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This study focuses on the fabrication and characterisation of single-walled carbon nanotube (SWCNT) buckypapers and polyethersulfone (PES) flat-sheet membranes using Cyrene, aiming toevaluate its efficacy as a green solvent for these applications. Pristine SWCNTs were dispersed inCyrene without surfactants and compared to N-Methyl-2-pyrrolidone (NMP) dispersions. Buckypapers were fabricated from these dispersions and characterised using Scanning ElectronMicroscopy (SEM), Atomic Force Microscopy (AFM), and infrared spectroscopy. Their performancewas tested in wastewater and oil-water emulsion filtrations and antimicrobial activity. PESmembranes incorporating SWCNTs were prepared using phase inversion and analysed via SEM,optical microscopy, and contact angle. Membrane properties and water permeability were assessed,and bacterial challenge tests evaluated antimicrobial activity. Cyrene enabled the dispersion ofSWCNTs at higher concentrations (0.038 mg mL⁻1) compared to NMP (0.013 mg mL⁻1). Transmission Electron Microscopy (TEM) analysis revealed that Cyrene effectively debundles SWCNTs, yielding better dispersion. Buckypapers fabricated with Cyrene demonstrated dense, uniform networks with enhanced surface smoothness and promising filtration performance for wastewater treatment and oil-water separation. PES membranes made with Cyrene exhibited well-organised finger-like structures, interconnected pores, superior porosity, and higher water permeability than NMP-based membranes. Incorporating SWCNTs further improved membrane performance. However, bacterial challenge tests indicated no significant antimicrobial activity. The findings highlight Cyrene's potential as a sustainable alternative to traditional solvents, offering improved material properties and filtration performance. Despite these advantages, further studies are necessary to address solvent residuals and long-term safety considerations, ensuring its suitability for broader applications. [ABSTRACT FROM AUTHOR]

The Electrodialysis with Filtration Membrane (EDFM) system has shown promise in juice enrichment, but further optimization is needed. This study evaluated the effect of processing duration (3 and 6 h) on juice composition, process efficiency, and membrane fouling. Results demonstrated a significant impact of processing time on juice composition, especially anthocyanin and mineral content. Two anthocyanin-depleted juices (−18.94% and −30.70%) and two anthocyanin-enriched juices (26.21% and 44.21%) were produced. Similar energy (1512.13 Wh/g of anthocyanins) was required to migrate equivalent amounts of anthocyanins over both time periods, with no impediment due to fouling observed, although the system's resistance increased (2.5-fold after 3 h, 3.2-fold after 6 h). Membrane fouling was characterized through conductivity, thickness, ATR-FTIR, SEM-EDX, and foulant identification. Minimal anthocyanin accumulation occurred on cation-exchange membranes (CEM), while anthocyanins and PACs concentrated within the filtering layer of filtration membranes (FM). However, fouling did not increase with longer processing. Structural alterations were noted in anion-exchange membranes (AEMs), suggesting instability under high electric fields. Overall, EDFM effectively enriched cranberry juice with anthocyanins, but further research is necessary to address AEM degradation under limiting current density conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A fully bio-based filtration membrane (SGFM) is fabricated based on the gel-confined phase separation. • SGFM can provide lower pressure drop, higher filtration efficiency, and superior microbial survivability for bioaerosol sampling. • By simplifying the elution and extraction process, maximum sample transfer and vigorous recovery was achieved by SGFM. • Green capture was first proposed in air filtration for accurate and sensitive detection of airborne microbes. Air filtration has become a desirable route for collecting airborne microbes. However, the potential biotoxicity and sterilization of current air filtration membranes often lead to undesired inactivation of captured microbes, which greatly limits microbial non-traumatic transfer and recovery. Herein, we report a gel-confined phase separation strategy to rationally fabricate a fully bio-based filtration membrane (SGFM) using soluble soybean polysaccharide and gelatin. The versatile SGFM features fascinating honeycomb micro-nano architecture and hierarchical interconnected porous structures for microbial capture, and achieves a lower pressure drop, higher interception efficiency (99.3%), and superior microbial survivability than commercial gelatin filtration membranes. Particularly, the water-dissolvable SGFM can greatly simplify the elution and extraction process after bioaerosol sampling, thereby bringing about maximum sample transfer and vigorous recovery of collected microbes. Meanwhile, green capture coupled with ATP bioluminescence endows the SGFM with rapid and quantitative detection capability for airborne microbes. This work may pave the way for designing green protocols for the detection of bioaerosols. [ABSTRACT FROM AUTHOR]

Many known purification systems have failed in the removal of per- and poly-fluoroalkyl substances (PFASs), and there is no known natural degradation process. PFAS are a group of synthetic fluoroorganic compounds that have a unique dual nature of both lipophobic and hydrophobic, as well as high-energy chemical bonds that make them pervasive in the environment. Currently, these compounds receive less attention; however, they pose serious health problems. Studies have shown PFAS's dispersion pathways, health concerns, and suggestions for their removal in soil and water, but there is still limited information on the natural or subjective degradation of the compounds. Several technologies, such as phytoremediation, reverse osmosis, nanofiltration, and photolysis, have been demonstrated to remove PFAS. However, these techniques come with their challenges and drawbacks, especially in the complete removal of the compounds. Thus, this overview described the pathways and mechanisms of some PFAS, including biotransformation pathways of 6:2 FTOH, biotransformation and degradation pathways of 8:2 FTOH, and fragmentation pathways for PFOA, PFOS, and 8:2 FTOH, degraded by the Phanerochaete chrysosporium fungus. Furthermore, this study suggests that the integration of plants and fungi into constructed wetland technology holds promise for effective PFAS removal.

This study is focused on fractionation of insulin-like growth factor I (IGF-I) and transforming growth factor-β2 (TGF-β2) using a new electro-based membrane process calledelectrodialysis with filtration membranes (EDFM). Before EDFM, different pretreatments were tested, and four pH conditions (4.25, 3.85, 3.45, and 3.05) were used during EDFM. It was demonstrated that a 1:1 dilution of defatted colostrum with deionized water to decrease mineral content followed by the preconcentration of GFs by UF is necessary and allow for these compounds to migrate to the recovery compartment during EDFM. MS analyses confirmed the migration, in low quantity, of only α-lactalbumin (α-la) and β-lactoglobulin (β-lg) from serocolostrum to the recovery compartment during EDFM. Consequently, the ratio of GFs to total protein in recovery compartment compared to that of feed serocolostrum solution was 60× higher at pH value 3.05, the optimal pH favoring the migration of IGF-I and TGF-β2. Finally, these optimal conditions were tested on acid whey to also demonstrate the feasibility of the proposed process on one of the main by-products of the cheese industry; the ratio of GFs to total protein was 2.7× higher in recovery compartment than in feed acid whey solution, and only α-la migrated. The technology of GF enrichment for different dairy solutions by combining ultrafiltration and electrodialysis technologies was proposed for the first time. [ABSTRACT FROM AUTHOR]

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Folia Pomeranae Universitatis Technologiae Stetinensis Agricultura Alimentaria Piscaria et Zootechnica is the property of West Pomeranian University of Technology in Szczecin and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Electrodialysis with Filtration Membrane (EDFM) system has shown promise in juice enrichment, but further optimization is needed. This study evaluated the effect of processing duration (3 and 6 h) on juice composition, process efficiency, and membrane fouling. Results demonstrated a significant impact of processing time on juice composition, especially anthocyanin and mineral content. Two anthocyanin-depleted juices (−18.94% and −30.70%) and two anthocyanin-enriched juices (26.21% and 44.21%) were produced. Similar energy (1512.13 Wh/g of anthocyanins) was required to migrate equivalent amounts of anthocyanins over both time periods, with no impediment due to fouling observed, although the system’s resistance increased (2.5-fold after 3 h, 3.2-fold after 6 h). Membrane fouling was characterized through conductivity, thickness, ATR-FTIR, SEM-EDX, and foulant identification. Minimal anthocyanin accumulation occurred on cation-exchange membranes (CEM), while anthocyanins and PACs concentrated within the filtering layer of filtration membranes (FM). However, fouling did not increase with longer processing. Structural alterations were noted in anion-exchange membranes (AEMs), suggesting instability under high electric fields. Overall, EDFM effectively enriched cranberry juice with anthocyanins, but further research is necessary to address AEM degradation under limiting current density conditions.

In this paper, the PES-g-PMBA membrane was prepared by gamma-ray irradiation-induced grafting reaction in a homogenous solution. Fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analysis (TGA) confirmed the effectiveness of the graft reaction and the formation of polyether sulfone grafted poly (N,N'-methylene bisacrylamide) (PES-g-PMBA) copolymer. The micro-surface and cross-section structure of the membrane was analyzed by scanning electron microscope (SEM), and too high a grafting rate might lead to the destruction of the membrane structure. The results of the contact angle (CA) measurement showed that the CA of the PES-g-PMBA membrane decreased significantly compared with the pristine PES membrane, indicating that the hydrophilicity of the membrane was improved. The test results of permeability, filtration, and anti-fouling performance show that the PES-g-PMBA membrane has good filtration and anti-fouling effects on bovine serum albumin (BSA) aqueous solution, and the rejection rate and flux recovery rate are maintained at a high level. [ABSTRACT FROM AUTHOR]

To optimize cranberry juice enrichment, correlation between physicochemical properties of filtration membranes (FM) and anthocyanin migration was investigated during electrodialysis with filtration membranes (EDFM) using redundancy (RDA) and multivariate regression (MRGA) analyses. Six polyether sulfone (PES) and polyvinylidene fluoride (PVDF) membranes with molecular weight cut-offs between 150 and 500 kDa, commercially available at large scale, were characterized in terms of nine physicochemical characteristics and used for EDFM. The highest migration of total anthocyanin was obtained with PVDF 250 kDa, with a global migration rate of 3.5 ± 0.4 g/m2·h. RDA showed that two FM properties (mesopore porosity and hydrophilic porosity) were significantly negatively correlated to the anthocyanin’s migration and explained 67.4% of their total variation in migration. Predictive MRGA models were also developed for each anthocyanin based on these significant FM properties. A combination of intermolecular interactions may lead to binding in a cooperative and synergistic mode and hinder the anthocyanin migration.

Filter membranes (pore size 0.2 μm) are frequently used to perform a sterile filtration. To characterize the pore size of filter membranes, a method to determine the particle retention of nanoparticles was defined. The Dynamic Light Scattering method was first analysed and calibrated to correlate the particle concentration with absolute intensity of scattered light. Afterwards, standard particle suspensions with particle sizes of 0.150 μm and 0.239 μm were lead through an infusion filter and the particle retention of the filter was evaluated by the determination of the original and the filtrated particle concentration. The test filter retained 91% of the smaller and 98% of the larger particles. Evaluating the particle retention with Dynamic Light Scattering could be a time saving method with lesser effort compared to existing methods.

In this work, new membrane was fabricated from polyester fabric (PF) as a substrate which was coated by a casting solution containing polyvinylidene fluoride (PVDF) blending by addition of MIL-101 (Cr) metal-organic framework (MOF)-molecularly imprinted 3-aminophenol hexamethylenetetramine (MIAPH) as filler and sodium dodecyl sulfate (SDS) as hydrophilic agent. The membrane was fabricated by phase inversion method (PVDF/MIAPH). The MIAPH has selective functional groups and was applied as filler in the mixed matrix membrane. The as-prepared MIAPH was characterized by FE-SEM, EDS, XRD, FTIR and BET-BJH analyses. The hydrophilic property, dye adsorption and filtration properties of the MIAPH/PVDF/PF membrane were studied for removal Trypan blue (TB) based on central composite design (CCD) technique through investigating operational variables (pH, TB concentration, pressure). In the fabrication of membranes, the optimal filtration properties appear at the 30 μL of SDS solution and 0.005 g MIAPH fillers. The fabricated MIAPH/PVDF/PF membrane indicates a high removal efficiency up to 94.9 % for the TB removal and has high selectivity. The data of the adsorption equilibrium were described by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms. The findings illustrated that appropriate of MIAPH in membranes could be an efficient and selective technique for TB elimination. [Display omitted] [ABSTRACT FROM AUTHOR]

Asymmetric porous ceramic membranes typically have a very thin top layer with finer pores covered on thick porous layers with micrometer‐scale pores. In this study, triple‐layer asymmetric MgAl2O4 filtration membranes composed of (i) an Al2O3 support layer (circular pellet with ~10 µm pores) prepared by dry pressing, (ii) a reactively sintered MgAl2O4 intermediate layer (~40 µm in thickness), prepared by dip‐coating with tackifier (PEG‐20000), and (iii) another reactively sintered finer MgAl2O4 membrane layer (~20 µm in thickness), prepared by dip‐coating without tackifier. Different from our previous studies for the microfiltration of submicrometer‐sized particles, in this study we have challenged the ultrafiltration of water‐soluble polymer molecules. Their filtration performance was investigated by removing 1 million molecular‐weight polyethylene oxide (PEO) from water. The rejection rate of the triple‐layer asymmetric filtration membrane to PEO was ~14%. The all‐ceramic membrane in this study showed a comparable rejection rate with the reported inorganic–organic membrane, and it must be promising for excellent chemical and thermal stabilities as well as long durability. [ABSTRACT FROM AUTHOR]

Harvesting microalgae is an important process to be carried out in the production of biodiesel from microalgae. The method of harvesting by filtration technique provides many advantages over other methods. Polymer is a membrane material that is often used for harvesting microalgae. However, polymer membranes have limited hydrophobic properties, thus, modification was needed to improve the hydrophilic properties and performance of polymer membranes. The polyvylene fluoride (PVDF) flat-sheet membrane has advantages over other membrane materials which are rated with a flux rate of 67.3 L / m2h and a rejection value of 100%. Then, the development with hollow fiber modulation on the PVDF membrane was considered very suitable, which was reported to have succeeded in increasing the membrane flux in the harvest of Scenedemus Acuminatus reaching up to 5136 L / m2h. The addition of PVDF with the inorganic additive LiCl was successful in increasing its hydrophilicity as the water permeation size increased up to 542 L / m2h. In addition, the use of triethyl phosphate (TEP) as a solvent is more environmentally friendly and compatible with PVDF membranes. As a result, it can increase membrane porosity by up to 92.7%. Apart from improving the membrane material, this review also reports the design and economic analysis to produce an effective and efficient of polymeric membranes for microalgae harvesting.

In the actual context of food safety and circular economy, the separation of the α137–141 antimicrobial peptide (TSKYR, 653 Da) coming from the hydrolysis of bovine hemoglobin, a non-valorized slaughterhouse by-product, and its reuse as a preservative agent for food products during storage would be of major interest. However, depending on the degree of hydrolysis (DH) of the bovine hemoglobin, the TSKYR peptide environment into the hydrolysate will be different and would impact its recovery yield by electrodialysis with ultrafiltration membranes (EDUF), a hybrid and eco-friendly technology. In this context, five DHs (3, 5, 10, 13 and 18%) were investigated to study the influence of the peptide populations on the α137–141 selective separation by EDUF. It appeared from these results that the most appropriate DH was of 5% since a lower population of peptides between 500 and 1000 Da was present and the subunits of hemoglobin were already digested. Hence, an enrichment factor of about 13 folds for the α137–141 was obtained in comparison with the initial hydrolysate. At our knowledge, it was the first time that the effect of the hydrolysis degree of a protein is demonstrated to impact preferentially the separation of a specific peptide by EDUF. [ABSTRACT FROM AUTHOR]

Plasma separation is of high interest for lateral flow tests using whole blood as sample liquids. Here, we built a passive microfluidic device for plasma separation with high performance. This device was made by blood filtration membrane and off-stoichiometry thiol–ene (OSTE) pillar forest. OSTE pillar forest was fabricated by double replica moldings of a laser-cut polymethylmethacrylate (PMMA) mold, which has a uniform microstructure. This device utilized a filtration membrane to separate plasma from whole blood samples and used hydrophilic OSTE pillar forest as the capillary pump to propel the plasma. The device can be used to separate blood plasma with high purity for later use in lateral flow tests. The device can process 45 μL of whole blood in 72 s and achieves a plasma separation yield as high as 60.0%. The protein recovery rate of separated plasma is 85.5%, which is on par with state-of-the-art technologies. This device can be further developed into lateral flow tests for biomarker detection in whole blood.

Electrodialysis with ultrafiltration membrane (EDUF) was selected to separate a herring milt hydrolysate (HMH) in a scale-up and long-term study for the recovery of bioactive peptides. The scale-up was performed to maximise peptide recovery by placing a total membrane area of 0.08 m2 for each anionic and cationic compartment. Twelve consecutive runs were carried out, for a total of 69 h, with minimal salt solution cleaning in between experiments. The final peptide migration rate showed that cationic peptides had a higher average migration rate (5.2 ± 0.8 g/m2·h), compared to anionic peptides (4.7 ± 1.1 g/m2·h). Migration was also selective according to peptide identifications and molecular mass distribution where only small molecular weights were found (

Membrane biofouling remains a major limiting factor for the membrane-based water purification technology. The development of antibacterial membrane surfaces is very important for membrane biofouling mitigation. In this study, we developed a one-pot method of synthesizing silver nanoparticles (Ag NPs) and immobilizing them onto membranes via simply soaking the membranes in a mixture solution of silver nitrate, poly (ethylene glycol) methyl ether thiol (mPEG-SH) and dopamine. Results illustrate that mPEG-SH works as a ligand to slow down the reduction process of silver ions by dopamine for the synthesis of Ag NPs in a controllable manner and also the prevention of Ag NPs aggregation in solution. Moreover, the Ag NPs could be in situ immobilized onto polysulfone ultrafiltration membrane, glass fiber membrane and stainless steel, regardless of their surface properties, but the size of Ag NPs was affected by the substrates. In addition, the Ag NPs immobilization on the polysulfone ultrafiltration membranes increased the bovine serum albumin rejection rate of membrane by 16%, but decreased membrane permeability by 14% compared to that of the pristine membranes. The Ag NPs containing membranes exhibited outstanding antibacterial properties with more than 90% antibacterial efficiency against both Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus . During the filtration test, the silver release from the Ag NPs containing polysulfone ultrafiltration membranes was very slow and the total accumulation of silver ions released from the membranes was only 7% of its initial Ag NPs loading after 24 h filtration operation. The silver ion concentration in the permeate water was 0.35 ± 0.16 ppb, far below the maximal contaminant limit of silver ions in drinking water with no risk for the application of Ag NPs incorporated membranes to treat water. Our work provides a facile and universal approach of synthetizing and simultaneously immobilizing Ag NPs onto diverse membranes for antibacterial properties. [ABSTRACT FROM AUTHOR]

Peptide fouling is a technological drawback in filtration membrane processes. The impact of membrane characteristics on fouling by peptides from a complex whey protein hydrolysate (WPH) fouling was assessed based on advanced statistical redundancy analysis. Six membranes were characterized and tested: PES, PVDF, CF55, S11, S11 + and S11 - . Among the eight physicochemical characteristics analyzed, zeta-potential (ZP) and roughness (Rz) were highly correlated with total fouling quantity (TFQ), suggesting that peptide fouling was mainly due to electrostatic interactions over wider surfaces. Concerning peptide sequences, redundancy analysis indicated that at least one characteristic among ZP, Rz, contact angle and thickness contributed significantly to the fouling of ALMPHIR, LIVTQTMK, TKIPAVFK, VLVLDTDYK, TPEVDDEALEK, TPEVDDEALEFDK or SLAMAASDISLLDAQSAPLR. It appeared that membranes with hydrophilic surfaces were more likely to be fouled by WPH regardless the peptide hydrophilicity. Besides, wider surface would enable more contact area for peptides, increasing consequently fouling. The TFQ was described by a statistical predictive model using the combined effect of ZP and Rz, of the form: ln(TFQ) = 8.64 + 0.072.X Rz + 0.088.X ZP (R 2 = 0.9098). Moreover, statistical models were also established for each peptide, enabling to predict their specific fouling on a variety of membranes with different physicochemical characteristics. [ABSTRACT FROM AUTHOR]

It is of great practical interest to combine membrane filtration with the removal of phosphate, which is the key nutrient in waters causing the eutrophication. In this study, we report the first example of in situ formation of La(OH) 3 nanorods in poly(vinylidene fluoride) (PVDF) membrane by adding LaCl 3 ·7H 2 O precursor in the membrane casting solution, after a non-solvent induced phase separation process in alkaline solution. The structures, morphologies, and surface properties of the La(OH) 3 -PVDF composite membranes were characterized by SEM, TEM, XRD, FT-IR, XPS, and water contact angle measurements. The adsorption and filtration experiments demonstrated that the La(OH) 3 -PVDF composite membrane exhibited a molecular weight cut-off of 16 kDa and superior adsorption and filtration properties, i.e. high adsorption capacity (256.6 mg P/g (La)), fast adsorption kinetics, excellent regenerability, negligible lanthanum leakage, efficient phosphate removal under high filtration permeability and simultaneous removal of organic pollutants and phosphate. We hope that our work has presented a new direction for the design of filtration membrane with superior adsorption properties. [ABSTRACT FROM AUTHOR]

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Antimicrobial polyvinylidene fluoride (PVDF) membrane modified by dodecyltrimethyl ammonium bromide (DTAB) has been electrospun using simple one‐step technology, where the modifying agent DTAB is dissolved in spinning solution. X‐ray photoelectron spectroscopy and electrokinetic analysis confirm reliably the presence of DTAB on the nanofibers surfaces; electrokinetic analysis shows the changes of zeta potential due to modification by DTAB. X‐ray diffraction shows that electrospinning converts the part of α phase (≈40%) present in PVDF powder into β phase with all trans (TTT) zigzag chains conformation in PVDF electrospun membrane. Surface modification does not affect the phase composition of PVDF nanofibers, just only leads to lower crystallinity (smaller size of crystallites) in PVDF nanofibers. DTAB causes the curling of fibers and their aggregation, what completely changed the membrane structure. DTAB‐modified membrane exhibits antibacterial properties against Staphylococcus aureus subsp. Aureus. Concentration of 0.5 wt% DTAB in spinning solution causes partial inhibition of bacterial growth only, while 1.0 wt% concentration leads to complete inhibition. [ABSTRACT FROM AUTHOR]

A new method was developed for effective enrichment of Cd2+ ions from water with a calcium alginate (CaAlg) hydrogel filtration membrane. First, the CaAlg hydrogel filtration membrane was prepared without a pore-forming agent. This membrane was used to remove Cd2+ via ion exchange with Ca2+, and the Cd2+ was preserved in the CaAlg hydrogel. Then, the CaAlg hydrogel containing Cd2+ was soaked in a sodium citrate solution, and the hydrogel was fully dissolved. The removal rate of the CaAlg filtration membrane reached almost 100% within 120 min when the Cd2+ concentration was under 1 mg/L. Factors affecting the removal rate were investigated, such as NaAlg concentration, operating pressure, operating time and the initial concentration of Cd2+. The effects of initial Cd2+ concentration, pressure and filtration time on the enrichment factor were also investigated. The results show that the enrichment factor reached 87.3 when the pressure was 0.18 MPa and the filtration time was 240 min. Different enrichment factors could be achieved by adjusting the operating pressure and filtration time. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fabrication of novel PVDF-rGO-IL nanocomposite inclusion membranes via phase inversion method. • Inducing porosity and hydrophilicity into nanocomposite inclusion membranes with rGO and IL. • Enhanced water flux PVDF-rGO-IL nanocomposite inclusion membranes after incorporation of rGO/ IL. • Removal of highly toxic heavy metals including As3+ from fabricated nanocomposite inclusion membranes. • Simultaneous high removal efficiency of divalent metal ions (Cu2+, Cd2+, Zn2+,Mn2+) and up to 70% removal efficiency for As3+. The biggest challenge around the world is water contamination by heavy metal ions. The detrimental effects of heavy metals on humans as well as on aquatic ecosystems are of great concern. In this regard, membrane technology is playing its role in the separation of these non-biodegradable heavy metal ions from the waste water, though improvement in the technology is still the need of time. The present work deals with the novel strategy of developing PVDF/rGO nanocomposite membrane with the inclusion of IL via phase inversion method to remove heavy metal ions. Inclusion of rGO and IL as filler into the PVDF hydrophobic matrix improved the antifouling characteristics and solvent contents of the hybrid ionogel membranes. In addition, the decrease in the contact angle from 90° (Pure PVDF) to 46° (PVDF/IL/rGO) was observed pointing towards the hydrophilic nature of the resulting membranes. Among various compositions, 0.5 w/v % rGO demonstrated maximum efficiency by removing up to 90% of various divalent cations including Cu2+, Cd2+, Zn2+, and Mn2+.The flux recovery ratio was observed to be 94% after testing the membrane several times. Up to 70% removal of As3+ from the same membrane is a hope to design a membrane with improved efficiency for removing As3+. [ABSTRACT FROM AUTHOR]

Residual antibiotics in water have become a primary source of water pollution due to their misuse. Recently, membranes, produced by layered nanomaterials such as graphene oxide (GO), boron nitride (BN) and transition metal dichalcogenides, have been used in water purification, desalination and molecule separation as they are energy saving and simple to operate. The performance of membranes is closely related to their structure and the properties of the nanomaterials used. In this work, BN nanosheets (BNNSs) and GO were used to fabricate a two-dimensional nanocomposite membrane in order to improve the membrane’s permeance. It should be mentioned that the corresponding equal mass of the pure GO membrane was almost impermeable for the antibiotic solution. Multi-walled carbon nanotubes (MWCNTs) were inserted into the GO layers to increase the interlayer spacing and adsorb more antibiotics from the water. The resultant MWCNTs/BNNSs/GO membranes showed improved permeance and stable sieving capability for the antibiotic and small species. Specifically, permeance reached 30.2 L m−2 h−1 bar−1, which was much higher than pure GO membrane and the antibiotic rejection was 96.1%.

The aim of this study was to develop a high flux three-tier composite membrane composed of a coating layer based on chitosan and chitosan with silver nanoparticles, electrospun alginate nanofibres as a midlayer and nonwoven as a mechanical support substrate. The nanofibres were prepared by electrospinning of alginate with the aid of synthetic electrospinnable polyethylene oxide (PEO), and ionically crosslinked with calcium chloride followed by chemical crosslinking using glutaraldehyde. The silver nanoparticles were synthesized using a chitosan solution and thermal treatment. The silver nanoparticles were found to be well dispersed on the coating layer, which improved the antibacterial activity of the membrane against both Gram negative and Gram positive bacteria. The chitosan and silver nanoparticles containing chitosan coated membrane displayed similar flux and a high rejection of nanoparticles (>98%) and oil (>93%). Both membranes showed a higher flux rate and oil rejection than the commercial membrane. The presence of silver nanoparticles improved the dye rejection, reaching more than 95% rejection throughout the five filtration cycles test. These observations show that the incorporation of silver nanoparticles can enhance the antibacterial activity of the membrane with a promising potential in the field of dye removal and oil separation. [ABSTRACT FROM AUTHOR]

Calcium alginate (CaAlg) hydrogel filtration membrane was prepared using urea as pore-forming agent. The effects of preparation and operating conditions on the removal rate of Cd2+ were researched. The removal mechanism of Cd2+ and the anti-fouling property of CaAlg membrane were investigated. The removal rate of the CaAlg filtration membrane reached over 99.5% within 120 min when 20 mg/L Cd2+ was used, and the flux was 15.5 L/m²h at 0.1 MPa when the thickness of the membrane was 0.28 ± 0.08 mm. However, the removal rate of Cd2+ was below 10.0% when the same concentration Cd2+ solution was adsorbed by CaAlg membrane with the same size. Energy dispersive spectroscope analysis demonstrated that the removal of Cd2+ depended on the adsorption and ion exchange of Ca2+ by Cd2+. CaAlg membrane exhibited a higher removal rate for Cd2+ (almost 100%). It was the filtration process that promoted the adsorption and ion exchange of Cd2+ in CaAlg hydrogel. [ABSTRACT FROM AUTHOR]

Faced on the threat of oil-contaminated wastewater to the environment and health of human body, we demonstrated, for the first time, a facile method for fabrication of novel nanoporous cellulose membranes derived from renewable marine resources (shell of tunicate). The fibrous tunicate cellulose nanocrystals (TCNCs) were prepared by acid hydrolysis, and exhibited high degree of crystallinity and distinct cholesteric liquid crystal behavior. Thus, the TCNC membranes were constructed by vacuum-assisted filtration of TCNCs suspensions, showing hierarchical structure, and superhydrophilic/underwater superoleophobic characters. The experimental results confirmed that the TCNC membranes were beneficial for highly efficient separation of oily water, which not only could separate various oil-in-water nanoemulsions, but also were applicable for oil-in-water microemulsions and water-in-oil emulsions. The thickness, pore size, water flux, and oil rejection of the TCNC membranes could be controlled by the dosage of TCNCs. Moreover, they exhibited high mechanical strength, excellent pH- and temperature-stability, and good cycling performance. On the basis of the combining of cholesteric liquid crystal structure and superhydrophilicity of fibrous tunicate cellulose nanocrystals, a new strategy to construct novel filter membranes for the highly effective oil/water separation was provided here. [ABSTRACT FROM AUTHOR]

Integrated membranes with filtration and photocatalytic functions have been considered as an effective strategy for purifying flowing wastewater, but the design and preparation of high-efficiency and low-cost membranes is still of great urgency. Herein, we report efficient recyclable BiOBr x I 1-x fibrous filter membranous photocatalyst prepared through the in-situ growth of BiOBr x I 1-x solid-solutions with tunable band-gaps on carbon fiber cloth (CFC). The fabrication was performed via a facile dipping-solvothermal synthesis of BiOBr x I 1-x solid-solutions nanoplates on CFC with different I/Br ratios in the precursor solution. With the increase of I/Br ratio from 0 to 4, CFC/BiOBr x I 1-x solid-solutions exhibit a re-shifted in the photoabsorption edge from 420 to 620 nm, leading to the tuning of the band-gap from 2.49 to 1.81 eV. Under visible light illumination for 120 min, CFC/BiOBr x I 1-x solid-solutions have the tuned photocatalytic activity, where CFC/BiOBr 0.8 I 0.2 shows the highest degradation efficiency toward various antibiotics (such as levofloxacin (LVFX, 94.1%), ciprofloxacin (CIP, 94.5%), and tetracycline (TC, 98.9%)) as well as dyes (such as acid orange 7 (AO7, 91.4%). Especially, when CFC/BiOBr 0.8 I 0.2 is used as a flexible membrane to a construct multi-grade unit for treating the flowing sewage, the degradation efficiency of LVFX goes up from 3.9% in the first grade to 96.2% in the tenth grade. Therefore, the present CFC/BiOBr 0.8 I 0.2 not only possesses great potential as a flexible membrane-shaped photocatalyst for purifying the flowing sewage efficiently but also provides some insights for developing new types of purifying membranes and devices. In-situ growth of BiOBr x I 1-x solid-solutions was realized on CFC as filter-membrane-shaped photocatalyst for removing pollutants in flowing wastewater. [Display omitted] • The in-situ growth of BiOBr x I 1-x solid-solutions on carbon fiber cloth. • High photocatalytic activity owing to tunable band-gaps. • Good stability and simple recyclable process. • Filter-membrane-shaped photocatalyst for purifying the flowing wastewater. [ABSTRACT FROM AUTHOR]

The article deals with the preparation and possibilities of using combined filtration sorption systems usable for the construction of folded filters or respirators. The studied materials are made of several structural layers—a filter membrane made of polymeric nanofibers, an adsorbent containing active carbon or porous silicon dioxide nanofibers, and a supporting or cover nonwoven bicomponent fabric. The layers are connected only by pressure at an elevated temperature without the use of binders, according to utility model PUV 31 375. The result is a compact fabric material of textile character with a high permeability, good mechanical resistance, which effectively catches the submicron particles and the gases of the organic substances. The prepared samples of the filter sorptive material have been evaluated not only from the point of view of morphology and microstructure, but also from the point of view of the capture of pollutants.

Cyclodextrins (CDs) can endow electrospun fibers with outstanding performance characteristics that rely on their ability to form inclusion complexes. The inclusion complexes can be blended with electrospinnable polymers or used themselves as main components of electrospun nanofibers. In general, the presence of CDs promotes drug release in aqueous media, but they may also play other roles such as protection of the drug against adverse agents during and after electrospinning, and retention of volatile fragrances or therapeutic agents to be slowly released to the environment. Moreover, fibers prepared with empty CDs appear particularly suitable for affinity separation. The interest for CD-containing nanofibers is exponentially increasing as the scope of applications is widening. The aim of this review is to provide an overview of the state-of-the-art on CD-containing electrospun mats. The information has been classified into three main sections: (i) fibers of mixtures of CDs and polymers, including polypseudorotaxanes and post-functionalization; (ii) fibers of polymer-free CDs; and (iii) fibers of CD-based polymers (namely, polycyclodextrins). Processing conditions and applications are analyzed, including possibilities of development of stimuli-responsive fibers. [ABSTRACT FROM AUTHOR]

Production of novel membranes for filtration applications is still a burgeoning demand with the rising environmental concern about pollution in different spheres of human biota. This paper presents a novel approach, yet a continuous production method, to fabricate bi-component cellular membranes. Multilayer membranes having thousands of alternating layers, where cells are aligned vertically and separated by thin, solid polymer layers, were produced using unique multilayer co-extrusion and multiplication technology. Post-drawing techniques, both uniaxial and biaxial, were employed to create interconnected through pores in cellular membranes. Two different polymer pairs, polystyrene/polypropylene (PS/PP) and polypropylene/nylon 6 (PP/PA6), have been chosen to develop multilayer cellular membranes. The modulus contrast between film and foam layers played an important role in creating hierarchical porous structures in the membrane. Uniaxially drawn membranes exhibit very narrow pore size distribution whereas biaxially drawn membranes exhibit slightly larger pore size distribution. In addition, the porosity can be varied (20–60%) either by changing the chemical blow agent (CBA) concentration, foam content or the draw ratios of membranes. The membranes also exhibit high water flux and high micro-particle separation efficiency. [ABSTRACT FROM AUTHOR]

Traditional polymer membranes prepared by phase inversion process have the problems of low flux and serious fouling when they were used for oil/water separation. In this work, an alkaline-induced phase inversion process is developed for the superhydrophilic/underwater superoleophobic polyacrylonitrile (PAN) ultrafiltration membrane. The as-prepared PAN ultrafiltration membrane could effectively separate oil-in-H 2 O emulsions with a high flux up to 2270 L/m 2 h bar and an extremely high rejection while the oil residual in filtrate after one-time separation is lower than 10 ppm. Also, the PAN membrane showed ultralow oil adhesion and antifouling properties and can be easily recycled with flux recovery ratio of 85%. This new PAN membrane has a great potential for treating oily wastewater. [ABSTRACT FROM AUTHOR]

Specific food proteins and peptides as well as amino acids released by enzymatic hydrolysis have demonstrated several biological activities, therefore they represent an interesting perspective in agrifood, biopharmaceutical and nutraceutical industries. However, these biomolecules are present at a significantly lower concentration in a complex mixture of different sizes, conformations and net charges. Separation or fractionation of such active molecules from the complex matrices is therefore vital in order to concentrate them in more purified form. In this context, conventional pressure-driven membrane processes like UF, NF and RO are widely used as a first choice for the separation and purification of proteins, peptides and amino acids. On the other side, innovative electromembrane processes such as EMF and EDFM are recently gaining much attentions and are regarded as favorable alternatives to the conventional methods. In addition, these methods could be potentially used for the efficient separation of charged compounds like proteins, peptides and amino acids. However, as observed for filtration membranes used in pressure-driven membrane filtration techniques (MF, UF, NF and RO), ion-exchange membranes stacked in an electrodialytic cell are also subject to fouling by protein, peptide and amino-acid. Indeed, fouling of ion-exchange membranes is a real challenge as these membranes are more easily affected and altered by aggressive chemical cleaning as compared to filtration membrane. Therefore, characterization of membrane fouling is essential to understand the mechanism of fouling to control this phenomenon. Consequently, this paper will review the conventional as well as more recent technologies used for the characterization of ion-exchange and filtration membranes fouling by proteins, peptides and amino acids. In addition, conventional methods of fouling characterization have been mainly developed for filtration membranes and information about the techniques that can be used in combination with ion-exchange membranes are still lacking. Accordingly, this work will create a bridge between the conventional and current characterization methods in relation to filtration as well as ion-exchange membranes. In addition, the pros and cons of each technique are discussed with some important points to be noted to avoid their misuse. Moreover, this paper will bring a clear insight about how the methods of fouling characterization have been evolving from qualitative to quantitative analyses. Till date, more than one method are used depending on nature of fouling, foulants and membrane used although, in-situ and non-destructive characterization methods are preferred. [ABSTRACT FROM AUTHOR]

Calcium alginate (CaAlg) hydrogel filtration membrane was prepared using polyethylene glycol (PEG) as the pore-forming agent. Ultrasonic time-domain reflectometry technology was employed to analyze the membrane-forming process. The CaAlg filtration membrane was characterized by SEM, FTIR, TG and DTG. The mechanical behavior of the membrane was also evaluated. Concentrations of sodium alginate (NaAlg) and PEG on the pure water flux (PWF) and filtration properties of lysozyme (Lyz) solutions were investigated. Results showed that the PWF increased with an increase in the pressure initially, and then reached a stable value. The CaAlg filtration membrane prepared with lower NaAlg concentration and higher PEG concentration had higher flux. CaAlg filtration membranes exhibited good anti-fouling properties. The rejection of PEG reached above 90% when the molecular weight ( M w ) of PEG in feed solution was larger than the pore-forming agent PEG for preparing the membranes. The CaAlg filtration membrane prepared using PEG400 as the pore-forming agent could reject almost 100% Brilliant Blue G250 ( M w =854.02 Da), and 99.5% Congo Red ( M w =696.68 Da). [ABSTRACT FROM AUTHOR]