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- Resumen es exacto "In this thesis a photocatalytic reactor model using a titanium dioxide slurry was developed. A batch laboratory scale photocatalytic reactor excited by an UVC lamp was built. Orange II was chosen as model contaminant. It was verified by means of optical microscopy that the operation in almost neutral conditions leads to the formation of agglomerates of TiO2 nanoparticles with characteristic sizes of tens of microns, which makes easier and more inexpensive the subsequent removal of the catalyst from the suspension. It was found that there is a linear relationship between the mean radius of the agglomerates and the catalyst concentration in the studied range. Optical propagation as a function of wavelength and ultrasound of different frequencies for different catalyst concentrations was studied. Based on the experimental results of diffuse reflectance, a scale function was proposed that links the extinction length of the radiation and the catalyst concentration, for different wavelengths of the incident radiation. It was determined that the excess ultrasonic attenuation (with respect to deionized water) depends linearly on the catalyst concentration and is inversely proportional to the square of the frequency. This makes it possible to estimate the concentration of the suspension as a linear function of the excess ultrasonic attenuation. Furthermore, it was found that the propagation speed of sound in the suspension coincides (within experimental uncertainty), with that of deionized water at the same temperature at all frequencies and concentrations studied. The reactor was modeled considering complete mixing and absence of direct photolysis of the model contaminant. These hypotheses were verified experimentally. The model takes into account the following aspects: (1) emission of radiation, (2) absorption and scattering of radiation, (3) mixing, and (4) degradation kinetics of the pollutant by photoconversion. The photoconversion kinetics was modeled using a system of differential equations, represented as an equivalent circuit. The parameters of the model were determined experimentally and a good agreement was obtained with the experimental data. From the developed model, the reactor parameters were optimized for the following criteria: (1) Conversion of the pollutant after 6 h of irradiation, (2) Specific energy consumption for 90% conversion and (3) Time for 90% conversion. For each of the criteria, the optimal values of electrical irradiation power, external radius of the annulus, and catalyst concentration were found. Finally, the model was applied to analyze the construction of a pilot scale reactor that has started."
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