalytic Hydrogen Production from Glucose on Ru-Doped LaFeO3

2017 ◽  
pp. 1-11
Keyword(s):  
Mathematical Model ◽  
Hydrogen Production ◽  
Irradiation Time ◽  
Reaction System ◽  
Glucose Consumption ◽  
Parameters Estimation ◽  
Model Parameters ◽  
Order Kinetic ◽  
Reaction Products ◽  
Experimental Conditions

In the present work the authors proposed a simplified mathematical model for the renewable hydrogen production by the photocatalytic degradation of glucose over an optimized Ru-doped LaFeO3 photocatalyst under UV irradiation emitted by light-emitting diodes (LEDs). To define the reaction system the analysis of liquid phase was coupled with the detection of reaction products in gaseous phase. The mathematical modeling of the system has been developed by using different kinetic approaches for glucose consumption. Model parameters estimation was realized by individuating the best agreement between the calculated values and experimental data as a function of irradiation time both for hydrogen production and glucose degradation degree evidencing that the best fitting has been obtained with zero order kinetic models. Finally, the accuracy of the model was tested in different experimental conditions, evidencing the ability of the mathematical model to be predictive.

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