Examinando por Materia "LVRPA"

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  • Miniatura
    PublicaciónAcceso abierto
    Modeling and experimental evaluation of a non-isothermal photocatalytic solar reactor: temperature effect on the reaction rate kinetics
    (Universidad del Valle, 2017-07-01) Molano Mendoza, Marena; Mueses, Miguel A.; Machuca Martinez, Fiderman
    (Eng) Mathematical modeling and experimental evaluation of temperature effects on photocatalytic degradation process and kinetic of a standard pollutants using solar radiation and suspended titanium dioxide were performed in a CPC reactor at pilot scale. The model of the system includes mass balance of the batch reactor with recycle, based on global isotropic parameters. The incident radiation was modeled using empirical models adjusted using experimental data from environmental reports and optimization algorithms in function of atmospheric variations. The effect of scattering-absorption of radiation inside the reactor was estimated by solving the radiative transfer equation. The effect of the temperature was modeled using a thermal balance coupled to heat transfer equations. The kinetic implemented model was a generalized model with a modification of the Arrhenius equation. It was found that the temperature affected the reaction rates by varying the oxygen concentration during the reaction. Process performance was improved under normal operating conditions without temperature control. The mathematical model and the established solution algorithm were highly predictive, generating correlation coefficients of 0.99 and errors below 2.5%.
  • Miniatura
    PublicaciónAcceso abierto
    Modeling of a Solar Heterogeneous Photocatalytic Reactor with TiO 2 for Treatment of Wastewater Contaminated By Albendazole.
    (Universidad del Valle, 2019-07-31) Colina Marquez, José; Guerra, María Margarita; Arrieta Pérez, Rodinson
    (Eng) 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 par ameters 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 ( k T ) and adsorption constant ( K 1 ), estimated from the parameter fitting, were 9.28×10 - 4 m 1.5 ppmW - 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 TiO 2 .