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Aqueous metronidazole degradation by UV/H2O2 process in single-and multi-lamp tubular photoreactors / Melody Blythe Johnson in Industrial & engineering chemistry research, Vol. 47 N°17 (Septembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N°17 (Septembre 2008) . - p. 6525–6537 Titre : Aqueous metronidazole degradation by UV/H2O2 process in single-and multi-lamp tubular photoreactors : kinetics and reactor design Type de document : texte imprimé Auteurs : Melody Blythe Johnson, Auteur ; Mehrab Mehrvar, Auteur Année de publication : 2008 Article en page(s) : p. 6525–6537 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Aqueous  metronidazole  Kinetic  model  UV/H2O2  process Résumé : A kinetic model was developed to predict the removal of aqueous metronidazole utilizing the UV/H2O2 process. The rate constant for the reaction between metronidazole and hydroxyl radicals was determined to be 1.98 × 109 M−1 s−1. The model was able to predict an optimal initial H2O2 dose and the inhibitory effects of high H2O2 doses and bicarbonate ions in the aqueous solution. Simulations were performed for three different photoreactors treating a 6 μM solution of metronidazole at various influent H2O2 doses and photoreactor radii. The predicted removal rates of metronidazole were 4.9−13% and 14−41% for the single-lamp and multilamp photoreactors, respectively. Selection of a photoreactor radius for maximum metronidazole removal varied with influent H2O2 concentration. The lowest operational cost of $0.05 per mmol removed was projected for the multilamp photoreactor. Operationally, it was cost-effective to utilize higher UV lamp output (36W), while keeping influent H2O2 concentration low (25 mg/L). En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071637v [article] Aqueous metronidazole degradation by UV/H2O2 process in single-and multi-lamp tubular photoreactors : kinetics and reactor design [texte imprimé] / Melody Blythe Johnson, Auteur ; Mehrab Mehrvar, Auteur . - 2008 . - p. 6525–6537. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°17 (Septembre 2008) . - p. 6525–6537 Mots-clés : Aqueous  metronidazole  Kinetic  model  UV/H2O2  process Résumé : A kinetic model was developed to predict the removal of aqueous metronidazole utilizing the UV/H2O2 process. The rate constant for the reaction between metronidazole and hydroxyl radicals was determined to be 1.98 × 109 M−1 s−1. The model was able to predict an optimal initial H2O2 dose and the inhibitory effects of high H2O2 doses and bicarbonate ions in the aqueous solution. Simulations were performed for three different photoreactors treating a 6 μM solution of metronidazole at various influent H2O2 doses and photoreactor radii. The predicted removal rates of metronidazole were 4.9−13% and 14−41% for the single-lamp and multilamp photoreactors, respectively. Selection of a photoreactor radius for maximum metronidazole removal varied with influent H2O2 concentration. The lowest operational cost of $0.05 per mmol removed was projected for the multilamp photoreactor. Operationally, it was cost-effective to utilize higher UV lamp output (36W), while keeping influent H2O2 concentration low (25 mg/L). En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071637v

CFD modeling of metronidazole degradation in water by the UV / H2O2 process in single and multilamp photoreactors / Mehrab Mehrvar in Industrial & engineering chemistry research, Vol. 49 N° 11 (Juin 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 11 (Juin 2010) . - pp. 5367–5382 Titre : CFD modeling of metronidazole degradation in water by the UV / H2O2 process in single and multilamp photoreactors Type de document : texte imprimé Auteurs : Mehrab Mehrvar, Auteur ; Farhad Ein-Mozaffari, Auteur Année de publication : 2010 Article en page(s) : pp. 5367–5382 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Metronidazole  Photoreactors Résumé : A dynamic model for the degradation of aqueous metronidazole by hydrogen peroxide and ultraviolet irradiation processes (UV/H2O2) as an advanced oxidation technology (AOT) in a single lamp tubular photoreactor as well as in a multilamp tubular photoreactor is developed. The model contains the main chemical and photochemical reactions in a medium flowing in the turbulent regime. The optimal hydrogen peroxide concentrations of 75, 150, and 200 mg L−1 were predicted for different alkalinity concentrations of 0, 1.5, and 3 μM, respectively. The model is validated with distilled water as well as alkaline water at different alkalinity concentrations. The model is validated by using the experimental data reported in the open literature. The velocity field and concentration profiles for the turbulent flow using the k−ε model are determined by computational fluid dynamics (CFD). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900906e [article] CFD modeling of metronidazole degradation in water by the UV / H2O2 process in single and multilamp photoreactors [texte imprimé] / Mehrab Mehrvar, Auteur ; Farhad Ein-Mozaffari, Auteur . - 2010 . - pp. 5367–5382. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 11 (Juin 2010) . - pp. 5367–5382 Mots-clés : Metronidazole  Photoreactors Résumé : A dynamic model for the degradation of aqueous metronidazole by hydrogen peroxide and ultraviolet irradiation processes (UV/H2O2) as an advanced oxidation technology (AOT) in a single lamp tubular photoreactor as well as in a multilamp tubular photoreactor is developed. The model contains the main chemical and photochemical reactions in a medium flowing in the turbulent regime. The optimal hydrogen peroxide concentrations of 75, 150, and 200 mg L−1 were predicted for different alkalinity concentrations of 0, 1.5, and 3 μM, respectively. The model is validated with distilled water as well as alkaline water at different alkalinity concentrations. The model is validated by using the experimental data reported in the open literature. The velocity field and concentration profiles for the turbulent flow using the k−ε model are determined by computational fluid dynamics (CFD). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900906e

Dynamic performance of continuous-flow mixing of pseudoplastic fluids exhibiting yield stress in stirred reactors / Dineshkumar Patel in Industrial & engineering chemistry research, Vol. 50 N° 15 (Août 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 9377–9389 Titre : Dynamic performance of continuous-flow mixing of pseudoplastic fluids exhibiting yield stress in stirred reactors Type de document : texte imprimé Auteurs : Dineshkumar Patel, Auteur ; Farhad Ein-Mozaffari, Auteur ; Mehrab Mehrvar, Auteur Année de publication : 2011 Article en page(s) : pp. 9377–9389 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Pseudoplastic  fluids Résumé : The core objectives of this work were to characterize and optimize the continuous-flow mixing of pseudoplastic fluids exhibiting yield stress in stirred reactors. To achieve these objectives, the effects of impeller type (for the seven axial-flow impellers A100, A200, A310, A315, A320, 3AH, and 3AM and the four radial-flow impellers R500, RSB, RT, and Scaba), impeller speed (50–800 rpm), impeller diameter (T/3.2–T/1.6, where T is the tank diameter), impeller off-bottom clearance (H/3.4–H/1.7, where H is the fluid height in the vessel), inlet and outlet locations (for the four configurations top inlet–top outlet, top inlet–bottom outlet, bottom inlet–bottom outlet, and bottom inlet–top outlet), pumping directions for axial-flow impellers (upward and downward pumping), fluid height in the vessel (T/1.06–T/0.83), residence time (257–328 s), and jet velocity (0.317–3.24 m s–1) on the dynamic performance of the mixing vessel were explored. To identify nonideal flows, dynamic tests were conducted using the frequency-modulated random binary input of a brine solution with the feed. The mixing quality in the vessel was substantially improved by increasing the impeller diameter, increasing the residence time, optimizing the impeller off-bottom clearance, decreasing the fluid height, optimizing the jet velocity, and using the up-pumping axial-flow impeller. Applying these findings will lead to improved quality of products and more efficient use of power in continuous-flow mixing of yield-pseudoplastic fluids. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102388y [article] Dynamic performance of continuous-flow mixing of pseudoplastic fluids exhibiting yield stress in stirred reactors [texte imprimé] / Dineshkumar Patel, Auteur ; Farhad Ein-Mozaffari, Auteur ; Mehrab Mehrvar, Auteur . - 2011 . - pp. 9377–9389. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 9377–9389 Mots-clés : Pseudoplastic  fluids Résumé : The core objectives of this work were to characterize and optimize the continuous-flow mixing of pseudoplastic fluids exhibiting yield stress in stirred reactors. To achieve these objectives, the effects of impeller type (for the seven axial-flow impellers A100, A200, A310, A315, A320, 3AH, and 3AM and the four radial-flow impellers R500, RSB, RT, and Scaba), impeller speed (50–800 rpm), impeller diameter (T/3.2–T/1.6, where T is the tank diameter), impeller off-bottom clearance (H/3.4–H/1.7, where H is the fluid height in the vessel), inlet and outlet locations (for the four configurations top inlet–top outlet, top inlet–bottom outlet, bottom inlet–bottom outlet, and bottom inlet–top outlet), pumping directions for axial-flow impellers (upward and downward pumping), fluid height in the vessel (T/1.06–T/0.83), residence time (257–328 s), and jet velocity (0.317–3.24 m s–1) on the dynamic performance of the mixing vessel were explored. To identify nonideal flows, dynamic tests were conducted using the frequency-modulated random binary input of a brine solution with the feed. The mixing quality in the vessel was substantially improved by increasing the impeller diameter, increasing the residence time, optimizing the impeller off-bottom clearance, decreasing the fluid height, optimizing the jet velocity, and using the up-pumping axial-flow impeller. Applying these findings will lead to improved quality of products and more efficient use of power in continuous-flow mixing of yield-pseudoplastic fluids. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102388y

Free-radical-induced degradation of aqueous polyethylene Oxide by UV/H2O2 / Samira Ghafoori in Industrial & engineering chemistry research, Vol. 51 N° 46 (Novembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 14980–14993 Titre : Free-radical-induced degradation of aqueous polyethylene Oxide by UV/H2O2 : Experimental design, reaction mechanisms, and kinetic modeling Type de document : texte imprimé Auteurs : Samira Ghafoori, Auteur ; Mehrab Mehrvar, Auteur ; Philip K. Chan, Auteur Année de publication : 2013 Article en page(s) : pp. 14980–14993 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Polyethylene  Oxide  Kinetic Résumé : The advanced oxidation of aqueous polyethylene oxide (PEO) is studied using the UV/H2O2 process in a batch recirculation photoreactor. The response surface methodology (RSM), combined with quadratic programming, is used for the experimental design, statistical analysis, and optimization of the process. In the second part, a detailed mathematical model is developed to predict the total organic carbon (TOC) removal as a function of time. Continuous distribution kinetics is applied to establish the kinetic model for the photodegradation of PEO. The model is validated at different influential operating conditions using experimental data obtained by a recirculating batch photoreactor. An excellent agreement between the model predictions and the experimental data is confirmed for all experimental conditions. Also, the intrinsic rate constants are estimated using an optimization algorithm. The model provides a good insight into the free-radical-induced degradation mechanisms and kinetics that could be considered for the process optimization. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3005995 [article] Free-radical-induced degradation of aqueous polyethylene Oxide by UV/H2O2 : Experimental design, reaction mechanisms, and kinetic modeling [texte imprimé] / Samira Ghafoori, Auteur ; Mehrab Mehrvar, Auteur ; Philip K. Chan, Auteur . - 2013 . - pp. 14980–14993. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 14980–14993 Mots-clés : Polyethylene  Oxide  Kinetic Résumé : The advanced oxidation of aqueous polyethylene oxide (PEO) is studied using the UV/H2O2 process in a batch recirculation photoreactor. The response surface methodology (RSM), combined with quadratic programming, is used for the experimental design, statistical analysis, and optimization of the process. In the second part, a detailed mathematical model is developed to predict the total organic carbon (TOC) removal as a function of time. Continuous distribution kinetics is applied to establish the kinetic model for the photodegradation of PEO. The model is validated at different influential operating conditions using experimental data obtained by a recirculating batch photoreactor. An excellent agreement between the model predictions and the experimental data is confirmed for all experimental conditions. Also, the intrinsic rate constants are estimated using an optimization algorithm. The model provides a good insight into the free-radical-induced degradation mechanisms and kinetics that could be considered for the process optimization. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3005995