scholarly journals Comprehensive Kinetics of the Photocatalytic Degradation of Emerging Pollutants in a LED-Assisted Photoreactor. S-Metolachlor as Case Study

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 48
Author(s):  
Laura Rancaño ◽  
Maria J. Rivero ◽  
Miguel Ángel Mueses ◽  
Inmaculada Ortiz
Keyword(s):  
Scale Up ◽  
Emerging Pollutants ◽  
Photon Absorption ◽  
Radiation Absorption ◽  
Reactor Performance ◽  
Photocatalytic Reactor ◽  
Operating Variables ◽  
Degradation Reactions ◽  
Volumetric Rate ◽  
Kinetics Of

Although the potential and beneficial characteristics of photocatalysis in the degradation of a good number of emerging pollutants have been widely studied and demonstrated, process design and scale-up are restrained by the lack of comprehensive models that correctly describe the performance of photocatalytic reactors. Together with the kinetics of degradation reactions, the distribution of the radiation field in heterogeneous photocatalytic systems is essential to the optimum design of the technology. Both the Local Volumetric Rate of Photon Absorption (LVRPA) and the Overall Volumetric Rate of Photon Absorption (OVRPA) help to understand this purpose. This work develops a Six-Flux radiation absorption–scattering model coupled to the Henyey–Greenstein scattering phase function to evaluate the LVRPA profile in a LED-assisted photocatalytic reactor. Moreover, the OVRPA has been calculated and integrated into the kinetic equation, accounting for the influence of the radiation distribution on the reaction rate. The model has been validated with experimental data for the degradation of S-Metolachlor (MTLC), and the set of operating variables that maximize the reactor performance, 0.5 g/L of TiO2 P25 and pH 3, has been determined.

scholarly journals Numerical modelling of a three-phase internal air-lift circulating photocatalytic reactor

2017 ◽  
Vol 76 (11) ◽  
pp. 3044-3053 ◽  
Author(s):  
Minghan Luo ◽  
Qiuwen Chen ◽  
Taeseop Jeong ◽  
Jing Chen
Keyword(s):  
Low Cost ◽  
Scale Up ◽  
Influential Factors ◽  
Phase Flow ◽  
Reactor Performance ◽  
Water And Wastewater Treatment ◽  
Photocatalytic Reactor ◽  
Three Phase ◽  
Three Phase Flow ◽  
Air Lift

Abstract The photocatalytic degradation process has been recognized as a low-cost, environmentally friendly and sustainable technology for water and wastewater treatment. As a key carrier of the photocatalytic process, the semiconductor TiO2 has been used in many studies. Analysis and modelling of hydrodynamics in the three-phase flow system can provide useful information for process design, operation and optimization of the three-phase flow photocatalytic reactor, which requires research on the mixing and flow characteristics of the interphase regions in the reactor. In this study, we modelled the hydrodynamics in an internal air-lift circulating photocatalytic reactor using an Eulerian multi-fluid approach. Localized information on phase holdup, fluid flow patterns and mixing characteristics was obtained. The simulation results revealed that the distribution of solid particle concentration depends on the flow field in the internal air-lift circulating photocatalytic reactor. The distance between the draft tube and wall of the reactor and changes in the superficial gas velocity (Ug) were found to be influential factors in reactor performance. The computational model developed could support optimizing reactor design to improve the hydrodynamics and provide guidance for scale-up.

Modeling of a Solar Heterogeneous Photocatalytic Reactor with TiO2 for Treatment of Wastewater Contaminated By Albendazole

2019 ◽  
Vol 21 (2) ◽  
pp. 1-10
Author(s):  
Jose Colina-Marquez ◽  
María Margarita Guerra ◽  
Rodinson Arrieta- Perez
Keyword(s):  
Heterogeneous Photocatalysis ◽  
Oxidation Products ◽  
Photochemical Oxidation ◽  
Photon Absorption ◽  
Catalyst Loading ◽  
Photocatalytic Reactor ◽  
Toc Removal ◽  
Volumetric Rate ◽  
Initial Ph ◽  
Flux Model

Albendazole is an anthelmintic drug with antiangiogenic properties, which means that inhibits the development of new blood vessels. This causes a serious risk for the growth of fetus during pregnancy as a result. Heterogeneous photocatalysis has been proposed as an alternative for removal of this contaminant. In this study, a solar compound parabolic collector (CPC) photocatalytic reactor was modeled and simulated in order to describe the total organic carbon (TOC) degradation of commercial albendazole. The Six Flux Model approach (SFM) was used to estimate the Local Velocity Volumetric Rate of Photon Absorption (LVRPA) coupled with a Langmuir-Hinshelwood (L-H) kinetic model in order to describe the photocatalytic degradation of the TOC content of the contaminant and its photochemical oxidation products. The parameters of the L-H model were estimated from experimental data obtained with a catalyst loading of 0.6 g/l, initial pH of 5.0 and three different initial TOC concentrations of the commercial albendazole (159.95, 75.58 and 40 ppm). The rate constant (kT) and adsorption constant (K1), estimated from the parameter fitting, were 9.28×10-4 m1.5ppmW-0.5 s-1 and 3.02 × 10-2 ppm-1, respectively. The model was validated with experimental results, achieving a TOC removal of 40% with the lowest concentration of the contaminant. By simulating the process with different catalyst loadings, the maximum TOC removal was achieved with 0.21 g/L of TiO2.

Quantum efficiencies in a multi-annular photocatalytic reactor

2007 ◽  
Vol 55 (12) ◽  
pp. 161-166 ◽  
Author(s):  
G.E. Imoberdorf ◽  
H.A. Irazoqui ◽  
A.E. Cassano ◽  
O.M. Alfano
Keyword(s):  
Mathematical Model ◽  
Quantum Efficiency ◽  
Absorption Efficiency ◽  
Radiative Energy ◽  
Radiation Absorption ◽  
Reactor Radiation ◽  
Photocatalytic Reactor ◽  
Operating Variables ◽  
Radiation Incidence

Radiative energy efficiencies of a multi-annular photocatalytic reactor were evaluated and analysed. The total quantum efficiency, defined as the ratio of the number of molecules of the pollutant reacted to the number of photons emitted by the lamp, is expressed as the product of three factors: (i) the reactor radiation incidence efficiency, (ii) the catalyst radiation absorption efficiency, and (iii) the overall reaction quantum efficiency. By means of a detailed mathematical model, the numerical values of each one were 83, 92, and 0–2.5%, respectively. The dependence of the overall reaction quantum efficiency upon operating variables was also studied.

Effect of volumetric rate of photon absorption on the kinetics of micropollutant removal by solar photo-Fenton with Fe3+-EDDS at neutral pH

2018 ◽  
Vol 331 ◽  
pp. 84-92 ◽  
Author(s):  
P. Soriano-Molina ◽  
J.L. García Sánchez ◽  
S. Malato ◽  
L.A. Pérez-Estrada ◽  
J.A. Sánchez Pérez
Keyword(s):  
Photon Absorption ◽  
Neutral Ph ◽  
Micropollutant Removal ◽  
Volumetric Rate ◽  
Kinetics Of

Effect of the Scale-Up Process on the Reactor Performance within the Riser: Simulation Using Ozone Decomposition

2021 ◽  
Author(s):  
Congjing Ren ◽  
Yao Yang ◽  
Zhengliang Huang ◽  
Jingyuan Sun ◽  
Yongrong Yang ◽  
...  
Keyword(s):  
Scale Up ◽  
Ozone Decomposition ◽  
Reactor Performance

Scale-Up Study of a Multiphase Photocatalytic Reactor—Degradation of Cyanide in Water over TiO2

2014 ◽  
Vol 48 (3) ◽  
pp. 1574-1581 ◽  
Author(s):  
Mahsa Motegh ◽  
J. Ruud van Ommen ◽  
Peter W. Appel ◽  
Michiel T. Kreutzer
Keyword(s):  
Scale Up ◽  
Photocatalytic Reactor ◽  
Scale Up Study

Water decolorization using UV radiation and hydrogen peroxide: A kinetic study

2001 ◽  
Vol 44 (5) ◽  
pp. 53-60 ◽  
Author(s):  
C.A. Martín ◽  
O.M. Alfano ◽  
A.E. Cassano
Keyword(s):  
Hydrogen Peroxide ◽  
Uv Radiation ◽  
Absorption Rate ◽  
Fulvic Acids ◽  
Photon Absorption ◽  
Contaminant Concentration ◽  
Organic Substances ◽  
Mechanistic Approach ◽  
Natural Contamination ◽  
Kinetics Of

Sometimes, provision of water for domiciliary consumption faces the problem of natural contamination originated by the presence of organic substances such as humic or fulvic acids. Very often, after conventional sanitary treatments this water exhibits a persistent yellowish coloration that affects its use. Moreover, these substances may act as precursors of tri-halomethanes formation during pre-desinfection with chlorine. This paper presents, with a simplified mechanistic approach, the intrinsic reaction kinetics of natural water decolorization employing UV radiation and hydrogen peroxide. The main variables for the model are: contaminant concentration expressed as TOC, hydrogen peroxide concentration and the photon absorption rate.

Photocatalytic degradation intrinsic kinetics of gaseous cyclohexane in a fluidized bed photocatalytic reactor

2012 ◽  
Vol 39 (4) ◽  
pp. 1711-1726 ◽  
Author(s):  
Qijin Geng ◽  
Qingming Wang ◽  
Yunchen Zhang ◽  
Lintong Wang ◽  
Huiqin Wang
Keyword(s):  
Photocatalytic Degradation ◽  
Fluidized Bed ◽  
Photocatalytic Reactor ◽  
Intrinsic Kinetics ◽  
Kinetics Of

Experimental and Kinetic Production of Ethanol Using Mucilage Juice Residues from Cocoa Processing

2018 ◽  
Vol 16 (11) ◽  
Author(s):  
Teresa Romero Cortes ◽  
Jaime A. Cuervo-Parra ◽  
Víctor José Robles-Olvera ◽  
Eduardo Rangel Cortes ◽  
Pablo A. López Pérez
Keyword(s):  
Ethanol Yield ◽  
Scale Up ◽  
Pilot Scale ◽  
Product Formation ◽  
Model Parameters ◽  
Pichia Kudriavzevii ◽  
Proposed Model ◽  
Analysis Of Results ◽  
Residual Plots ◽  
Kinetics Of

AbstractEthanol was produced using mucilage juice residues from processed cocoa with Pichia kudriavzevii in batch fermentation. Experimental results showed that maximum ethanol concentration was 13.8 g/L, ethanol yield was 0.50 g-ethanol/g glucose with a productivity of 0.25 g/L h. Likewise, a novel phenomenological model based on the mechanism of multiple parallel coupled reactions was used to describe the kinetics of substrate, enzyme, biomass and product formation. Model parameters were optimized by applying the Levenberg-Marquardt approach. Analysis of results was based on statistical metrics (such as confidence interval), sensitivity and by comparing calculated curves with the experimental data (residual plots). The efficacy of the proposed mathematical model was statistically evaluated using the dimensionless coefficient for efficiency. Results indicated that the proposed model can be applied as a way of augmenting bioethanol production from laboratory scale up to semi-pilot scale.

Kinetic Assessment of the Dry Reforming of Methane over a Solid Solution Ni–La Oxide Catalyst

2021 ◽  
Author(s):  
Victor Stivenson Sandoval-Bohorquez ◽  
Edgar M. Morales-Valencia ◽  
Carlos Omar Castillo-Araiza ◽  
Luz Marina Ballesteros Rueda ◽  
Víctor Gabriel Baldovino Medrano
Keyword(s):  
Solid Solution ◽  
Active Sites ◽  
Oxide Catalyst ◽  
Bond Cleavage ◽  
Scale Up ◽  
Active Surface ◽  
Dry Reforming ◽  
Dry Reforming Of Methane ◽  
Nickel Surface ◽  
Kinetics Of

The dry reforming of methane is a promising technology for the abatement of CH<sub>4</sub> and CO<sub>2</sub>. Solid solution Ni–La oxide catalysts are characterized by their long–term stability (100h) when tested at full conversion. The kinetics of dry reforming over this type of catalysts has been studied using both power law and Langmuir–Hinshelwood based approaches. However, these studies typically deal with fitting the net CH<sub>4</sub> rate hence disregarding competing and parallel surface processes and the different possible configurations of the active surface. In this work, we synthesized a solid solution Ni–La oxide catalyst and tested six Langmuir–Hinshelwood mechanisms considering both single and dual active sites for assessing the kinetics of dry reforming and the competing reverse water gas shift reaction and investigated the performance of the derived kinetic models. In doing this, it was found that: (1) all the net rates were better fitted by a single–site model that considered that the first C–H bond cleavage in methane occurred over a <a>metal−oxygen </a>pair site; (2) this model predicted the existence of a nearly saturated nickel surface with chemisorbed oxygen adatoms derived from the dissociation of CO<sub>2</sub>; (3) the dissociation of CO<sub>2</sub> can either be an inhibitory or an irrelevant step, and it can also modify the apparent activation energy for CH<sub>4</sub> activation. These findings contribute to a better understanding of the dry reforming reaction's kinetics and provide a robust kinetic model for the design and scale–up of the process.

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