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Analysis of photocatalytic reactors employing the photonic efficiency and the removal efficiency parameters: degradation of radiation absorbing and nonabsorbing pollutants / Gerd Sagawe in Industrial & engineering chemistry research, Vol. 49 N° 15 (Août 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 15 (Août 2010) . - pp 6898–6908 Titre : Analysis of photocatalytic reactors employing the photonic efficiency and the removal efficiency parameters: degradation of radiation absorbing and nonabsorbing pollutants Type de document : texte imprimé Auteurs : Gerd Sagawe, Auteur ; Maria L. Satuf, Auteur ; Rodolfo J. Brandi, Auteur Année de publication : 2010 Article en page(s) : pp 6898–6908 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Photocatalytic  reactors  Photonic  Nonabsorbing  pollutants. Résumé : The photocatalytic degradation of radiation absorbing and nonabsorbing pollutants in slurry reactors is analyzed in terms of two performance parameters: the observed photonic efficiency (OPE) and the removal efficiency (RE) [Sagawe et al. Chem. Eng. Sci. 2003, 58, 2587]. The OPE proposal permits a simple approach to analyze complex reacting systems. Conversely, to calculate the RE, the modeling of radiation absorption and scattering inside the reactors is necessary, which requires the determination of the optical properties of the catalyst and the modeling of the optical effects of the reactor walls. The degradation of dichloroacetic acid, phenol, and 4-nitrophenol was studied employing aeroxide TiO2 P25 from Evonik-Degussa in well-mixed batch reactors irradiated by UV lamps. 4-Nitrophenol has the particular characteristic to compete with titania for the absorption of photons in the employed wavelength range of irradiation. Two reaction kinetics proposals were considered to interpret experimental data: a “photocatalytic” Langmuir−Hinshelwood model (the L-HPh model) and a “photocatalytic” Langmuir−Hinshelwood linear model (the L-HPh/1 model). The good agreement observed between experimental results and model simulations confirms the usefulness of the proposed OPE approximation and the more accurate information provided by the RE performance parameter. The inclusion of 4-nitrophenol allowed inference of the situation that would be encountered when treating real samples contaminated with strong radiation absorbing compounds. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901753k [article] Analysis of photocatalytic reactors employing the photonic efficiency and the removal efficiency parameters: degradation of radiation absorbing and nonabsorbing pollutants [texte imprimé] / Gerd Sagawe, Auteur ; Maria L. Satuf, Auteur ; Rodolfo J. Brandi, Auteur . - 2010 . - pp 6898–6908. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 15 (Août 2010) . - pp 6898–6908 Mots-clés : Photocatalytic  reactors  Photonic  Nonabsorbing  pollutants. Résumé : The photocatalytic degradation of radiation absorbing and nonabsorbing pollutants in slurry reactors is analyzed in terms of two performance parameters: the observed photonic efficiency (OPE) and the removal efficiency (RE) [Sagawe et al. Chem. Eng. Sci. 2003, 58, 2587]. The OPE proposal permits a simple approach to analyze complex reacting systems. Conversely, to calculate the RE, the modeling of radiation absorption and scattering inside the reactors is necessary, which requires the determination of the optical properties of the catalyst and the modeling of the optical effects of the reactor walls. The degradation of dichloroacetic acid, phenol, and 4-nitrophenol was studied employing aeroxide TiO2 P25 from Evonik-Degussa in well-mixed batch reactors irradiated by UV lamps. 4-Nitrophenol has the particular characteristic to compete with titania for the absorption of photons in the employed wavelength range of irradiation. Two reaction kinetics proposals were considered to interpret experimental data: a “photocatalytic” Langmuir−Hinshelwood model (the L-HPh model) and a “photocatalytic” Langmuir−Hinshelwood linear model (the L-HPh/1 model). The good agreement observed between experimental results and model simulations confirms the usefulness of the proposed OPE approximation and the more accurate information provided by the RE performance parameter. The inclusion of 4-nitrophenol allowed inference of the situation that would be encountered when treating real samples contaminated with strong radiation absorbing compounds. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901753k

Efficiency evaluation of different TiO2 coatings on the photocatalytic inactivation of airborne bacterial spores / Silvia M. Zacarias in Industrial & engineering chemistry research, Vol. 51 N° 42 (Octobre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13599-13608 Titre : Efficiency evaluation of different TiO2 coatings on the photocatalytic inactivation of airborne bacterial spores Type de document : texte imprimé Auteurs : Silvia M. Zacarias, Auteur ; Maria L. Satuf, Auteur ; Maria C. Vaccari, Auteur Année de publication : 2012 Article en page(s) : pp. 13599-13608 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Metabolic  inactivation  Photocatalysis  Titanium  oxide Résumé : The performance of different TiO2 coatings is compared for the photocatalytic inactivation of dry Bacillus subtilis spores dispersed on TiO2 films under UV-A radiation. Three different TiO2 coatings were assayed: Degussa P-2S, sol-gel, and composite sol―gel/Degussa P-25. The influence of the increase in the number of TiO2 layers was also studied. Furthermore, the amount of TiO2 deposited on the borosilicate glass plates and the fraction of energy effectively absorbed by the catalytic films were determined. Spectral diffuse transmittance and reflectance measurements were performed using a spectroradiometer with an integrating-sphere attachment. The net-radiation method was then applied to evaluate the fraction of energy absorbed by the coatings. To objectively compare the performance of the catalytic films, two types of efficiencies were calculated: the photonic efficiency and the quantum efficiency of inactivation. The highest quantum efficiency was obtained with the TiO2 Degussa P-2S coating with two layers. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26508183 [article] Efficiency evaluation of different TiO2 coatings on the photocatalytic inactivation of airborne bacterial spores [texte imprimé] / Silvia M. Zacarias, Auteur ; Maria L. Satuf, Auteur ; Maria C. Vaccari, Auteur . - 2012 . - pp. 13599-13608. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13599-13608 Mots-clés : Metabolic  inactivation  Photocatalysis  Titanium  oxide Résumé : The performance of different TiO2 coatings is compared for the photocatalytic inactivation of dry Bacillus subtilis spores dispersed on TiO2 films under UV-A radiation. Three different TiO2 coatings were assayed: Degussa P-2S, sol-gel, and composite sol―gel/Degussa P-25. The influence of the increase in the number of TiO2 layers was also studied. Furthermore, the amount of TiO2 deposited on the borosilicate glass plates and the fraction of energy effectively absorbed by the catalytic films were determined. Spectral diffuse transmittance and reflectance measurements were performed using a spectroradiometer with an integrating-sphere attachment. The net-radiation method was then applied to evaluate the fraction of energy absorbed by the coatings. To objectively compare the performance of the catalytic films, two types of efficiencies were calculated: the photonic efficiency and the quantum efficiency of inactivation. The highest quantum efficiency was obtained with the TiO2 Degussa P-2S coating with two layers. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26508183