Estudio electroquímico y recuperación del estaño y del paladio mediante un reactor electroquímico de compartimentos separados

La Tesis Doctoral "Estudio electroquímico y recuperación del estaño y del paladio mediante un reactor electroquímico de compartimentos separados" se centra en el estudio de la posibilidad de recuperación del estaño y del paladio procedentes de las disoluciones de activado de las industrias de metalizado de plásticos mediante la utilización de un reactor electroquímico de compartimentos separados mediante un diafragma cerámico. Con la recuperación de estos metales se pretende por una parte minimizar la contaminación producida en la etapa de activado, y por otra parte conseguir un ahorro de materias primas puesto que una vez recuperados los metales podrían ser utilizados de nuevo en el proceso de activado. Para que el proceso de activado se desarrolle de manera óptima debe de existir una relación determinada entre el Sn(II) y el Sn(IV), por tanto es necesario conocer en todo momento la concentración de ambas especies. Así en la primera parte de la Tesis se ha puesto a punto una nueva técnica polarográfica capaz de determinar el contenido en Sn(II) y en Sn(IV) del baño de activado con el objeto de evitar su degradación. El estudio electroquímico de los baños de activado ha permitido seleccionar las condiciones idóneas de trabajo, potencial de electrodo e intensidad de corriente, para recuperar ambos metales sobre la superficie del cátodo de manera conjunta o separada. Por otra parte, se ha realizado un estudio de diferentes separadores cerámicos situados entre los compartimentos del reactor electroquímico con el objetivo de seleccionar aquel cuya resistencia a la migración iónica sea la mínima pero que a la vez su resistencia a la convección y a la difusión de especies sea la máxima. Mediante el separador seleccionado se pretende evitar el paso del Sn(II) hacia el compartimiento anódico, donde se oxidaría a Sn(IV) produciendo un menor rendimiento del proceso. Por último, con los estudios previos se ha realizado la puesta a punto del reactor electroquímico donde se ha evaluado el efecto de la intensidad y el potencial de trabajo sobre los depósitos metálicos formados y sobre las principales "figuras de mérito" del reactor, como son la conversión de reactivo, la productividad específica, el rendimiento eléctrico del proceso y la energía específica consumida.Al Ministerio de Ciencia y Tecnología por su ayuda a través del financiamiento del Proyecto PPQ2000-0689-C02-01 en el cual se enmarca mi Tesis Doctoral. Al Ministerio de Educación y Cultura por la concesión de una beca predoctoral de Formación de Profesorado Universitario para el desarrollo de la Tesis.García Gabaldón, M. (2005). Estudio electroquímico y recuperación del estaño y del paladio mediante un reactor electroquímico de compartimentos separados [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/135281TESI

Study of the zinc recovery from spent pickling baths by means of an electrochemical membrane reactor using a cation-exchange membrane under galvanostatic control

The performance of a cation-exchange membrane (CEM) used for recovering zinc from real spent pickling baths is studied in this work. These spent baths contain high amounts of ZnCl2 and FeCl2 in aqueous HCl media. The results obtained with this membrane are compared with those obtained with an anion-exchange membrane (AEM) treating the same effluent. The effect of the presence or absence of initial zinc in the cathodic compartment is also studied. The absence of initial zinc in the cathodic compartment in the CEM experiments permits iron codeposition. Furthermore, the results obtained with the CEM are worse than those obtained with the AEM for all the figures of merit. This fact shows the need of filling the cathodic compartment with a synthetic zinc solution. The presence of zinc in the cathodic compartment from the beginning of the electrolysis not only inhibits iron codeposition but also favors zinc deposition as the hydrogen evolution reaction becomes a secondary reaction, improving by this way the results of all the figures of merit of the reactor with the CEM. A deep study about the effect of the applied current and the concentration of the synthetic zinc solution placed in the cathodic compartment permits to reach the equilibrium between the zinc transferred through the membrane and that deposited on the cathode. Therefore, the synthetic cathodic zinc is not consumed at any time. Moreover, under this circumstances iron codeposition is also avoided.The authors want to express their gratitude to the Generalitat Valenciana for a postgraduate Grant (GV/2010/029) and to the Ministerio de Economia y Competitividad for financing the project number CTQ2012-37450-C02-01/PPQ.Carrillo Abad, J.; García Gabaldón, M.; Pérez Herranz, V. (2014). Study of the zinc recovery from spent pickling baths by means of an electrochemical membrane reactor using a cation-exchange membrane under galvanostatic control. Separation and Purification Technology. 132:479-486. https://doi.org/10.1016/j.seppur.2014.05.052S47948613

pH effect on zinc recovery from the spent pickling baths of hot dip galvanizing industries

[EN] In this work, the pH effect on the zinc electrowinning present in the spent pickling baths (SPBs) is analysed with the aim of decreasing the energetic cost of the process. Specifically, the effect of increasing the initial pH with and without its control during the whole electrolysis experiment is studied on synthetic solutions with concentration values similar to those present in the spent pickling baths. Finally, real SPBs are treated under pH control and the results obtained are also compared with those acquired with the direct electrolysis of these SPBs in a membrane reactor. The modification of the initial pH on synthetic solutions shows an increase in zinc deposition rate as the initial pH is risen. However, the zinc redissolution phenomenon is present during the whole experiment. On the other hand, when the pH is controlled, the results obtained are much better as zinc redissolution is prevented and the hydrogen evolution reaction rate is decreased. Comparing the behaviour between the reactor under pH control and that in the presence of an anion exchange membrane, reflects zinc conversion values slightly higher for the membrane reactor due to the zinc precipitation occurring in the reactor under pH control, which is higher as the pH rises. However, the specific energy consumption is considerably higher in the membrane reactor mainly due to the ohmic drop introduced by the membrane. (C) 2016 Elsevier B.V. All rights reserved.Carrillo Abad, J.; García Gabaldón, M.; Pérez-Herranz, V. (2017). pH effect on zinc recovery from the spent pickling baths of hot dip galvanizing industries. Separation and Purification Technology. 177:21-28. doi:10.1016/j.seppur.2016.12.034S212817

Regeneration of hexavalent chromium from a simulated rinse etching solution using an electrochemical reactor with two compartments separated by a ceramic membrane

[EN] The performance of a batch electrochemical reactor with two compartments separated by a ceramic diaphragm for the regeneration of Cr(VI) from a simulated rinse etching solution has been studied under constant cell voltage mode and in galvanostatic operation. The effect of the applied current (I) and cell voltage (U) on the Figures of Merit (fractional conversion, current efficiency, space-time yield and specific energy consumption) for the Cr(III) to Cr(VI) electrochemical oxidation is analyzed. As both I and U parameters increase, the current efficiency () for the electrochemical oxidation of Cr(III) is decreased due to the oxygen evolution side reaction, which causes an increment in the specific energy consumption (Es). On the other hand, an increment of the values of I and U leads to greater values of both Cr(III) fractional conversion (X) and space-time yield () due to the oxygen turbulence-promoting action. Comparing the results obtained under both operation modes, in galvanostatic operation higher values of X,  and  coupled with lower values of Es are obtained. Hence, working in galvanostatic operation at a relatively low applied current (1.5A) is the optimum option since the energy consumed is quite low, the current efficiency is relatively high and the amount of Cr(VI) recovered is close to 70%.We wish to express our gratitude for the support of this work by the Ministerio de Ciencia e Innovacion (convention no. CTQ2008-06750-C02-01/PPQ).García Gabaldón, M.; Pérez Herranz, V.; Reyes, H. (2011). Regeneration of hexavalent chromium from a simulated rinse etching solution using an electrochemical reactor with two compartments separated by a ceramic membrane. International Journal of Electrochemical Science. 6(5):1493-1507. http://hdl.handle.net/10251/63601S149315076

Algorithm for Assessing the Convergence of a Cyclic Voltammetry to Its Limit Cycle

[EN] Cyclic voltammetry is one of today's standard electrochemical measurement techniques. What characterizes cyclic voltammetry is that potential is linearly ramped in cycles. In general, in this kind of measurements, the system tends to a stationary state, which is known as limit cycle. The common practice for assessing the voltammogram convergence is to perform a multicycle cyclic voltammetry, and visually compare the sequential cycles in order to see if there are significant changes from one cycle to the following one. The main limitation of visual comparison is its limited accuracy and its dependence on the analyst's subjectivity. In this work, an algorithm for quantitatively assessing the convergence of experimental cyclic voltammograms (CVs) was developed. The algorithm was successfully validated experimentally using two systems: it is able to determine whether the CV converged to its limit cycle, and when it converged. Moreover, the algorithm is able to quantify the measurement noise. The low computational cost of the developed algorithm allows to execute it in real time during the cyclic voltammetry measurement. In this way, it can be used in order to automate the measurement process which would decide, according to predefined convergence criteria, when to stop cycling.The authors are very grateful to the Generalitat Valenciana (Vali+d postdoctoral grant APOSTD/2018/001), to the Ministerio de Economia y Competitividad (Project CTQ2015-65202-C2-1-R), to the European Regional Development Fund (FEDER) and to the European Social Fund, for their economic support.Giner-Sanz, JJ.; Ortega Navarro, EM.; García Gabaldón, M.; Pérez-Herranz, V. (2019). Algorithm for Assessing the Convergence of a Cyclic Voltammetry to Its Limit Cycle. Journal of The Electrochemical Society. 166(6):H224-H232. https://doi.org/10.1149/2.1111906jesSH224H2321666Zoski C. G. , Handbook of electrochemistry, Elsevier, Paris (2007).Skoog D. A. West D. M. Holler F. J. Crouch S. , Fundamentals of analytical chemistry, Brook & Cole, New York (2013).Sides, W., Kassouf, N., & Huang, Q. (2019). Electrodeposition of Ferromagnetic FeCo and FeCoMn Alloy from Choline Chloride Based Deep Eutectic Solvent. Journal of The Electrochemical Society, 166(4), D77-D85. doi:10.1149/2.0181904jesZhang, S. S., Chen, J., & Wang, C. (2019). Elemental Sulfur as a Cathode Additive for Enhanced Rate Capability of Layered Lithium Transition Metal Oxides. Journal of The Electrochemical Society, 166(4), A487-A492. doi:10.1149/2.0101904jesMeng, Z., Huang, Y., Li, J., Yang, R., Wang, X., Guo, Y., … Wang, L. (2019). Deposition of Cross-Linked Dopamine and Polyethylenimine on Polypropylene Separators via One-Step Soaking Method for Li-S Batteries. Journal of The Electrochemical Society, 166(4), A546-A550. doi:10.1149/2.0351904jesWatanabe, S., Mori, D., Taminato, S., Matsuda, Y., Yamamoto, O., Takeda, Y., & Imanishi, N. (2019). Aqueous Lithium Rechargeable Battery with a Tin(II) Chloride Aqueous Cathode and a Water-Stable Lithium-Ion Conducting Solid Electrolyte. Journal of The Electrochemical Society, 166(4), A539-A545. doi:10.1149/2.0331904jesZhou, X., Pu, T., Yang, G., Ma, W., Yang, B., & Dai, Y. (2019). Origin and Effect of Oxygen Defect in Li4Ti5O12 Prepared with Carbon Source. Journal of The Electrochemical Society, 166(4), A448-A454. doi:10.1149/2.0011904jesGiner-Sanz, J. J., Ortega, E. M., & Pérez-Herranz, V. (2015). Statistical Analysis of the Effect of the Temperature and Inlet Humidities on the Parameters of a PEMFC Model. Fuel Cells, 15(3), 479-493. doi:10.1002/fuce.201400163Giner-Sanz, J. J., Ortega, E. M., & Pérez-Herranz, V. (2014). Hydrogen crossover and internal short-circuit currents experimental characterization and modelling in a proton exchange membrane fuel cell. International Journal of Hydrogen Energy, 39(25), 13206-13216. doi:10.1016/j.ijhydene.2014.06.157Naresh, V., & Martha, S. K. (2019). Carbon Coated SnO2 as a Negative Electrode Additive for High Performance Lead Acid Batteries and Supercapacitors. Journal of The Electrochemical Society, 166(4), A551-A558. doi:10.1149/2.0291904jesFan, T., Sun, P., Zhao, J., Cui, Z., & Cui, G. (2019). Facile Synthesis of Three-Dimensional Ordered Porous Amorphous Ni-P for High-Performance Asymmetric Supercapacitors. Journal of The Electrochemical Society, 166(2), D37-D43. doi:10.1149/2.0521902jesXu, L., Wang, Y., Xu, Q., & Duan, H. (2019). Comparison of the Properties of Low-Dimensional Nano-Ti/SnO2-Sb-Fe Electrodes Prepared by Different Methods. Journal of The Electrochemical Society, 166(4), E69-E76. doi:10.1149/2.0051904jesSánchez‐Rivera, M., Giner‐Sanz, J. J., Pérez‐Herranz, V., & Mestre, S. (2018). CuO improved (Sn,Sb)O2ceramic anodes for electrochemical advanced oxidation processes. International Journal of Applied Ceramic Technology, 16(3), 1274-1285. doi:10.1111/ijac.13149Giner‐Sanz, J. J., Sánchez‐Rivera, M. J., García‐Gabaldón, M., Ortega, E. M., Mestre, S., & Pérez‐Herranz, V. (2019). Improvement of the Electrochemical Behavior of (Sb, Sn, Cu)O Ceramic Electrodes as Electrochemical Advanced Oxidation Anodes. ChemElectroChem, 6(9), 2430-2437. doi:10.1002/celc.201801766Dong, S., Cui, H., Zhang, D., & Tong, M. (2019). C-reactive Protein and Glucose Electrochemical Sensors Based on Zr(IV) Organic Framework with 2,5-thiophenedicarboxylate Anion. Journal of The Electrochemical Society, 166(4), B193-B199. doi:10.1149/2.0171904jesWu, J., Zhu, Y., Yan, K., & Zhang, J. (2019). Photovoltammetry of p-Phenylenediamine Mediated by Hexacyanoferrate Immobilized on CdS-Graphene Nanocomposites. Journal of The Electrochemical Society, 166(4), H87-H93. doi:10.1149/2.0041904jesAtta, N. F., Galal, A., El-Ads, E. H., & Galal, A. E. (2019). New Insight in Fabrication of a Sensitive Nano-Magnetite/Glutamine/Carbon Based Electrochemical Sensor for Determination of Aspirin and Omeprazole. Journal of The Electrochemical Society, 166(2), B161-B172. doi:10.1149/2.1241902jesMa, K., Sinha, A., Dang, X., & Zhao, H. (2019). Electrochemical Preparation of Gold Nanoparticles-Polypyrrole Co-Decorated 2D MoS2 Nanocomposite Sensor for Sensitive Detection of Glucose. Journal of The Electrochemical Society, 166(2), B147-B154. doi:10.1149/2.1231902jesOsti, N. C., Dyatkin, B., Gallegos, A., Voneshen, D., Keum, J. K., Littrell, K., … Mamontov, E. (2019). Cation Molecular Structure Affects Mobility and Transport of Electrolytes in Porous Carbons. Journal of The Electrochemical Society, 166(4), A507-A514. doi:10.1149/2.0131904jesLoguercio, L. F., de Matos, C. F., de Oliveira, M. C., Marin, G., Khan, S., Dupont, J., … Santos, M. J. L. (2019). Polypyrrole/Ionic Liquid/Au Nanoparticle Counter-Electrodes for Dye-Sensitized Solar Cells: Improving Charge-Transfer Resistance at the CE/Electrolyte Interface. Journal of The Electrochemical Society, 166(5), H3188-H3194. doi:10.1149/2.0271905jesThomas, S., Kowalski, D., Molinari, M., & Mallet, J. (2018). Role of electrochemical process parameters on the electrodeposition of silicon from 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquid. Electrochimica Acta, 265, 166-174. doi:10.1016/j.electacta.2018.01.139Zhang, Q., Liu, X., Yin, L., Chen, P., Wang, Y., & Yan, T. (2018). Electrochemical impedance spectroscopy on the capacitance of ionic liquid–acetonitrile electrolytes. Electrochimica Acta, 270, 352-362. doi:10.1016/j.electacta.2018.03.059Viada, B. N., Juárez, A. V., Pachón Gómez, E. M., Fernández, M. A., & Yudi, L. M. (2018). Determination of the critical micellar concentration of perfluorinated surfactants by cyclic voltammetry at liquid/liquid interfaces. Electrochimica Acta, 263, 499-507. doi:10.1016/j.electacta.2017.11.053Vijayakumar, E., Yun, Y.-H., Quy, V. H. V., Lee, Y.-H., Kang, S.-H., Ahn, K.-S., & Lee, S. W. (2019). Development of Tungsten Trioxide Using Pulse and Continuous Electrodeposition and Its Properties in Electrochromic Devices. Journal of The Electrochemical Society, 166(4), D86-D92. doi:10.1149/2.0271904jesKosswattaarachchi, A. M., VanGelder, L. E., Nachtigall, O., Hazelnis, J. P., Brennessel, W. W., Matson, E. M., & Cook, T. R. (2019). Transport and Electron Transfer Kinetics of Polyoxovanadate-Alkoxide Clusters. Journal of The Electrochemical Society, 166(4), A464-A472. doi:10.1149/2.1351902jesTang, B., Zhou, J., Fang, G., Guo, S., Guo, X., Shan, L., … Liang, S. (2019). Structural Modification of V2O5 as High-Performance Aqueous Zinc-Ion Battery Cathode. Journal of The Electrochemical Society, 166(4), A480-A486. doi:10.1149/2.0081904jesLi, Y., Zhang, Y., Ma, J., Yang, L., Li, X., Zhao, E., … Yang, C. (2019). Synthesis of LiFePO4 Nanocomposite with Surface Conductive Phase by Zr Doping with Li Excess for Fast Discharging. Journal of The Electrochemical Society, 166(2), A410-A415. doi:10.1149/2.1331902jesLi, M., Li, Y., & Wang, Z. (2019). Electrochemical Reduction of Zirconium Oxide and Co-Deposition of Al-Zr Alloy from Cryolite Molten Salt. Journal of The Electrochemical Society, 166(2), D65-D68. doi:10.1149/2.1291902jesDu, L., Wu, W., Luo, C., Xu, D., Guo, H., Wang, R., … Deng, Y. (2019). Lignin-Derived Nitrogen-Doped Porous Carbon as a High-Rate Anode Material for Sodium Ion Batteries. Journal of The Electrochemical Society, 166(2), A423-A428. doi:10.1149/2.1361902jesMora-Gómez, J., García-Gabaldón, M., Ortega, E., Sánchez-Rivera, M.-J., Mestre, S., & Pérez-Herranz, V. (2018). Evaluation of new ceramic electrodes based on Sb-doped SnO2 for the removal of emerging compounds present in wastewater. Ceramics International, 44(2), 2216-2222. doi:10.1016/j.ceramint.2017.10.178Montilla, F., Morallón, E., De Battisti, A., & Vázquez, J. L. (2004). Preparation and Characterization of Antimony-Doped Tin Dioxide Electrodes. Part 1. Electrochemical Characterization. The Journal of Physical Chemistry B, 108(16), 5036-5043. doi:10.1021/jp037480bDaubinger, P., Kieninger, J., Unmüssig, T., & Urban, G. A. (2014). Electrochemical characteristics of nanostructured platinum electrodes – a cyclic voltammetry study. Phys. Chem. Chem. Phys., 16(18), 8392-8399. doi:10.1039/c4cp00342

Theoretical Determination of the Stabilization Time in Galvanostatic EIS Measurements: The Simplified Randles Cell

[EN] Usually, EIS measurements are performed in 2 steps: a stabilization step followed by an acquisition step. The first is necessary in order to ensure that the impedance is determined when the system has reached its stationary state. In this work, a theoretical framework is proposed for estimating the required stabilization time for EIS measurements. Here, it was applied to the simplest case: the simplified Randles cell. In order to calculate the required stabilization time for performing EIS measurements, a theoretical dynamic model of a Randles cell under galvanostatic sinusoidal perturbation was developed. The proposed model can be used to estimate, from a theoretical point of view, the required stabilization time for performing EIS measurements in a Randles-like system. Even though, this work focuses on the simplest case, the developed theoretical framework can be applied to any system, however complex it may be.The authors are very grateful to the Generalitat Valenciana (Vali+d postdoctoral grant APOSTD/2018/001), to the Ministerio de Economia y Competitividad (Project CTQ2015-65202-C2-1-R), to the European Regional Development Fund (FEDER) and to the European Social Fund, for their economic support.Giner-Sanz, JJ.; Ortega Navarro, EM.; García-Gabaldón, M.; Pérez-Herranz, V. (2018). Theoretical Determination of the Stabilization Time in Galvanostatic EIS Measurements: The Simplified Randles Cell. Journal of The Electrochemical Society. 165(13):E628-E636. https://doi.org/10.1149/2.0271813jesSE628E6361651

Chronopotentiometric study of ceramic cation-exchange membranes based on zirconium phosphate in contact with nickel sulfate solutions

In this article, the innovative cation-exchange membranes obtained from ceramic materials are presented. Different microporous ceramic supports were obtained from an initial mixture of alumina and kaolin, to which a varying content of starch was added in order to obtain supports with different pore size distributions. The deposition of zirconium phosphate into the porous supports generates membranes with cation-exchange properties. The fabrication of ion-exchange membranes which could resist aggressive electrolytes such as strong oxidizing spent chromium plating baths or radioactive solutions would allow the application of electrodialysis for the decontamination and regeneration of these industrial effluents. The performance of the manufactured membranes was studied in nickel sulfate solutions by means of chronopotentiometry. An increase of the membrane voltage drop during chronopotentiometric measurements was observed in some membranes, which seems to be a consequence of concentration polarization phenomena resulting from the ionic transfer occurred through the membranes. Current voltage curves were obtained for the different ceramic membranes, allowing the calculation of their ohmic resistance. The ohmic resistance of the membranes increased when the open porosity (OP) of the samples was incremented up to a value of 50%. For values of OP higher than 50%, the resistance of the membranes decreased significantly with porosity.Martí Calatayud, MC.; García Gabaldón, M.; Pérez-Herranz, V.; Sales, S.; Mestre, S. (2013). Chronopotentiometric study of ceramic cation-exchange membranes based on zirconium phosphate in contact with nickel sulfate solutions. Desalination and Water Treatment. 51(1-3):597-605. doi:10.1080/19443994.2012.714629597605511-3L. Harttinger, Handbook of Effluent Treatment and Recycling for The Metal Finishing Industry, Finishing Publications Ltd.; ASM International, Stevenage 1994.Balagopal, S., Landro, T., Zecevic, S., Sutija, D., Elangovan, S., & Khandkar, A. (1999). Selective sodium removal from aqueous waste streams with NaSicon ceramics. Separation and Purification Technology, 15(3), 231-237. doi:10.1016/s1383-5866(98)00104-xHobbs, D. . (1999). Caustic recovery from alkaline nuclear waste by an electrochemical separation process. Separation and Purification Technology, 15(3), 239-253. doi:10.1016/s1383-5866(98)00105-1Dzyazko, Y. S., Mahmoud, A., Lapicque, F., & Belyakov, V. N. (2006). Cr(VI) transport through ceramic ion-exchange membranes for treatment of industrial wastewaters. Journal of Applied Electrochemistry, 37(2), 209-217. doi:10.1007/s10800-006-9243-7García-Gabaldón, M., Pérez-Herranz, V., Sánchez, E., & Mestre, S. (2006). Effect of porosity on the effective electrical conductivity of different ceramic membranes used as separators in eletrochemical reactors. Journal of Membrane Science, 280(1-2), 536-544. doi:10.1016/j.memsci.2006.02.007Linkov, V. ., & Belyakov, V. . (2001). Novel ceramic membranes for electrodialysis. Separation and Purification Technology, 25(1-3), 57-63. doi:10.1016/s1383-5866(01)00090-9Tripathi, B. P., & Shahi, V. K. (2007). SPEEK–zirconium hydrogen phosphate composite membranes with low methanol permeability prepared by electro-migration and in situ precipitation. Journal of Colloid and Interface Science, 316(2), 612-621. doi:10.1016/j.jcis.2007.08.038Clearfield, A., & Smith, G. D. (1969). Crystallography and structure of .alpha.-zirconium bis(monohydrogen orthophosphate) monohydrate. Inorganic Chemistry, 8(3), 431-436. doi:10.1021/ic50073a005Alberti, G., Bernasconi, M. G., Casciola, M., & Costantino, U. (1978). Ion exchange of some divalent and trivalent cations on the surface of zirconium acid phosphate micro-crystals. Journal of Chromatography A, 160(1), 109-115. doi:10.1016/s0021-9673(00)91786-2Yaroslavtsev, A. B. (2003). Ion DiffusionThrow Interface in Heterogeneous Solid Systems with the Modified Surface. Defect and Diffusion Forum, 216-217, 133-140. doi:10.4028/www.scientific.net/ddf.216-217.133Yaroslavtsev, A. B. (2009). Composite materials with ionic conductivity: from inorganic composites to hybrid membranes. Russian Chemical Reviews, 78(11), 1013-1029. doi:10.1070/rc2009v078n11abeh004066Yaroslavtsev, A. B., Nikonenko, V. V., & Zabolotsky, V. I. (2003). Ion transfer in ion-exchange and membrane materials. Russian Chemical Reviews, 72(5), 393-421. doi:10.1070/rc2003v072n05abeh000797Davis, M. E. (2002). Ordered porous materials for emerging applications. Nature, 417(6891), 813-821. doi:10.1038/nature00785Taky, M., Pourcelly, G., Lebon, F., & Gavach, C. (1992). Polarization phenomena at the interfaces between an electrolyte solution and an ion exchange membrane. Journal of Electroanalytical Chemistry, 336(1-2), 171-194. doi:10.1016/0022-0728(92)80270-eSistat, P., & Pourcelly, G. (1997). Chronopotentiometric response of an ion-exchange membrane in the underlimiting current-range. Transport phenomena within the diffusion layers. Journal of Membrane Science, 123(1), 121-131. doi:10.1016/s0376-7388(96)00210-4Pismenskaia, N., Sistat, P., Huguet, P., Nikonenko, V., & Pourcelly, G. (2004). Chronopotentiometry applied to the study of ion transfer through anion exchange membranes. Journal of Membrane Science, 228(1), 65-76. doi:10.1016/j.memsci.2003.09.012Martí-Calatayud, M. C., García-Gabaldón, M., Pérez-Herranz, V., & Ortega, E. (2011). Determination of transport properties of Ni(II) through a Nafion cation-exchange membrane in chromic acid solutions. Journal of Membrane Science, 379(1-2), 449-458. doi:10.1016/j.memsci.2011.06.014García-Gabaldón, M., Pérez-Herranz, V., & Ortega, E. (2011). Evaluation of two ion-exchange membranes for the transport of tin in the presence of hydrochloric acid. Journal of Membrane Science, 371(1-2), 65-74. doi:10.1016/j.memsci.2011.01.015GARCIAGABALDON, M., PEREZHERRANZ, V., SANCHEZ, E., & MESTRE, S. (2008). Effect of tin concentration on the electrical properties of ceramic membranes used as separators in electrochemical reactors. Journal of Membrane Science, 323(1), 213-220. doi:10.1016/j.memsci.2008.06.03

Un modelo simple de Simulink de un sistema de conductividad para explorar el desempeño de un predictor de Smith

[EN] In this work, a simple Simulink® model of a conductivity control system, based on a Smith’s predictor, is presented. This model has three main didactic outcomes. First, it allows to show to the students how a computational tool can be used to solve problems that would require a fair amount of work if they were solved analytically. Second, it allows to present an example of advanced controller: the Smith’s predictor. Finally, using this model, students can “play” with the system in order to study the effect of the different system and controller parameters on the performance of the controlled system.[ES] En este trabajo se presenta un modelo sencillo de Simulink de un sistema de control de conductividad, basado en un predictor de Smith. Este modelo tiene tres objetivos didácticos principales. En primer lugar, permite mostrar a los estudiantes cómo se puede usar una herramienta computacional para resolver problemas que requerirán una cantidad considerable de trabajo si se resolvieran analíticamente. En segundo lugar, permite presentar un ejemplo de controlador avanzado: el predictor de Smith. En último lugar, empleando este modelo los estudiantes pueden "jugar" con el sistema para estudiar el efecto de los diferentes parámetros del sistema y del controlador sobre el desempeño del sistema controlado.The authors are very grateful to the Generalitat Valenciana and to the European Social Fund, for their economic support in the form of Vali+d postdoctoral grant (APOSTD-2018- 001)Giner-Sanz, JJ.; García Gabaldón, M.; Ortega Navarro, EM.; Pérez Herranz, V. (2020). A simple Simulink® model of a conductivity system for exploring the performance of a Smith’s predictor. Modelling in Science Education and Learning. 13(1):13-20. https://doi.org/10.4995/msel.2020.12111OJS1320131Ambrose, S.A., Bridges, M.W., DiPietro, M., Lovett, M.C., Norman, M.K. (2010). What factors moti-vate students to learn. How learning works: Seven research based principles for smart teaching, 66-90. New York, USA: John Wiley & Sons.Astrom, K., Ostberg, A.B. (1986). A teaching laboratory for process control. IEEE Control Systems Magazine 6, 37-42. https://doi.org/10.1109/MCS.1986.1105142Edgar, T.F., Ogunnaike, B.A., Downs, J.J., Muske, K.R., Bequette, B.W. (2006). Renovating the undergraduate process control course. Computers & chemical engineering 30, 1749-1762. https://doi.org/10.1016/j.compchemeng.2006.05.012Giner-Sanz, J.J., García-Gabaldón, M., Ortega, E.M., Pérez-Herranz, V. (2014). A simple Simulink® model of a conductivity system for exploring PID controller performance. IV Congreso de Innovación Docente en Ingeniería Química (CIDIQ). Santander, Spain.Hernández-Armenteros, J., Pérez-García, J.A. (2018). La Universidad Española en Cifras 2016-2017. Valencia, Spain: Crue Universidades Españolas.Johansson, K.H., Horch, A., Wijk, O., Hansson, A. (1999). Teaching multivariable control using the quadruple-tank process. 38th IEEE Conference on Decision and Control. Phoenix, USA. https://doi.org/10.1109/CDC.1999.832889Salmerón-Manzano, E., Manzano-Agugliaro, F. (2018). The Higher Education Sustainability through Virtual Laboratories: The Spanish University as Case of Study. Sustainability 10, 4040. https://doi.org/10.3390/su1011404

Chronopotentiometric study of the transport of phosphoric acid anions through an anion-exchange membrane under different pH values

[EN] Phosphate is the main cause of eutrophication in many water bodies. Its presence in waters is associated to the fact that is not completely removed in conventional wastewater treatment plants. On the other side, phosphate rocks are a non-renewable resource and considered as a critical raw material. A membrane separation process, able to recover phosphate from wastewater, is a promising process to avoid pollution and to reuse phosphate. This paper investigates the transport of salts of phosphoric acid through an anion-exchange membrane (AEM) by means of chronopotentiograms and polarization curves (CVCs). The presence of multiple transition times in the chronopotentiograms and the corresponding limiting current densities in the CVCs indicate a change in the species being transported in the membrane/diffusion boundary layer system, due to the hydrolysis reactions that take place when the concentration polarization is reached. Under the experimental conditions tested, coupled convection (gravitational and elctroconvection) occurs when a certain threshold in the membrane voltage drop is surpassed independently of the electrolyte concentration. However, at high pH values, only one transition time in the chronopotentiograms, due to the transfer of OH- ions with greater concentration and mobility. This fact is reflected in the CVCs by the large plateaus obtained, which hinders the occurrence of coupled convection phenomena, and consequently, water splitting can be considered as the main mechanism responsible for the overlimiting regime.The authors wish to thank the financial support from FINEP, FAPERGS, CAPES and CNPq (Brazil), from the BRICS-STI/CNPq (BRICS STI Framework Programme), from the European Union through the Erasmus Mundus Program (EBW +) and from the CYTED (Network 318RT0551).Gally, C.; García Gabaldón, M.; Ortega Navarro, EM.; Bernardes, A.; Pérez-Herranz, V. (2020). Chronopotentiometric study of the transport of phosphoric acid anions through an anion-exchange membrane under different pH values. Separation and Purification Technology. 238:1-10. https://doi.org/10.1016/j.seppur.2019.116421S110238Cordell, D., Drangert, J.-O., & White, S. (2009). The story of phosphorus: Global food security and food for thought. Global Environmental Change, 19(2), 292-305. doi:10.1016/j.gloenvcha.2008.10.009Cordell, D., Rosemarin, A., Schröder, J. J., & Smit, A. L. (2011). Towards global phosphorus security: A systems framework for phosphorus recovery and reuse options. Chemosphere, 84(6), 747-758. doi:10.1016/j.chemosphere.2011.02.032Van Vuuren, D. P., Bouwman, A. F., & Beusen, A. H. W. (2010). Phosphorus demand for the 1970–2100 period: A scenario analysis of resource depletion. Global Environmental Change, 20(3), 428-439. doi:10.1016/j.gloenvcha.2010.04.004Gilbert, N. (2009). Environment: The disappearing nutrient. Nature, 461(7265), 716-718. doi:10.1038/461716aHao, X., Wang, C., van Loosdrecht, M. C. M., & Hu, Y. (2013). Looking Beyond Struvite for P-Recovery. Environmental Science & Technology, 47(10), 4965-4966. doi:10.1021/es401140sArnaldos, M., & Pagilla, K. (2010). Effluent dissolved organic nitrogen and dissolved phosphorus removal by enhanced coagulation and microfiltration. Water Research, 44(18), 5306-5315. doi:10.1016/j.watres.2010.06.066Babatunde, A. O., & Zhao, Y. Q. (2010). Equilibrium and kinetic analysis of phosphorus adsorption from aqueous solution using waste alum sludge. Journal of Hazardous Materials, 184(1-3), 746-752. doi:10.1016/j.jhazmat.2010.08.102Kralchevska, R. P., Prucek, R., Kolařík, J., Tuček, J., Machala, L., Filip, J., … Zbořil, R. (2016). Remarkable efficiency of phosphate removal: Ferrate(VI)-induced in situ sorption on core-shell nanoparticles. Water Research, 103, 83-91. doi:10.1016/j.watres.2016.07.021Maher, C., Neethling, J. B., Murthy, S., & Pagilla, K. (2015). Kinetics and capacities of phosphorus sorption to tertiary stage wastewater alum solids, and process implications for achieving low-level phosphorus effluents. Water Research, 85, 226-234. doi:10.1016/j.watres.2015.08.025Furuya, K., Hafuka, A., Kuroiwa, M., Satoh, H., Watanabe, Y., & Yamamura, H. (2017). Development of novel polysulfone membranes with embedded zirconium sulfate-surfactant micelle mesostructure for phosphate recovery from water through membrane filtration. Water Research, 124, 521-526. doi:10.1016/j.watres.2017.08.005Zhang, Y., Desmidt, E., Van Looveren, A., Pinoy, L., Meesschaert, B., & Van der Bruggen, B. (2013). Phosphate Separation and Recovery from Wastewater by Novel Electrodialysis. Environmental Science & Technology, 47(11), 5888-5895. doi:10.1021/es4004476Valverde-Pérez, B., Wágner, D. S., Lóránt, B., Gülay, A., Smets, B. F., & Plósz, B. G. (2016). Short-sludge age EBPR process – Microbial and biochemical process characterisation during reactor start-up and operation. Water Research, 104, 320-329. doi:10.1016/j.watres.2016.08.026Chen, X., Zhou, H., Zuo, K., Zhou, Y., Wang, Q., Sun, D., … Huang, X. (2017). Self-sustaining advanced wastewater purification and simultaneous in situ nutrient recovery in a novel bioelectrochemical system. Chemical Engineering Journal, 330, 692-697. doi:10.1016/j.cej.2017.07.130Le Corre, K. S., Valsami-Jones, E., Hobbs, P., & Parsons, S. A. (2009). Phosphorus Recovery from Wastewater by Struvite Crystallization: A Review. Critical Reviews in Environmental Science and Technology, 39(6), 433-477. doi:10.1080/10643380701640573Ueno, Y., & Fujii, M. (2001). Three Years Experience of Operating and Selling Recovered Struvite from Full-Scale Plant. Environmental Technology, 22(11), 1373-1381. doi:10.1080/09593332208618196Battistoni, P., Boccadoro, R., Fatone, F., & Pavan, P. (2005). Auto-Nucleation and Crystal Growth of Struvite in a Demonstrative Fluidized Bed Reactor (FBR). Environmental Technology, 26(9), 975-982. doi:10.1080/09593332608618486Liu, R., Wang, Y., Wu, G., Luo, J., & Wang, S. (2017). Development of a selective electrodialysis for nutrient recovery and desalination during secondary effluent treatment. Chemical Engineering Journal, 322, 224-233. doi:10.1016/j.cej.2017.03.149Ren, S., Li, M., Sun, J., Bian, Y., Zuo, K., Zhang, X., … Huang, X. (2017). A novel electrochemical reactor for nitrogen and phosphorus recovery from domestic wastewater. Frontiers of Environmental Science & Engineering, 11(4). doi:10.1007/s11783-017-0983-xWimalasiri, Y., Mossad, M., & Zou, L. (2015). Thermodynamics and kinetics of adsorption of ammonium ions by graphene laminate electrodes in capacitive deionization. Desalination, 357, 178-188. doi:10.1016/j.desal.2014.11.015Huang, G.-H., Chen, T.-C., Hsu, S.-F., Huang, Y.-H., & Chuang, S.-H. (2013). Capacitive deionization (CDI) for removal of phosphate from aqueous solution. Desalination and Water Treatment, 52(4-6), 759-765. doi:10.1080/19443994.2013.826331Wang, X., Wang, Y., Zhang, X., Feng, H., Li, C., & Xu, T. (2013). Phosphate Recovery from Excess Sludge by Conventional Electrodialysis (CED) and Electrodialysis with Bipolar Membranes (EDBM). Industrial & Engineering Chemistry Research, 52(45), 15896-15904. doi:10.1021/ie4014088Ebbers, B., Ottosen, L. M., & Jensen, P. E. (2015). Electrodialytic treatment of municipal wastewater and sludge for the removal of heavy metals and recovery of phosphorus. Electrochimica Acta, 181, 90-99. doi:10.1016/j.electacta.2015.04.097Pismenskaya, N., Nikonenko, V., Auclair, B., & Pourcelly, G. (2001). Transport of weak-electrolyte anions through anion exchange membranes. Journal of Membrane Science, 189(1), 129-140. doi:10.1016/s0376-7388(01)00405-7Belashova, E. D., Kharchenko, O. A., Sarapulova, V. V., Nikonenko, V. V., & Pismenskaya, N. D. (2017). Effect of Protolysis Reactions on the Shape of Chronopotentiograms of a Homogeneous Anion-Exchange Membrane in NaH2PO4 Solution. Petroleum Chemistry, 57(13), 1207-1218. doi:10.1134/s0965544117130035Belashova, E. D., Pismenskaya, N. D., Nikonenko, V. V., Sistat, P., & Pourcelly, G. (2017). Current-voltage characteristic of anion-exchange membrane in monosodium phosphate solution. Modelling and experiment. Journal of Membrane Science, 542, 177-185. doi:10.1016/j.memsci.2017.08.002Melnikova, E. D., Pismenskaya, N. D., Bazinet, L., Mikhaylin, S., & Nikonenko, V. V. (2018). Effect of ampholyte nature on current-voltage characteristic of anion-exchange membrane. Electrochimica Acta, 285, 185-191. doi:10.1016/j.electacta.2018.07.186Paltrinieri, L., Poltorak, L., Chu, L., Puts, T., van Baak, W., Sudhölter, E. J. R., & de Smet, L. C. P. M. (2018). Hybrid polyelectrolyte-anion exchange membrane and its interaction with phosphate. Reactive and Functional Polymers, 133, 126-135. doi:10.1016/j.reactfunctpolym.2018.10.005Rybalkina, O., Tsygurina, K., Melnikova, E., Mareev, S., Moroz, I., Nikonenko, V., & Pismenskaya, N. (2019). Partial Fluxes of Phosphoric Acid Anions through Anion-Exchange Membranes in the Course of NaH2PO4 Solution Electrodialysis. International Journal of Molecular Sciences, 20(14), 3593. doi:10.3390/ijms20143593Martí-Calatayud, M. C., Buzzi, D. C., García-Gabaldón, M., Bernardes, A. M., Tenório, J. A. S., & Pérez-Herranz, V. (2014). Ion transport through homogeneous and heterogeneous ion-exchange membranes in single salt and multicomponent electrolyte solutions. Journal of Membrane Science, 466, 45-57. doi:10.1016/j.memsci.2014.04.033Benvenuti, T., García-Gabaldón, M., Ortega, E. M., Rodrigues, M. A. S., Bernardes, A. M., Pérez-Herranz, V., & Zoppas-Ferreira, J. (2017). Influence of the co-ions on the transport of sulfate through anion exchange membranes. Journal of Membrane Science, 542, 320-328. doi:10.1016/j.memsci.2017.08.021Ray, P., Shahi, V. K., Pathak, T. V., & Ramachandraiah, G. (1999). Transport phenomenon as a function of counter and co-ions in solution: chronopotentiometric behavior of anion exchange membrane in different aqueous electrolyte solutions. Journal of Membrane Science, 160(2), 243-254. doi:10.1016/s0376-7388(99)00088-5Martí-Calatayud, M. C., García-Gabaldón, M., Pérez-Herranz, V., & Ortega, E. (2011). Determination of transport properties of Ni(II) through a Nafion cation-exchange membrane in chromic acid solutions. Journal of Membrane Science, 379(1-2), 449-458. doi:10.1016/j.memsci.2011.06.014Marder, L., Ortega Navarro, E. M., Pérez-Herranz, V., Bernardes, A. M., & Ferreira, J. Z. (2006). Evaluation of transition metals transport properties through a cation-exchange membrane by chronopotentiometry. Journal of Membrane Science, 284(1-2), 267-275. doi:10.1016/j.memsci.2006.07.039Herraiz-Cardona, I., Ortega, E., & Pérez-Herranz, V. (2010). Evaluation of the Zn2+ transport properties through a cation-exchange membrane by chronopotentiometry. Journal of Colloid and Interface Science, 341(2), 380-385. doi:10.1016/j.jcis.2009.09.053Martí-Calatayud, M. C., García-Gabaldón, M., & Pérez-Herranz, V. (2012). Study of the effects of the applied current regime and the concentration of chromic acid on the transport of Ni2+ ions through Nafion 117 membranes. Journal of Membrane Science, 392-393, 137-149. doi:10.1016/j.memsci.2011.12.012Pismenskaia, N., Sistat, P., Huguet, P., Nikonenko, V., & Pourcelly, G. (2004). Chronopotentiometry applied to the study of ion transfer through anion exchange membranes. Journal of Membrane Science, 228(1), 65-76. doi:10.1016/j.memsci.2003.09.012Taky, M., Pourcelly, G., Lebon, F., & Gavach, C. (1992). 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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