Recuperación de compuestos fenólicos contenidos en la salmuera residual del proceso de fermentación de las aceitunas de mesa mediante procesos de membrana: combinación de la ultrafiltración y la nanofiltración

Wastewater generated by the industry of table olives production stands out by its high salinity and high organic matter load and phenolic compounds concentration, which are difficult to degrade. These compounds have a double characteristic, on one hand, they have a fitotoxic nature harmful to the ground, but on the other hand, they also possess an antioxidant nature, which has a great interest for the food, cosmetic and pharmaceutic industries. The main aim of this work is the recovery of phenolic compounds from the residual brine generated in the table olives fermentation process. For this purpose, membrane processes, both ultrafiltration (UF) and nanofiltration (NF), and adsorption with resins have been considered. The permeate from the UF was used as feed for the NF step and the NF permeate was submitted to a non-ionic resins adsorption process. The UF and the NF experiments were performed at laboratory scale using flat organic membranes of different molecular weight cut off and material (UP005 and UH030 UF membranes and NF245 and NF270 NF membranes). The following operating conditions were varied: the transmembrane pressure (for each type of membranes, a range of 1 to 3 bar and 5 to 15 bar were considered, respectively), the crossflow velocity (between 2.2 to 3.7 m¿s-1 and 0.5 to 1.5 m¿s-1, for each type of membranes, respectively) and the volume reduction factor. The effect of these parameters on the permeate flux and the recovery of the phenolic compounds was studied. Furthermore, the influence of these parameters on the membrane fouling was analysed and the optimal cleaning protocols were selected. Moreover, the experimental results obtained in the UF step were fitted to mathematical models to predict the evolution of permeate flux with time. Adsorption was performed using a non-ionic resin, and desorption was carried out by using ethanol as a solvent. Results showed that the UF membranes were capable of eliminate nearly all the turbidity of the residual brine, obtaining a permeate stream with a greater purity of phenolic compounds. The best results in terms of permeate flux, chemical oxygen demand elimination and phenolic compounds recovery were reached using a UP005 membrane at 3 bar and 2.2 m¿s-1. The NF membranes could remove practically all the colour of the residual brine and to increase to a greater extent the purity of phenolic compounds in the permeate stream. The best results in terms of permeate flux, chemical oxygen demand elimination and phenolic compounds recovery were obtained using a NF245 membrane at 15 bar and 1.5 m¿s-1. The combination of both membrane processes increased the phenolic compounds/DQO ratio by 60% when compared to the residual brine. The subsequent adsorption step showed that it is possible to recover a high fraction (98 %) of the phenolic compounds (hydroxytyrosol and tyrosol) present in the NF permeate, achieving a high purity (97%), and obtaining also an acid saline stream with low concentration of phenolic compounds.Las aguas residuales generadas en el proceso de elaboración de aceitunas de mesa destacan por su elevada salinidad y su elevada concentración de materia orgánica y de compuestos fenólicos, los cuales son difíciles de degradar. Estos compuestos tienen una característica dual, por un lado, tienen carácter fitotóxico para el suelo, pero por contra, tienen un fuerte carácter antioxidante, lo que resulta de gran interés para las industrias alimentaria, cosmética y farmacéutica. El objetivo principal de este proyecto es la recuperación de los compuestos fenólicos presentes en la salmuera residual del proceso de fermentación de las aceitunas de mesa, mediante la utilización de procesos de membrana, tanto ultrafiltración (UF) como nanofiltración (NF), y adsorción con resinas. El permeado obtenido en la UF fue utilizado como alimentación de la NF, y el permeado obtenido en la NF se sometió a una etapa de adsorción con resinas no iónicas. Los ensayos de UF (UP005 y UH030) y NF (NF245 y NF270) se realizaron a escala de laboratorio con membranas planas orgánicas de distinto corte molecular, variando en cada ensayo la velocidad tangencial (entre 2.2 y 3.7 m¿s-1, y 0.5 y 1.5 m¿s-1, respectivamente), la presión transmembranal (entre 1 y 3 bar, y 5 y 15 bar, respectivamente) y el factor de reducción de volumen. Se estudió cómo afectan estos parámetros a la densidad de flujo de permeado y a la recuperación de compuestos fenólicos. Así mismo, también se estudió el efecto que tienen estos parámetros sobre el ensuciamiento de las membranas y se seleccionaron los protocolos óptimos de limpieza de las mismas. Además, los resultados experimentales obtenidos en los ensayos con las membranas de ultrafiltración se ajustaron a modelos matemáticos para predecir la variación de la densidad de flujo de permeado con el tiempo. La adsorción se realizó con una resina no iónica, y la desorción se realizó utilizando etanol como disolvente. Los resultados obtenidos mostraron que las membranas de UF son capaces de eliminar casi totalmente la turbidez de la salmuera residual, logrando producir una corriente de permeado con un mayor grado de pureza de compuestos fenólicos. Las mejores condiciones de operación en la ultrafiltración, en términos de densidad de flujo de permeado, eliminación de demanda química de oxígeno y recuperación de compuestos fenólicos, se obtuvieron con la membrana UP005 a 3 bar y 2.2 m¿s-1. Las membranas de NF consiguieron reducir casi completamente el color de la salmuera residual y enriquecer más corriente de permeado en compuestos fenólicos. Las mejores condiciones de operación en la nanofiltración, en términos de densidad de flujo de permeado, eliminación de demanda química de oxígeno y recuperación de compuestos fenólicos, se obtuvieron con la membrana NF245 a 15 bar y 1.5 m¿s-1. Mediante la combinación de estos procesos de membranas se aumentó el ratio compuestos fenólicos/DQO un 60% respecto de la salmuera inicial. La adsorción mostró que es posible recuperar una elevada fracción de los compuestos fenólicos, 98%, (hidroxitirosol y tirosol) presentes en la corriente de permeado de la NF con una alta pureza (97%), obteniéndose por otro lado una corriente salina ácida con muy baja concentración de compuestos fenólicos.Les aigües residual generades en el procés d'elaboració d'olives de taula destaquen per la seua elevada salinitat i la seua elevada concentració de matèria orgànica i de compostos fenòlics, els quals són difícils de degradar. Estos compostos tenen una característica dual, d'una banda, tenen caràcter fitotòxic, i d'un altra, tenen un fort caràcter antioxidant, el que fa que tinguen un gran interès per a les industries alimentaries, cosmètiques i farmacèutiques. L'objectiu principal d'aquest projecte és la recuperació de compostos fenòlics continguts en la salmorra residual del procés de fermentació de les olives de taula, mitjançant l'utilització de processos de membrana, tant d'ultrafiltració (UF), com de nanofiltració (NF), i adsorció amb resines. El corrent de permeat obtingut en la UF va ser utilitzat com alimentació de la NF, i el permeat obtingut en la NF va ser sotmès a una etapa d'adsorció amb resines no iòniques. Els assajos d'UF (UP005 i UH030) i NF (NF245 i NF270) es realitzaren a escala de laboratori amb membranes planes orgàniques de distint tall molecular, variant en cada assaig la velocitat tangencial (entre 2.2 i 3.7 m¿s-1, i 0.5 i 1.5 m¿s-1, respectivament), la pressió transmembranal (entre 1 i 3 bar, i 5 i 15 bar, respectivament) i el factor de reducció de volum. Es va estudiar com afecten aquests paràmetres a la densitat de flux de permeat i a la recuperació dels compostos fenòlics. Així mateix, també es va estudiar l'efecte que tenen aquests paràmetres sota l'embrutament de les membranes i es van seleccionar el protocols òptims de neteja de les mateixes. A més, els resultats experimentals obtinguts en els assajos amb les membranes d'ultrafiltració es van ajustar a models matemàtics per a predir la variació de la densitat de flux de permeat amb el temps. L'adsorció es realitzà amb una resina no iònica, i la desorció es realitzà utilitzant etanol com a dissolvent. Els resultats obtinguts mostraren que les membranes d'UF poden eliminar quasi completament la terbolesa de la salmorra residual, aconseguint produir un corrent de permeat amb un major grau de puresa de compostos fenòlics. Les millors condicions d'operació en la ultrafiltració, en els termes de la densitat de flux de permeat, l'eliminació de la demanda química d'oxigen i la recuperació dels compostos fenòlics, es van obtindré amb la membrana UP005 a 3 bar i 2.2 m¿s-1. Les membranes de NF van aconseguir reduir quasi completament el color de la salmorra residual i enriquir més el corrent de permeat en compostos fenòlics. Les millors condicions d'operació en la nanofiltració, en els termes de la densitat de flux de permeat, l'eliminació de la demanda química d'oxigen i la recuperació de compostos fenòlics, es van obtindré amb la membrana NF245 a 15 bar i 1.5 m¿s-1. Mitjançant la combinació d'aquests processos de membranes s'augmentà el rati de compostos fenòlics/DQO un 60% respecte de la salmorra inicial. L'adsorció va mostrar que es possible recuperar una elevada fracció del compostos fenòlics, 98%, (hidroxitirosol i tirosol) presents en el corrent de permeat de la NF amb una alta puresa (97%), obtenint-se per un altre costat un corrent salí àcid amb una baixa concentració de compostos fenòlics.Carbonell Alcaina, C. (2017). Recuperación de compuestos fenólicos contenidos en la salmuera residual del proceso de fermentación de las aceitunas de mesa mediante procesos de membrana: combinación de la ultrafiltración y la nanofiltración [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/86142TESI

Removal of pharmaceutically active compounds using low-pressure membrane processes

This is an Accepted Manuscript of an article published by Taylor & Francis in Desalination and water treatment on 2017, available online: http://doi.org/10.5004/dwt.2017.0449[EN] The increasing demand on water resources throughout the world has motivated researchers to seek new ways to obtain quality water increasing their interest in water reclamation. However, the presence of harmful organic chemicals such as pharmaceutically active compounds (PhACs) is a serious environmental concern. The objective of this study was to investigate the influence of the pH on the rejection of seven target PhACs (acetaminophen, caffeine, erythromycin, ibuprofen, naproxen, sulfamethoxazole, and trimethoprim) by different low-pressure membranes within the fine ultrafiltration (UF) and loose nanofiltration (NF) range. For this purpose, three ceramic membranes and a polyamide membrane were used for UF and NF experiments, respectively. Experimental results indicated that PhACs with negative charge were effectively rejected at basic conditions (< 75% for UF, < 90% for NF), improving both their hydrophilicity and solubility with increasing pH. Furthermore, high soluble PhACs with high pKa values showed low rejection values (similar to 15% for UF, similar to 30% for NF) and a pH-independent behaviour during low-pressure filtration experiments. Therefore, the use of low-pressure membranes could be considered as an appropriate and sustainable supplemental technique to remove PhACs in a wastewater treatment plant.The authors of this work wish to gratefully acknowledge the financial support from the Spanish Ministry of Economy and Competitiveness through the project CTM2013-42342-P.García-Ivars, J.; Iborra Clar, MI.; Massella, M.; Carbonell Alcaina, C.; Alcaina-Miranda, MI. (2017). Removal of pharmaceutically active compounds using low-pressure membrane processes. Desalination and Water Treatment. 69:252-260. https://doi.org/10.5004/dwt.2017.0449S2522606

Rejection of trace pharmaceutically active compounds present in municipal wastewaters using ceramic fine ultrafiltration membranes: Effect of feed solution pH and fouling phenomena

[EN] This study investigates the influence of feed solution pH and fouling on the rejection of ten selected pharmaceutically active compounds (PhACs) with different physicochemical characteristics (molecular weight, water solubility, log Kow, pKa, dipole moment, etc.) by three multichannel ceramic ultrafiltration membranes, ranging from 1 to 8 kDa, in order to improve their removal from water. For this purpose, the comparison between filtration of PhACs in deionised water (Feed I) and in real wastewater effluent (Feed II) was performed, demonstrating that the variation of pH and the formation of a foulant layer altered the separation mechanism and hence the rejection values of each PhAC varied. Higher rejections of most of the PhACs were higher at slightly alkaline pH, especially for anionic compounds in the filtration with real wastewater. In these conditions, flux decline was more severe. The formed fouling layer onto the hydrophilic membrane surface acted as a secondary barrier for separation with different properties like hydrophobicity and charge. Electrostatic interactions were the main separation mechanism in the filtration of PhACs in deionised water, while the hydrophobic/hydrophilic interactions played a crucial role in the filtration experiments with real wastewater effluent. Thus, the reported results indicated that the rejection of pharmaceutically active compounds was strongly pH-dependent, except for hydrophilic neutral compounds (acetaminophen and caffeine), which showed a pH-independent behaviour with low rejection values. (C) 2016 Elsevier B.V. All rights reserved.The authors of this work wish to gratefully acknowledge the financial support from the Spanish Ministry of Economy and Competitiveness through the project CTM2013-42342-P.García-Ivars, J.; Dura-Maria, J.; Moscardo-Carreño, C.; Carbonell Alcaina, C.; Alcaina-Miranda, MI.; Iborra Clar, MI. (2017). Rejection of trace pharmaceutically active compounds present in municipal wastewaters using ceramic fine ultrafiltration membranes: Effect of feed solution pH and fouling phenomena. Separation and Purification Technology. 175:58-71. https://doi.org/10.1016/j.seppur.2016.11.027S587117

Ultrafiltration of residual fermentation brines from the production of table olives at different operating conditions

[EN] The membrane process of ultrafiltration (UF) has been investigated as a pretreatment previous to the further recovery and concentration of phenolic compounds from residual table olives fermentation brines. Two UF membranes were tested: a permanently hydrophilic polyethersulfone (PES) membrane with a molecular weight cut-off (MWCO) of 30 kDa and a PES membrane with a MWCO of 5 kDa. Transmembrane pressure and crossflow velocity were varied from 1 to 3 bar and from 2.2 to 3.7 m s(-1), respectively. The best membrane in terms of permeate flux and selectivity was that with MWCO of 5 kDa and the best operating conditions were transmembrane pressure of 3 bar and crossflow velocity of 2.2 m s(-1). In these conditions permeate flux was 21.6 L h(-1).m(-2), while the rejection of COD and phenolic compounds were 50.0% and 21.9%, respectively and the removal of colour and turbidity was almost complete. In addition, an alkaline cleaning protocol was proposed, which was effective to restore the initial permeability of the selected membrane. (C) 2018 Elsevier Ltd. All rights reserved.The authors of this work wish to gratefully acknowledge the financial support of CDTI (Centre for Industrial Technological Development) depending on the Spanish Ministry of Science and Innovation (INNPRONTA program, ITP-20111020).Carbonell Alcaina, C.; Alvarez Blanco, S.; Bes-Piá, M.; Mendoza Roca, JA.; Pastor Alcañiz, L. (2018). Ultrafiltration of residual fermentation brines from the production of table olives at different operating conditions. Journal of Cleaner Production. 189:662-672. https://doi.org/10.1016/j.jclepro.2018.04.127S66267218

Effect of the operating conditions on a nanofiltration process to separate low-molecular-weight phenolic compounds from the sugars present in olive mill wastewaters

[EN] The efficiency of nanofiltration to purify the tyrosol present in the olive mill wastewaters (OMWWs) has been studied. The similar molecular weight of tyrosol and the sucrose existing in this kind of by-products restricts the discrimination between both molecules through a membrane process, but the interest of phenolic compounds to be applied in cosmetics and pharmacology greatly motivates its recovery at the highest purity possible. Thus, two different simulated OMWWs composed of tyrosol and mixtures of tyrosol and sucrose, respectively, were nanofiltered using the NF270 membrane. Three transmembrane pressures (TMPs) and three cross-flow velocities were tested. The optimum results were obtained at 0.5 m.s(-1) and 15 bar. The rejections of the chemical oxygen demand (COD) were above 78 %, whereas phenolic compounds were barely retained. This indicates that the sugar was accurately separated from tyrosol, which was recovered in the permeate stream at a high purity.This work was supported by the Spanish Ministry of Economy, Industry and Competitiveness through the project CTM201788645-R, and by the Spanish Ministry of Science, Innovation and Universities through the PRE2018-085245 pre-doctoral grant.Sánchez-Arévalo, CM.; Jimeno-Jiménez, Á.; Carbonell Alcaina, C.; Vincent Vela, MC.; Alvarez Blanco, S. (2021). Effect of the operating conditions on a nanofiltration process to separate low-molecular-weight phenolic compounds from the sugars present in olive mill wastewaters. Process Safety and Environmental Protection. 148:428-436. https://doi.org/10.1016/j.psep.2020.10.00242843614

HOW TO GUIDE CHEMICAL ENGINEERING STUDENTS IN THE SOLUTION OF COMPLEX ENGINEERING PROBLEMS

[EN] If we analyse some of the specific skills of Chemical Engineering degree, and it would not be very different in other disciplines of engineering, the verbs design, analyse or simulate stand out above all. In essence, calculating is an intrinsic activity for the engineer and, therefore, for engineering students. How is this activity developed? When we face a real problem we translate it into mathematical language (modelling). We solve the resulting mathematical problem to obtain the mathematical solution (simulation). The analysis of the results allows us to extract information from the real problem. If the interpretation of the results does not fit with the real problem studied, we must rethink the mathematical model obtained, and so on. Teachers often restrict the real problems that students face to simple situations so that the resulting mathematical problem is simple and, if possible, provides an analytical solution. Why should we do this today if we have numerical methods, a big computing power and mathematical software available to our students? Examples of complex mathematical problems arise from analysis and design of heat exchangers, chemical reactors, distillation columns, etc, both in steady and transitory regimes. These mathematical problems can be classified in groups: solving algebraic equations, ordinary differential equations or partial differential equations systems. According to this classification, some teachers of the Chemical Engineering degree at Campus of Alcoy are providing our students with Matlab guide templates to solve these types of mathematical problems, regardless of the subjects in which these problems appear. This action makes it easier for students to face real problems by reducing the mathematical difficulties associated. This paper shows how these Matlab guide templates are and how students use them in different subjects. It allows students to focus on the engineering aspect of the processes, leaving the difficulty of the associated mathematical problem in a second plane. It also makes easy to modify process parameters to quickly see the effect on the main variables of the process (what if? analysis). Consequently, students improve their ability to analyse and interpret the results obtained and their critical thinking skills. And, finally, they know useful computer tools that can be used both academically and professionallyCarbonell Alcaina, C.; Cardona, SC.; Domínguez-Candela, I.; Fombuena, V.; López Pérez, MF.; Lora-García, J. (2021). HOW TO GUIDE CHEMICAL ENGINEERING STUDENTS IN THE SOLUTION OF COMPLEX ENGINEERING PROBLEMS. IATED. 9442-9450. https://doi.org/10.21125/inted.2021.1977S9442945

Determination of fouling mechanisms in polymeric ultrafiltration membranes using residual brines from table olive storage wastewaters as feed

[EN] In this work, the fouling mechanisms that dominate the ultrafiltration of residual brines from table olive packing plant wastewaters were investigated. For that purpose, Hermia's models adapted to crossflow filtration, resistance-in-series model and a model combining intermediate blocking and cake formation mechanisms were fitted to the experimental data. Tests were performed with a 5 kDa polyethersulfone membrane at transmembrane pressures between 1 and 3 bar and crossflow velocities between 2.2 and 3.7 m s(-1). Results demonstrated that the resistance-in-series model was the most accurate to predict permeate flux evolution with time. The predominant fouling mechanism was cake formation followed by intermediate blocking/adsorption. The fouling resistances that were determined by means of the resistance in series model were tested using a well-established mathematical model proposed by Mondal and De that also combines both fouling phenomena (intermediate pore blocking and cake formation). Results demonstrated that the predicted resistances are consistent with those determined by Mondal and De's model. (C) 2016 Elsevier Ltd. All rights reserved.The authors of this work wish to gratefully acknowledge the financial support of CDTI (Centre for Industrial Technological Development) depending on the Spanish Ministry of Science and Innovation (INNPRONTA program, ITP-20111020).Carbonell Alcaina, C.; Corbatón Báguena, MJ.; Alvarez Blanco, S.; Bes-Piá, M.; Mendoza Roca, JA.; Pastor Alcañiz, L. (2016). Determination of fouling mechanisms in polymeric ultrafiltration membranes using residual brines from table olive storage wastewaters as feed. Journal of Food Engineering. 187:14-23. https://doi.org/10.1016/j.jfoodeng.2016.04.016S142318

Project-Based Learning as a Coordination Methodology between Subjects in a Chemical Engineering Degree

[EN] An important issue in any academic degree is to develop a high level of vertical/horizontal coordination between the different subjects taught along the four courses. This activity takes into account the coordination of the contents and methodologies that the teachers teach and the students acquire, the timing when the students learn them and the homework/exams that they do. As a result, both teachers and students gain an overall view of the degree and the teaching-learning process improves. According to this idea, the teachers of the Chemical Engineering degree at Campus of Alcoy are participating in an Educational Innovation and Improvement Project (EIIP) for applying the project-based learning methodology to the design of an adsorption system for the elimination of dyes in wastewater from the textile industry. This work is scheduled along the four courses and is distributed between some of the basic or specialized subjects that the students attend. The adsorption column design is partially solved in each subject and the results obtained in one subject are used in the following. As a result, the project is completed sequentially throughout the degree applying a methodology based on teamwork. This paper shows some of the activities proposed in different subjects, their timing and assessments during four courses. These activities include laboratory work for obtaining adsorption equilibrium and adsorption kinetics experimental data together with column dynamic performance. Other activities belong to the modelling and simulation domain for establishing the mathematical equations corresponding to the different phenomena linked to adsorption. Also there are activities focused on experimental data treatment for estimating the parameters characterizing the adsorption isotherms or mass transfer coefficients. Finally, other activities are devoted to the column design and control, cost estimation, and oral/writing communication of the work done by the students.This article has been supported by Universitat Politècnica de València, particularly by the Vice-rectorate for Digital Resources and Documentation (Vicerrectorado de Recursos Digitales y Documentación) and Vice-Rectorate for Studies, Quality and Accreditation (Vicerrectorado de Estudios, Calidad y Acreditación) under the Call for Learning + Teaching (Convocatoria A+D2019: Aprendizaje + Docencia. Proyectos de Innovación y Mejora Educativa) and Project Code: A157. The authors would like to acknowledge the support of the Institute of Educational Sciences (Instituto de Ciencias de la Educación), the Evaluation and Monitoring Commission for Educational Innovation and Improvement Projects (Comisión de Evaluación y Seguimiento de Proyectos de Innovación y Mejora Educativa (CESPIME) and Escuela Politécnica Superior de Alcoy.Carbonell Alcaina, C.; Cardona, SC.; Domínguez-Candela, I.; Fombuena, V.; López Pérez, MF.; Lora-García, J.; Sanchis, R. (2021). Project-Based Learning as a Coordination Methodology between Subjects in a Chemical Engineering Degree. INTED proceedings (Online). 5965-5974. https://doi.org/10.21125/inted.2021.1193S5965597

Analysis of energy consumption as a key factor in seawater desalination projects

[EN] A global scenario of increasing vulnerability of water resources in Spain makes it increasingly necessary to find alternative sources to meet demand and to encourage natural resources conservation. Among others, desalination of seawater and brackish waters It is one of the most developed options. The desalination capacity of Spain by using reverse osmosis membranes is higher than 3 hm3/day, which represents 2% of the supply in agriculture and 5% of domestic consumption. Its energy intensity that has been decreasing in recent years up to 2.5 kWh/m3 for seawater, makes the costs of the water produced are still high compared to conventional water supply. That is why desalination plants only operate at full capacity during periods of high drought despite the high investment made. In this paper a new energy approach of the desalination process is presented to show which variables affect energy consumption. In addition, different future actions are explored that will reduce this consumption even further to make desalination more economically viable as a new safe water resource securing the water supply at any time.[ES] La situación de vulnerabilidad creciente de los recursos hídricos en España hace que cada vez sea más necesaria la búsqueda de fuentes alternativas para satisfacer la demanda y favorecer la conservación de los medios naturales. Entre otras, la desalación de aguas marinas y salobres es una opción de las más desarrolladas. La capacidad desaladora de España mediante membranas de osmosis inversa supera los 3 hm3/dia lo que representa el 2% del suministro en agricultura y el 5% del consumo doméstico. Su intensidad energética que ha ido disminuyendo en los últimos años hasta 2.5 kWh/m3 para agua de mar, hace que los costes del agua producida sean todavía elevados en comparación con el agua potabilizada convencional. Por ello, las plantas desaladoras solo funcionan a pleno rendimiento en periodos de elevada sequía a pesar de la elevada inversión realizada. En este trabajo se aborda un nuevo análisis energético de la desalación de agua de mar para observar que variables afectan en mayor medida al consumo de energía. Además, se exploran diferentes acciones de futuro que permitirán reducir aún más dicho consumo para hacer más económicamente viable la desalación como una nueva fuente segura de agua que garantice el suministro en todo momento.Lora-García, J.; López Pérez, MF.; Cardona, SC.; Fombuena, V.; Carbonell Alcaina, C. (2020). Análisis del consumo energético como factor clave en proyectos de desalación de agua de mar. Asociación Española de Dirección e Ingeniería de Proyectos (AIEPRO). 991-1003. http://hdl.handle.net/10251/178934S991100

Desalination of brackish water and reverse osmotic retentate using nanofiltration membranes: effects of TMP and feed concentration on the treatment

This is an Accepted Manuscript of an article published by Taylor & Francis in Desalination and water treatment on 2017, available online: http://doi.org/10.5004/dwt.2017.20841[EN] Nanofiltration (NF) membrane with low-pressure operating conditions and high flux permeability seems to be an attractive alternative for water softening and desalination. In order to study the performance of NF membrane on treating real brackish water, with mixture of mono and divalent ions, two commercial flat sheet nanofiltration membranes (NF90 and NP030) were used. The experiments were carried out with transmembrane pressure from 4 to 12 bar with three brackish waters having different ions concentrations. The results obtained showed that the high hydrophilicity of NF90 and its small pore size were the main advantages that allow this membrane to have the highest permeability and salt rejection for both mono and divalent ions in comparison with NP030. The results also showed that the permeate flux and rejection increased linearly with increasing in TMP. NF90 membrane performance was assessed by studying the effect of feed ions concentration. It was observed that the permeate flux decreased with increasing in salts concentration due to concentration polarization. Additionally, the study of scaling problem showed that its contribution in permeate flux decreasing was not as much significant and that the membrane permeability, recovered after the cleaning step, was 90%. In the other hand, the salts rejection of NF90 remained high (more than 80%) for all the studied concentrations due to its separation mechanism.This work was carried out with the support of scholarship awarded by the National Center for Scientific and Technical Research (CNRST) - Morocco.Mountadar, S.; Carbonell Alcaina, C.; Lujan Facundo, MJ.; Ferrer-Polonio, E.; Soler Cabezas, JL.; Mendoza Roca, JA.; Tahiri, S. (2017). Desalination of brackish water and reverse osmotic retentate using nanofiltration membranes: effects of TMP and feed concentration on the treatment. Desalination and Water Treatment. 87:68-75. doi:10.5004/dwt.2017.21312S68758