Congo Red Research Articles

Efficient Photocatalytic System based on Schiff‐Base Type Hybrid Polymers for Energy Conversion and Water Treatment

AbstractIn this contribution, a new Schiff‐base hybrid cross‐linked polymer (TFPT‐SHCP) derived from triazine derivatives and silsesquioxanes was developed, and its photocatalytic performance was systematically investigated. Compared with traditional organic Schiff base catalysts, in TFPT‐SHCP, organic inorganic hybrid silsesquioxanes monomers at the molecular level can serve as a sturdy host backbone, bringing structural ultrastability to the final material. And their excellent strength and durability make them have good application prospects in water treatment. Furthermore, the introduction of triazine derivatives with excellent photoelectric performance and the construction of −C=N‐ result in excellent photocatalytic performance of TFPT‐SHCP. The as‐prepared TFPT‐SHCP exhibits excellent degradation capacity of various organic pollutants under visible light catalysis, with degradation rate constants for Congo Red (CR), rhodamine B (RB) and tetracycline hydrochloride (TH) reaching 0.302 min−1, 0.121 min−1, 0.161 min−1, respectively. Under simulated outdoor conditions, dye solutions with concentrations up to 500 ppm can be degraded to complete decolorization within 5 weeks. This work demonstrates the enormous potential of POSS‐based Schiff base materials as a platform for visible light catalysts, paving the way for the pre design and functionalization of related materials in the future.

Synthesis of silver‐doped TiO2 nanoparticles with highly efficient adsorption of Congo red

AbstractTiO2 nanoparticles (NPs) doped with Ag were produced through a solvothermal method, with varying amounts of silver doping ranging from 0.5% to 1.5%. The samples were analyzed for crystallite sizes, structure, and metallic bondings using XRD, SEM, EDXS, and FTIR techniques. The BET surface areas were determined through nitrogen adsorption isotherms. The efficiency of the silver‐doped TiO2 NPs for removing Congo red (CR) was tested through adsorption experiments. The results showed that the synthesized TiO2 NPs doped with Ag were uniformly spherical in shape, with tiny average sizes ranging from 7.97 to 12.74 nm and large BET surface areas (98.41–166.1 m2 g−1). The silver‐doped TiO2 samples with a 0.5% Ag doping amount exhibited the highest adsorption capacity in CR removal, with a maximum adsorption capacity of 454.55 mg of dye per gram of adsorbent and a lower contact time of 20 min than other metal oxide NPs. The CR adsorption onto 0.5% Ag‐TiO2 obeyed the Langmuir isotherm model (R2 = 0.989), and the adsorption followed a pseudo‐second‐order kinetic equation. The adsorbent could be efficiently reused for five consecutive cycles to remove CR.

The effective treatment of dye-containing simulated wastewater by using the cement kiln dust as an industrial waste adsorbent

This study compares the adsorption behavior of both Methylene Blue (MB) and Congo Red (CR) dyes on the surfaces of cement kiln dust (CKD) powder from the experimentally simulated wastewater solution. The cement kiln dust powder was characterized using X-ray Fluorescence (XRF), X-ray diffraction (XRD), N2 adsorption–desorption Brunauer–Emmett–Teller (BET), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) tests. The adsorption for such dyes was studied under varying mixing contact times, temperatures, and pH as well as various initial concentrations of both dyes and adsorbent using the batch mode experiments. Pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were applied, and the results revealed that the pseudo-second-order fitted well to the kinetic data. Thermodynamic parameters stated that the adsorption process was endothermic. Studying Linear and nonlinear forms of Langmuir and Freundlich's adsorption isotherms revealed that the adsorption process was followed by both homogeneous mono-layer and heterogeneous multilayer coverage on the active sites of cement kiln dust particles. The data showed that the adsorption capacities of the methylene blue and Congo red dyes were 58.43 and 123.42 mg/g, respectively and cement kiln dust is an adsorbent with little cost for the treatment of wastewater.

Synthesis and Characterization of Nanoparticle Composite CaO/Fe3O4 from Duck Egg Shells and Its Application for Congo Red and Procion Red MX-5b Dyes Adsorption

Synthesis and Characterization of Nanoparticle Composite CaO/Fe3O4 from Duck Egg Shells and Its Application for Congo Red and Procion Red MX-5b Dyes Adsorption

Highly permeable carbon nanotube membranes for efficient surface water treatment through separation and adsorption–electrochemical regeneration

Membrane-based processes feature many advantages for surface water treatment over other technologies; however, the trade-off between membrane selectivity and permeability usually results in the failure to obtain high-quality filtrate at a high permeance. In this study, we report a highly permeable sodium alginate/glutaraldehyde cross-linked carbon nanotube (CNT/SA-GA) membrane with high adsorption ability for surface water treatment. The CNT/SA-GA membranes have a well-formed hollow fiber morphology and good conductivity of 166–261 S/m. They could reject >98 % of large-sized molecules (e.g., Alcian Blue 8GX and Congo Red) at high permeances of 137–227 L/(m2·h·bar). Moreover, they could remove ~100 % of smaller molecules (e.g., Rhodamine B (RhB)) through dynamic adsorption with a capacity of ~57.3 mg/g. Benefiting from their good conductivity, the CNT/SA-GA membranes could easily decompose the pollutants after adsorption saturation through electrochemical oxidation and then regenerated themselves. Though the switch between adsorption and electrochemical oxidation (2.0 V), the CNT/SA-GA membranes could remove ~100 % RhB at a high permeance of 342 L/(m2·h·bar), which is one order of magnitude higher than those of nanofiltration membranes. When used for surface water treatment, the CNT/SA-GA membranes exhibited a much higher TOC removal rate than commercial poly(acrylonitrile) (PAN) membranes (56.2 % vs. 7.2 %). LC-MS/MS analysis showed that many small molecules such as caffeine could be effectively removed by the CNT/SA-GA membranes. In addition, they exhibited a higher fouling resistance than PAN membranes, evidenced by their lower permeance decline ratio (10.1 % vs. 43.7 %). This study will promote the development and applications of the CNT-based membranes for water purification.

Solvothermal Synthesis of Cu2ZnSnSe4 Nanoparticles and Their Visible-Light-Driven Photocatalytic Activity.

Cu2ZnSnSe4 (CZTSe) nanoparticles (NPs) were successfully synthesized via a solvothermal method. Their structural, compositional, morphological, optoelectronic, and electrochemical properties have been characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Field-emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), UV-vis absorption spectroscopy, and electrochemical impedance spectroscopy (EIS) techniques. Porosimetry and specific surface area in terms of the Brunauer-Emmett-Teller (BET) technique have also been studied. XRD indicates the formation of a polycrystalline kesterite CZTSe phase. Raman peaks at 173 and 190 cm-1 confirm the formation of a pure phase. TEM micrographs revealed the presence of nanoparticles with average sizes of ~90 nm. A BET surface area of 7 m2/g was determined. The CZTSe NPs showed a bandgap of 1.0 eV and a p-type semiconducting behavior. As a proof of concept, for the first time, the CZTSe NPs have been used as a visible-light-driven photocatalyst to Congo red (CR) azo dye degradation. The nanophotocatalyst material under simulated sunlight results in almost complete degradation (96%) of CR dye after 70 min, following a pseudo-second-order kinetic model (rate constant of 0.334 min-1). The prepared CZTSe was reusable and can be repeatedly used to remove CR dye from aqueous solutions.

Synthesis of Ag2O/CaMoO4 S-type heterojunction with enhanced sonocatalytic performance to remove crystal violet in dye wastewater

Herein, an S-type of Ag2O/CaMoO4 heterojunction was prepared by combining CaMoO4 with Ag2O and characterized. The sonocatalytic performance of the Ag2O/CaMoO4 composite was evaluated by analyzing the degradation of basic dye crystal violet (CV). The results showed that the Ag2O/CaMoO4 composite had the best sonocatalytic performance when the molar ratio of Ag2O to CaMoO4 in the Ag2O/CaMoO4 composite was 10 %. When the ultrasonic time was 120 min, the ultrasonic power was 200 W, the addition amount of 10 % Ag2O/CaMoO4 composite was 1.00 g/L and the initial concentration of CV solution was 5 mg/L, the removal rate of CV could reach 97.36 ± 1.46(%). In addition, 10 % Ag2O/CaMoO4 composite showed excellent sonocatalytic degradation performance to cationic dyes Rhodamine B (RhB) and methylene blue (MB), anionic dye Orange II (AO II) and azo dye Congo red (CR), indicating that the catalyst had a wide range of application. The study on the mechanism of sonocatalysis showed that the construction of S-type Ag2O/CaMoO4 heterojunction effectively separated the electron-hole (e−-h+) pairs in the sonocatalysis process, significantly improved the sonocatalytic performance of CaMoO4, and effectively degraded CV, and the degradation of CV was caused by the active components such as h+, superoxide anion radical (O2–) and hydroxyl radical (OH). Furthermore, the 10% Ag2O/CaMoO4 composite showed excellent repeatability and stability. In addition, the sonocatalytic degradation products of CV were detected and the possible degradation pathways of CV were summarized. These results suggested that the Ag2O/CaMoO4 composite was an extremely appropriate sonocatalyst for sonocatalytic degradation of organic pollutants and would provide a valuable research basis for the development of efficient sonocatalysts.

Green synthesis of nano-MgO using lemon juice for amplified photocatalytic degradation of organic pollutants

This study examines the photocatalytic activity of the green synthesized (using lemon juice) MgO nanoparticles under a halogen light for the degradation of Congo Red (CR). The characterization of the prepared sample was studied by applying Fourier Transform Infrared (FTIR) Spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Thermogravimetric Analysis (TGA). By applying XRD analysis, the crystallographic variables of the MgO NPs were determined and the crystallite size was obtained from a variety of formulas/models (Scherrer equation, Williamson-Hall model, Monshi-Scherrer model, Size-Strain Plot, Halder-Wagner model, etc). The crystallite size was found in a valid range of 4.62–99.03 nm. Photocatalytic degradation of Congo Red (CR) has been made under halogen light by considering a dye concentration of 20 ppm at 40 mL solution for 0.05 g of the catalyst sample. Operating conditions were fixed as neutral pH, 25 °C temperature, and 40 min exposure time of the halogen lamp.

Multifunctional assessment of copper-doped ZnO nanoparticles synthesized via gliding arc discharge plasma technique: antioxidant, antibacterial, and photocatalytic performance.

In this paper, undoped and copper-doped ZnO nanoparticles (NPs) were successfully synthesized using a gliding arc discharge (GAD) plasma technique, which is a sustainable, cost-effective, and scalable method. This method offers several advantages over traditional synthesis methods. The synthesized NPs were characterized by various techniques to understand their physicochemical properties. XRD analysis confirmed the presence of characteristic peaks of pure ZnO, while doped samples exhibited additional peaks corresponding to CuO crystal planes, indicating the successful incorporation of Cu into the lattice. As obvious, bare ZnO showed absorption peak at 378 nm corresponding to the band gap of 3.21 eV. The band gap of Cu-doped samples increased systematically, i.e., 3.35 eV for 2% Cu, 3.47 eV for 4% Cu, and 3.66 eV for 6% Cu. SEM images revealed aggregation and increase in particle size with the increasing in Cu concentration. EDAX analysis revealed a decrease in the weight percentage of oxygen and zinc with the increase in Cu concentration, suggesting structural changes within the lattice. Furthermore, the antibacterial activity against Gram-positive and Gram-negative bacteria, antioxidant activity, and photocatalytic activity against three different organic dyes such as Brilliant Cresyl Blue (BCB), Methylene Blue (MB), and Congo Red (CR) was studied. It is found that the photocatalytic activity of ZnO NPs varies with Cu concentration, leading to a decrease in its performance. The antibacterial activity of the NPs was also assessed, with undoped ZnO NPs showing dose-dependent effects against bacteria, while the Cu-doped ZnO NPs exhibited decreased efficacy. Interestingly, Cu doping significantly enhanced the antioxidant activity of the NPs compared to the undoped ZnO.

Machine learning-assisted fluorescence/fluorescence colorimetric sensor array for discriminating amyloid fibrils

Misfolding and aggregation of proteins often lead to the development of diseases, and amyloid has gained widespread attention as a biomarker for a variety of diseases. In this study, we developed a fluorescence/fluorescence colorimetric dual-mode sensor array for the detection of amyloid fibrils using several commercially available organic small molecular dyes and alkaloids, including Thioflavin T, Congo Red, 8-anilino-1-naphthalenesulfonic acid, Safranine T, berberine and coptisine, as the elements. Herein, the array could not only use the fluorescence intensities change before and after protein interaction as a pattern recognition signal, but also read the ΔR/ΔG/ΔB values of the photos taken in the UV dark box on a smartphone-based platform, which converted the chromaticity information into intuitive data. Five studied amyloid fibrils, i.e. insulin, lysozyme, bovine serum albumin, amyloid-β 42 and α-synuclein fibrils, were properly distinguished with data processing assisted by machine learning algorithms, i.e. linear discriminant analysis, principal component analysis and hierarchical cluster analysis. After reducing the number of elements by principal component analysis, a simplified array quantified individual amyloid fibrils at 0.05–5 μM and 0.5–10 μM with fluorescence and fluorescence colorimetric signals, respectively, and successfully identified 25 unknown samples with high accuracy in diluted human plasma matrix and artificial cerebrospinal fluid. The array had good selectivity and sensitivity, providing a simple and inexpensive method for amyloid discrimination.

Self-cleaning of metal-organic framework membranes achieved by photocatalytic ZIFs for dye and antibiotic separation

The progress of membrane-based applications is hindered by widespread membrane fouling, which leads to a significant decrease in separation effectiveness and lifespan, even though membrane separations have shown great potential in the treatment of dye wastewater. The metal-organic framework MOFs (ZIF-8) display strong thermal and chemical stability and an exceptional capacity to degrade organic molecules under visible light, making them extremely promising for the development of self-cleaning membranes. In this investigation, a ZIF-8/L-DOPA/PVDF mixed matrix membrane with excellent self-cleaning properties was constructed using the in-situ growth technique. The characterization results confirmed the formation of a continuous ZIF-8 coating layer, considerably increasing the surface roughness of the composite membrane from 22.9 nm to 76.3 nm compared to L-DOPA/PVDF substrates. The ZIF-8 layer deposited on the L-DOPA/PVDF membrane surface reduced the contact angle from 75.71° to 40.94°. The highest-performing ZIF-8/L-DOPA/PVDF membranes show a higher water permeability of 159.63 (L·m−2 h−1 bar−1) and superior dye rejection rates (Congo red: 97.3 %, Methylene Blue: 98.32 %, Methyl Blue: 98.62 %), along with enhanced removal of antibiotics (e.g., Tetracycline: 95.3 % and Ciprofloxacin: 93.34 %), and long-term nanofiltration stability. Furthermore, the treated membrane recovers almost all of its initial separation efficacy after exposure to visible light due to the successful removal of attached dyes from the membrane surface through photocatalysis. This work presents the potential to fabricate membranes with advantageous photocatalytic properties and effectively treat dye wastewater using self-cleaning membranes.

A facile synthesis of bimetallic Ni/Co-BTC hollow MOFs for effective removal of congo red

ABSTRACT In this work, we employ an eco-friendly and highly efficient method for the successful removal of anionic azo dye (CR) using emerging Ni/Co-BTC hollow Metal-Organic Frameworks (MOFs). The MOFs was developed via a solvothermal synthesis method. Various kinetic models, adsorption capacities, isotherms (Langmuir and Freundlich), and thermodynamic stability assessments were used to predict the adsorption mechanism and the types of interactions present between CR dyes and Hollow MOFs. Our findings suggest that the adsorption process follows Freundlich isotherm, with PSO kinetic models indicating chemisorption and a maximum Langmuir adsorption capacity of 168.03 mgg−1. We observed a removal efficiency of 74% in neutral medium and 85% in acidic medium. Thermodynamic studies reveal the spontaneity of the process with endothermic enthalpy, attributed to the hydrogen bonding and electrostatic interactions between the dye molecule and the adsorbent. Furthermore, to investigate practical applicability, we conducted studies in real water and dye mixtures. All studies demonstrated that the prepared Ni/Co-BTC hollow MOFs show promising potential adsorbents for the CR dye removal from the wastewater, owing to their high efficiency and reusability.

The use of artificial neural network for modelling adsorption of Congo red onto activated hazelnut shell.

Activated hazelnut shell (HSAC), an organic waste, was utilized for the adsorptive removal of Congo red (CR) dye from aqueous solutions, and a modelling study was conducted using artificial neural networks (ANNs). The structure and characteristic functional groups of the material were examined by the FTIR method. The BET surface area of the synthesized material, named HSAC, was 812 m2/g. Conducted in a batch system, the adsorption experiments resulted in a notable removal efficiency of 87% under optimal conditions. The kinetic data for hazelnut shell activated carbon (HSAC) removal of CR were most accurately represented by the pseudo-second-order kinetic model (R2 = 0.998). Furthermore, the equilibrium data demonstrated a strong agreement with the Freundlich model. The maximum adsorption capacity of HSAC for CR was determined to be 34.8 mg/g. The optimum adsorption parameters were determined to be pH 6, contact time of 60 min, 10 g/L of HSAC, and a concentration of 400 mg/L for CR. Considering the various experimental parameters influencing CR adsorption, an artificial neural network (ANN) model was constructed. The analysis of the ANN model revealed a correlation of 98%, indicating that the output parameter could be reliably predicted. Thus, it was concluded that ANN could be employed for the removal of CR from water using HSAC.

Adsorption properties of cellulose-derived hydrogel and magnetic hydrogels from Sophora flavescens on Cu2+ and Congo red

This study synthesized a robust, magnetically responsive hydrogel from Sophora flavescens-modified cellulose and chitosan, employing Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA and DTG), and scanning electron microscopy (SEM) to confirm the preservation of cellulose's intrinsic properties and the hydrogel's remarkable elasticity, toughness, and porosity. These hydrogels integrate cellulose's structural backbone with functional moieties from chitosan, enhancing adsorption capabilities for Cu2+ ions and Congo red (CR) dye. Kinetic and thermodynamic analyses reveal that adsorption is spontaneous and endothermic, following a pseudo-second-order model and the Freundlich isotherm. Notably, Cu2+ adsorption capacity increases with pH, while CR adsorption initially decreases before rising, demonstrating the hydrogels' potential as effective, sustainable adsorbents for removing pollutants from water.

Optimization of anionic dye removal using cross-linked chitosan composite as eco-friendly bio-adsorbent

The environmental impact of wastewater discharged from the textile dyeing industry has a significant challenge and influence on aquatic ecosystems and human health if not properly managed. This study aimed to develop a novel cross-linked chitosan composite, denoted as chitosan/fly ash/polyvinyl alcohol (Ch/FA/PVA), as a bio-adsorbent for removing Congo Red (CR) textile dye from industrial wastewater. The synthesis involved the incorporation of FA into the chitosan matrix at various ratios to optimize the process. A specifically tailored composite, Ch/FA0.75/PVA, exhibited superior performance with a remarkable 99.7% CR removal under optimum conditions: adsorbent dose (0.9 g/l), contact time (50 min), and dye concentration (40 mg/l). The characterization of Ch/FA0.75/PVA through SEM–EDX, BET, FTIR, and pHzpc confirmed its suitability for adsorption. Employing Box–Behnken design and analysis of variance (ANOVA) facilitated the optimization of key adsorption variables. The Freundlich model described the adsorption equilibrium, indicating a maximum adsorption capacity of 263.15 mg/g for CR dye. The pseudo-second-order model demonstrated favorable kinetics. The study was scaled up to the practical application of Ch/FA0.75/PVA in a pilot plant for industrial wastewater treatment, revealing substantial removal percentages for dye, color, COD, BOD5 and TDS. This comprehensive approach highlights the promising efficacy of Ch/FA0.75/PVA in addressing environmental concerns associated with textile dye wastewater.

Food Additive Mediated Biosynthesis of AgNPs with Antimicrobial Activity Against Hypermucoviscous Enterotoxigenic Foodborne Klebsiella pneumoniae

This study was aimed to adopt an ecofriendly method to synthesize nanoparticles with an effective antibacterial and anti-biofilm activity. A food origin hypermucoviscous Klebsiella pneumoniae was isolated from food samples and identified using biochemical tests and the Vitek system. A string test was depended on to identify hypermucoviscous isolates. Enterotoxicity of foodborne hypermucoviscous K. pneumoniae isolates was detected phenotypically using suckling mouse bioassay. Biofilm forming ability was tested for all the isolated bacteria using the Microtiter plate method and Congo Red Agar. A natural food additive Syzygium aromaticum (clove) aqueous extract was used for the biosynthesis of silver nanoparticles in optimized conditions. The biosynthesized clove-silver nanoparticles (Clove-AgNps) were characterized by several techniques, and their antimicrobial and antibiofilm activity was determined. The results of this study revealed that the isolation of 28 K. pneumoniae isolates were isolated from 200 food samples. String test results showed that 16/28 (57.14%) K. pneumoniae isolates were hypermucoviscous. Eleven of these isolates (68.75%) were enterotoxigenic. Using clove aqueous extract as a biological agent was successful in the biosynthesis of AgNPs with an average diameter of 14.12 nm as measured by AFM. The optimum biosynthesis conditions were: 1mM of AgNO3 concentration, pH 7, at 37 °C, and 24 hours. The minimum inhibitory concentration of the clove-AgNPs was detected as 62.5 µg.mL-1. Sub-inhibitory concentration of 31.25 µg.mL-1 of Clove-AgNPs resulted in: 91% decrease in the formed biofilm. It can be concluded that using Syzygium aromaticum is an effective ecofriendly method for AgNPs biosynthesis with excellent antibacterial and anti-biofilm activity against enterotoxigenic hypermucoviscous K. pneumoniae.

Simultaneous removal of Ni2+ and Congo red from wastewater by crystalline nanocellulose - Modified coal bionanocomposites: Continuous adsorption study with mathematical modeling

Due to ultra-fast technological improvement and rapid urbanization nowadays, industries have generated a huge amount of wastewater that is discharged directly into the environment. Resulting in harsh damage to ecology and public safety/security by contaminating the ground/surface water sources. Therefore, it is very crucial to purify this wastewater before discharging/reusing. This study will be devoted to the latest enhancements along with the new route of production of the multifunctional Crystalline Nanocellulose-Modified Bituminous Coal (CNC-MC) bionanocomposites. Besides these, the significant implementation of the fabricated CNC-MC bionanosorbents for the simultaneous removal of Ni2+ and Congo red (CR) from bulk-scale industrial wastewater has been stated. Conversely, influential parameters like inlet concentration (25–45 ppm), flow rate (3–5 mL/min), and adsorbent bed height (0.2–0.8 cm) were explored. The bionanosorbents were characterized by using some state-of-the-art equipment such as FTIR-ATR, XRD, BET, FESEM, and TGA analysis, while the water samples were analyzed by AAS and UV-NIR techniques. Results suggested that the fabricated CNC-MC bionanocomposites possessed a considerable amount of active binding sites/functional groups, showed high thermal stability up to 700°C, and had a high crystallinity index (around 92.41 ± 0.009%). They revealed a noteworthy honeycomb-like mesoporous microstructure with a significant specific surface area. Due to these outstanding features, this multifunctional bionanosorbents has exhibited sensational adsorption performance. Meanwhile, the maximum removal efficiency and percentage were observed at approximately 328.7 and 478.3 mg/g, as well as around 67.95 and 76.65% for Ni2+ and CR. The experimental data was evaluated by three well-known column models, namely the Thomas, Adam-Bohart, and Yoon-Nelson models, and respectable agreement was found. That is similarly appropriate for the justification of the experimental breakthrough curve by supporting the Langmuir isotherm and 2nd-order reversible reaction kinetics. Hence, this novel CNC-MC bionanosorbent could be beneficially used to purify industrial wastewater in an economical and eco-friendly way for sustainable environmental safety.

Cross-linked g-C3N4 nanofibers enable thermal stable composite membranes for high-performance loose nanofiltration

Loose nanofiltration (LNF) membranes show applications in various fields such as the separation of dyes and salts. The development of LNF membranes with high permeability and high dye/salt selectivity has received great attention in recent years. In this study, inorganic graphitic carbon nitride (g-C3N4) nanofibers modified with polyethyleneimine (PEI) were cross-linked by glutaraldehyde to fabricate a novel LNF membrane on polyethersulfone (PES) microfiltration membrane. Owing to the great hydrophilicity, electro-positivity, and unique structure, the composite membrane exhibits excellent Congo red (CR)/NaCl selectivity of 301.8 with water permeance as high as 162.7 L m−2 h−1 bar−1. Moreover, the cross-linked inorganic separation layer enables the membranes with excellent alkali and temperature resistance. After being immersed in an acidic solution (pH = 1) or an alkaline solution (pH = 13) for 48 h, the rejection to CR does not significantly decrease. Furthermore, the nanofiltration membrane maintains structural stability without obvious decline in CR rejections over the temperature range of 25 ∼ 95 °C, demonstrating the potential in high temperature separation. The present work will open up an avenue for designing and fabricating high-performance nanofiltration membranes.

Efficient preparation of anisotropic cellulose sponge from cotton stalks: An excellent material for separation applications

Water pollution and solid waste resource reuse demand immediate attention and research. Here, we present a method to create anisotropic cellulose sponges from cotton stalk waste. Using the inherent structure of cotton stalks, we selectively remove lignin and hemicellulose via acid and alkali pretreatment. This process yields cellulose sponges with a natural pore structure. Our findings demonstrate that these sponges retain the original pore configuration of cotton stalks, providing excellent connectivity and compressibility due to their unique anisotropic three-dimensional structure. Moreover, these sponges exhibit exceptional super-hydrophilic and underwater super-oleophobic properties, with underwater oil contact angles exceeding 150° for all tested oils. External pressure can reduce the pore size of the cellulose sponge, facilitating the gravity-driven separation and removal of dyes and emulsions. Remarkably, removal efficiencies for Methylene Blue (MB), Congo Red (CR), water-in-oil (w/o) emulsions, and oil-in-water (o/w) emulsions exceed 99 %, 97 %, 99 %, and 99 %, respectively, highlighting superior removal and recyclability. Further investigation into the mechanisms of dye and emulsion removal employs X-ray photoelectron spectroscopy (XPS) characterization and molecular dynamics (MD) simulation. These insights lay the groundwork for the efficient recycling and resource utilization of waste cotton stalks, offering promising applications in water purification.

Congophilic fibrils in the glomeruli with polyclonal immunoglobulin gamma staining - another cause for diagnostic overlap: A case report

BACKGROUND Glomerulopathy with fibrillary deposits is not uncommon in routine nephropathology practice, with amyloidosis and fibrillary glomerulonephritis being the two most frequently encountered entities. Renal amyloid heavy and light chain (AHL) is relatively uncommon and its biopsy diagnosis is usually limited to cases that show strong equivalent staining for a single immunoglobulin (Ig) heavy chain and a single light chain, further supported by mass spectrometry (MS) and serum studies for monoclonal protein. But polyclonal light chain staining can pose a challenge. CASE SUMMARY Herein we present a challenging case of renal AHL with polyclonal and polytypic Ig gamma (IgG) staining pattern by immunofluorescence. The patient is a 62-year-old Caucasian male who presented to an outside institution with a serum creatinine of up to 8.1 mg/dL and nephrotic range proteinuria. Despite the finding of a polyclonal and polytypic staining pattern on immunofluorescence, ultrastructural study of the renal biopsy demonstrated the presence of fibrils with a mean diameter of 10 nm. Congo red was positive while DNAJB9 was negative. MS suggested a diagnosis of amyloid AHL type with IgG and lambda, but kappa light chains were also present supporting the immunofluorescence staining results. Serum immunofixation studies demonstrated IgG lambda monoclonal spike. The patient was started on chemotherapy. The chronic renal injury however was quite advanced and he ended up needing dialysis shortly after. CONCLUSION Tissue diagnosis of AHL amyloid can be tricky. Thorough confirmation using other available diagnostic techniques is recommended in such cases.