Modelado dinámico de procesos de ultrafiltración tangencial aplicados a la separación de macromoléculas

En la presente Tesis Doctoral se analizó la aplicación de modelos dinámicos tanto teóricos como semi-empíricos para predecir el descenso de la densidad de flujo de permeado con el tiempo debido al ensuciamiento en procesos de ultrafiltración tangencial de macromoléculas. Los fenómenos de ensuciamiento están presentes en todas las aplicaciones de los procesos de ultrafiltración y son el principal factor limitante en la aplicación de la tecnología de membranas. Se realizaron ensayos en planta piloto con dos membranas cerámicas de ultrafiltración y con una alimentación consistente en una disolución acuosa de polietilenglicol. En los ensayos experimentales se varió la velocidad tangencial, la presión transmembranal, la concentración de polietilenglicol y la temperatura. Los datos experimentales obtenidos se compararon con los resultados predichos por los modelos. Los resultados demostraron la imposibilidad de predecir de manera totalmente teórica la variación de la densidad de flujo de permeado con el tiempo bajo diferentes condiciones experimentales. Uno de los motivos es la dificultad para estimar de forma teórica todos los parámetros de los modelos. Sin embargo, por medio de los Modelos de Hermia modificados para filtración tangencial, se logró predecir con buen grado de ajuste a los resultados experimentales la variación de la densidad de flujo de permeado con el tiempo para todas las condiciones experimentales ensayadas utilizando únicamente como datos experimentales la densidad de flujo de permeado inicial y estacionaria. El resto de los parámetros se calcularon a partir de correlaciones teóricas.Vincent Vela, MC. (2006). Modelado dinámico de procesos de ultrafiltración tangencial aplicados a la separación de macromoléculas [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/1871Palanci

Evaluation of fouling resistances during the ultrafiltration of whey model solutions

[EN] In the last decades, the ultrafiltration of whey has grown in importance as a "green" technique. However, since fouling is an important drawback, researchers focused on its prediction by mathematical models. In this work, three ultrafiltration membranes of different molecular weight cut-offs and materials were used to ultrafilter whey model solutions of different protein concentrations. As a novelty, a resistance-in-series model that accounts for the time evolution of the fouling resistances was considered. The results demonstrated that the higher the protein and salt concentrations in the feed solutions were, the greater the fouling degree was. The resistance-in-series model was accurately fitted to the experimental data for each membrane and feed solution used. The results showed that the resistance due to adsorption dominated the first minutes of operation, while the membrane characteristics (surface roughness and hydrophilicity/hydrophobicity) played an important role in the growth of the cake layer. (C) 2017 Elsevier Ltd. All rights reserved.The authors of this work wish to gratefully acknowledge the financial support provided by the Spanish Ministry of Science and Innovation through its project CTM2010-20186.Corbatón Báguena, MJ.; Alvarez Blanco, S.; Vincent Vela, MC. (2018). Evaluation of fouling resistances during the ultrafiltration of whey model solutions. Journal of Cleaner Production. 172:358-367. https://doi.org/10.1016/j.jclepro.2017.10.149S35836717

Exploring the extraction of the bioactive content from the two-phase olive mill waste and further purification by ultrafiltration

[EN] The two-phase olive mill waste is enormously produced in the Mediterranean area. This major waste is significantly rich in bioactive compounds that are highly valued by industry, such as phenolic and triterpenic compounds. Here, a thorough study of the most suitable solvent, extraction time and temperature for the largevolume, solid-liquid extraction of bioactive compounds has been made, in order to achieve maximum concentrations of the target compounds. Ultrasound effect has been considered. A deep characterization of the extracts by high-performance liquid chromatography coupled with electrospray-quadrupole-time of flight-mass spectrometry (LC-ESI-qToF-MS) has contributed to evaluate the effect of the operational parameters on the extraction performance. Forty-four compounds have been found and classified in their corresponding chemical families. At the optimum experimental conditions (EtOH 50% (v/v), 40 degrees C, ultrasound-assisted), more than 6.8 mg/g of bioactive content was recovered, and it was later purified by means of ultrafiltration. The membrane UP005 retained a significant percentage of the organic matter, whereas most of the bioactive compounds were recovered in the permeate. This contributed not only to revalorize this waste, but also to reduce its organic load and phytotoxicity, thus protecting the ecosystem of the final disposal zone of the residue.Funding Grant CTM2017-88645-R, funded by MCIN/AEI/10.13039/501100011033 and by ERDF A way of making Europe. Additionally, the grant PRE2018-08524 was funded by MCIN/AEI/10.13039/501100011033 and by ESF Investing in your future. Funding for open access charge: CRUE-Universitat Politècnica de València.Sánchez-Arévalo, CM.; Iborra Clar, A.; Vincent Vela, MC.; Alvarez Blanco, S. (2022). Exploring the extraction of the bioactive content from the two-phase olive mill waste and further purification by ultrafiltration. LWT - Food Science and Technology. 165:1-12. https://doi.org/10.1016/j.lwt.2022.11374211216

Utilization of NaCl solutions to clean ultrafiltration membranes fouled by whey protein concentrates

In this work, whey protein concentrate (WPC) solutions at different concentrations (22.2, 333 and 150 g L-1) were used to foul three ultrafiltration (UF) membranes of different materials and molecular weight cut-offs (MWCOs): a polyethersulfone (PES) membrane of 5 kDa, a ceramic ZrO2-TiO2 membrane of 15 kDa and a permanently hydrophilic polyethersulfone (PESH) membrane of 30 kDa. NaCl solutions at different salt concentrations, temperatures and crossflow velocities were used to clean the UF membranes tested. The cleaning efficiency was related to the MWCO, membrane material and operating conditions during fouling and cleaning steps. NaCl solutions were able to completely clean the membranes fouled with the WPC solutions at the lowest concentration tested. As WPC concentration increased, the hydraulic cleaning efficiency (HCE) decreased. The results demonstrated that an increase in temperature and crossflow velocity of the cleaning solution caused an increase in the HCE. Regarding NaCl concentration, the HCE increased up to an optimal value. As the concentration was greater than this value, the cleaning efficiency decreased. In addition, an equation that correlates the cleaning efficiency to the operating parameters studied in this work (temperature, NaCl concentration, crossflow velocity in the cleaning procedure and WPC concentration during the fouling step) was developed and then, an optimization analysis was performed to determine the values of the parameters that lead to a 100% cleaning efficiency.The authors of this work wish to gratefully acknowledge the financial support from the Spanish Ministry of Science and Innovation through the project CTM2010-20186.Corbatón Báguena, MJ.; Alvarez Blanco, S.; Vincent Vela, MC.; Lora-García, J. (2015). Utilization of NaCl solutions to clean ultrafiltration membranes fouled by whey protein concentrates. Separation and Purification Technology. 150:95-101. https://doi.org/10.1016/j.seppur.2015.06.039S9510115

Analysis of two ultrafiltration fouling models and estimation of model parameters as a function of operational conditions

This work analyses the measure of fit of experimental data of permeate flux decline with time for ultrafiltration experiments performed with polyethylene glycol aqueous solutions to two different ultrafiltration models. A feed solution of 5 kg/m of polyethylene glycol and a monotubular ceramic membrane of - were used in the experiments. The first model considered was developed by Ho and Zydney and it considers two different fouling mechanisms: pore blocking and gel layer formation. The second model was proposed by Yee et al. It is an exponential model that considers three stages: concentration polarization, molecule deposition on the membrane surface and long-term fouling. The results show that both models give very accurate predictions for the severe fouling conditions (high transmembrane pressures and low crossflow velocities). However, both models cannot explain the experimental results obtained for all the experimental conditions tested. An equation for Ho and Zydney's model parameters as a function of operating conditions was obtained by means of multiple regression analysis.The authors of this work wish to gratefully acknowledge the financial support of the Universidad Politecnica de Valencia through the Project No. 2010.1009 and the Spanish Ministry of Science and Technology through the project CTM2010-20186.Corbatón Báguena, MJ.; Vincent Vela, MC.; Alvarez Blanco, S.; Lora García, J. (2013). Analysis of two ultrafiltration fouling models and estimation of model parameters as a function of operational conditions. Transport in Porous Media. 99(2):391-411. https://doi.org/10.1007/s11242-013-0192-4S391411992Alventosa-deLara, E., Barredo-Damas, S., Alcaina-Miranda, M.I., Iborra-Clar, M.I.: Ultrafiltration technology with a ceramic membrane for reactive dye removal: optimization of membrane performance. J. Hazard. Mater. 209–210, 492–500 (2012)Baldasso, C., Barros, T.C., Tessaro, I.C.: Concentration and purification of whey proteins by ultrafiltration. Desalination 278, 381–386 (2011)Bhattacharjee, C., Datta, S.: Analysis of polarized layer resistance during ultrafiltration of PEG-6000: an approach based on filtration theory. Sep. Purif. Technol. 33, 115–126 (2003)Buetehorn, S., Carstensen, F., Wintgens, T., Melin, T., Volmering, D., Vossenkaul, K.: Permeate flux decline in crossflow microfiltration at constant pressure. Desalination 250, 985–990 (2010)Chan, R., Chen, V.: Characterization of protein fouling on membranes: opportunities and challenges. J. Membr. Sci. 242, 169–188 (2004)Cheryan, M.: Ultrafiltration and Microfiltration Handbook. Technomic Publishing Company, Inc., Lancaster (1998)de Barros, S.T.D., Andrade, C.M.G., Mendes, E.S., Peres, L.: Study of fouling mechanism in pineapple juice clarification by ultrafiltration. J. Membr. Sci. 215, 213–224 (2003)de la Casa, E.J., Guadix, A., Ibáñez, R., Camacho, F., Guadix, E.M.: A combined fouling model to describe the influence of the electrostatic environment on the cross-flow microfiltration of BSA. J. Membr. Sci. 318, 247–254 (2008)Espina, V., Jaffrin, M.Y., Ding, L., Cancino, B.: Fractionation of pasteurized skim milk proteins by dynamic filtration. Food Res. Int. 43, 1335–1346 (2010)Fernández-Sempere, J., Ruiz-Beviá, F., García-Algado, P., Salcedo-Díaz, R.: Visualization and modeling of the polarization layer and a reversible adsorption process in PEG-10000 dead-end ultrafiltration. J. Membr. Sci. 342, 279–290 (2009)Field, R.W., Wu, D., Howell, J.A., Gupta, B.B.: Critical flux concept for microfiltration fouling. J. Membr. Sci. 100, 259–272 (1995)Hermia, J.: Constant pressure blocking filtration laws—application to powerlaw non-Newtonian fluids. Trans. IChemE 60, 183–187 (1982)Ho, C.-C., Zydney, A.L.: A combined pore blockage and cake filtration model for protein fouling during microfiltration. J. Colloid Interface Sci. 232, 389–399 (2000)Karasu, K., Yoshikawa, S., Ookawara, S., Ogawa, K., Kentish, S.E., Stevens, G.W.: A combined model for the prediction of the permeation flux during the cross-flow ultrafiltration of a whey suspension. J. Membr. Sci. 361, 71–77 (2010)Ko, M.K., Pellegrino, J.J.: Determination of osmotic pressure and fouling resistances and their effects on performance of ultrafiltration membranes. J. Membr. Sci. 74, 141–157 (1992)Lin, S.-H., Hung, C.-L., Juang, R.-S.: Applicability of the exponential time dependence of flux decline during dead-end ultrafiltration of binary protein solutions. Chem. Eng. J. 145, 211–217 (2008)Mondal, S., De, S.: A fouling model for steady state crossflow membrane filtration considering sequential intermediate pore blocking and cake formation. Sep. Purif. Technol. 75, 222–228 (2010)Mondor, M., Girard, B., Moresoli, C.: Modeling flux behaviour for membrane filtration of apple juice. Food Res. Int. 33, 539–548 (2000)Muthukumaran, S., Kentish, S.E., Ashokkumar, M., Stevens, G.W.: Mechanisms for the ultrasonic enhancement of dairy whey ultrafiltration. J. Membr. Sci. 258, 106–114 (2005)Peng, H., Tremblay, A.Y.: Membrane regeneration and filtration modeling in treating oily wastewaters. J. Membr. Sci. 324, 59–66 (2008)Popović, S., Milanović, S., Iličić, M., Djurić, M., Tekić, M.: Flux recovery of tubular ceramic membranes fouled with whey proteins. Desalination 249, 293–300 (2009)Purkait, M.K., DasGupta, S., De, S.: Resistance in series model for micellar enhanced ultrafiltration of eosin dye. J. Colloid Interface Sci. 270, 496–506 (2004)Rinaldoni, A.N., Taragaza, C.C., Campderrós, M.E., Pérez, Padilla A.: Assessing performance of skim milk ultrafiltration by using technical parameters. J. Food Eng. 92, 226–232 (2009)Santafé-Moros, A., Gozálvez-Zafrilla, J.M.: Nanofiltration study of the interaction between bicarbonate and nitrate ions. Desalination 250, 773–777 (2010)Song, L.: Flux decline in crossflow microfiltration and ultrafiltration: mechanisms and modeling of membrane fouling. J. Membr. Sci. 139, 183–200 (1998)Vincent Vela, M.C., Álvarez, Blanco S., Lora, García J., Gozálvez Zafrilla, J.M., Bergantiños, Rodríguez E.: Modelling of flux decline in crossflow ultrafiltration of macromolecules: comparison between predicted and experimental results. Desalination 204, 328–334 (2007a)Vincent Vela, M.C., Álvarez, Blanco S., Lora, García J., Gozálvez Zafrilla, J.M., Bergantiños, Rodríguez E.: Utilization of a shear induced diffusion model to predict permeate flux in the crossflow ultrafiltration of macromolecules. Desalination 206, 61–68 (2007b)Vincent Vela, M.C., Álvarez, Blanco S., Lora, García J., Bergantiños, Rodríguez E.: Analysis of membrane pore blocking models applied to the ultrafiltration of PEG. Sep. Purif. Technol. 62, 489–498 (2008a)Vincent Vela, M.C., Álvarez, Blanco S., Lora, García J., Bergantiños, Rodríguez E.: Fouling dynamics modelling in the ultrafiltration of PEGs. Desalination 222, 451–456 (2008b)Vincent Vela, M.C., Álvarez, Blanco S., Lora, García J., Bergantiños, Rodríguez E.: Analysis of membrane pore blocking models to crossflow ultrafiltration in the ultrafiltration of PEG. Chem. Eng. J. 149, 232–241 (2009)Vincent-Vela, C., Cuartas-Uribe, B., Álvarez-Blanco, S., Lora-García, J., Bergantiños-Rodríguez, E.: Analysis of ultrafiltration processes with dilatant macromolecular solutions by means of dimensionless numbers and hydrodynamic parameters. Sep. Purif. Technol. 75, 332–339 (2010)Wang, L., Song, L.: Flux decline in crossflow microfiltration and ultrafiltration: experimental verification of fouling dynamics. J. Membr. Sci. 160, 41–50 (1999)Yee, K.W.K., Wiley, D.E., Bao, J.: A unified model of the time dependence of flux decline for the long-term ultrafiltration of whey. J. Membr. Sci. 332, 69–70 (2009

Improving the Signal Propagation at 2.4 GHz Using Conductive Membranes

© 2017 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works[EN] When IEEE 802.11 at 2.4-GHz signal crosses different surfaces, it is generally reduced, but we have seen that it does not happen for all materials. Conductive membranes are able to transport electric charges when they are submerged into water with electrolytes, so we take profit of their features in order to know in which cases the received signal strength indicator (RSSI) can be improved. In order to achieve our goal, the RSSI is measured at different distances using different environments for the membranes, air, and water environment with different conductivities (distillated water, tap water, and salty water). Results show that different membranes environment produce different signal strengths. Moreover, they can be positive or negative depending on the environment of the membranes and the distance from the access point. In some cases, we registered an increase of more than 14 dBm of the signal when we were using those membranes.This work was supported in part by the "Ministerio de Ciencia e Innovacion," through the "Plan Nacional de I+D+i 2008-2011" in the "Subprograma de Proyectos de Investigacion Fundamental," project TEC2011-27516.Parra-Boronat, L.; Sendra, S.; Vincent Vela, MC.; García Gabaldón, M.; Lloret, J. (2017). Improving the Signal Propagation at 2.4 GHz Using Conductive Membranes. IEEE Systems Journal. 11(4):2315-2324. https://doi.org/10.1109/JSYST.2015.2496204S2315232411

Evolución de una Experiencia de Formación Semipresencial para una Empresa Nacional

[Otros] This paper presents a training plan in the form of blended learning carried out with professionals of the national company ADIF. Throughout this study, we will present the course content and the pursued objectives. This paper also analyzes the profile of the students included in this course and reviews, in terms of age and gender, how they impact to the class results. Most of the course is conducted through two learning platforms. But during the attendance days, students perform collaborative practice on real devices. We explain each activity incorporated to the course, virtual practices simulators, real and remote practices, exams performed and their weight over the final grade, etc..) Finally, we will show the alumni opinions and their qualifications during the years which we have followed this training plan. As we will see in the results, the best or worst acceptance of this type of teaching innovations are affected by the age of the participants and their knowledge of these new technologies.[ES] Este artículo expone un plan formativo en régimen semi-presencial llevado a cabo con profesionales de la empresa nacional ADIF. A lo largo de este estudio, se presenta en contenido del curso y los objetivos que persigue. Así mismo, analizaremos el perfil de los alumnos a los que dirigimos este curso y veremos qué alumnos recibimos, en lo referente a edades y género. La mayor parte del curso se realiza a través de 2 plataformas de aprendizaje, pero se incluyen jornadas presenciales para la realización de prácticas colaborativas sobre dispositivos reales. Se explicará cada una de las actividades incorporadas en el curso, como prácticas virtuales con simuladores, prácticas remotas reales, prácticas presenciales, exámenes a realizar y su peso sobre la nota final, etc.) Finalmente, se presentan las opiniones de los alumnos de los 3 años durante los cuales se ha seguido este plan formativo y las calificaciones obtenidas. Como veremos en los resultados, la mejor o peor aceptación de este tipo de innovaciones docentes, se ven afectadas por la edad de los participantes y su conocimiento de estas nuevas tecnologías.Sendra, S.; Jimenez, JM.; Lloret, J.; Vincent Vela, MC. (2014). Evolución de una Experiencia de Formación Semipresencial para una Empresa Nacional. Editorial Universitat Politècnica de València. 576-590. http://hdl.handle.net/10251/168736S57659

Simultaneous concentration of nutrients from anaerobically digested sludge centrate and pre-treatment of industrial effluents by forward osmosis

[EN] In the last years, forward osmosis (FO) has gained increasing prominence, new membranes are being developed and new applications are being considered. In this study, the recovery of nitrogen and phosphorus of the anaerobically digested sludge centrate was studied by FO using two industrial effluents characterized by high osmotic pressure (residual stream from an absorption process for ammonia elimination and brine from a seawater desalination facility) as draw solutions. The experiments were carried out in a laboratory plant testing two FO membranes (CTA-NW and Aquaporin Inside membrane). Results showed that nitrogen concentration was achieved with both membranes and both draw solutions. The use of the effluent from ammonia absorption enhanced of the nitrogen concentration in the feed stream to the FO membrane. The reached concentration factor in the laboratory tests was 1.61 when Aquaporin membrane was used. Phosphorus could not be concentrated because of its precipitation as calcium phosphate (confirmed by EDX analysis) as a consequence of the high calcium concentration of the municipal wastewater.This study was supported by the Spanish Ministry of Economy and Competitiveness through the project RTC-2015-3582-5-AR.Soler Cabezas, JL.; Mendoza Roca, JA.; Vincent Vela, MC.; Lujan Facundo, MJ.; Pastor Alcañiz, L. (2018). Simultaneous concentration of nutrients from anaerobically digested sludge centrate and pre-treatment of industrial effluents by forward osmosis. Separation and Purification Technology. 193:289-296. https://doi.org/10.1016/j.seppur.2017.10.058S28929619

Analysis and optimization of the influence of operating conditions in the ultrafiltration of macromolecules using a response surface methodological approach

[EN] In this work, the ultrafiltration of macromolecules was analysed using a response surface methodological approach. The behaviour of two different inorganic membranes was investigated. The membranes selected were a Carbosep M2 membrane (Orelis, France) with a molecular weight cut-off (MWCO) of 15 kDa and a Tami MSKT membrane (Tami Industries, France) with a MWCO of 5 kDa. The solute employed was polyethylene glycol of 35 kDa molecular weight. The influence of transmembrane pressure (0.1, 0.2, 0.3, 0.4 and 0.5 MPa), crossflow velocity (1, 2 and 3 m/s) and feed concentration (5, 10 and 15 g/L) on permeate flux and permeate flux decline was investigated. Analysis of variance was proved to be a useful tool to determine the effect of operating variables on both parameters. The method used demonstrated the presence of coupled effects between factors as well as squared effects that are relevant to the ultrafiltration process. The surface contours obtained from fitted models were used for the optimization of the operating conditions. The goal was to simultaneously maximize the average permeate flux and minimize the flux decline. The optimal operating conditions for the Carbosep M2 membrane were a transmembrane pressure of 0.38 MPa and a crossflow velocity of 3 m/s. The optimal operating conditions for the Tami MSKT membrane could not be determined by means of multiple response optimization due to the low accuracy of the regression model obtained for the cumulative permeate flux decline (SFD) response variable. (C) 2009 Elsevier B.V. All rights reserved.The authors of this work wish to gratefully acknowledge the financial support of the Spanish Ministry of Science and Technology (MCYT) through the project no. CTQ2005-03398.Martí Calatayud, MC.; Vincent Vela, MC.; Alvarez Blanco, S.; Lora-García, J.; Bergantinos Rodríguez, E. (2010). Analysis and optimization of the influence of operating conditions in the ultrafiltration of macromolecules using a response surface methodological approach. Chemical Engineering Journal. 156(2):337-346. https://doi.org/10.1016/j.cej.2009.10.031S337346156

A comparative study of the influence of salt concentration on the performance of an osmotic membrane bioreactor and a sequencing batch reactor

[EN] BACKGROUNDAn osmotic membrane bioreactor (OMBR) is a wastewater treatment technique that presents low energy requirements, low membrane fouling and high removal of nutrients and organic matter. However, reverse salt flux is the main disadvantage because it causes conductivity increase in the bioreactor. This study compares the performance of a sequencing batch reactor (SBR) and an OMBR in terms of chemical oxygen demand (COD) removal, soluble microbial products (SMP) and extracellular polymeric substances (EPS) production. For that, the influent conductivity in the SBR was increased as this increases conductivity in the osmotic membrane bioreactor. RESULTSComparing the results obtained at two mixed liquor suspended solids (MLSS) concentrations in terms of membrane fouling, a concentration of 5 g L-1 of MLSS was chosen for the comparison with the SBR. The SBR achieved slightly higher COD removal efficiencies than the OMBR is spite of the accumulation of cellular debris in the membrane bioreactor. The accumulation of SMP and EPS in the OMBR was also higher than in the SBR due to the cellular debris and organic matter accumulation. In both reactors the microbial activity measured in terms of standard oxygen uptake rate decreased due to the increase of salt concentration in the bioreactor. CONCLUSIONSAs a conclusion, OMBR will be especially feasible when the draw solution is a residual stream of the same industry, like tannery wastewater or table olive processing. (c) 2017 Society of Chemical IndustryThis study was supported by the Spanish Ministry of Economy and Competitiveness through the project RTC-2015-3582-5-AR.Soler Cabezas, JL.; Lujan Facundo, MJ.; Mendoza Roca, JA.; Vincent Vela, MC.; Pastor Alcañiz, L. (2018). A comparative study of the influence of salt concentration on the performance of an osmotic membrane bioreactor and a sequencing batch reactor. Journal of Chemical Technology & Biotechnology. 93(1):72-79. https://doi.org/10.1002/jctb.5321S727993