Membranes

Research

21 pages, 7518 KiB

Open AccessArticle

Novel Electrospun Composite Membranes Based on Polyhydroxybutyrate and Poly(vinyl formate) Loaded with Protonated Montmorillonite for Organic Dye Removal: Kinetic and Isotherm Studies

by Hristo Penchev, Ahmed E. Abdelhamid, Eman A. Ali, Dessislava Budurova, Georgy Grancharov, Filip Ublekov, Neli Koseva, Katerina Zaharieva, Ahmed A. El-Sayed and Ahmed M. Khalil

Membranes 2023, 13(6), 582; https://doi.org/10.3390/membranes13060582 - 3 Jun 2023

Cited by 7 | Viewed by 1898

Abstract

The use of biodegradable polyesters derived from green sources and their combination with natural abundantly layered aluminosilicate clay, e.g., natural montmorillonite, meets the requirements for the development of new sustainable, disposable, and biodegradable organic dye sorbent materials. In this regard, novel electrospun composite [...] Read more.

The use of biodegradable polyesters derived from green sources and their combination with natural abundantly layered aluminosilicate clay, e.g., natural montmorillonite, meets the requirements for the development of new sustainable, disposable, and biodegradable organic dye sorbent materials. In this regard, novel electrospun composite fibers, based on poly β-hydroxybutyrate (PHB) and in situ synthesized poly(vinyl formate) (PVF), loaded with protonated montmorillonite (MMT-H) were prepared via electrospinning in the presence of formic acid, a volatile solvent for polymers and a protonating agent for the pristine MMT-Na. The morphology and structure of electrospun composite fibers were investigated through SEM, TEM, AFM, FT-IR, and XRD analyses. The contact angle (CA) measurements showed increased hydrophilicity of the composite fibers incorporated with MMT-H. The electrospun fibrous mats were evaluated as membranes for removing cationic (methylene blue) and anionic (Congo red) dyes. PHB/MMT 20% and PVF/MMT 30% showed significant performance in dye removal compared with the other matrices. PHB/MMT 20% was the best electrospun mat for adsorbing Congo red. The PVF/MMT 30% fibrous membrane exhibited the optimum activity for the adsorption of methylene blue and Congo red dyes. Full article

(This article belongs to the Special Issue Recent Advances in Membrane Filtration and Purification Technologies)

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13 pages, 4232 KiB

Open AccessArticle

Evaluation of Surface Properties and Separation Performance of NF and RO Membranes for Phthalates Removal

by En Qi Lim, Mei Qun Seah, Woei Jye Lau, Hasrinah Hasbullah, Pei Sean Goh, Ahmad Fauzi Ismail and Daryoush Emadzadeh

Membranes 2023, 13(4), 413; https://doi.org/10.3390/membranes13040413 - 6 Apr 2023

Cited by 2 | Viewed by 2233

Abstract

Many studies indicated that phthalates, a common plasticizer, lurk silently in water bodies and can potentially harm living organisms. Therefore, removing phthalates from water sources prior to consumption is crucial. This study aims to evaluate the performance of several commercial nanofiltrations (NF) (i.e., [...] Read more.

Many studies indicated that phthalates, a common plasticizer, lurk silently in water bodies and can potentially harm living organisms. Therefore, removing phthalates from water sources prior to consumption is crucial. This study aims to evaluate the performance of several commercial nanofiltrations (NF) (i.e., NF3 and Duracid) and reverse osmosis (RO) membranes (i.e., SW30XLE and BW30) in removing phthalates from simulated solutions and further correlate the intrinsic properties of membranes (e.g., surface chemistry, morphology, and hydrophilicity) with the phthalates removal. Two types of phthalates, i.e., dibutyl phthalate (DBP) and butyl benzyl phthalate (BBP), were used in this work, and the effects of pH (ranging from 3 to 10) on the membrane performance were studied. The experimental findings showed that the NF3 membrane could yield the best DBP (92.5–98.8%) and BBP rejection (88.7–91.7%) regardless of pH, and these excellent results are in good agreement with the surface properties of the membrane, i.e., low water contact angle (hydrophilicity) and appropriate pore size. Moreover, the NF3 membrane with a lower polyamide cross-linking degree also exhibited significantly higher water flux compared to the RO membranes. Further investigation indicated that the surface of the NF3 membrane was severely covered by foulants after 4-h filtration of DBP solution compared to the BBP solution. This could be attributed to the high concentration of DBP presented in the feed solution owing to its high-water solubility (13 ppm) compared to BBP (2.69 ppm). Further research is still needed to study the effect of other compounds (e.g., dissolved ions and organic/inorganic matters that might be present in water) on the performance of membranes in removing phthalates. Full article

(This article belongs to the Special Issue Recent Advances in Membrane Filtration and Purification Technologies)

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14 pages, 2724 KiB

Open AccessArticle

Anion Effect on Forward Osmosis Performance of Tetrabutylphosphonium-Based Draw Solute Having a Lower Critical Solution Temperature

by Jihyeon Moon and Hyo Kang

Membranes 2023, 13(2), 211; https://doi.org/10.3390/membranes13020211 - 8 Feb 2023

Cited by 6 | Viewed by 2523

Abstract

The applicability of ionic liquids (ILs) as the draw solute in a forward osmosis (FO) system was investigated through a study on the effect of the structural change of the anion on the FO performance. This study evaluated ILs composed of tetrabutylphosphonium cation [...] Read more.

The applicability of ionic liquids (ILs) as the draw solute in a forward osmosis (FO) system was investigated through a study on the effect of the structural change of the anion on the FO performance. This study evaluated ILs composed of tetrabutylphosphonium cation ([P₄₄₄₄]⁺) and benzenesulfonate anion ([BS]⁻), para-position alkyl-substituted benzenesulfonate anions (p-methylbenzenesulfonate ([MBS]⁻) and p-ethylbenzenesulfonate ([EBS⁻]), and methanesulfonate anion ([MS]⁻). The analysis of the thermo-responsive properties suggested that the [P₄₄₄₄][MBS] and [P₄₄₄₄][EBS] ILs have lower critical solution temperatures (LCSTs), which play a beneficial role in terms of the reusability of the draw solute from the diluted draw solutions after the water permeation process. At 20 wt% of an aqueous solution, the LCSTs of [P₄₄₄₄][MBS] and [P₄₄₄₄][EBS] were approximately 36 °C and 25 °C, respectively. The water flux and reverse solute flux of the [P₄₄₄₄][MBS] aqueous solution with higher osmolality than [P₄₄₄₄][EBS] were 7.36 LMH and 5.89 gMH in the active-layer facing the draw solution (AL-DS) mode at osmotic pressure of 25 atm (20 wt% solution), respectively. These results indicate that the [P₄₄₄₄]⁺-based ionic structured materials with LCST are practically advantageous for application as draw solutes. Full article

(This article belongs to the Special Issue Recent Advances in Membrane Filtration and Purification Technologies)

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9 pages, 2035 KiB

Open AccessArticle

Microstructure and Hydrogen Permeability of Nb-Ni-Ti-Zr-Co High Entropy Alloys

by Egor Kashkarov, Dmitriy Krotkevich, Maxim Koptsev, Sergei Ognev, Leonid Svyatkin, Nahum Travitzky and Andrey Lider

Membranes 2022, 12(11), 1157; https://doi.org/10.3390/membranes12111157 - 17 Nov 2022

Cited by 7 | Viewed by 2679

Abstract

Hydrogen separation membranes are one of the most promising technologies for hydrogen purification. The development of high-entropy alloys (HEAs) for hydrogen separation membranes is driven by a “cocktail effect” of elements with different hydrogen affinities to prevent hydride formation and retain high permeability [...] Read more.

Hydrogen separation membranes are one of the most promising technologies for hydrogen purification. The development of high-entropy alloys (HEAs) for hydrogen separation membranes is driven by a “cocktail effect” of elements with different hydrogen affinities to prevent hydride formation and retain high permeability due to the single-phase BCC structure. In this paper, equimolar and non-equimolar Nb-Ni-Ti-Zr-Co high entropy alloys were fabricated by arc melting. The microstructure and phase composition of the alloys were analyzed by scanning electron microscopy and X-ray diffraction, respectively. The hydrogen permeation experiments were performed at 300–500 °C and a hydrogen pressure of 4 bar. In order to estimate the effect of composition and lattice structure on hydrogen location and diffusivity in Nb-Ni-Ti-Zr-Co alloy, ab initio calculations of hydrogen binding energy were performed using virtual crystal approximation. It was found that Nb-enriched and near equimolar BCC phases were formed in Nb₂₀Ni₂₀Ti₂₀Zr₂₀Co₂₀ HEA while Nb-enriched BCC and B2-Ni(Ti, Zr) were formed in Nb₄₀Ni₂₅Ti₁₈Zr₁₂Co₅ alloy. Hydrogen permeability tests showed that Nb₂₀Ni₂₀Ti₂₀Zr₂₀Co₂₀ HEA shows lower activation energy and higher permeability at lower temperatures as well as higher resistance to hydrogen embrittlement compared to Nb₄₀Ni₂₅Ti₁₈Zr₁₂Co₅ alloy. The effect of composition, microstructure and hydrogen binding energies on permeability of the fabricated alloys was discussed. Full article

(This article belongs to the Special Issue Recent Advances in Membrane Filtration and Purification Technologies)

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10 pages, 723 KiB

Open AccessArticle

Reverse Osmosis Membrane Zero Liquid Discharge for Agriculture Drainage Water Desalination: Technical, Economic, and Environmental Assessment

by Marwa M. El Sayed, Abdelghani M. G. Abulnour, Shadia R. Tewfik, Mohamed H. Sorour, Heba A. Hani and Hayam F. Shaalan

Membranes 2022, 12(10), 923; https://doi.org/10.3390/membranes12100923 - 23 Sep 2022

Cited by 4 | Viewed by 2025

Abstract

Agricultural drainage water (ADW) represents a potential source for fresh water after receiving appropriate treatments to satisfy the water quality requirements. Desalination of ADW with medium salinity and moderate contamination with organic and inorganic chemical pollutants could provide a techno-economically feasible approach for [...] Read more.

Agricultural drainage water (ADW) represents a potential source for fresh water after receiving appropriate treatments to satisfy the water quality requirements. Desalination of ADW with medium salinity and moderate contamination with organic and inorganic chemical pollutants could provide a techno-economically feasible approach for facing water scarcity in arid areas. The current work presents a conceptual zero liquid discharge ADW desalination system proposed to treat 300,000 m³/d. The system is based on pretreatment to remove impurities harmful to desalination by staged reverse osmosis (RO) membrane. The brine from the last RO stage is treated via thermal vapor compression followed by evaporation in solar ponds to recover more fresh water and salts of economic value. The essential technical features of the proposed system components are formulated. The proposed system components and its technical and economic indicators are deduced using available software for water pretreatment, RO membrane, desalination, thermal desalination, and solar evaporation ponds. The system provides total distilled water recovery of about 98% viz. 294,000 m³/d in addition to recovered salts of 245,000 t/y. The net cost of water production amounts to USD 0.46 /m³. The environmental considerations of the system are addressed and advantages of applying zero liquid discharge system are elucidated. Full article

(This article belongs to the Special Issue Recent Advances in Membrane Filtration and Purification Technologies)

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17 pages, 5114 KiB

Open AccessArticle

Photocatalytic Performance Improvement by Doping Ag on ZnO/MWCNTs Nanocomposite Prepared with Pulsed Laser Ablation Method Based Photocatalysts Degrading Rhodamine B Organic Pollutant Dye

by Tahani A. Alrebdi, Reham A. Rezk, Shoug M. Alghamdi, Hoda A. Ahmed, Fatemah H. Alkallas, Rami Adel Pashameah, Ayman M. Mostafa and Eman A. Mwafy

Membranes 2022, 12(9), 877; https://doi.org/10.3390/membranes12090877 - 11 Sep 2022

Cited by 16 | Viewed by 2584

Abstract

ZnO/MWCNTs nanocomposite has significant potential in photocatalytic and environmental treatment. Unfortunately, its photocatalytic efficacy is not high enough due to its poor light absorbance and quick recombination of photo-generated carriers, which might be improved by incorporation with noble metal nanoparticles. Herein, Ag-doped ZnO/MWCNTs [...] Read more.

ZnO/MWCNTs nanocomposite has significant potential in photocatalytic and environmental treatment. Unfortunately, its photocatalytic efficacy is not high enough due to its poor light absorbance and quick recombination of photo-generated carriers, which might be improved by incorporation with noble metal nanoparticles. Herein, Ag-doped ZnO/MWCNTs nanocomposite was prepared using a pulsed laser ablation approach in the liquid media and examined as a degradable catalyst for Rhodamine B. (RhB). Different techniques were used to confirm the formation of the nanostructured materials (ZnO and Ag) and the complete interaction between them and MWCNTs. X-ray diffraction pattern revealed the hexagonal wurtzite crystal structure of ZnO and Ag. Additionally, UV-visible absorption spectrum was used to study the change throughout the shift in the transition energies, which affected the photocatalytic degradation. Furthermore, the morphological investigation by a scanning electron microscope showed the successful embedding and decoration of ZnO and Ag on the outer surface of CNTs. Moreover, the oxidation state of the formed final nanocomposite was investigated via an X-ray photoelectron spectrometer. After that, the photocatalytic degradations of RhB were tested using the prepared catalysts. The results showed that utilizing Ag significantly impacted the photo degradation of RhB by lowering the charge carrier recombination, leading to 95% photocatalytic degradation after 12 min. The enhanced photocatalytic performance of the produced nanocomposite was attributed to the role of the Ag dopant in generating more active oxygen species. Moreover, the impacts of the catalyst amount, pH level, and contact time were discussed. Full article

(This article belongs to the Special Issue Recent Advances in Membrane Filtration and Purification Technologies)

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10 pages, 2320 KiB

Open AccessArticle

Ag/ZnO Thin Film Nanocomposite Membrane Prepared by Laser-Assisted Method for Catalytic Degradation of 4-Nitrophenol

by Tahani A. Alrebdi, Hoda A. Ahmed, Fatemah H. Alkallas, Rami Adel Pashameah, Salhah H. Alrefaee, Emaan Alsubhe, Ayman M. Mostafa and Eman A. Mwafy

Membranes 2022, 12(8), 732; https://doi.org/10.3390/membranes12080732 - 24 Jul 2022

Cited by 8 | Viewed by 2036

Abstract

Zinc oxide thin film (ZnO thin film) and a silver-doped zinc oxide nanocomposite thin film (Ag/ZnO thin film) were prepared by the technique of the pulsed laser deposition at 600 °C to be applicable as a portable catalytic material for the removal of [...] Read more.

Zinc oxide thin film (ZnO thin film) and a silver-doped zinc oxide nanocomposite thin film (Ag/ZnO thin film) were prepared by the technique of the pulsed laser deposition at 600 °C to be applicable as a portable catalytic material for the removal of 4-nitrophenol. The nanocomposite was prepared by making the deposition of the two targets (Zn and Ag), and it was analyzed by different techniques. According to the XRD pattern, the hexagonal wurtzite crystalline form of Ag-doped ZnO NPs suggested that the samples were polycrystalline. Additionally, the shifting of the diffraction peaks to the higher angles, which denotes that doping reduces the crystallite size, illustrated the typical effect of the dopant Ag nanostructure on the ZnO thin film, which has an ionic radius less than the host cation. From SEM images, Ag-doping drastically altered the morphological characteristics and reduced the aggregation. Additionally, its energy band gap decreased when Ag was incorporated. UV spectroscopy was then used to monitor the catalysis process, and Ag/ZnO thin films had a larger first-order rate constant of the catalytic reaction K than that of ZnO thin film. According to the catalytic experiment results, the Ag/ZnO thin film has remarkable potential for use in environmentally-favorable applications. Full article

(This article belongs to the Special Issue Recent Advances in Membrane Filtration and Purification Technologies)

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16 pages, 3493 KiB

Open AccessArticle

Removal of Ni(II) Ions by Poly(Vinyl Alcohol)/Al₂O₃ Nanocomposite Film via Laser Ablation in Liquid

by Fatemah H. Alkallas, Hoda A. Ahmed, Tahani A. Alrebdi, Rami Adel Pashameah, Salhah H. Alrefaee, Emaan Alsubhe, Amira Ben Gouider Trabelsi, Ayman M. Mostafa and Eman A. Mwafy

Membranes 2022, 12(7), 660; https://doi.org/10.3390/membranes12070660 - 27 Jun 2022

Cited by 13 | Viewed by 2159

Abstract

Al₂O₃-poly(vinyl alcohol) nanocomposite (Al₂O₃-PVA nanocomposite) was generated in a single step using an eco-friendly method based on the pulsed laser ablation approach immersed in PVA solution to be applicable for the removal of Ni(II) [...] Read more.

Al₂O₃-poly(vinyl alcohol) nanocomposite (Al₂O₃-PVA nanocomposite) was generated in a single step using an eco-friendly method based on the pulsed laser ablation approach immersed in PVA solution to be applicable for the removal of Ni(II) from aqueous solution, followed by making a physicochemical characterization by SEM, XRD, FT-IR, and EDX. After that, the effect of adsorption parameters, such as pH, contact time, initial concentration of Ni(II), and medium temperature, were investigated for removal Ni(II) ions. The results showed that the adsorption was increased when pH was 5.3, and the process was initially relatively quick, with maximum adsorption detected within 90 min of contact time with the endothermic sorption process. Moreover, the pseudo-second-order rate kinetics (k₂ = 9.9 × 10⁻⁴ g mg⁻¹ min⁻¹) exhibited greater agreement than that of the pseudo-first-order. For that, the Ni(II) was effectively collected by Al₂O₃-PVA nanocomposite prepared by an eco-friendly and simple method for the production of clean water to protect public health. Full article

(This article belongs to the Special Issue Recent Advances in Membrane Filtration and Purification Technologies)

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