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Adolfo López Mateos, Mexico

Martinez-Delgadillo S.A.,Metropolitan Autonomous University | Mendoza-Escamilla V.X.,Metropolitan Autonomous University | Mollinedo-Ponce H.R.,SEPI ESIME Zacatenco IPN | Puebla H.,Metropolitan Autonomous University | Mendez-Contreras J.M.,Instituto Tecnologico De Orizaba
Industrial and Engineering Chemistry Research

The electroplating, leather tanning, and textile industries are facilities that discharge wastewaters contaminated with high concentrations of Cr(VI), which is carcinogenic and has negative health effects. Low-cost technologies to remove this pollutant must be generated with high-efficiency reactors. Electrochemical Cr(VI) reduction is a low-cost alternative process, which has been studied and applied with success at the laboratory level. In this work, the hydrodynamic behavior of the fluid into the sonoelectrochemical tubular flow reactor with spiral-helicoid-wire low-cost electrode material (carbon steel) was evaluated. The fluid behavior was evaluated by computational fluid dynamics (CFD). In addition, the dispersion the reactor was evaluated experimentally and by CFD. The reactor presented large dispersion that was considered into the model to describe the sonoelectrochemical process to reduce the Cr(VI) in wastewaters. Moreover, an empirical model to describe the electrochemical reduction of the Cr(VI), with and without ultrasonic irradiation, was validated experimentally at different pHs. © 2010 American Chemical Society. Source

Martinez-Delgadillo S.A.,Metropolitan Autonomous University | Mollinedo-Ponce H.,SEPI ESIME Zacatenco IPN | Mendoza-Escamilla V.,Metropolitan Autonomous University | Barrera-Diaz C.,Autonomous University of Mexico State
Chemical Engineering Journal

In Mexico, the concentration of Cr(VI) in plating industries wastewater is well above Mexican environmental regulations (0.5. mg/L). The electrochemical Cr(VI) reduction, using iron electrodes has been an alternative process, which has been applied with success to remove Cr(VI) from wastewaters. However, few studies have been performed to evaluate the flow field behavior into the electrochemical reactors. In this work, tests at a novel tubular electrochemical reactor were performed. Five different inlet flow velocities with three different inlet positions (central, lateral and tangential inlets) were tested to evaluate their effect on the reactor performance. To study the flow field behavior throughout the reactor, CFD simulations were carried out. The results showed that at low inlet velocities, the reactor dispersion has strong dependence on the inlet position. On the other hand, when the reactor was operated at higher inlet velocities, the dispersion is reduced and presented similar values for the three reactor inlets. As a consequence of the dispersion reduction in the reactor, the residence time required to reduce the Cr(VI) concentration from 1000. mg/L to <0.5. mg/L, can be decreased until 20%. © 2010 Elsevier B.V. Source

Martinez-Delgadillo S.A.,Metropolitan Autonomous University | Mollinedo P. H.R.,SEPI ESIME Zacatenco IPN | Gutierrez M.A.,Metropolitan Autonomous University | Barcelo I.D.,Metropolitan Autonomous University | Mendez J.M.,Instituto Tecnologico De Orizaba
Computers and Chemical Engineering

In the present work, the performance of a tubular electrochemical reactor operated with three different inlets (central, lateral and tangential) was evaluated. Fluid flow simulations through the electrochemical reactor were performed using computational fluid dynamics (CFD). The steady state fluid flow was simulated to visualize the velocity field behavior along the reactor for each different inlet. The type of reactor inlet affects clearly the performance of the reactor. It was found that axial velocity distribution is more homogeneous when the reactor is operated with the tangential inlet than with the other inlets. The dispersion number (Nd) and the residence time in the reactor were obtained for each type of inlet. These parameters were used to evaluate the performance of the electrochemical reactor to reduce the Cr(VI) concentration at values lower than 0.5 mg/L. The reactor operated with the tangential inlet had the best performance. © 2009 Elsevier Ltd. All rights reserved. Source

Martinez-Delgadillo S.A.,Metropolitan Autonomous University | Mollinedo-P H.,National Polytechnic Institute of Mexico | Mendoza-Escamilla V.X.,Metropolitan Autonomous University | Huerta O.,SEPI ESIME Zacatenco IPN
Chemical Engineering Transactions

Chemical precipitation, ion exchange, evaporation and reverse osmosis processes have been applied to remove hexavalent chromium Cr(VI) from industrial wastewaters. However, some of chemical precipitation methods use great quantities of chemical and flocculating that produce elevated quantities of sludge that must be treated, handled and disposed, increasing the process costs. The other methods require high capital and operating costs. The electrochemical process is an alternative method to remove Cr(VI) from industrial wastewaters process. However, in electrochemical plug flow reactors with no liquid mixing or static electrodes, iron salt film is formed on the electrodes surface (electrode passivation) because of the poor diffusion and mass transfer that reduces the Cr (VI) removal efficiency and causes greater energy consumption. Therefore, the electrochemical reactors require to be designed to provide high mass transfer between the bulk liquid and the electrodes. However, their performance generally has been evaluated as if they were a "black box". In this work, the performance of an electrochemical reactor with rotating ring electrodes was evaluated using state-of the-art computational fluid dynamics (CFD) tools at different rotational speeds to evaluate their effect on the electrochemical process to remove Cr(VI) from wastewater. Copyright © 2011, AIDIC Servizi S.r.l. Source

Peralta-Sanchez E.,SEPI ESIME Zacatenco IPN | Smith A.C.,University of Manchester | Rodriguez-Rivas J.J.,SEPI ESIME Zacatenco IPN
IEEE Transactions on Magnetics

This paper describes the development of an analytical method for predicting the steady-state response of an integrated pump-motor-containment. These pumps employ a canned line-start permanent-magnet motor providing synchronous operation and high load efficiencies. The steady-state performance of the pump motor is assessed under different operating conditions. A laboratory prototype machine is used to validate the model. © 2011 IEEE. Source

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