Management of post-transplant diabetes mellitus: an opportunity for novel therapeutics

Post-transplant diabetes mellitus (PTDM) is a common problem after kidney transplantation (KT), occurring in 50% of high-risk recipients. The clinical importance of PTDM lies in its impactas a significant risk factor for cardiovascular and chronic kidney disease (CKD) after solid organ transplantation. Kidney Disease: Improving Global Outcomes (KDIGO) has recently updated the treatment guidelines for diabetes management in CKD with emphasis on the newer antidiabetic agents such as dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists and sodium-glucose co-transporter 2 inhibitors as add-on therapy to metformin. Given all these new diabetes treatments and the updated KDIGO guidelines, it is necessary to evaluate and give guidance on their use for DM management in KT recipients. This review summarizes the scarce published literature about the use of these new agents in the KT field. In summary, it is absolutely necessary to generate evidence in order to be able to safely use these new treatments in the KT population to improve blood glucose control, but specially to evaluate their potential cardiovascular and renal benefits that would seem to be independent of blood glucose control in PTDM patients

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

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

How Nanophotonic Label-Free Biosensors Can Contribute to Rapid and Massive Diagnostics of Respiratory Virus Infections : COVID-19 Case

Altres ajuts: Generalitat de Catalunya /CERCAThis ACS article is provided to You under the terms of this Standard ACS AuthorChoice License. License: https://pubs.acs.org/page/policy/authorchoice_termsofuse.htmlThe global sanitary crisis caused by the emergence of the respiratory virus SARS-CoV-2 and the COVID-19 outbreak has revealed the urgent need for rapid, accurate, and affordable diagnostic tests to broadly and massively monitor the population in order to properly manage and control the spread of the pandemic. Current diagnostic techniques essentially rely on polymerase chain reaction (PCR) tests, which provide the required sensitivity and specificity. However, its relatively long time-to-result, including sample transport to a specialized laboratory, delays massive detection. Rapid lateral flow tests (both antigen and serological tests) are a remarkable alternative for rapid point-of-care diagnostics, but they exhibit critical limitations as they do not always achieve the required sensitivity for reliable diagnostics and surveillance. Next-generation diagnostic tools capable of overcoming all the above limitations are in demand, and optical biosensors are an excellent option to surpass such critical issues. Label-free nanophotonic biosensors offer high sensitivity and operational robustness with an enormous potential for integration in compact autonomous devices to be delivered out-of-the-lab at the point-of-care (POC). Taking the current COVID-19 pandemic as a critical case scenario, we provide an overview of the diagnostic techniques for respiratory viruses and analyze how nanophotonic biosensors can contribute to improving such diagnostics. We review the ongoing published work using this biosensor technology for intact virus detection, nucleic acid detection or serological tests, and the key factors for bringing nanophotonic POC biosensors to accurate and effective COVID-19 diagnosis on the short term

Effect of COVID-19 pandemic on perceptions and career goals of undergraduate tourism students in Ecuador

Este artículo explora las percepciones y objetivos profesionales que tienen los estudiantes de pregrado de Turismo, antes y durante la pandemia COVID-19, en la Universidad Estatal de Milagro, en Milagro, Ecuador. El estudio se basa en un enfoque cuantitativo. La muestra se compone de 207 estudiantes durante el 2018 (antes de la pandemia COVID-19) y de 161 estudiantes en el 2020 (durante el COVID-19). El cuestionario incluyó preguntas sobre percepciones profesionales y preguntas acerca de los objetivos profesionales que tienen los estudiantes a corto y largo plazo. Finalmente, se midieron las percepciones exclusivamente relacionadas al COVID-19. Los resultados mostraron que la gran mayoría de estudiantes están altamente motivados y comprometidos con seguir una carrera en la industria del turismo. Un alto porcentaje de los participantes expresó su deseo de hacer una Maestría en Turismo y emprender sus propios negocios turísticos, a pesar de la incertidumbre ahora generada por el COVID-19. Los hallazgos también reafirmaron la importancia para orientar mejoras en la educación superior del turismo y en la industria del turismo, con el objetivo de asegurar la calidad de los servicios turísticos, con profesionales altamente calificados, especialmente en destinos turísticos emergentes como Ecuador.This paper explored the perceptions and career goals of undergraduate tourism students, before and during the pandemic COVID-19, in the Universidad Estatal de Milagro, in Milagro, Ecuador. The study is based on a quantitative approach. The sample is made up of 207 students during 2018 (before the COVID-19 pandemic) and 161 students in 2020 (during COVID-19). The questionnaire included questions about professional perceptions and questions about the professional goals that students have in the short and long term. Finally, perceptions exclusively related to COVID-19 were measured.  The results showed that the vast majority of the students are highly motivated and committed to pursue a career in the tourism industry. A high percentage of the participants expressed their desire to do a Tourism master degree and undertake their own tourism businesses, despite the uncertainty now generated by COVID-19. The findings also reaffirmed the importance of guiding improvements on tourism higher education and tourism industry, with the aim of ensuring the quality of the tourist services, with highly skilled professionals, especially in emerging tourist destinations as Ecuador

Tirzepatide and prevention of chronic kidney disease

Chronic kidney disease; Diabetes mellitus; ObesityMalaltia renal crònica; Diabetis mellitus; ObesitatEnfermedad renal crónica; Diabetes mellitus; ObesidadTirzepatide is a twincretin recently approved to improve glycemic control in type 2 diabetes mellitus (T2DM). More specifically, tirzepatide is an agonist of both the glucose-dependent insulinotropic polypeptide (GIP) and the glucagon-like peptide-1 (GLP1) receptors. In recent clinical trials in persons with obesity or overweight with associated conditions, tirzepatide decreased body weight and other cardiorenal risk factors (blood pressure, low-density lipoprotein cholesterol, glycated hemoglobin and albuminuria). Moreover, in a post hoc analysis of the SURPASS-4 randomized clinical trial, tirzepatide decreased albuminuria and total estimated glomerular filtration rate (eGFR) slopes and nearly halved the risk of a pre-specified composite kidney endpoint (eGFR decline ≥40%, renal death, kidney failure or new-onset macroalbuminuria) in participants with T2DM and high cardiovascular risk when compared with insulin glargine. Similar to other kidney-protective drugs, tirzepatide, alone or combined with sodium-glucose co-transporter 2 inhibitors, caused an early dip in eGFR. Moreover, tirzepatide also decreased eGFR slopes in participants with eGFR >60 mL/min/1.73 m2 or with normoalbuminuria. We now review the potential kidney health implications of tirzepatide, addressing its structure and function, relationship to current GLP1 receptor agonists, impact of recent results for the treatment and prevention of kidney disease, and expectations for the future.FIS/Fondos FEDER (PI18/01366, PI19/00588, PI19/00815, PI20/00744, DTS18/00032, ERA-PerMed-JTC2018 KIDNEY AT390 TACK AC18/00064 and PERSTIGAN AC18/00071, ISCIII-RETIC REDinREN RD016/0009), Sociedad Española de Nefrología, Sociedad Madrileña de Nefrología (SOMANE), FRIAT, Comunidad de Madrid en Biomedicina (B2017/BMD-3686 and CIFRA2-CM). Instituto de Salud Carlos III (ISCIII) RICORS program (RICORS2040-395 , RD21/0005/0001) and SPACKDc PMP21/00109, FEDER funds funded by European Union—Next Generation EU’, Mecanismo para la Recuperación y la Resiliencia (MRR) and RD16/0009

Maar-diatreme infill features recorded in borehole imaging

Oriented borehole images recorded with an ultrasonic acoustic televiewer and continuous coring recovery has allowed the characterization of different facies and volcanic processes involved in the infill of a maar-diatreme volcano type. Maar-diatremes are associated with strong explosions throughout most of their development, focused along feeder dikes and generally attributed to magma-water interaction. In the case study of Camp dels Ninots maar-diatreme (Girona, Spain) we have recognized four facies types located in the center of the maar-diatreme: volcanic ash, phreatomagmatic breccia with lithics and juveniles, vesicular pyroclasts (scoria), massive basalt or welded pyroclastic fragments. Ultrasonic televiewer images allow to characterize the different volcanic facies, since they display a different degree of reflectivity and textures. Other features such as fracturing and grain size can be directly measured on the images.Projects 2014-100575 from Departament de Cultura de and SGR2014-901 from AGAUR (both from Generalitat de Catalunya) financed the drilling campaigns.Peer Reviewe

Evolutionary trajectories of new duplicated and putative de novo genes

The formation of new genes during evolution is an important motor of functional innovation, but the rate at which new genes originate and the likelihood that they persist over longer evolutionary periods are still poorly understood questions. Two important mechanisms by which new genes arise are gene duplication and de novo formation from a previously noncoding sequence. Does the mechanism of formation influence the evolutionary trajectories of the genes? Proteins arisen by gene duplication retain the sequence and structural properties of the parental protein, and thus they may be relatively stable. Instead, de novo originated proteins are often species specific and thought to be more evolutionary labile. Despite these differences, here we show that both types of genes share a number of similarities, including low sequence constraints in their initial evolutionary phases, high turnover rates at the species level, and comparable persistence rates in deeper branchers, in both yeast and flies. In addition, we show that putative de novo proteins have an excess of substitutions between charged amino acids compared with the neutral expectation, which is reflected in the rapid loss of their initial highly basic character. The study supports high evolutionary dynamics of different kinds of new genes at the species level, in sharp contrast with the stability observed at later stages.We acknowledge funding from Ministerio de Ciencia e Innovación Agencia Estatal de Investigación grant PGC2018-094091-B-I00 (cofunded by Fondo Europeo de Desarrollo Regional), as well as grants PID2021-122726NB-I00 and PID2021-122830OB-C43 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF: A way of making Europe”, by the “European Union”. We also acknowledge funding from Generalitat de Catalunya, grant 2021SGR00042. The work was also funded by the European Union (ERC, NovoGenePop, project number 101052538).Peer ReviewedPostprint (published version

A Step Forward to the Characterization of Secondary Effuents to Predict Membrane Fouling in a Subsequent Ultrafiltration

[EN] Nowadays, wastewater reuse in Mediterranean countries is necessary to cover the water demand. This contributes to the protection of the environment and encourages the circular economy. Due to increasingly strict regulation, the secondary effluent of a wastewater treatment plant requires further (tertiary) treatment to reach enough quality for its reuse in agriculture. Ultrafiltration is a membrane technique suitable for tertiary treatment. However, the most important drawback of ultrafiltration is membrane fouling. The aim of this work is to predict membrane fouling and ultrafiltered wastewater permeate quality for a particular membrane, using the information given by an exhaustive secondary effluent characterization. For this, ultrafiltration of real and simulated wastewaters and of their components after fractionation has been performed. In order to better characterize the secondary effluent, resin fractionation and further membrane ultrafiltration of the generated fractions and wastewater were performed. The results indicated that hydrophobic substances were lower than hydrophilic ones in the secondary effluent. Supelite DAX-8, Amberlite XAD-4 and Amberlite IRA-958 resins were found not to be specific for humic acids, proteins and carbohydrates, which are the main components of the effluent organic matter. Two models have been performed using statistics (partial least squares, PLS) and an artificial neural network (ANN), respectively. The results showed that the ANN model predicted permeate quality and membrane fouling with higher accuracy than PLS.This study was funded by Generalitat Valenciana (Project AICO 18/319).Anderson-Alejandro Benites-Zelaya; Soler Cabezas, JL.; Ferrer-Polonio, E.; Mendoza Roca, JA.; Vincent Vela, MC. (2020). A Step Forward to the Characterization of Secondary Effuents to Predict Membrane Fouling in a Subsequent Ultrafiltration. Water. 12(7):1-17. https://doi.org/10.3390/w12071975S117127European Commission—Environmenthttps://ec.europa.eu/environment/water/reuse.htmRippey, S. R., & Watkins, W. D. (1992). Comparative Rates of Disinfection of Microbial Indicator Organisms in Chlorinated Sewage Effluents. Water Science and Technology, 26(9-11), 2185-2189. doi:10.2166/wst.1992.0693Mounaouer, B., & Abdennaceur, H. (2016). Modeling and kinetic characterization of wastewater disinfection using chlorine and UV irradiation. Environmental Science and Pollution Research, 23(19), 19861-19875. doi:10.1007/s11356-016-7173-4Hijnen, W. A. M., Beerendonk, E. F., & Medema, G. J. (2006). Inactivation credit of UV radiation for viruses, bacteria and protozoan (oo)cysts in water: A review. Water Research, 40(1), 3-22. doi:10.1016/j.watres.2005.10.030Cervero-Aragó, S., Rodríguez-Martínez, S., Puertas-Bennasar, A., & Araujo, R. M. (2015). Effect of Common Drinking Water Disinfectants, Chlorine and Heat, on Free Legionella and Amoebae-Associated Legionella. PLOS ONE, 10(8), e0134726. doi:10.1371/journal.pone.0134726Anfruns-Estrada, E., Bruguera-Casamada, C., Salvadó, H., Brillas, E., Sirés, I., & Araujo, R. M. (2017). Inactivation of microbiota from urban wastewater by single and sequential electrocoagulation and electro-Fenton treatments. Water Research, 126, 450-459. doi:10.1016/j.watres.2017.09.056Tchobanoglous, G., Darby, J., Bourgeous, K., McArdle, J., Genest, P., & Tylla, M. (1998). Ultrafiltration as an advanced tertiary treatment process for municipal wastewater. Desalination, 119(1-3), 315-321. doi:10.1016/s0011-9164(98)00175-1Lubello, C., Gori, R., de Bernardinis, A. M., & Simonelli, G. (2003). Ultrafiltration as tertiary treatment for industrial reuse. Water Supply, 3(4), 161-168. doi:10.2166/ws.2003.0058Illueca-Muñoz, J., Mendoza-Roca, J. A., Iborra-Clar, A., Bes-Piá, A., Fajardo-Montañana, V., Martínez-Francisco, F. J., & Bernácer-Bonora, I. (2008). Study of different alternatives of tertiary treatments for wastewater reclamation to optimize the water quality for irrigation reuse. Desalination, 222(1-3), 222-229. doi:10.1016/j.desal.2007.01.157Delgado, S., Dı́az, F., Vera, L., Dı́az, R., & Elmaleh, S. (2004). Modelling hollow-fibre ultrafiltration of biologically treated wastewater with and without gas sparging. Journal of Membrane Science, 228(1), 55-63. doi:10.1016/j.memsci.2003.09.011Filloux, E., Labanowski, J., & Croue, J. P. (2012). Understanding the fouling of UF/MF hollow fibres of biologically treated wastewaters using advanced EfOM characterization and statistical tools. Bioresource Technology, 118, 460-468. doi:10.1016/j.biortech.2012.05.081Shon, H. K., Vigneswaran, S., & Snyder, S. A. (2006). Effluent Organic Matter (EfOM) in Wastewater: Constituents, Effects, and Treatment. Critical Reviews in Environmental Science and Technology, 36(4), 327-374. doi:10.1080/10643380600580011Wang, Z.-P., & Zhang, T. (2010). Characterization of soluble microbial products (SMP) under stressful conditions. Water Research, 44(18), 5499-5509. doi:10.1016/j.watres.2010.06.067Ferrer-Polonio, E., White, K., Mendoza-Roca, J. A., & Bes-Piá, A. (2018). The role of the operating parameters of SBR systems on the SMP production and on membrane fouling reduction. Journal of Environmental Management, 228, 205-212. doi:10.1016/j.jenvman.2018.09.036Ferrer-Polonio, E., Fernández-Navarro, J., Alonso-Molina, J. L., Bes-Piá, A., & Mendoza-Roca, J. A. (2018). Influence of organic matter type in wastewater on soluble microbial products production and on further ultrafiltration. Journal of Chemical Technology & Biotechnology, 93(11), 3284-3291. doi:10.1002/jctb.5689Leenheer, J. A. (1981). Comprehensive approach to preparative isolation and fractionation of dissolved organic carbon from natural waters and wastewaters. Environmental Science & Technology, 15(5), 578-587. doi:10.1021/es00087a010Imai, A., Fukushima, T., Matsushige, K., Kim, Y.-H., & Choi, K. (2002). Characterization of dissolved organic matter in effluents from wastewater treatment plants. Water Research, 36(4), 859-870. doi:10.1016/s0043-1354(01)00283-4Zheng, X., Khan, M. T., & Croué, J.-P. (2014). Contribution of effluent organic matter (EfOM) to ultrafiltration (UF) membrane fouling: Isolation, characterization, and fouling effect of EfOM fractions. Water Research, 65, 414-424. doi:10.1016/j.watres.2014.07.039Ferrer-Polonio, E., McCabe, M., Mendoza-Roca, J. A., & Vincent-Vela, M.-C. (2018). Fractionation of secondary effluents of wastewater treatment plants in view of the evaluation of membrane fouling in a further ultrafiltration step. Journal of Chemical Technology & Biotechnology, 93(5), 1495-1501. doi:10.1002/jctb.5520Chaloulakou, A., Grivas, G., & Spyrellis, N. (2003). Neural Network and Multiple Regression Models for PM10 Prediction in Athens: A Comparative Assessment. Journal of the Air & Waste Management Association, 53(10), 1183-1190. doi:10.1080/10473289.2003.10466276Kalogirou, S. A. (2000). Applications of artificial neural-networks for energy systems. Applied Energy, 67(1-2), 17-35. doi:10.1016/s0306-2619(00)00005-2Hamed, M. M., Khalafallah, M. G., & Hassanien, E. A. (2004). Prediction of wastewater treatment plant performance using artificial neural networks. Environmental Modelling & Software, 19(10), 919-928. doi:10.1016/j.envsoft.2003.10.005Shon, H. K., Vigneswaran, S., Kim, I. S., Cho, J., & Ngo, H. H. (2006). Fouling of ultrafiltration membrane by effluent organic matter: A detailed characterization using different organic fractions in wastewater. Journal of Membrane Science, 278(1-2), 232-238. doi:10.1016/j.memsci.2005.11.006Marhaba, T. F. (2000). Fluorescence Technique for Rapid Identification of DOM Fractions. Journal of Environmental Engineering, 126(2), 145-152. doi:10.1061/(asce)0733-9372(2000)126:2(145)Teodosiu, C. (2000). Neural network models for ultrafiltration and backwashing. Water Research, 34(18), 4371-4380. doi:10.1016/s0043-1354(00)00217-7Delgrange-Vincent, N., Cabassud, C., Cabassud, M., Durand-Bourlier, L., & Laîné, J. M. (2000). Neural networks for long term prediction of fouling and backwash efficiency in ultrafiltration for drinking water production. Desalination, 131(1-3), 353-362. doi:10.1016/s0011-9164(00)90034-1Vincent Vela, M. C., Álvarez Blanco, S., Lora García, J., & Bergantiños Rodríguez, E. (2009). Analysis of membrane pore blocking models adapted to crossflow ultrafiltration in the ultrafiltration of PEG. Chemical Engineering Journal, 149(1-3), 232-241. doi:10.1016/j.cej.2008.10.027Zuriaga-Agustí, E., Bes-Piá, A., Mendoza-Roca, J. A., & Alonso-Molina, J. L. (2013). Influence of extraction methods on proteins and carbohydrates analysis from MBR activated sludge flocs in view of improving EPS determination. Separation and Purification Technology, 112, 1-10. doi:10.1016/j.seppur.2013.03.048Frølund, B., Palmgren, R., Keiding, K., & Nielsen, P. H. (1996). Extraction of extracellular polymers from activated sludge using a cation exchange resin. Water Research, 30(8), 1749-1758. doi:10.1016/0043-1354(95)00323-1Juang, L.-C., Tseng, D.-H., Chen, Y.-M., Semblante, G. U., & You, S.-J. (2013). The effect soluble microbial products (SMP) on the quality and fouling potential of MBR effluent. Desalination, 326, 96-102. doi:10.1016/j.desal.2013.07.005Ayache, C., Pidou, M., Croué, J. P., Labanowski, J., Poussade, Y., Tazi-Pain, A., … Gernjak, W. (2013). Impact of effluent organic matter on low-pressure membrane fouling in tertiary treatment. Water Research, 47(8), 2633-2642. doi:10.1016/j.watres.2013.01.043Barker, D. J., & Stuckey, D. C. (1999). A review of soluble microbial products (SMP) in wastewater treatment systems. Water Research, 33(14), 3063-3082. doi:10.1016/s0043-1354(99)00022-6Haberkamp, J., Ernst, M., Böckelmann, U., Szewzyk, U., & Jekel, M. (2008). Complexity of ultrafiltration membrane fouling caused by macromolecular dissolved organic compounds in secondary effluents. Water Research, 42(12), 3153-3161. doi:10.1016/j.watres.2008.03.007Yigit, N. O., Harman, I., Civelekoglu, G., Koseoglu, H., Cicek, N., & Kitis, M. (2008). Membrane fouling in a pilot-scale submerged membrane bioreactor operated under various conditions. Desalination, 231(1-3), 124-132. doi:10.1016/j.desal.2007.11.041Yammine, S., Rabagliato, R., Vitrac, X., Mietton Peuchot, M., & Ghidossi, R. (2019). Selecting ultrafiltration membranes for fractionation of high added value compounds from grape pomace extracts. OENO One, 53(3). doi:10.20870/oeno-one.2019.53.3.2343Babcock, J. J., & Brancaleon, L. (2013). Bovine serum albumin oligomers in the E- and B-forms at low protein concentration and ionic strength. International Journal of Biological Macromolecules, 53, 42-53. doi:10.1016/j.ijbiomac.2012.10.030Zirnsak, M. A., & Boger, D. V. (1998). Axisymmetric entry flow of semi-dilute xanthan gum solutions: prediction and experiment. Journal of Non-Newtonian Fluid Mechanics, 79(2-3), 105-136. doi:10.1016/s0377-0257(98)00104-9Corbatón-Báguena, M.-J., Álvarez-Blanco, S., & Vincent-Vela, M.-C. (2015). Fouling mechanisms of ultrafiltration membranes fouled with whey model solutions. Desalination, 360, 87-96. doi:10.1016/j.desal.2015.01.019Maruyama, T., Katoh, S., Nakajima, M., & Nabetani, H. (2001). Mechanism of bovine serum albumin aggregation during ultrafiltration. Biotechnology and Bioengineering, 75(2), 233-238. doi:10.1002/bit.10001Soler-Cabezas, J. L., Torà-Grau, M., Vincent-Vela, M. C., Mendoza-Roca, J. A., & Martínez-Francisco, F. J. (2014). Ultrafiltration of municipal wastewater: study on fouling models and fouling mechanisms. Desalination and Water Treatment, 56(13), 3427-3437. doi:10.1080/19443994.2014.969320Vela, M. C. V., Blanco, S. Á., García, J. L., & Rodríguez, E. B. (2008). Analysis of membrane pore blocking models applied to the ultrafiltration of PEG. Separation and Purification Technology, 62(3), 489-498. doi:10.1016/j.seppur.2008.02.028Mah, S.-K., Chuah, C.-K., Cathie Lee, W. P., & Chai, S.-P. (2012). Ultrafiltration of palm oil–oleic acid–glycerin solutions: Fouling mechanism identification, fouling mechanism analysis and membrane characterizations. Separation and Purification Technology, 98, 419-431. doi:10.1016/j.seppur.2012.07.020Saha, S., & Das, C. (2015). Analysis of Fouling Characteristics and Flux Decline during Humic Acids Batch Ultrafiltration. Journal of Chemical Engineering & Process Technology, 06(05). doi:10.4172/2157-7048.1000252Acero, J. L., Benitez, F. J., Leal, A. I., Real, F. J., & Teva, F. (2010). Membrane filtration technologies applied to municipal secondary effluents for potential reuse. Journal of Hazardous Materials, 177(1-3), 390-398. doi:10.1016/j.jhazmat.2009.12.045Muthukumaran, S., Nguyen, D. A., & Baskaran, K. (2011). Performance evaluation of different ultrafiltration membranes for the reclamation and reuse of secondary effluent. Desalination, 279(1-3), 383-389. doi:10.1016/j.desal.2011.06.040Pao, H.-T. (2008). A comparison of neural network and multiple regression analysis in modeling capital structure. Expert Systems with Applications, 35(3), 720-727. doi:10.1016/j.eswa.2007.07.01

A study of the osmotic membrane bioreactor process using a sodium chloride solution and an industrial effluent as draw solutions

[EN] Osmotic membrane bioreactor (OMBR) is an emerging membrane process which has gained interest in the recent years because of the low energy consumption and the high effluent quality. The osmotic membrane bioreactor combines a forward osmosis (FO) membrane and a biological treatment. However, salt reverse flux is the main problem because of the negative effect of the salt concentration increase in the reactor on the microbial activity. This is the reason why the study of a suitable draw solution (DS) is very important in the overall performance of the reactor. This study compares the process performance using two draw solutions: a 53 g L-1 NaCI solution and a real waste water solution (waste water from an absorption column consisting mainly of SO42- and NH4-N with concentrations of 153 g L-1 and 19 g L-1, respectively). The comparison is focused on the salt reverse flux during the reactor operation, the mixed liquor characteristics, the membrane fouling and the overall performance. The results indicated that the industrial wastewater showed a higher salt reverse flux, but also a less severe fouling and a higher the osmotic pressure difference in comparison with the NaCl solution. In terms of chemical oxygen demand (COD) removal efficiencies, both draw solutions attained values higher than 80%, though the efficiency was slightly lower when the industrial effluent was used as DS. This was related to the higher conductivity reached in the bioreactor when the industrial effluent was used as draw solution. In spite of it, the use of this industrial effluent as draw solution is strongly recommended because of the high permeate fluxes yielded, the low membrane fouling and the lack of necessity of regenerating the draw solution. (C) 2017 Elsevier B.V. All rights reserved.This study was supported by the Spanish Ministry of Economy and Competitiveness (Spain) through the project RTC-2015-3582-5-AR.Lujan Facundo, MJ.; Soler Cabezas, JL.; Mendoza Roca, JA.; Vincent Vela, MC.; Bes-Piá, M.; Doñate Hernández, S. (2017). A study of the osmotic membrane bioreactor process using a sodium chloride solution and an industrial effluent as draw solutions. Chemical Engineering Journal. 322:603-610. doi:10.1016/j.cej.2017.04.062S60361032