| 1. |
- Essalhi, Mohamed, et al.
(författare)
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Gamma-irradiated janus electrospun nanofiber membranes for desalination and nuclear wastewater treatment
- 2024
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Ingår i: Journal of Membrane Science. - : Elsevier. - 0376-7388 .- 1873-3123. ; 700
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Tidskriftsartikel (refereegranskat)abstract
- This study presents the fabrication of double-layer electrospun nanofibrous membranes (DL-ENMs) using polyvinylidene fluoride (PVDF) and polyether sulfone (PES) based polymers with different degrees of hydrophilicity (PES, sulfonated PES, and PES with hydroxyl terminals). A comparative analysis was carried out with single-layer electrospun nanofiber membranes (SL-ENM) with a total thickness of about 375 μm. Using feed solutions, including sodium chloride, sodium nitrate, and simulated nuclear wastewater (SNWW), the performance of DL-ENMs was evaluated for desalination and radionuclide decontamination by direct contact membrane distillation (DCMD) and air gap membrane distillation (AGMD) techniques. The results showed that DL-ENMs, especially those incorporating a sulfonated PES-based hydrophilic layer, exhibited superior permeate fluxes, reaching values of 72.72 kg/m2h and 73.27 kg/m2h in the DCMD using aqueous feed solutions of NaCl and NaNO3, respectively, and 70.80 kg/m2h and 41.96 kg/m2h using aqueous feed solutions of SNWW in DCMD and AGMD, respectively. Both SL-ENMs and DL-ENMs exhibited high rejection efficiencies and decontamination factors for the feed solutions (>99.9%). In addition, the prepared ENMs were exposed to gamma radiation to evaluate their applicability in real-life applications. The result of irradiation revealed the negative impact of gamma radiation on the fluorine content of PVDF which could be a critical point in using PVDF as a hydrophobic material for decontaminating nuclear wastewater by membrane distillation.
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| 2. |
- Essalhi, Mohamed, et al.
(författare)
-
Gamma-irradiated janus electrospun nanofiber membranes for desalination and nuclear wastewater treatment
- 2024
-
Ingår i: Journal of Membrane Science. - : Elsevier B.V.. - 0376-7388 .- 1873-3123. ; 700
-
Tidskriftsartikel (refereegranskat)abstract
- This study presents the fabrication of double-layer electrospun nanofibrous membranes (DL-ENMs) using polyvinylidene fluoride (PVDF) and polyether sulfone (PES) based polymers with different degrees of hydrophilicity (PES, sulfonated PES, and PES with hydroxyl terminals). A comparative analysis was carried out with single-layer electrospun nanofiber membranes (SL-ENM) with a total thickness of about 375 μm. Using feed solutions, including sodium chloride, sodium nitrate, and simulated nuclear wastewater (SNWW), the performance of DL-ENMs was evaluated for desalination and radionuclide decontamination by direct contact membrane distillation (DCMD) and air gap membrane distillation (AGMD) techniques. The results showed that DL-ENMs, especially those incorporating a sulfonated PES-based hydrophilic layer, exhibited superior permeate fluxes, reaching values of 72.72 kg/m2.h and 73.27 kg/m2.h in the DCMD using aqueous feed solutions of NaCl and NaNO3, respectively, and 70.80 kg/m2.h and 41.96 kg/m2.h using aqueous feed solutions of SNWW in DCMD and AGMD, respectively. Both SL-ENMs and DL-ENMs exhibited high rejection efficiencies and decontamination factors for the feed solutions (>99.9%). In addition, the prepared ENMs were exposed to gamma radiation to evaluate their applicability in real-life applications. The result of irradiation revealed the negative impact of gamma radiation on the fluorine content of PVDF which could be a critical point in using PVDF as a hydrophobic material for decontaminating nuclear wastewater by membrane distillation.
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| 3. |
- Essalhi, Mohamed, et al.
(författare)
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Polyvinylidene fluoride membrane formation using carbon dioxide as a non-solvent additive for nuclear wastewater decontamination
- 2022
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 446:4
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Tidskriftsartikel (refereegranskat)abstract
- Polyvinylidene fluoride (PVDF) membranes were prepared by phase inversion in the most commonly used solvents for membrane manufacture, with CO2 as a non-solvent additive. The effects of changing the polymer concentration (10, 12.5 and 15% by weight), the type of solvent (NMP, DMAc and DMF) and the coagulation bath with three levels of CO2 concentration on the phase inversion process, as well as the phase diagram, morphology and transport properties of the membranes were studied. The best performing membranes were used to desalinate salt aqueous solutions and decontaminated simulated nuclear wastewater by membrane distillation using two configurations (DCMD and AGMD). All selected membranes showed high rejection with acceptable permeate fluxes reaching an infinite decontamination factor. The proposed approach of this novel idea of using CO2 dissolved in water as a coagulation medium in the field of membranes avoids the increase of the harmful effect on the environment caused by the addition of a harsh non-solvent to the coagulation bath. It constitutes a beneficial use of carbon dioxide that reduces the negative environmental impact of membrane manufacturing and represents a decisive step towards its sustainability. Furthermore, this study highlights the potential benefits of using these membranes in DM for desalination and treatment of simulated nuclear wastewater.
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| 4. |
- Hudson, Lawrence N, et al.
(författare)
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The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project
- 2017
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Ingår i: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 7:1, s. 145-188
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Tidskriftsartikel (refereegranskat)abstract
- The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
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| 5. |
- Ismail, Norafiqah, et al.
(författare)
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Investigating the potential of membranes formed by the vapor induced phase separation process
- 2020
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Ingår i: Journal of Membrane Science. - : Elsevier. - 0376-7388 .- 1873-3123. ; 597
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Forskningsöversikt (refereegranskat)abstract
- About 100 years ago, Zsigmondy and Bachmann invented a new method to induce phase inversion, the so-called vapor induced phase separation (VIPS). Since then many researchers have demonstrated this method in membrane fabrication. Here we present a review on membrane fabrication via VIPS to provide insights into membrane formation parameters in order to achieve desired properties for different applications. The key factors upon membrane preparation including solution parameters (i.e. polymer type and concentration, type of solvent, and additives) as well as operating parameters (i.e. exposure time, relative humidity, dissolution temperature, and vapor temperature) are comprehensively discussed. Furthermore, the design of a fouling-resistance membrane by the VIPS process has recently gained attention and is elaborated in details. The applications of the produced membranes via VIPS in water and wastewater treatment, gas separations, electrochemical applications (i.e. secondary batteries and supercapacitors) as well as in medical and biological applications are summarized and an outlook for future investigation is presented.
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| 6. |
- Ismail, Norafiqah, et al.
(författare)
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Non-ionic deep eutectic solvents for membrane formation
- 2022
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Ingår i: Journal of Membrane Science. - : Elsevier. - 0376-7388 .- 1873-3123. ; 646
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Tidskriftsartikel (refereegranskat)abstract
- Deep eutectic solvents (DES) have recently emerged as a new class of inexpensive biodegradable solvents and additives with diverse applications. In this study, a new family of non-ionic deep eutectic solvents (NIDES) is proposed for the first time for membrane preparation. Three types of NIDES, N-methylacetamide-acetamide (DES-1), N-methyl acetamide-N-methyl urea (DES-2), and N-methyl acetamide-N,N′-dimethyl urea (DES-3) were synthesized and used to dissolve polyvinylidene fluoride (PVDF) polymer. The effects of the additive polyvinylpyrrolidone (PVP) and the type of NIDES on the PVDF membrane characteristics, water permeability and bovine serum albumin (BSA) separation were studied. The membranes prepared with DES-1 and 2 wt% PVP exhibited a good water permeate flux (96.82 L/m2.h) and a high BSA separation factor (96.32%). High performance PVDF membranes can thus be efficiently prepared using biodegradable inexpensive NIDES.
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| 7. |
- Paziresh, Shadi, et al.
(författare)
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Modeling membrane formation
- 2024
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Ingår i: Polymeric membrane formation by phase inversion. - : Elsevier. - 9780323956284 - 9780323956291 ; , s. 345-394
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Engineering the properties of the membrane system has become a fundamental goal to achieve a membrane with an optimal structure and pore size distribution. Several parameters such as contact phase, composition of phases, polymer solution temperature, and nonsolvent/solvent species must be controlled to achieve this goal. Due to the multiplicity of process variables, the complexity of the interactions, as well as the speed of the process, it is difficult to determine and observe the PI process only through laboratory techniques. Modeling the phase separation process and developing efficient numerical models capable of predicting the final membrane morphology as accurately as possible, depending on the wide range of parameters. In this chapter, two top-down approaches—macroscopic transport models and mesoscopic PF models—as well as bottom-up molecular/particle scale simulations (such as molecular dynamics [MD], Monte Carlo and dissipative particle dynamics [DPD]), are presented to describe the processes of phase inversion, transfer phenomena, and membrane formation. Furthermore, a comprehensive view of the development of models over time and the presentation of numerical results from different models was provided to readers as a key solution for better understanding the limitations and capabilities of the simulations. Additionally, the use of machine learning as a robust tool for predicting membrane performance prior to fabrication is discussed.
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