103 results on '"Crespo JG"'
Search Results
2. Type 2 diabetes and tuberculosis in a dynamic bi-national border population.
- Author
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Restrepo BI, Fisher-Hoch SP, Crespo JG, Whitney E, Perez A, Smith B, McCormick JB, Nuevo Santander Tuberculosis Trackers, Restrepo, B I, Fisher-Hoch, S P, Crespo, J G, Whitney, E, Perez, A, Smith, B, and McCormick, J B
- Abstract
The epidemic of type 2 diabetes in the United States prompted us to explore the association between diabetes and tuberculosis (TB) on the South Texas-Mexico border, in a large population of mostly non-hospitalized TB patients. We examined 6 years of retrospective data from all TB patients (n=5049) in South Texas and northeastern Mexico and found diabetes self-reported by 27.8% of Texan and 17.8% of Mexican TB patients, significantly exceeding national self-reported diabetes rates for both countries. Diabetes comorbidity substantially exceeded that of HIV/AIDS. Patients with TB and diabetes were older, more likely to have haemoptysis, pulmonary cavitations, be smear positive at diagnosis, and remain positive at the end of the first (Texas) or second (Mexico) month of treatment. The impact of type 2 diabetes on TB is underappreciated, and in the light of its epidemic status in many countries, it should be actively considered by TB control programmes, particularly in older patients. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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3. Hydroxytyrosol recovery from olive pomace: a simple process using olive mill industrial equipment and membrane technology.
- Author
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Romeu MFC, Bernardo J, Daniel CI, Costa N, Crespo JG, Silva Pinto L, Nunes da Ponte M, and Nunes AVM
- Abstract
In this work, pilot-scale nanofiltration was used to obtain aqueous solutions rich in hydroxytyrosol and tyrosol from olive oil by-products. A large-scale simple process involving olive mill standard machinery (blender and decanter) was used for the olive pomace pre-treatment with water. The aqueous extract was then directly fed to a nanofiltration unit and concentrated by reverse osmosis. Final concentration factors ranged between 7 and 9 for hydroxytyrosol and between 4 and 7 for tyrosol. The final aqueous solution, obtained as retentate stream of reverse osmosis, was highly concentrated in hydroxytyrosol and tyrosol and their concentrations remained stable over at least 14 months., Competing Interests: Conflict of interestThere is no conflict of interest., (© The Author(s) 2023.)
- Published
- 2024
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4. Antineoplastic drugs in urban wastewater: Occurrence, nanofiltration treatment and toxicity screening.
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Gouveia TIA, Cristóvão MB, Pereira VJ, Crespo JG, Alves A, Ribeiro AR, Silva A, and Santos MSF
- Subjects
- Wastewater, Waste Disposal, Fluid, Eukaryota, Pharmaceutical Preparations, Environmental Monitoring, Antineoplastic Agents toxicity, Water Pollutants, Chemical analysis
- Abstract
Antineoplastic drugs are pharmaceuticals that have been raising concerns among the scientific community due to: (i) their increasing prescription in the fight against the disease of the twentieth century (cancer); (ii) their recalcitrance to conventional wastewater treatments; (iii) their poor environmental biodegradability; and (iv) their potential risk to any eukaryotic organism. This emerges the urgency in finding solutions to mitigate the entrance and accumulation of these hazardous chemicals in the environment. Advanced oxidation processes (AOPs) have been taken into consideration to improve the degradation of antineoplastic drugs in wastewater treatment plants (WWTPs), but the formation of by-products that are more toxic or exhibit a different toxicity profile than the parent drug is frequently reported. This work evaluates the performance of a nanofiltration pilot unit, equipped with a Desal 5DK membrane, in the treatment of real WWTP effluents contaminated (without spiking) with eleven pharmaceuticals, five of which were never studied before. Average removals of 68 ± 23% were achieved for the eleven compounds, with decreasing risks from feed to permeate for aquatic organisms from receiving waterbodies (with the exception of cyclophosphamide, for which a high risk was estimated in the permeate). Aditionally, no significative impact on the growth and germination of three different seeds (Lepidium sativum, Sinapis alba, and Sorghum saccharatum) were determined for permeate matrix in comparison to the control., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2023
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5. Occurrence and Treatment of Antibiotic-Resistant Bacteria Present in Surface Water.
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Sério J, Marques AP, Huertas R, Crespo JG, and Pereira VJ
- Abstract
According to the World Health Organization, antibiotic resistance is one of the main threats to global health. The excessive use of several antibiotics has led to the widespread distribution of antibiotic-resistant bacteria and antibiotic resistance genes in various environment matrices, including surface water. In this study, total coliforms, Escherichia coli and enterococci, as well as total coliforms and Escherichia coli resistant to ciprofloxacin, levofloxacin, ampicillin, streptomycin, and imipenem, were monitored in several surface water sampling events. A hybrid reactor was used to test the efficiency of membrane filtration, direct photolysis (using UV-C light emitting diodes that emit light at 265 nm and UV-C low pressure mercury lamps that emit light at 254 nm), and the combination of both processes to ensure the retention and inactivation of total coliforms and Escherichia coli as well as antibiotic-resistant bacteria (total coliforms and Escherichia coli ) present in river water at occurrence levels. The membranes used (unmodified silicon carbide membranes and the same membrane modified with a photocatalytic layer) effectively retained the target bacteria. Direct photolysis using low-pressure mercury lamps and light-emitting diode panels (emitting at 265 nm) achieved extremely high levels of inactivation of the target bacteria. The combined treatment (unmodified and modified photocatalytic surfaces in combination with UV-C and UV-A light sources) successfully retained the bacteria and treated the feed after 1 h of treatment. The hybrid treatment proposed is a promising approach to use as point-of-use treatment by isolated populations or when conventional systems and electricity fail due to natural disasters or war. Furthermore, the effective treatment obtained when the combined system was used with UV-A light sources indicates that the process may be a promising approach to guarantee water disinfection using natural sunlight.
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- 2023
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6. Donnan Dialysis for Recovering Ammonium from Fermentation Solutions Rich in Volatile Fatty Acids.
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Barros KS, Carvalheira M, Marreiros BC, Reis MAM, Crespo JG, Pérez-Herranz V, and Velizarov S
- Abstract
For the production of polyhydroxyalkanoates (PHA) using nitrogen-rich feedstocks (e.g., protein-rich resources), the typical strategy of restricting cell growth as a means to enhance overall PHA productivity by nitrogen limitation is not applicable. In this case, a possible alternative to remove the nitrogen excess (NH
4 + /NH3 ) is by applying membrane separation processes. In the present study, the use of Donnan dialysis to separate ammonium ions from volatile fatty acids present in the media for the production of PHA was evaluated. Synthetic and real feed solutions were used, applying NaCl and HCl receiver solutions separated by commercial cation-exchange membranes. For this specific purpose, Fumasep and Ralex membranes showed better performance than Ionsep. Sorption of ammonium ions occurred in the Ralex membrane, thus intensifying the ammonium extraction. The separation performances with NaCl and HCl as receiver solutions were similar, despite sorption occurring in the Ralex membrane more intensely in the presence of NaCl. Higher volumetric flow rates, NaCl receiver concentrations, and volume ratios of feed:receiver solutions enhanced the degree of ammonium recovery. The application of an external electric potential difference to the two-compartment system did not significantly enhance the rate of ammonium appearance in the receiver solution. The results obtained using a real ammonium-containing solution after fermentation of cheese whey showed that Donnan dialysis can be successfully applied for ammonium recovery from such solutions.- Published
- 2023
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7. Development and Implementation of MBR Monitoring: Use of 2D Fluorescence Spectroscopy.
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Galinha CF and Crespo JG
- Abstract
The monitoring of a membrane bioreactor (MBR) requires the assessment of both biological and membrane performance. Additionally, the development of membrane fouling and the requirements for frequent membrane cleaning are still major concerns during MBR operation, requiring tight monitoring and system characterization. Transmembrane pressure is usually monitored online and allows following the evolution of membrane performance. However, it does not allow distinguishing the fouling mechanisms occurring in the system or predicting the future behavior of the membrane. The assessment of the biological medium requires manual sampling, and the analyses involve several steps that are labor-intensive, with low temporal resolution, preventing real-time monitoring. Two-dimensional fluorescence spectroscopy is a comprehensive technique, able to assess the system status at real-time without disturbing the biological system. It provides large sets of data (system fingerprints) from which meaningful information can be extracted. Nevertheless, mathematical data analysis (such as machine learning) is essential to properly extract the information contained in fluorescence spectra and correlate it with operating and performance parameters. The potential of 2D fluorescence spectroscopy as a process monitoring tool for MBRs is, therefore, discussed in the present work in view of the actual knowledge and the authors' own experience in this field.
- Published
- 2022
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8. Comparative Analysis of Bio-Vanillin Recovery from Bioconversion Media Using Pervaporation and Vacuum Distillation.
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Valério R, Brazinha C, and Crespo JG
- Abstract
The increasing demand for natural products has led to biotechnological vanillin production, which requires the recovery of vanillin (and vanillyl alcohol at trace concentrations, as in botanical vanillin) from the bioconversion broth, free from potential contaminants: the substrate and metabolites of bioconversion. This work discusses the recovery and fractionation of bio-vanillin, from a bioconversion broth, by pervaporation and by vacuum distillation, coupled with fractionated condensation. The objective was to recover vanillin free of potential contaminants, with maximised fluxes and selectivity for vanillin against water and minimised energy consumption per mass of vanillin recovered. In vacuum distillation fractionated condensation, adding several consecutive water pulses to the feed increased the percentage of recovered vanillin. In pervaporation-fractionated condensation and vacuum distillation-fractionated condensation processes, it was possible to recover vanillin and traces of vanillyl alcohol without the presence of potential contaminants. Vacuum distillation-experiments presented higher vanillin fluxes than pervaporation fractionated condensation experiments, 2.7 ± 0.1 g·m
-2 h-1 and 1.19 ± 0.01 g·m-2 h-1 , respectively. However, pervaporation fractionated condensation assures a selectivity of vanillin against water of 4.5 on the pervaporation step (acting as a preconcentration step) and vacuum distillation fractionated condensation requires a higher energy consumption per mass of vanillin recovered when compared with pervaporation- fractionated condensation, 2727 KWh kgVAN -1 at 85 °C and 1361 KWh kgVAN -1 at 75 °C, respectively.- Published
- 2022
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9. Design of Enzyme Loaded W/O Emulsions by Direct Membrane Emulsification for CO 2 Capture.
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Mondal S, Alke B, de Castro AM, Ortiz-Albo P, Syed UT, Crespo JG, and Brazinha C
- Abstract
Membrane-based gas separation is a promising unit operation in a low-carbon economy due to its simplicity, ease of operation, reduced energy consumption and portability. A methodology is proposed to immobilise enzymes in stable water-in-oil (W/O) emulsions produced by direct membrane emulsification systems and thereafter impregnated them in the pores of a membrane producing emulsion-based supported liquid membranes. The selected case-study was for biogas (CO
2 and CH4 ) purification. Upon initial CO2 sorption studies, corn oil was chosen as a low-cost and non-toxic bulk phase (oil phase). The emulsions were prepared with Nadir® UP150 P flat-sheet polymeric membranes. The optimised emulsions consisted of 2% Tween 80 ( w / w ) in corn oil as the continuous phase and 0.5 g.L-1 carbonic anhydrase enzyme with 5% PEG 300 ( w / w ) in aqueous solution as the dispersed phase. These emulsions were impregnated onto a porous hydrophobic PVDF membrane to prepare a supported liquid membrane for gas separation. Lastly, gas permeability studies indicated that the permeability of CO2 increased by ~15% and that of CH4 decreased by ~60% when compared to the membrane without carbonic anhydrase. Thus, a proof-of-concept for enhancement of CO2 capture using emulsion-based supported liquid membrane was established.- Published
- 2022
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10. Protein Attachment Mechanism for Improved Functionalization of Affinity Monolith Chromatography (AMC).
- Author
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Nayak N, Mazzei R, Giorno L, Crespo JG, Portugal CAM, and Poerio T
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- Adsorption, Amines, Chromatography, Affinity methods, Ligands, Antibodies, Serum Albumin, Bovine
- Abstract
This work aims at understanding the attachment mechanisms and stability of proteins on a chromatography medium to develop more efficient functionalization methodologies, which can be exploited in affinity chromatography. In particular, the study was focused on the understanding of the attachment mechanisms of bovine serum albumin (BSA), used as a ligand model, and protein G on novel amine-modified alumina monoliths as a stationary phase. Protein G was used to develop a column for antibody purification. The results showed that, at lower protein concentrations (i.e., 0.5 to 1.0 mg·mL
-1 ), protein attachment follows a 1st-order kinetics compatible with the presence of covalent binding between the monolith and the protein. At higher protein concentrations (i.e., up to 10 mg·mL-1 ), the data preferably fit a 2nd-order kinetics. Such a change reflects a different mechanism in the protein attachment which, at higher concentrations, seems to be governed by physical adsorption resulting in a multilayered protein formation, due to the presence of ligand aggregates. The threshold condition for the prevalence of physical adsorption of BSA was found at a concentration higher than 1.0 mg·mL-1 . Based on this result, protein concentrations of 0.7 and 1.0 mg·mL-1 were used for the functionalization of monoliths with protein G, allowing a maximum attachment of 1.43 mg of protein G/g of monolith. This column was then used for IgG binding-elution experiments, which resulted in an antibody attachment of 73.5% and, subsequently, elution of 86%, in acidic conditions. This proved the potential of the amine-functionalized monoliths for application in affinity chromatography.- Published
- 2022
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11. A Study on Biofouling and Cleaning of Anion Exchange Membranes for Reverse Electrodialysis.
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Tiago G, Cristóvão MB, Marques AP, Huertas R, Merino-Garcia I, Pereira VJ, Crespo JG, and Velizarov S
- Abstract
This study covers the modification, (bio)fouling characterization, use, and cleaning of commercial heterogeneous anion exchange membranes (AEMs) to evaluate their feasibility for reverse electrodialysis (RED) applications. A surface modification with poly (acrylic) acid resulted in an improved monovalent perm-selectivity (decreased sulfate membrane transport rate). Moreover, we evaluated the (bio)fouling potential of the membrane using sodium dodecyl sulfate (SDS), sodium dodecyl benzenesulfonate (SDBS), and Aeromonas hydrophila as model organic foulants and a biofoulant, respectively. A detailed characterization of the AEMs (water contact angle, ion exchange capacity (IEC), scanning electron microscopy (SEM), cyclic voltammetry (CV), and Fourier Transform Infrared (FTIR) spectra) was carried out, verifying that the presence of such foulants reduces IEC and the maximum current obtained by CV. However, only SDS and SDBS affected the contact angle values. Cleaning of the biofouled membranes using a sodium hypochlorite aqueous solution allows for (partially) recovering their initial properties. Furthermore, this work includes a fouling characterization using real surface and sea water matrixes, confirming the presence of several types of fouling microorganisms in natural streams. A lower adhesion of microorganisms (measured in terms of total bacteria counts) was observed for the modified membranes compared to the unmodified ones. Finally, we propose a cleaning strategy to mitigate biofouling in AEMs that could be easily applied in RED systems for an enhanced long-term process performance.
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- 2022
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12. Perspectives of fluorescence spectroscopy for online monitoring in microalgae industry.
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Sá M, Ferrer-Ledo N, Gao F, Bertinetto CG, Jansen J, Crespo JG, Wijffels RH, Barbosa M, and Galinha CF
- Subjects
- Agriculture, Biological Factors, Biomass, Spectrometry, Fluorescence, Cosmetics, Microalgae chemistry
- Abstract
Microalgae industrial production is viewed as a solution for alternative production of nutraceuticals, cosmetics, biofertilizers, and biopolymers. Throughout the years, several technological advances have been implemented, increasing the competitiveness of microalgae industry. However, online monitoring and real-time process control of a microalgae production factory still require further development. In this mini-review, non-destructive tools for online monitoring of cellular agriculture applications are described. Still, the focus is on the use of fluorescence spectroscopy to monitor several parameters (cell concentration, pigments, and lipids) in the microalgae industry. The development presented makes it the most promising solution for monitoring up-and downstream processes, different biological parameters simultaneously, and different microalgae species. The improvements needed for industrial application of this technology are also discussed., (© 2022 The Authors. Microbial Biotechnology published by Society for Applied Microbiology and John Wiley & Sons Ltd.)
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- 2022
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13. Nanofiltration as an Efficient Tertiary Wastewater Treatment: Elimination of Total Bacteria and Antibiotic Resistance Genes from the Discharged Effluent of a Full-Scale Wastewater Treatment Plant.
- Author
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Oliveira M, Leonardo IC, Silva AF, Crespo JG, Nunes M, and Crespo MTB
- Abstract
Wastewater reuse for agricultural irrigation still raises important public health issues regarding its safety, due to the increasing presence of emerging contaminants, such as antibiotic resistant bacteria and genes, in the treated effluents. In this paper, the potential for a commercial Desal 5 DK nanofiltration membrane to be used as a tertiary treatment in the wastewater treatment plants for a more effective elimination of these pollutants from the produced effluents was assessed on laboratory scale, using a stainless steel cross-flow cell. The obtained results showed high concentrations of total bacteria and target carbapenem and (fluoro)quinolone resistance genes ( bla
KPC , blaOXA-48 , blaNDM , blaIMP , blaVIM , qnr A, qnr B and qnr S) not only in the discharged, but also in the reused, effluent samples, which suggests that their use may not be entirely safe. Nevertheless, the applied nanofiltration treatment achieved removal rates superior to 98% for the total bacteria and 99.99% for all the target resistance genes present in both DNA and extracellular DNA fractions, with no significant differences for these microbiological parameters between the nanofiltered and the control tap water samples. Although additional studies are still needed to fully optimize the entire process, the use of nanofiltration membranes seems to be a promising solution to substantially increase the quality of the treated wastewater effluents.- Published
- 2022
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14. Nannochloropsis sp. Biorefinery: Recovery of Soluble Protein by Membrane Ultrafiltration/Diafiltration.
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Ribeiro C, Santos ET, Costa L, Brazinha C, Saraiva P, and Crespo JG
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This work proposes a way to maximize the potential of a Nannochloropsis sp. biorefinery process, through membrane technology, producing an extract enriched in soluble proteins, free from the insoluble protein fraction, with a low lipid content and eliminating the colored chlorophyll-a. This procedure, following the principles of a circular economy approach, allows for the valorization of a stream from the biorefining of Nannochloropsis sp. that, otherwise, would be considered a residue without commercial value. The process proposed minimizes fouling phenomena at the membrane surface, making it possible to achieve high permeate fluxes, thus reducing the need for membrane cleaning and, therefore, contributing to an extended membrane lifetime. Supernatant obtained after centrifugation of a suspension of ruptured Nannochloropsis sp. cells was processed by ultrafiltration using a membrane with a cut-off of 100 kDa MWCO. Two different operating approaches were evaluated-controlled transmembrane pressure and controlled permeate flux-under concentration and diafiltration modes. Ultrafiltration operated in a diafiltration mode, under controlled permeate flux conditions, led to the highest soluble protein recovery (78%) with the highest constant permeate flux (12 L·m
-2 ·h-1 ) and low membrane fouling.- Published
- 2022
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15. Overview of Membrane Science and Technology in Portugal.
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Tomé LC, Santos DMF, Velizarov S, Coelhoso IM, Mendes A, Crespo JG, and de Pinho MN
- Abstract
Membrane research in Portugal is aligned with global concerns and expectations for sustainable social development, thus progressively focusing on the use of natural resources and renewable energy. This review begins by addressing the pioneer work on membrane science and technology in Portugal by the research groups of Instituto Superior Técnico - Universidade de Lisboa (IST), NOVA School of Science and Technology - Universidade Nova de Lisboa (FCT NOVA) and Faculdade de Engenharia - Universidade do Porto (FEUP) aiming to provide an historical perspective on the topic. Then, an overview of the trends and challenges in membrane processes and materials, mostly in the last five years, involving Portuguese researchers, is presented as a contribution to a more sustainable water-energy-material-food nexus.
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- 2022
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16. Nitrate Removal by Donnan Dialysis and Anion-Exchange Membrane Bioreactor Using Upcycled End-of-Life Reverse Osmosis Membranes.
- Author
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Lejarazu-Larrañaga A, Ortiz JM, Molina S, Pawlowski S, Galinha CF, Otero V, García-Calvo E, Velizarov S, and Crespo JG
- Abstract
This work explores the application of Reverse Osmosis (RO) upcycled membranes, as Anion Exchange Membranes (AEMs) in Donnan Dialysis (DD) and related processes, such as the Ion Exchange Membrane Bioreactor (IEMB), for the removal of nitrate from contaminated water, to meet drinking water standards. Such upcycled membranes might be manufactured at a lower price than commercial AEMs, while their utilization reinforces the commitment to a circular economy transition. In an effort to gain a better understanding of such AEMs, confocal µ-Raman spectroscopy was employed, to assess the distribution of the ion-exchange sites through the thickness of the prepared membranes, and 2D fluorescence spectroscopy, to evaluate alterations in the membranes caused by fouling and chemical cleaning The best performing membrane reached a 56% average nitrate removal within 24 h in the DD and IEMB systems, with the latter furthermore allowing for simultaneous elimination of the pollutant by biological denitrification, thus avoiding its discharge into the environment. Overall, this work validates the technical feasibility of using RO upcycled AEMs in DD and IEMB processes for nitrate removal. This membrane recycling concept might also find applications for the removal and/or recovery of other target negatively charged species.
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- 2022
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17. Predicting the concentration of hazardous phenolic compounds in refinery wastewater-a multivariate data analysis approach.
- Author
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Bastos PDA, Galinha CF, Santos MA, Carvalho PJ, and Crespo JG
- Subjects
- Data Analysis, Oil and Gas Industry, Phenols analysis, Environmental Pollutants, Wastewater
- Abstract
The present study focused on the methodology for identification of the wastewater stream that presents the highest phenolic impact at a large oil refinery. As a case-study, the oil refinery, Petrogal S.A., in Sines, Portugal, was selected. Firstly, stripped sour water from the cracking complex was identified as the most relevant wastewater stream concerning phenolic emission. Secondly, multivariate data analysis was used, through projection to latent structures (PLS) regression, to find existing correlations between process parameters and phenols content in stripped sour water. The models developed allowed the prediction of phenols concentration with predictive errors down to 20.16 mg/L (corresponding to 8.2% average error), depending on the complexity of the correlation used, and R
2 values as high as 0.85. Models were based in input parameters related to fluid catalytic crackers (FCC) feedstock quality, crudemix and steam injected in the catalyst stripper. The studied data analysis approach showed to be useful as a tool to predict the phenolic content in stripped sour water. Such prediction would help improve the wastewater management system, especially the units responsible for phenol degradation. The methodology shown in this work can be used in other refineries containing catalytic cracking complexes, providing a tool which allows the online prediction of phenols in stripped sour water and the identification of the most relevant process parameters. An optimised system at any refinery leads to an improvement in the wastewater quality and costs associated with pollutant discharge; thus, the development of monitoring online tools, as proposed in this work, is essential., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2022
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18. Stability of Polymeric Membranes to UV Exposure before and after Coating with TiO 2 Nanoparticles.
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Labuto G, Sanches S, Crespo JG, Pereira VJ, and Huertas RM
- Abstract
The combination of photocatalysis and membrane filtration in a single reactor has been proposed, since the photocatalytic treatment may degrade the pollutants retained by the membrane and reduce fouling. However, polymeric membranes can be susceptible to degradation by UV radiation and free radicals. In the present study, five commercial polymeric membranes were exposed to ultraviolet (UV) radiation before and after applying a sol-gel coating with TiO
2 nanoparticles. Membrane stability was characterized by changes in hydrophilicity as well as analysis of soluble substances and nanoparticles detached into the aqueous medium, and by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and energy-dispersive X-ray spectrometry (EDS) for structural, morphological, and elemental distribution analysis, respectively. The TiO2 coating conferred photocatalytic properties to the membranes and protected them during 6 h of UV radiation exposures, reducing or eliminating chemical and morphological changes, and in some cases, improving their mechanical resistance. A selected commercial nanofiltration membrane was coated with TiO2 and used in a hybrid reactor with a low-pressure UV lamp, promoting photocatalysis coupled with cross-flow filtration in order to remove 17α-ethinylestradiol spiked into an aqueous matrix, achieving an efficiency close to 100% after 180 min of combined filtration and photocatalysis, and almost 80% after 90 min.- Published
- 2021
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19. Degradation of Neonicotinoids and Caffeine from Surface Water by Photolysis.
- Author
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Raschitor A, Romero A, Sanches S, Pereira VJ, Crespo JG, and Llanos J
- Abstract
Along with rapid social development, the use of insecticides and caffeine-containing products increases, a trend that is also reflected in the composition of surface waters. This study is focused on the phototreatment of a surface water containing three neonicotinoids (imidacloprid, thiamethoxam, and clothianidin) and caffeine. Firstly, the radiation absorption of the target pollutants and the effect of the water matrix components were evaluated. It was observed that the maximum absorption peaks appear at wavelengths ranging from 246 to 274 nm, and that the water matrix did not affect the efficiency of the removal of the target pollutants. It was found that the insecticides were efficiently removed after a very short exposure to UV irradiation, while the addition of hydrogen peroxide was needed for an efficient caffeine depletion. The electrical energy per order was estimated, being the lowest energy required (9.5 kWh m
-3 order-1 ) for the depletion of thiamethoxan by indirect photolysis, and a concentration of hydrogen peroxide of 5 mg dm-3 . Finally, a preliminary evaluation on the formation of by-products reveals that these compounds play a key role in the evolution of the ecotoxicity of the samples, and that the application of direct photolysis reduces the concentration of these intermediates.- Published
- 2021
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20. Detection of anticancer drugs in wastewater effluents: Grab versus passive sampling.
- Author
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Cristóvão MB, Bento-Silva A, Bronze MR, Crespo JG, and Pereira VJ
- Subjects
- Environmental Monitoring, Organic Chemicals, Wastewater analysis, Antineoplastic Agents, Water Pollutants, Chemical analysis
- Abstract
The occurrence of six anticancer drugs was evaluated in wastewater effluents. Several grab samples from wastewater effluent were collected throughout a year. Capecitabine, cyclophosphamide and ifosfamide were detected at concentrations ranging from 8 to 46 ng·L
-1 . Capecitabine was detected in all the sampling events whereas cyclophosphamide and ifosfamide were detected less frequently. Additionally, the suitability of using pharmaceutical-polar organic chemical integrative samplers (POCIS) to monitor the target drugs in wastewater effluents was assessed. Capecitabine, ifosfamide and cyclophosphamide were detected with POCIS and showed a linear uptake over 15 days. The sampling rates, determined in situ, were used to estimate time-weighted average concentrations. A good correlation was found between the concentration of capecitabine detected with POCIS deployed during five days (32 ± 1 ng·L-1 ) and the average concentrations obtained in grab samples. The use of passive samplers has advantages over grab samples: easier analysis, less time and costs associated with the analytical method. Passive samplers also provide a time-weighted information about the concentration of pollutants in the aquatic environment. However, information may be lost when the concentration of the target compounds in wastewater effluents is low and the passive samplers are deployed for a short time., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
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21. From Black Box to Machine Learning: A Journey through Membrane Process Modelling.
- Author
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Galinha CF and Crespo JG
- Abstract
Membrane processes are complex systems, often comprising several physicochemical phenomena, as well as biological reactions, depending on the systems studied. Therefore, process modelling is a requirement to simulate (and predict) process and membrane performance, to infer about optimal process conditions, to assess fouling development, and ultimately, for process monitoring and control. Despite the actual dissemination of terms such as Machine Learning, the use of such computational tools to model membrane processes was regarded by many in the past as not useful from a scientific point-of-view, not contributing to the understanding of the phenomena involved. Despite the controversy, in the last 25 years, data driven, non-mechanistic modelling is being applied to describe different membrane processes and in the development of new modelling and monitoring approaches. Thus, this work aims at providing a personal perspective of the use of non-mechanistic modelling in membrane processes, reviewing the evolution supported in our own experience, gained as research group working in the field of membrane processes. Additionally, some guidelines are provided for the application of advanced mathematical tools to model membrane processes.
- Published
- 2021
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22. Protein Crystallization in a Microfluidic Contactor with Nafion ® 117 Membranes.
- Author
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Polino M, Rho HS, Pina MP, Mallada R, Carvalho AL, Romão MJ, Coelhoso I, Gardeniers JGE, Crespo JG, and Portugal CAM
- Abstract
Protein crystallization still remains mostly an empirical science, as the production of crystals with the required quality for X-ray analysis is dependent on the intensive screening of the best protein crystallization and crystal's derivatization conditions. Herein, this demanding step was addressed by the development of a high-throughput and low-budget microfluidic platform consisting of an ion exchange membrane (117 Nafion
® membrane) sandwiched between a channel layer (stripping phase compartment) and a wells layer (feed phase compartment) forming 75 independent micro-contactors. This microfluidic device allows for a simultaneous and independent screening of multiple protein crystallization and crystal derivatization conditions, using Hen Egg White Lysozyme (HEWL) as the model protein and Hg2+ as the derivatizing agent. This microdevice offers well-regulated crystallization and subsequent crystal derivatization processes based on the controlled transport of water and ions provided by the 117 Nafion® membrane. Diffusion coefficients of water and the derivatizing agent (Hg2+ ) were evaluated, showing the positive influence of the protein drop volume on the number of crystals and crystal size. This microfluidic system allowed for crystals with good structural stability and high X-ray diffraction quality and, thus, it is regarded as an efficient tool that may contribute to the enhancement of the proteins' crystals structural resolution.- Published
- 2021
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23. Feeding strategies to optimize vanillin production by Amycolatopsis sp. ATCC 39116.
- Author
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Valério R, Bernardino ARS, Torres CAV, Brazinha C, Tavares ML, Crespo JG, and Reis MAM
- Subjects
- Benzyl Alcohols, Biomass, Coumaric Acids chemistry, Culture Media, Glucose chemistry, Hydrogen-Ion Concentration, Kinetics, Phenol chemistry, Vanillic Acid chemistry, Amycolatopsis metabolism, Benzaldehydes chemistry, Bioreactors, Biotechnology methods, Industrial Microbiology methods, Oxygen chemistry
- Abstract
The growing consumer demand for natural products led to an increasing interest in vanillin production by biotechnological routes. In this work, the biotechnological vanillin production by Amycolatopsis sp. ATCC 39116 is studied using ferulic acid as precursor, aiming to achieve maximized vanillin productivities. During biotech-vanillin production, the effects of glucose, vanillin and ferulic acid concentrations in the broth proved to be relevant for vanillin productivity. Concerning glucose, its presence in the broth during the production phase avoids vanillin conversion to vanillic acid and, consequently, increases vanillin production. To avoid the accumulation of vanillin up to a toxic concentration level, a multiple-pulse-feeding strategy is implemented, with intercalated vanillin removal from the broth and biomass recovery. This strategy turned out fruitful, leading to 0.46 g L
-1 h-1 volumetric productivity of vanillin of and a production yield of 0.69 gvanillin gferulic acid -1 , which are among the highest values reported in the literature for non-modified bacteria.- Published
- 2021
- Full Text
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24. Block Copolymer-Based Magnetic Mixed Matrix Membranes-Effect of Magnetic Field on Protein Permeation and Membrane Fouling.
- Author
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Upadhyaya L, Semsarilar M, Quemener D, Fernández-Pacheco R, Martinez G, Coelhoso IM, Nunes SP, Crespo JG, Mallada R, and Portugal CAM
- Abstract
In this study, we report the impact of the magnetic field on protein permeability through magnetic-responsive, block copolymer, nanocomposite membranes with hydrophilic and hydrophobic characters. The hydrophilic nanocomposite membranes were composed of spherical polymeric nanoparticles (NPs) synthesized through polymerization-induced self-assembly (PISA) with iron oxide NPs coated with quaternized poly(2-dimethylamino)ethyl methacrylate. The hydrophobic nanocomposite membranes were prepared via nonsolvent-induced phase separation (NIPS) containing poly (methacrylic acid) and meso-2,3-dimercaptosuccinic acid-coated superparamagnetic nanoparticles (SPNPs). The permeation experiments were carried out using bovine serum albumin (BSA) as the model solute, in the absence of the magnetic field and under permanent and cyclic magnetic field conditions OFF/ON (strategy 1) and ON/OFF (strategy 2). It was observed that the magnetic field led to a lower reduction in the permeate fluxes of magnetic-responsive membranes during BSA permeation, regardless of the magnetic field strategy used, than that obtained in the absence of the magnetic field. Nevertheless, a comparative analysis of the effect caused by the two cyclic magnetic field strategies showed that strategy 2 allowed for a lower reduction of the original permeate fluxes during BSA permeation and higher protein sieving coefficients. Overall, these novel magneto-responsive block copolymer nanocomposite membranes proved to be competent in mitigating biofouling phenomena in bioseparation processes.
- Published
- 2021
- Full Text
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25. Occurrence of Antibiotics, Antibiotic Resistance Genes and Viral Genomes in Wastewater Effluents and Their Treatment by a Pilot Scale Nanofiltration Unit.
- Author
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Cristóvão MB, Tela S, Silva AF, Oliveira M, Bento-Silva A, Bronze MR, Crespo MTB, Crespo JG, Nunes M, and Pereira VJ
- Abstract
Broad-spectrum fluoroquinolone antibiotics (ciprofloxacin and levofloxacin), carbapenem and fluoroquinolone resistance genes, as well as viral genomes, were detected in grab samples of wastewater effluents. Passive samplers, which are simpler and easier to use and provide information about the concentrations and combination of contaminants present in a certain fluid matrix over time, proved to be extremely promising devices to monitor the presence of the target antibiotics in wastewater effluents. Nanofiltration was tested with a pilot-scale unit installed at a domestic wastewater treatment facility, using a Desal 5DK membrane operated at a constant transmembrane pressure of 6 bar and 70% recovery rate. In a 24 h experimental assay, the variation of the membrane permeance was low (6.3%). High rejections of the target contaminants from the wastewater effluent were obtained by the pilot-scale treatment. Hence, nanofiltration using the Desal 5DK membrane is considered to be a promising treatment to cope with chemical and biological contaminants present in wastewater effluents.
- Published
- 2020
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26. Tannery Effluent Treatment by Nanofiltration, Reverse Osmosis and Chitosan Modified Membranes.
- Author
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Zakmout A, Sadi F, Portugal CAM, Crespo JG, and Velizarov S
- Abstract
The objective of this work is to develop an appropriate technology for environmentally sound membrane-based purification of a tannery effluent assuring, simultaneously, the recovery of chromium, considered as the most hazardous inorganic water pollutant extensively used in leather tanning. A comparison between the permeate fluxes obtained during treatment of a synthetic tannery effluent through nanofiltration (NF270 and NF90 membranes) and reverse osmosis (BW30 and SW30) membranes was first performed. Then, a dedicated polymeric membrane was prepared by coating chitosan (cs) on a polyethersulfone (PES) microfiltration membrane (cs-PES MFO22) support. The resulting membrane was characterized by Fourier Transforms Infrared Spectroscopy Attenuated Total Reflectance (FTIR-ATR), Emission Scanning Electronic Microscopy (SEM) to confirm the process of surface modification and cross-linking of chitosan with glutaraldehyde. This membrane was found to be highly effective for chromium removal (>99%), which was more than eight times higher in reference to monovalent cations (e.g., Na
+ and K+ ) and more than six times higher in reference to the divalent cations (Mg2+ and Ca2+ ) studied. The reverse osmosis permeate conforms to local Algerian regulations regarding being discharged directly into the natural environment (in this case, Reghaia Lake) or into urban sewers linked to wastewater biological treatment stations. While the SW30 membrane proved to be the most effective for purification of the tannery effluent, the chitosan modified membrane proved to be appropriate for recovery of chromium from the reverse osmosis concentrate.- Published
- 2020
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27. Development of bioactive films based on chitosan and Cynara cardunculus leaves extracts for wound dressings.
- Author
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Brás T, Rosa D, Gonçalves AC, Gomes AC, Alves VD, Crespo JG, Duarte MF, and Neves LA
- Subjects
- Bandages, Cell Line, Cell Survival drug effects, Fibroblasts drug effects, Humans, Lactones chemistry, Microscopy, Electron, Scanning methods, Sesquiterpenes chemistry, Skin drug effects, Chitosan chemistry, Cynara chemistry, Plant Extracts chemistry, Plant Extracts pharmacology, Plant Leaves chemistry, Wound Healing drug effects
- Abstract
The development of natural based, effective and protective wound dressings associated to local treatment applied on chronic wounds, represents a major challenge nowadays. In this work chitosan-based films were prepared with different concentrations of ethanolic ultrasound assisted extracts from Cynara cardunculus leaves (EtPUAE). The physico-chemical film properties revealed that extract incorporation influences the volumetric swelling capacity and mechanical properties of the films, leading to materials with a lower fluid absorption capacity and more fragile. However, no impact was detected on the thermal properties of the films, as well as on their dense structure characterized by Scanning Electronic Microscopy (SEM) analysis. Biological screening of chitosan-based films show that chitosan with a 1% (w/w) and a 5% (w/w) EtPUAE loading did not induce cytotoxicity on normal human skin fibroblasts (Bj5-ta cell line), mainly attributed to cynaropicrin (extract key active compound) present in the film below its IC
50 value. Nevertheless, chitosan-based films with 5% (w/w) EtPUAE presented an interesting anti-inflammatory activity. Bj5-ta cells stimulated with liposaccharides (LPS), presented a reduction of 86% on IL-6 cytokine levels, after exposure to chitosan with 5% EtPUAE film extract. The results obtained in this study open up the possibility of successfully using chitosan films doped with EtPUAE for development of chronic wound dressings, with the advantage of using naturally-sourced materials with anti-inflammatory activity., (Copyright © 2020 Elsevier B.V. All rights reserved.)- Published
- 2020
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28. A corrosion evaluation of mild carbon steel in reclaimed refinery stripped sour water.
- Author
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Bastos PDA, Bastos AC, Ferreira MGS, Santos MA, Carvalho PJ, and Crespo JG
- Subjects
- Corrosion, Waste Disposal, Fluid, Water, Carbon, Steel
- Abstract
Reclaiming water for cooling systems in oil refineries has been strongly encouraged over the past years for decreasing the large consumption of fresh water, thus contributing to the efficient use of this valuable resource. In a recent study [Journal of Environmental Management 261 (2020) 110229], some of the authors studied the retention of phenols in refinery wastewater through reverse osmosis (RO) and found rejections of up to 98% of phenols and 99% of both chemical oxygen demand (COD) and total organic carbon (TOC). The permeates complied with the quality standards for make-up water in cooling processes. A missing aspect, important for the water to be used in the oil and gas industry, was the level of corrosivity of the new permeates. In this work the corrosion of mild carbon steel in the permeates and in the original cooling tower make-up water was studied by electrochemical techniques. The corrosion rate of steel in the permeates in aerated conditions was lower (between 0.053 ± 0.006 and 0.123 ± 0.011 mm year
-1 ) than in the make-up water (0.167 ± 0.030 mm year-1 ), confirming their suitability for replacing make-up water in the cooling towers. The low corrosion of carbon steel was attributed to the low conductivity and absence of oxidizing species in the fluids, compared to fresh water., (Copyright © 2020 Elsevier Ltd. All rights reserved.)- Published
- 2020
- Full Text
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29. Characterization of Poly(Acrylic) Acid-Modified Heterogenous Anion Exchange Membranes with Improved Monovalent Permselectivity for RED.
- Author
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Merino-Garcia I, Kotoka F, Portugal CAM, Crespo JG, and Velizarov S
- Abstract
The performance of anion-exchange membranes (AEMs) in Reverse Electrodialysis is hampered by both presence of multivalent ions and fouling phenomena, thus leading to reduced net power density. Therefore, we propose a monolayer surface modification procedure to functionalize Ralex-AEMs with poly(acrylic) acid (PAA) in order to (i) render a monovalent permselectivity, and (ii) minimize organic fouling. Membrane surface modification was carried out by putting heterogeneous AEMs in contact with a PAA-based aqueous solution for 24 h. The resulting modified membranes were firstly characterized by contact angle, water uptake, ion exchange capacity, fixed charge density, and swelling degree measurements, whereas their electrochemical responses were evaluated through cyclic voltammetry. Besides, their membrane electro-resistance was also studied via electrochemical impedance spectroscopy analyses. Finally, membrane permselectivity and fouling behavior in the presence of humic acid were evaluated through mass transport experiments using model NaCl containing solutions. The use of modified PAA-AEMs resulted in a significantly enhanced monovalent permselectivity (sulfate rejection improved by >35%) and membrane hydrophilicity (contact angle decreased by >15%) in comparison with the behavior of unmodified Ralex-AEMs, without compromising the membrane electro-resistance after modification, thus demonstrating the technical feasibility of the proposed membrane modification procedure. This study may therefore provide a feasible way for achieving an improved Reverse Electrodialysis process efficiency.
- Published
- 2020
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- View/download PDF
30. Predicted concentrations of anticancer drugs in the aquatic environment: What should we monitor and where should we treat?
- Author
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Cristóvão MB, Janssens R, Yadav A, Pandey S, Luis P, Van der Bruggen B, Dubey KK, Mandal MK, Crespo JG, and Pereira VJ
- Subjects
- Antineoplastic Agents urine, Drug Utilization, Environmental Monitoring, Feces chemistry, Fresh Water analysis, Hospitals, Housing, Humans, India, Portugal, Wastewater, Water Pollutants, Chemical urine, Antineoplastic Agents analysis, Water Pollutants, Chemical analysis
- Abstract
Anticancer drugs have been detected in the aquatic environment, they have a potent mechanism of action and their consumption is expected to drastically increase in the future. Consequently, it is crucial to routinely monitor the occurrence of anticancer drugs and to develop effective treatment options to avoid their release into the environment. Prior to implementing a monitoring program, it is important to define which anticancer drugs are more prone to be found in the surface waters. In this study the consumption of anticancer drugs in the Lisbon region (Portugal), Belgium and Haryana state (India) were used to estimate the concentrations that can be expected in surface waters. Moreover, one important aspect is to define the major entry route of anticancer drugs in the aquatic environment: is it hospital or household effluents? The results disclosed in this study showed that in Belgium and Lisbon, 94 % of the total amount of anticancer drugs were delivered to outpatients, indicating that household effluents are the primary input source of these drugs and thus, upgrading the treatment in the domestic wastewater facilities should be the focus., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
31. Fluorescence spectroscopy and chemometrics for simultaneous monitoring of cell concentration, chlorophyll and fatty acids in Nannochloropsis oceanica.
- Author
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Sá M, Bertinetto CG, Ferrer-Ledo N, Jansen JJ, Wijffels R, Crespo JG, Barbosa M, and Galinha CF
- Subjects
- Industrial Microbiology, Microalgae growth & development, Stramenopiles growth & development, Biomass, Chlorophyll metabolism, Fatty Acids metabolism, Spectrometry, Fluorescence, Stramenopiles metabolism
- Abstract
Online monitoring of algal biotechnological processes still requires development to support economic sustainability. In this work, fluorescence spectroscopy coupled with chemometric modelling is studied to monitor simultaneously several compounds of interest, such as chlorophyll and fatty acids, but also the biomass as a whole (cell concentration). Fluorescence excitation-emission matrices (EEM) were acquired in experiments where different environmental growing parameters were tested, namely light regime, temperature and nitrogen (replete or deplete medium). The prediction models developed have a high R
2 for the validation data set for all five parameters monitored, specifically cell concentration (0.66), chlorophyll (0.78), and fatty acid as total (0.78), saturated (0.81) and unsaturated (0.74). Regression coefficient maps of the models show the importance of the pigment region for all outputs studied, and the protein-like fluorescence region for the cell concentration. These results demonstrate for the first time the potential of fluorescence spectroscopy for in vivo and real-time monitoring of these key performance parameters during Nannochloropsis oceanica cultivation.- Published
- 2020
- Full Text
- View/download PDF
32. Reverse osmosis performance on stripped phenolic sour water treatment - A study on the effect of oil and grease and osmotic pressure.
- Author
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Bastos PDA, Santos MA, Carvalho PJ, and Crespo JG
- Subjects
- Filtration, Hydrocarbons, Membranes, Artificial, Osmosis, Osmotic Pressure, Phenols, Wastewater, Waste Disposal, Fluid, Water Purification
- Abstract
Technologies for water recycling within oil refineries have been gaining interest at an extensive rate due to the large volume of wastewater generated, high dependency of water and the progressive scarcity of this valuable resource. Phenols are part of a specific class of organic pollutants that have been contributing to a low-quality effluent in oil refineries due to their hazardous nature and strict environmental legislation associated. The reuse of stripped sour water within refineries is often blocked due to its rich phenolic content. This study evaluates the retention of phenols in refinery wastewater through reverse osmosis (RO) at its major source of emission, for water reclamation. The RO membrane selected exhibited rejections of up to 98% of phenols and 99% of both chemical oxygen demand (COD) and total organic carbon (TOC). Permeate quality remained intact despite flux decline caused by phenolic and hydrocarbon adsorption when the oil content, in the feed, reached 771 ppm. The effluent's low conductivity due to lack of salts led to minor osmotic pressure differences (less than 2.5 bar at a volume concentration factor of 3), therefore, showing appealing performances of reverse osmosis filtration. Characterization of all permeates obtained from cross-flow filtration experiments showed COD levels in line with water reuse quality standards for make-up water in cooling processes., (Copyright © 2020. Published by Elsevier Ltd.)
- Published
- 2020
- Full Text
- View/download PDF
33. Biocatalytic CO 2 Absorption and Structural Studies of Carbonic Anhydrase under Industrially-Relevant Conditions.
- Author
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Castro AM, Ferreira E, Portugal C, Neves LA, and Crespo JG
- Subjects
- Biocatalysis, Chemical Engineering methods, Enzyme Stability, Greenhouse Gases chemistry, Hydrogen-Ion Concentration, Structure-Activity Relationship, Temperature, Carbon Dioxide chemistry, Carbonic Anhydrases chemistry
- Abstract
The unprecedently high CO
2 levels in the atmosphere evoke the urgent need for development of technologies for mitigation of its emissions. Among the alternatives, the biocatalytic route has been claimed as one of the most promising. In the present work, the carbonic anhydrase from bovine erythrocytes (BCA) was employed as a model enzyme for structural studies in an aqueous phase at alkaline pH, which is typical of large-scale absorption processes under operation. Circular dichroism (CD) analysis revealed a high enzymatic stability at pH 10 with a prominent decrease of the melting temperature above this value. The CO2 absorption capacity of the aqueous solutions were assessed by online monitoring of pressure decay in a stainless-steel cell, which indicated a better performance at pH 10 with a kinetic rate increase of up to 43%, as compared to non-biocatalytic conditions. Even low enzyme concentrations (0.2 mg g-1 ) proved to be sufficient to improve the overall CO2 capture process performance. The enzyme-enhanced approach of CO2 capture presents a high potential and should be further studied.- Published
- 2020
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- View/download PDF
34. Biorefinery of Dunaliella salina: Sustainable recovery of carotenoids, polar lipids and glycerol.
- Author
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Monte J, Ribeiro C, Parreira C, Costa L, Brive L, Casal S, Brazinha C, and Crespo JG
- Subjects
- Glycerides, Glycerol, Lipids, Carotenoids, Microalgae
- Abstract
Dunaliella salina is well-known for its high content in carotenoids and glycerol. Nevertheless, Dunaliella salina has also a high content in lipids, including polar lipids, which are suitable for nutraceutical/cosmeceutical applications. This work proposes a sustainable process to maximise the potential of Dunaliella salina for the production of distinct fractions of carotenoids, glycerol, polar lipids and proteins, which may contribute to improve the revenues of the microalgae industry. In this work, extraction with non-hazardous solvents and organic solvent nanofiltration are integrated, in order to obtain added-value products and glycerol. Also, aiming to separate carotenoids from glycerides, a saponification process is proposed. High overall recoveries were obtained for carotenoids (85%), glycerol (86%), polar lipids (94%) and proteins (95%). In order to evaluate the profitability of the proposed biorefinery, an economic assessment was accomplished. Both CAPEX and OPEX (Capital and Operating expenditure) were calculated, likewise the Return of Investment (ROI)., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
35. Solvent-Free Process for the Development of Photocatalytic Membranes.
- Author
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Huertas RM, Fraga MC, Crespo JG, and Pereira VJ
- Subjects
- Catalysis, Methylene Blue chemistry, Temperature, Photochemistry methods, Solvents chemistry
- Abstract
This work described a new sustainable method for the fabrication of ceramic membranes with high photocatalytic activity, through a simple sol-gel route. The photocatalytic surfaces, prepared at low temperature and under solvent-free conditions, exhibited a narrow pore size distribution and homogeneity without cracks. These surfaces have shown a highly efficient and reproducible behavior for the degradation of methylene blue. Given their characterization results, the microfiltration photocatalytic membranes produced in this study using solvent-free conditions are expected to effectively retain microorganisms, such as bacteria and fungi that could then be inactivated by photocatalysis., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
- Published
- 2019
- Full Text
- View/download PDF
36. An efficient method for anthocyanins lipophilization based on enzyme retention in membrane systems.
- Author
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Guimarães M, Pérez-Gregorio M, Mateus N, de Freitas V, Galinha CF, Crespo JG, Portugal CAM, and Cruz L
- Subjects
- Anthocyanins chemistry, Antioxidants chemistry, Enzymes, Immobilized metabolism, Glucosides chemistry, Anthocyanins metabolism, Fatty Acids metabolism, Fungal Proteins metabolism, Glucosides metabolism, Lipase metabolism
- Abstract
Anthocyanin lipophilization emerged as an efficient technique to improve their chemical stability, liposolubility and antioxidant properties for novel technological applications. This work describes an efficient method for the synthesis of cyanidin-3-glucoside-fatty acid conjugate using a Candida antarctica lipase B-rich extract, without further purification and retained in a porous membrane. Due to the enzyme retention within the membrane structure it was possible to improve the yield of the lipophilization reaction by 2.5-fold as well as obtaining the product in a shorter period of time comparing with its free form. Furthermore, the membrane retention allowed for enzyme reusability, since the same conversion yield was obtained in three consecutive reaction cycles., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
37. Magnetic Responsive PVA Hydrogels for Remote Modulation of Protein Sorption.
- Author
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Manjua AC, Alves VD, Crespo JG, and Portugal CAM
- Subjects
- Ferric Compounds chemistry, Nanoparticles chemistry, Hydrogels chemistry, Magnetic Fields, Proteins chemistry
- Abstract
This work shows the ability to reversibly modulate the hydrophilicity of the hydrogels doped with iron oxide nanoparticles (MNPs) in a noninvasive way when exposed to a cyclic variation of the intensity (ON/OFF) of an external magnetic field. A reversible switching of surface contact angles was observed for magnetic PVA hydrogels when exposed to consecutive variation of the magnetic field intensity between 0 and 0.08 T. Motivated by the magnetic dependence of the hydrophilicity of these hybrid hydrogels, the impact of the magnetic field on protein sorption was also evaluated. The noninvasive regulation of protein sorption-released mechanisms was achieved by ON/OFF magnetic field switches, suggesting the possible influence of magnetic-induced hydrogel shrinking effect and changes of surface wettability on protein sorption. The capacity to magnetically modulate surface wettability and protein sorption make these magnetic hydrogels promising candidates for development of functional devices for tissue engineering, drug release applications, or biosensor systems, where the control of protein sorption and mobility are essential steps to improve the efficiency of these processes.
- Published
- 2019
- Full Text
- View/download PDF
38. Profiled Ion Exchange Membranes: A Comprehensible Review.
- Author
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Pawlowski S, Crespo JG, and Velizarov S
- Subjects
- Dialysis methods, Diffusion, Divorce, Electric Impedance, Filtration methods, Hydrodynamics, Ion Exchange, Printing, Three-Dimensional, Salinity, Membranes, Artificial
- Abstract
Profiled membranes (also known as corrugated membranes, micro-structured membranes, patterned membranes, membranes with designed topography or notched membranes) are gaining increasing academic and industrial attention and recognition as a viable alternative to flat membranes. So far, profiled ion exchange membranes have shown to significantly improve the performance of reverse electrodialysis (RED), and particularly, electrodialysis (ED) by eliminating the spacer shadow effect and by inducing hydrodynamic changes, leading to ion transport rate enhancement. The beneficial effects of profiled ion exchange membranes are strongly dependent on the shape of their profiles (corrugations/patterns) as well as on the flow rate and salts' concentration in the feed streams. The enormous degree of freedom to create new profile geometries offers an exciting opportunity to improve even more their performance. Additionally, the advent of new manufacturing methods in the membrane field, such as 3D printing, is anticipated to allow a faster and an easier way to create profiled membranes with different and complex geometries.
- Published
- 2019
- Full Text
- View/download PDF
39. Influence of Magnetic Nanoparticles on PISA Preparation of Poly(Methacrylic Acid)-b-Poly(Methylmethacrylate) Nano-Objects.
- Author
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Upadhyaya L, Egbosimba C, Qian X, Wickramasinghe R, Fernández-Pacheco R, Coelhoso IM, Portugal CAM, Crespo JG, Quemener D, and Semsarilar M
- Subjects
- Coated Materials, Biocompatible chemistry, Magnetic Fields, Magnetite Nanoparticles ultrastructure, Membranes, Artificial, Microscopy, Electron, Scanning Transmission, Nanoparticles ultrastructure, Polymerization, Polymers chemical synthesis, Porosity, Chemistry Techniques, Synthetic methods, Magnetite Nanoparticles chemistry, Nanoparticles chemistry, Polymers chemistry, Polymethacrylic Acids chemistry, Polymethyl Methacrylate chemistry
- Abstract
This article presents the synthesis of poly(methacrylic acid)-b-poly(methyl methacrylate) diblock copolymer via polymerization-induced self-assembly in the presence of iron-oxide nanoparticles. Detailed phase diagrams with and without inorganic nanoparticles were constructed. Scanning transmission electron microscopy and energy dispersive X-ray photometry studies confirme the decoration of the polymeric nanoparticles with the iron-oxide nanoparticles. These hybrid nanoparticles were used to prepare porous thin film membranes by spin coating. Finally, the magneto-responsive properties of the membranes were assessed using water filtration tests in the presence and absence of a magnetic field., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2019
- Full Text
- View/download PDF
40. Development and characterisation of hybrid polysaccharide membranes for dehydration processes.
- Author
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Meireles IT, Huertas RM, Torres CAV, Coelhoso IM, and Crespo JG
- Abstract
The purpose of this work is the development and characterisation of new hybrid polysaccharide (FucoPol) membranes. These membranes were prepared by incorporation of a SiO
2 network homogeneously dispersed by using a sol-gel method with GPTMS as a crosslinker silica precursor. They were further crosslinked with CaCl2 for reinforcement of mechanical properties and improvement of their permeation performance. They were characterised in terms of their structural, mechanical and thermal properties. They presented a dense and homogeneous structure, resistant to deformation, with a Tg of 43 °C and a thermal decomposition between 240 and 251 °C. The hybrid FucoPol membranes were tested for ethanol dehydration by pervaporation and also for nitrogen dehydration. They exhibited high water selectivity values, similar to PERVAP® 4101, however they lost their stability when exposed to solutions of 10.0 wt.% water in ethanol. In contrast, these membranes were stable when applied in N2 dehydration, leading to reproducible performance and very high water selectivities., (Copyright © 2018 Elsevier Ltd. All rights reserved.)- Published
- 2018
- Full Text
- View/download PDF
41. Bronfenbrenner's Bioecological Theory Revision: Moving Culture From the Macro Into the Micro.
- Author
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Vélez-Agosto NM, Soto-Crespo JG, Vizcarrondo-Oppenheimer M, Vega-Molina S, and García Coll C
- Subjects
- Humans, Culture, Human Development, Psychological Theory, Social Environment
- Abstract
Bronfenbrenner's bioecological theory of human development is one of the most widely known theoretical frameworks in human development. In spite of its popularity, the notion of culture within the macrosystem, as a separate entity of everyday practices and therefore microsystems, is problematic. Using the theoretical and empirical work of Rogoff and Weisner, and influenced as they are by Vygotsky's sociocultural perspective, we reconceptualize Bronfenbrenner's model by placing culture as an intricate part of proximal development processes. In our model, culture has the role of defining and organizing microsystems and therefore becomes part of the central processes of human development. Culture is an ever changing system composed of the daily practices of social communities (families, schools, neighborhoods, etc.) and the interpretation of those practices through language and communication. It also comprises tools and signs that are part of the historical legacy of those communities, and thus diversity is an integral part of the child's microsystems, leading to culturally defined acceptable developmental processes and outcomes.
- Published
- 2017
- Full Text
- View/download PDF
42. Assessment of a New Silicon Carbide Tubular Honeycomb Membrane for Treatment of Olive Mill Wastewaters.
- Author
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Fraga MC, Sanches S, Crespo JG, and Pereira VJ
- Abstract
Extremely high removals of total suspended solids and oil and grease were obtained when olive mill wastewaters were filtered using new silicon carbide tubular membranes. These new membranes were used at constant permeate flux to treat real olive mill wastewaters at pilot scale. The filtration conditions were evaluated and optimized in terms of the selection of the permeate flux and flux maintenance strategies employed-backpulsing and backwashing-in order to reduce fouling formation. The results obtained reveal that the combination of backpulses and backwashes helps to maintain the permeate flux, avoids transmembrane pressure increase and decreases the cake resistance. Moreover, membrane cleaning procedures were compared and the main agents responsible for fouling formation identified. Results also show that, under total recirculation, despite an increased concentration of pollutants in the feed stream, the quality of the permeate is maintained. Membrane filtration using silicon carbide membranes is an effective alternative to dissolved air flotation and can be applied efficiently to remove total suspended solids and oil and grease from olive mill wastewaters.
- Published
- 2017
- Full Text
- View/download PDF
43. Pilot scale nanofiltration treatment of olive mill wastewater: a technical and economical evaluation.
- Author
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Sanches S, Fraga MC, Silva NA, Nunes P, Crespo JG, and Pereira VJ
- Subjects
- Biological Oxygen Demand Analysis, Filtration, Phenols analysis, Pilot Projects, Waste Disposal, Fluid, Water Purification economics, Water Purification methods, Nanotechnology economics, Nanotechnology methods, Olea chemistry, Wastewater chemistry
- Abstract
The treatment of large volumes of olive mill wastewater is presently a challenge. This study reports the technical and economical feasibility of a sequential treatment of olive mill wastewater comprising a dissolved air flotation pre-treatment and nanofiltration. Different pilot nanofiltration assays were conducted in a concentration mode up to different volume reduction factors (29, 45, 58, and 81). Data attained demonstrated that nanofiltration can be operated at considerably high volume reduction factors and still be effective towards the removal of several components. A flux decline of approximately 50% was observed at the highest volume reduction factor, mainly due to increase of the osmotic pressure. Considerably high rejections were obtained across all experiments for total suspended solids (83 to >99%), total organic carbon (64 to 99%), chemical oxygen demand (53 to 77%), and oil and grease (67 to >82%). Treated water was in compliance with European legal limits for discharge regarding total suspended solids and oil and grease. The potential recovery of phenolic compounds was evaluated and found not relevant. It was demonstrated that nanofiltration is economically feasible, involving operation costs of approximately 2.56-3.08 €/m
3 , depending on the working plan schedule and volume reduction factor, and requiring a footprint of approximately 52 m2 to treat 1000 m3 of olive mill wastewater.- Published
- 2017
- Full Text
- View/download PDF
44. Development of fluorescent thermoresponsive nanoparticles for temperature monitoring on membrane surfaces.
- Author
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Santoro S, Sebastian V, Moro AJ, Portugal CAM, Lima JC, Coelhoso IM, Crespo JG, and Mallada R
- Abstract
In this work, tris(phenantroline)ruthenium(II) chloride (Ru(phen)
3 ) was immobilized in silica nanoparticles prepared according to the Stöber method. Efforts were devoted on the optimization of the nano-thermometer in terms of size, polydispersity, intensity of the emission and temperature sensitivity. In particular, the immobilization of the luminophore in an external thin shell made of silica grown in a second step on bare silica nanoparticles allowed producing fluorescent monodisperse silica nanoparticles (420±20nm). A systematic study was addressed to maximize the intensity of the emission of the fluorescent nanoparticles by adjusting the concentration of Ru(phen)3 2+ in the shell from 0.2 to 24wt.%, whereas the thickness of the shell is affected by the amount of silica precursor employed. The luminescent activity of the doped nanoparticles was found to be sensitive to the temperature. In fact, the intensity of the emission linearly decreased by increasing the temperature from 20°C to 65°C. The thermoresponsive nanoparticles were functionalized with long aliphatic chains in order to obtain hydrophobic nanoparticles. The developed nanoparticles were immobilized via dip-coating procedure on the surface of hydrophobic porous membranes, such as Polyvinylidene fluoride (PVDF) prepared via Non-Solvent Induced Phase Separation (NIPS), providing local information about the membrane surface temperature., (Copyright © 2016 Elsevier Inc. All rights reserved.)- Published
- 2017
- Full Text
- View/download PDF
45. Oil refinery hazardous effluents minimization by membrane filtration: An on-site pilot plant study.
- Author
-
Santos B, Crespo JG, Santos MA, and Velizarov S
- Subjects
- Pilot Projects, Polymers, Wastewater analysis, Conservation of Natural Resources methods, Industrial Waste analysis, Membranes, Artificial, Oil and Gas Industry, Ultrafiltration methods, Waste Disposal, Fluid methods
- Abstract
Experiments for treating two different types of hazardous oil refinery effluents were performed in order to avoid/minimize their adverse impacts on the environment. First, refinery wastewater was subjected to ultrafiltration using a ceramic membrane, treatment, which did not provide an adequate reduction of the polar oil and grease content below the maximal contaminant level allowed. Therefore the option of reducing the polar oil and grease contamination at its main emission source point in the refinery - the spent caustic originating from the refinery kerosene caustic washing unit - using an alkaline-resistant nanofiltration polymeric membrane treatment was tested. It was found that at a constant operating pressure and temperature, 99.9% of the oil and grease and 97.7% of the COD content were rejected at this emission point. Moreover, no noticeable membrane fouling or permeate flux decrease were registered until a spent caustic volume concentration factor of 3. These results allow for a reuse of the purified permeate in the refinery operations, instead of a fresh caustic solution, which besides the improved safety and environmentally related benefits, can result in significant savings of 1.5 M€ per year at the current prices for the biggest Portuguese oil refinery. The capital investment needed for nanofiltration treatment of the spent caustic is estimated to be less than 10% of that associated with the conventional wet air oxidation treatment of the spent caustic that is greater than 9 M€. The payback period was estimated to be 1.1 years. The operating costs for the two treatment options are similar, but the reuse of the nanofiltration spent caustic concentrate for refinery pH control applications can further reduce the operating expenditures. Overall, the pilot plant results obtained and the process economics evaluation data indicate a safer, environmentally friendly and highly competitive solution offered by the proposed nanofiltration treatment, thus representing a promising alternative to the use of conventional spent caustic treatment units., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
46. Comparison of UV photolysis, nanofiltration, and their combination to remove hormones from a drinking water source and reduce endocrine disrupting activity.
- Author
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Sanches S, Rodrigues A, Cardoso VV, Benoliel MJ, Crespo JG, and Pereira VJ
- Subjects
- Drinking Water standards, Endocrine Disruptors radiation effects, Hormones radiation effects, Photolysis, Water Pollutants, Chemical radiation effects, Water Quality, Drinking Water analysis, Endocrine Disruptors analysis, Filtration, Hormones analysis, Ultraviolet Rays, Water Pollutants, Chemical analysis, Water Purification methods
- Abstract
A sequential water treatment combining low pressure ultraviolet direct photolysis with nanofiltration was evaluated to remove hormones from water, reduce endocrine disrupting activity, and overcome the drawbacks associated with the individual processes (production of a nanofiltration-concentrated retentate and formation of toxic by-products). 17β-Estradiol, 17α-ethinylestradiol, estrone, estriol, and progesterone were spiked into a real water sample collected after the sedimentation process of a drinking water treatment plant. Even though the nanofiltration process alone showed similar results to the combined treatment in terms of the water quality produced, the combined treatment offered advantage in terms of the load of the retentate and decrease in the endocrine-disrupting activity of the samples. Moreover, the photolysis by-products produced, with higher endocrine disrupting activity than the parent compounds, were effectively retained by the membrane. The combination of direct LP/UV photolysis with nanofiltration is promising for a drinking water utility that needs to cope with sudden punctual discharges or deterioration of the water quality and wants to decrease the levels of chemicals in the nanofiltration retentate.
- Published
- 2016
- Full Text
- View/download PDF
47. 2D fluorescence spectroscopy for monitoring ion-exchange membrane based technologies - Reverse electrodialysis (RED).
- Author
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Pawlowski S, Galinha CF, Crespo JG, and Velizarov S
- Subjects
- Fresh Water chemistry, Principal Component Analysis, Seawater chemistry, Electrochemical Techniques, Humic Substances, Ion Exchange, Membranes, Artificial, Salinity, Spectrometry, Fluorescence methods
- Abstract
Reverse electrodialysis (RED) is one of the emerging, membrane-based technologies for harvesting salinity gradient energy. In RED process, fouling is an undesirable operation constraint since it leads to a decrease of the obtainable net power density due to increasing stack electric resistance and pressure drop. Therefore, early fouling detection is one of the main challenges for successful RED technology implementation. In the present study, two-dimensional (2D) fluorescence spectroscopy was used, for the first time, as a tool for fouling monitoring in RED. Fluorescence excitation-emission matrices (EEMs) of ion-exchange membrane surfaces and of natural aqueous streams were acquired during one month of a RED stack operation. Fouling evolvement on the ion-exchange membrane surfaces was successfully followed by 2D fluorescence spectroscopy and quantified using principal components analysis (PCA). Additionally, the efficiency of cleaning strategy was assessed by measuring the membrane fluorescence emission intensity before and after cleaning. The anion-exchange membrane (AEM) surface in contact with river water showed to be significantly affected due to fouling by humic compounds, which were found to cross through the membrane from the lower salinity (river water) to higher salinity (sea water) stream. The results obtained show that the combined approach of using 2D fluorescence spectroscopy and PCA has a high potential for studying fouling development and membrane cleaning efficiency in ion exchange membrane processes., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
48. (1)H NMR Relaxation Study of a Magnetic Ionic Liquid as a Potential Contrast Agent.
- Author
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Daniel CI, Vaca Chávez F, Portugal CA, Crespo JG, and Sebastião PJ
- Abstract
A proton nuclear magnetic relaxation dispersion (1)H NMRD study of the molecular dynamics in mixtures of magnetic ionic liquid [P66614][FeCl4] with [P66614][Cl] ionic liquid and mixtures of [P66614][FeCl4] with dimethyl sulfoxide (DMSO) is presented. The proton spin-lattice relaxation rate, R1, was measured in the frequency range of 8 kHz-300 MHz. The viscosity of the binary mixtures was measured as a function of an applied magnetic field, B, in the range of 0-2 T. In the case of DMSO/[P66614][FeCl4] the viscosity was found to be independent from the magnetic field, while in the case of the [P66614][Cl]/[P66614][FeCl4] system viscosity decreased with the increase of the magnetic field strength. The spin-lattice relaxation results were analyzed for all systems taking into account the relaxation mechanisms associated with the molecular motions with correlation times in a range between 10(-11) and 10(-7)s, usually observed by NMRD, and the paramagnetic relaxation contributions associated with the presence of the magnetic ions in the systems. In the case of the DMSO/[P66614][FeCl4] system the R1 dispersion shows the relaxation enhancement due to the presence of the magnetic ions, similar to that reported for contrast agents. For the [P66614][Cl]/[P66614][FeCl4] system, the R1 dispersion presents a much larger paramagnetic relaxation contribution, in comparison with that observed for the DMSO/[P66614][FeCl4] mixtures but different from that reported for other magnetic ionic liquid system. In the [P66614][Cl]/[P66614][FeCl4] system the relaxation enhancement associated with the paramagnetic ions is clearly not proportional to the concentration of magnetic ions, in contrast with what is observed for the DMSO/[P66614][FeCl4] system.
- Published
- 2015
- Full Text
- View/download PDF
49. Male moths optimally balance take-off thoracic temperature and warm-up duration to reach a pheromone source quickly.
- Author
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Crespo JG, Vickers NJ, and Goller F
- Abstract
Animal activities, such as foraging and reproduction, are constrained by decisions about how to allocate energy and time efficiently. Overall, male moths invest less in reproduction than females, but they are thought to engage in a scramble competition for access to females that advertise readiness to mate by releasing sexual pheromones. However, before male moths can follow the pheromone, they often need to heat their flight muscles by shivering to produce sufficient power for sustained flight. Here, we show that Helicoverpa zea males that sense the female pheromone at high ambient temperatures take off with higher thoracic temperature, shiver for less time and warm up faster than males tested at lower ambient temperatures. These higher take-off temperatures translate into higher airspeeds, underscoring the importance of thoracic temperature for flight performance. Furthermore, shorter combined duration for warm-up and pheromone-mediated optomotor anemotaxis is consistent with the idea that males engage in scramble competition for access to females in nature. Our results strongly suggest that male moths minimize the time between perceiving the female's pheromone signal and arriving at the source by optimizing thermoregulatory behaviour and temperature-dependent flight performance in accordance with ambient temperature conditions. Our finding that moths engage in a trade-off between rapid flight initiation and suboptimal flight performance suggests a sensorimotor control mechanism that involves a complex interaction with the thermal environment.
- Published
- 2014
- Full Text
- View/download PDF
50. Effect of tissue scaffold topography on protein structure monitored by fluorescence spectroscopy.
- Author
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Portugal CA, Truckenmüller R, Stamatialis D, and Crespo JG
- Subjects
- Biocompatible Materials chemistry, Lactic Acid chemistry, Polyesters, Polymers chemistry, Proteins chemistry, Spectrometry, Fluorescence methods, Tissue Scaffolds chemistry
- Abstract
The impact of surface topography on the structure of proteins upon adhesion was assessed through non-invasive fluorescence monitoring. This study aimed at obtaining a better understanding about the role of protein structural status on cell-scaffold interactions. The changes induced upon adsorption of two model proteins with different geometries, trypsin (globular conformation) and fibrinogen (rod-shaped conformation) on poly-l-lactic acid (PLLA) scaffolds with different surface topographies, flat, fibrous and surfaces with aligned nanogrooves, were assessed by fluorescence spectroscopy monitoring, using tryptophan as structural probe. Hence, the maximum emission blue shift and the increase of fluorescence anisotropy observed after adsorption of globular and rod-like shaped proteins on surfaces with parallel nanogrooves were ascribed to more intense protein-surface interactions. Furthermore, the decrease of fluorescence anisotropy observed upon adsorption of proteins to scaffolds with fibrous morphology was more significant for rod-shaped proteins. This effect was associated to the ability of these proteins to adjust to curved surfaces. The additional unfolding of proteins induced upon adsorption on scaffolds with a fibrous morphology may be the reason for better cell attachment there, promoting an easier access of cell receptors to initially hidden protein regions (e.g. RGDS sequence), which are known to have a determinant role in cell attaching processes., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
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