M Milagros Ballari

Heterogeneous Photocatalysis Applied to Concrete Pavement for Air Remediation

In the present work the degradation of nitrogen oxides (NOx) by concrete paving stones containing TiO2 to be applied in road construction is studied. A kinetic model is proposed to describe the photocatalytic reaction of nitric oxide (NO) in a standard flow laminar photoreactor irradiated with UV lamps. In addition the influence of several parameters that can affect the performance of these stones under outdoor conditions are investigated, such as irradiance, relative humidity and wind speed. The kinetic parameters present in the NO reaction rate are estimated employing experimental data obtained in the photoreactor. The obtained model predictions employing the determined kinetic constants are in good agreement with the experimental results of NO concentration at the reactor outlet.

Experimental Study and Modeling of the Photocatalytic Oxidation of No in Indoor Conditions

Heterogeneous photocatalytic oxidation (PCO) has shown to be a promising air purifying technology. Nitrogen monoxide (NO) is one common indoor air pollutant. The present paper addresses the PCO reaction in indoor conditions using NO as target pollutant with the gypsum plasterboard as a special substrate and carbon-doped TiO2 as photocatalyst. A photocatalytic reaction setup is introduced for the assessment of the indoor air quality. The PCO effect of the carbon-doped TiO2 is evaluated using different light wavelengths. Furthermore, the influence of the reactor volume on the PCO rate is studied. The Langmuir-Hinshelwood model is applied to describe the photocatalytic reaction mechanism. Experimental results show the validity of the L-H model in the present research. Using this model, a mathematical expression is proposed to describe the concentration change in the reactor.

Heterogeneous photocatalysis applied to indoor building material : towards an improved indoor air quality

In the present article, kinetics of the photocatalytic oxidation (PCO) of nitric oxide (NO, as a typical air pollutant) is addressed. An extended Langmuir-Hinshelwood reaction rate model is proposed to describe the PCO of NO under indoor air conditions. The derived model incorporates the influence of the indoor air conditions in the process of the PCO. The good agreement between the predictions from the model and experimental results indicates the validity of the proposed model.

The effect of various process conditions on the photocatalytic degradation of NO

This paper presents the research conducted on photocatalytic concrete products with respect to the evaluation of the effect of varying process conditions on the degradation of nitric oxide (NO). The degradation process under laboratory conditions is modeled using the Langmuir-Hinshelwood kinetic model as basic reaction model. The suitability of the model is validated by experimental data as well as data obtained from literature. Furthermore, the effect of variations of process conditions like irradiance and relative humidity on the reaction rate constant k and adsorption equilibrium constant K d are considered in the model.