Search Results (34)

A ceramic–metal composite was synthesized using sol–gel and electrospinning methods to serve as a SERS substrate. The precursors used were tetraethyl orthosilicate, aluminum nitrate, and zirconium, and polyvinylpyrrolidone was added to electrospun nonwoven fibrous membranes. The membranes were sintered, decorated with silver nanoparticles. The enhancement substrates were made of fibers of cylindric morphology with an average diameter of approximately 190 nm, a smooth surface, and 9 nm spherical particles decorating the surface of the fibers. The enhancement capacity of the substrates was tested using pyridine, methyl orange, methylene blue, crystal violet, and Eriochrome black T at different concentrations with Raman spectroscopy to determine whether the size and complexity of the analyte has an impact on the enhancement capacity. Enhancement factors of 2.53 × 10², 3.06 × 10¹, 2.97 × 10³, 4.66 × 10³, and 1.45 × 10³ times were obtained for the signal of pyridine, methyl orange, methylene blue, crystal violet, and Eriochrome black T at concentrations of 1 nM. Full article

This study investigates the catalytic potential of silver nanoparticles (AgNPs) synthesized using aqueous Cymbopogon citratus (lemongrass) extract for the degradation of toxic textile dyes, offering an eco-friendly solution to industrial wastewater treatment. The green-synthesized AgNPs demonstrated remarkable degradation efficiency (>94%) for multiple dyes, such as rhodamine B, methyl red, methyl orange, methylene blue, eosin yellow, and Eriochrome black T, in the presence of sodium borohydride. Optimization studies employing a one-factor-at-a-time approach revealed the critical influence of AgNPs and reductant concentration, temperature, and pH. Kinetic analysis confirmed pseudo-first-order degradation behavior. Reactive species scavenging experiments established that hydroxyl radicals and holes played dominant roles in the degradation mechanism. Notably, the AgNPs retained catalytic activity across eight reuse cycles with negligible performance loss, demonstrating strong potential for repeated application. Comparative analysis with data from the literature highlights the superior performance of C. citratus-derived AgNPs in terms of reaction rate and efficiency. This work underscores the value of plant-extract-mediated AgNPs synthesis not only for its environmental compatibility but also for its catalytic effectiveness. The study advances the practical applicability of green nanotechnology in wastewater remediation and supports its integration into sustainable industrial practices. Full article

Precise separation and antifouling capabilities are critical for the application of membrane separation technology. In this work, we developed a multiplayer layer-by-layer assembly strategy to sequentially deposit tannic acid (TA) and lysozyme (Lys) onto polyethersulfone/iron (PES/Fe) ultrafiltration membrane substrates, enabling the simple and efficient fabrication of a biofouling-resistant loose nanofiltration (LNF) membrane with superior dye/salt separation performance. This approach fully leverages the multifunctionality of TA by exploiting its coordination with Fe³⁺ and non-covalent interactions with Lys. The obtained PES/Fe-TA-Lys LNF membrane exhibits a pure water flux of 57.5 L·m⁻²·h⁻¹, along with exceptional dye rejection rates (98.3% for Congo Red (CR), 99.2% for Methyl Blue (MB), 98.4% for Eriochrome Black T (EBT), and 67.6% for Acid Orange 74 (AO74)) while maintaining minimal salt retention (8.2% for Na₂SO₄, 4.3% for MgSO₄, 3.5% for NaCl, and 2.4% for MgCl₂). The PES/Fe-TA-Lys LNF membrane also displays outstanding antifouling performance against bovine serum albumin (BSA), humic acid (HA), and CR, along with strong biofouling resistance against Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) via synergistic anti-adhesion and biofilm inhibiting effects. This work presents a novel and scalable approach to fabricating biofouling-resistant LNF membranes, offering great potential for dye/salt separation in textile wastewater treatment. Full article

The widespread discharge of synthetic dyes such as Eriochrome Black T (EBT) into water bodies poses significant environmental and health concerns due to their toxicity, persistence, and resistance to degradation. In response to this issue, the removal of EBT dye from aqueous solutions using nickel-modified orange peel biochar (MOPB) was investigated in this study at various experimental conditions such as adsorbent dose, pH, concentration of dye, temperature, and contact time. Biochar was prepared from orange peels via pyrolysis, and structural characterization was performed using FTIR, XRD, and SEM to assess morphological changes, pore structure, and functional groups post-modification. MOPB exhibited significantly enhanced adsorption capacity compared to unmodified biochar. Optimal removal (at 0.1 g adsorbent dose, 25 ppm dye concentration, 90 min contact time, 35 °C, and pH 4) resulted in maximum EBT elimination. The equilibrium dataset was evaluated using Langmuir and Freundlich isotherm models. The Langmuir model (R² = 0.99) best described the uptake of EBT dye, which implies that the adsorption of EBT dye onto MOPB was monolayered. The kinetic data were also analyzed using pseudo-first-order and pseudo-second-order models. The pseudo-second-order kinetic model was found to be the best fit (R² = 0.99), indicating that it governs the rate-limiting step of the reaction. Thermodynamic parameters confirmed that the adsorption process is spontaneous and exothermic. These findings demonstrate the potential of MOPB as a low-cost, sustainable adsorbent for the efficient removal of EBT from industrial wastewater. Full article

The contamination of water bodies with toxic compounds from the agricultural, industrial, and domestic sectors is a serious environmental problem. Adsorption is one of the simplest, most functional, and economical methods for treating large volumes of water and removing its contaminant load. Thanks to its nanoporous structure, versatility, chemical inertness, and low-cost synthesis, anodic aluminum oxide (AAO) can be used as an adsorbent in a wide range of applications. In this work, nanostructured AAO coatings were successfully synthesized, and their performance as adsorbents was evaluated in decolorization tests of Eriochrome Black T (EBT) solutions. The adsorption process was found to be dependent on the initial dye concentration, agitation, temperature, and contact time. At 25 °C and 16 mg·L⁻¹ initial EBT concentration, a maximum removal efficiency (%R) of 78% was obtained after 4.5 h at 500 rpm and after 5.5 h at 100 rpm, while without agitation, after 8.3 h of treatment, the highest %R was 40%. Furthermore, the adsorption rate increased significantly with temperature, reaching a %R of 99% after 2.25 h at 60 °C and 500 rpm. Additionally, it was demonstrated that the adsorbent can be used up to four times with a removal efficiency greater than 50%. Full article

Cement-based foam composites have gained attention as innovative and high-performing adsorbents for wastewater treatment due to their lightweight, porous, and structurally robust properties. This study investigates the adsorption of Eriochrome Black T dye onto biochar-modified cement foam, providing a cost-effective solution for industrial wastewater management. The integration of biochar into cement foam enhances its surface area and adsorption capabilities while maintaining structural stability and tunable porosity. The composites were characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy to verify quality and functionality. The adsorption process adhered to the Freundlich isotherm model (R² = 0.967), indicating multilayer adsorption, with a maximum capacity of 13.33 mg/g under optimal conditions. Kinetic studies showed a pseudo-first-order fit (R² = 0.981), while thermodynamic analysis revealed a spontaneous and endothermic process, with ΔH° = 28.84 KJ/mol and ΔG° values ranging from −0.457 to −2.36 KJ/mol. These results demonstrate the composite’s exceptional efficiency and scalability, making it a sustainable and practical option for removing persistent dyes such as Eriochrome Black T. This work contributes significantly to the advancement of environmentally friendly wastewater treatment technologies. Full article

Platanus officinalis fibers (PFs) taking advantage of high-availability, eco-friendly and low-cost characteristics have attracted significant focus in the field of biomaterial application. Polyethyleneimine grafted with polydopamine on magnetic Platanus officinalis fibers (PEI-PDA@M-PFs) were prepared through a two-step process of mussel inspiration and the Michael addition reaction, which can work as an effective multifunctional biomass adsorbent for anionic dye with outstanding separation capacity and efficiency. The as-prepared PEI-PDA@M-PFs possess desirable hydrophilicity, magnetism and positive charge, along with abundant amino functional groups on the surface, facilitating efficient adsorption and the removal of Eriochrome Black T (EBT) dyes from water. In addition to the formation mechanism, the adsorption properties, including adsorption isotherms, kinetics, and the reusability of the absorbent, were studied intensively. The as-prepared PEI-PDA@M-PFs achieved a theoretical maximum adsorption capacity of 166.11 mg/g under optimal conditions (pH 7.0), with 10 mg of the adsorbent introduced into the EBT solution. The pseudo-second-order kinetic and Langmuir models were well matched with experimental data. Moreover, thermodynamic data ΔH > 0 revealed homogeneous chemical adsorption with a heat-absorption reaction. The adsorbent remained at high stability and recyclability even after five cycles of EBT adsorption processes. These above findings provide new insights into the adsorption processes and the development of biologic material for sustainable applications. Full article

Herein, we synthesized Ti-MOF through a solvothermal method and subsequently calcined it to form anatase TiO₂. We further developed a Bi₂O₃@TiO₂ mixed oxide using impregnation and calcination processes. These oxides showed significant photocatalytic activity for degrading Eriochrome Black T (EBT) dye under visible light irradiation. We characterized the prepared samples using various techniques, including XRD, XPS, FTIR, BET, SEM, EDX, TEM, and UV-DRS analyses. Our results indicated that TiO₂ and 10%Bi₂O₃@TiO₂ achieved 80% and 100% degradation of EBT dye solution (50 ppm) within 30 min in acidic medium with a 50 mg catalyst dose, respectively. The calcination of the Ti-MOF into TiO₂ improved its sensitivity to visible light. The Bi₂O₃@TiO₂ composite was also effective in degrading other organic pollutants, such as Congo Red (degradation ~99%), Malachite Green (degradation ~95%), Methylene Blue (degradation ~81%), and Safranine O (degradation ~69%). The impregnation of Bi₂O₃ increased the surface acidity of TiO₂, enhancing its photocatalytic activity by promoting hydroxyl group formation through increased water adsorption. Additionally, 10%Bi₂O₃@TiO₂ demonstrated excellent chemical stability and reusability, maintaining high degradation efficiency over four cycles. Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) calculations were performed to understand the degradation mechanisms. UV-Vis absorption spectrum simulations suggested that the anionic HEB⁻² (O24) or EB⁻³ forms of the EBT dye are likely to undergo degradation. This study highlights the potential of Bi₂O₃@TiO₂ composites for effective photocatalytic applications in environmental remediation. Full article

In this study, methylene blue (MB) and eriochrome black T (EBT) dyes were removed with the waste Pinus nigra Arn. powders from Anatolian black pinecone (PC-PnA) within the framework of sustainability. UV–Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray (EDX), fourier transform infrared spectroscopy (FTIR), thermogravimetry–differential thermal analysis (TGA-DTA), Brunauer–Emmett–Teller (BET) surface area, and point of zero charge (pH_pzc) analyses were performed for the characterization of PC-PnAs. The effects of pH, amount of adsorbent, time, initial concentration and temperature were determined by batch adsorption experiments. Four kinetic and isotherm models were examined, and error function tests were used for the most suitable model. According to this, the average pore diameters, mass losses at 103.9 and 721.6 °C and pH_pzc values of PC-PnAs were found as 61.661 Å, 5.9%, 30%, and 5.77, respectively. Additionally, the most suitable kinetic and isotherm models for the removal of both dyes were Langmuir and pseudo-second-order. The maximum removal efficiencies (q_max) for MB and EBT dyes was calculated as 91.46 and 15.85 mg/g, respectively and the adsorption process was found to be endothermic. As a result, PC-PnA particles can be used as an alternative sorbent for the removal of MB and EBT dyes. Full article

Eriochrome black T is considered as one of the anionic dyes with potential harmful effects on human health and the environment. Among other processes, adsorption can contribute to the removal of these dyes. In the present study, two adsorbent materials, pseudo-boehmite (γ-AlOOH) and gamma alumina (γ-Al₂O₃), were synthesized and tested in the removal of the Eriochrome black T molecule (EBT). γ-AlOOH and γ-Al₂O₃ were obtained by precipitation from NaAlO₂ solution at pH = 7, at a temperature of 80 °C, and by the thermal transformation of γ-AlOOH at 800 °C, respectively. In order to gain insights into the structural, chemical, thermal and morphological properties of these materials, numerous analytical techniques were involved, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), differential thermogravimetric–thermal analysis (TGA-DTA), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and specific surface area measurement using the Brunauer–Emmett–Teller (BET) method. Several adsorption parameters were studied, such as the adsorbent dose, initial concentration, pH, contact time and reaction temperature. The kinetic study showed that EBT adsorption follows the pseudo-second-order model. The Langmuir isotherm model revealed a maximum EBT adsorption capacity of 344.44 mg g⁻¹ and 421.94 mg g⁻¹ for γ-AlOOH and γ-Al₂O₃, respectively. A textural and structural analysis after adsorption highlighted the effective adsorption of the dye. Full article

Molecularly imprinted polymers (MIPs) have garnered significant attention as a promising material for engineering specific biological receptors with superior chemical complementarity to target molecules. In this study, we present an electrochemical biosensing platform incorporating MIP films for the selective detection of the interleukin-1β (IL-1β) biomarker, particularly suitable for mobile point-of-care testing (POCT) applications. The IL-1β-imprinted biosensors were composed of poly(eriochrome black T (EBT)), including an interlayer of poly(3,4-ethylene dioxythiophene) and a 4-aminothiophenol monolayer, which were electrochemically polymerized simultaneously with template proteins (i.e., IL-1β) on custom flexible screen-printed carbon electrodes (SPCEs). The architecture of the MIP films was designed to enhance the sensor sensitivity and signal stability. This approach involved a straightforward sequential-electropolymerization process and extraction for leaving behind cavities (i.e., rebinding sites), resulting in the efficient production of MIP-based biosensors capable of molecular recognition for selective IL-1β detection. The electrochemical behaviors were comprehensively investigated using cyclic voltammograms and electrochemical impedance spectroscopy responses to assess the imprinting effect on the MIP films formed on the SPCEs. In line with the current trend in in vitro diagnostic medical devices, our simple and effective MIP-based analytical system integrated with mobile POCT devices offers a promising route to the rapid detection of biomarkers, with particular potential for periodontitis screening. Full article

Recently, there has been an active search for new modifiers to create hybrid polymeric materials for various applications, in particular, membrane technology. One of the topical modifiers is metal-organic frameworks (MOFs), which can significantly alter the characteristics of obtained mixed matrix membranes (MMMs). In this work, new holmium-based MOFs (Ho-MOFs) were synthesized for polyether block amide (PEBA) modification to develop novel MMMs with improved properties. The study of Ho-MOFs, polymers and membranes was carried out by methods of X-ray phase analysis, scanning electron and atomic force microscopies, Fourier transform infrared spectroscopy, low-temperature nitrogen adsorption, dynamic and kinematic viscosity, static and dynamic light scattering, gel permeation chromatography, thermogravimetric analysis and contact angle measurements. Synthesized Ho-MOFs had different X-ray structures, particle forms and sizes depending on the ligand used. To study the effect of Ho-MOF modifier on membrane transport properties, PEBA/Ho-MOFs membrane retention capacity was evaluated in vacuum fourth-stage filtration for dye removal (Congo Red, Fuchsin, Glycine thymol blue, Methylene blue, Eriochrome Black T). Modified membranes demonstrated improved flux and rejection coefficients for dyes containing amino groups: Congo Red, Fuchsin (PEBA/Ho-1,3,5-H₃btc membrane possessed optimal properties: 81% and 68% rejection coefficients for Congo Red and Fuchsin filtration, respectively, and 0.7 L/(m²s) flux). Full article

In order to remove and reuse the ecotoxic dye Eriochrome black T (EBT) from dyeing wastewater, we used a process called cetyltrimethylammonium bromide (CTAB)-assisted foam fractionation. By optimizing this process with response surface methodology, we achieved an enrichment ratio of 110.3 ± 3.8 and a recovery rate of 99.1 ± 0.3%. Next, we prepared composite particles by adding β-cyclodextrin (β-CD) to the foamate obtained through foam fractionation. These particles had an average diameter of 80.9 μm, an irregular shape, and a specific surface area of 0.15 m²/g. Using these β-CD-CTAB-EBT particles, we were able to effectively remove trace amounts of Cu²⁺ ions (4 mg/L) from the wastewater. The adsorption of these ions followed pseudo-second-order kinetics and Langmuir isotherm models, and the maximal adsorption capacities at different temperatures were 141.4 mg/g at 298.15 K, 143.1 mg/g at 308.15 K, and 144.5 mg/g at 318.15 K. Thermodynamic analysis showed that the mechanism of Cu²⁺ removal via β-CD-CTAB-EBT was spontaneous and endothermic physisorption. Under the optimized conditions, we achieved a removal ratio of 95.3 ± 3.0% for Cu²⁺ ions, and the adsorption capacity remained at 78.3% after four reuse cycles. Overall, these results demonstrate the potential of β-CD-CTAB-EBT particles for the recovery and reuse of EBT in dyeing wastewater. Full article

A batch system was applied to study the adsorption of three dyes (methyl violet, eriochrom black T and helianthin) from aqueous solution onto β-cyclodextrin polymer, synthesized by using citric acid as a cross linking agent. This polymer lets to adsorb only methyl violet for this effect, several operator variables was checked only with this kind of dye, the removal efficiently increases with increase in adsorbent amount; elevation of temperature lets also to improve the dye adsorption; ionic strength has not effect on dye adsorption process, for the pH we have remarked a slight decrease in removal efficiently with increasing of pH values. Equilibrium study was investigated by applying three models (Langumir, Frendlich and Temkin), results show that Langumir isotherm is the appropriate model. FTIR spectra show the complex inclusion formation which dominates the adsorption mechanism, confirmed by the absence of characteristic peaks of methyl violet in ß-cyclodextrin after adsorption. Full article

Pressure-based membrane processes represent excellent water resource recovery prospects from industrial waste streams. In contrast with conventional pretreatment technologies, studies have shown that membrane pretreatment applications, such as microfiltration (MF), are more cost-effective and improve the results of the overall treatment processes. Hence, enhancing rejection efficiency of MF will enhance the performance of any downstream treatment processes. In this study, 0.45 µm cellulose acetate (CA) microfiltration membranes were modified by vacuum filtration-assisted layer-by-layer deposition of bilayers composed of negatively charged graphene oxide (GO) and positively charged polyethyleneimine (PEI). The performance of 1-, 2-, and 4-bilayer GO–PEI-modified membranes were investigated for their dye-rejection of anionic eriochrome black T (EBT) dye and cationic methylene blue (MB) dye in a cross-flow membrane module. As the number of bilayers on the membrane increased, the membrane thicknesses increased, and the deionized (DI) water flux through the membranes decreased from 4877 LMH/bar for the control (no bilayer) membrane to 2890 LMH/bar for the 4-bilayer membrane. Conversely, the dye-rejection performance of the modified membranes increased as increasing bilayers of GO–PEI deposited on the membranes. The anionic EBT dye saw superior rejection (~90% rejection) compared to the cationic MB dye (~80% rejection), which can be attributable to the electrostatic repulsion between the negatively charged GO surface and anionic EBT dye. After 50% recovery of the saline and dye-laden feed water, there was an observed drop in DI water fluxes of ~40–41% and 36%, respectively. There was also a slight increase in EBT dye-rejection during the composite feed-water experiments, attributed to the precipitation of salts on the membrane feed side or pore spaces, which subsequently reduce the membrane pore sizes. Full article