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Considering the carcinogenic and mutagenic properties of azo anionic dyes on the environment and human health, the development of efficient adsorbents for the removal of these water pollutants is very important. Therefore, the main aim of this research is to develop cost-effective and efficient melamine-formaldehyde (MF) microspheres for the removal of anionic dyes from wastewater. MF nanocomposite (MF-NGQD) microspheres were prepared using varying amounts of N-doped graphene quantum dots (NGQDs) through a simple polycondensation method. According to the SEM images, the MF-NGQD microspheres contain up to 10 wt% monodisperse, with an average diameter of 427 nm, which is smaller than the MF microspheres with a diameter of ⁓2.1 μm. The measurement of zeta potential (ZP) as a function of solution pH showed that the amount of ZP is significantly affected not only by the pH of the solution but also by the content of NGQDs in the microspheres. BET results revealed higher surface area and larger pore volume of nanocomposite microspheres (11.40 m2 g−1 and 0.030 cm3 g−1) compared to MF microspheres (5.40 cm3 g−1 and 0.017 cm3 g−1). Batch adsorption experiments were carried out to investigate the adsorption properties of microspheres on Congo Red (CR). The results indicated that MF-NGQD microspheres with an amount of 0.05 g/25 mL were able to remove CR up to 97% at pH 6.0 with C0 of 50 mg L−1 in 45 min with an adsorption capacity of 91.74 mg g−1. Adsorption processes were further analyzed through isotherm and kinetic studies, which showed a better fit with the Freundlich model and pseudo-second-order model, respectively. In conclusion, our finding demonstrates that MF-NGQD-10 microspheres are highly effective adsorbents for the removal of anionic dyes such as Congo Red from textile effluents, offering a promising solution for wastewater treatment. Future studies should explore the scalability and real-world application of these microspheres. [ABSTRACT FROM AUTHOR]

AbstractIn this work, the biowaste of Musa paradisiaca (Banana) was used for removing contaminants from water by adsorption on a batch scale using Congo red (CR) dye as a test case. Although banana peel adsorbents have been the subject of much research for a range of applications, including the removal of colors from wastewater, our study differs from others in that we treated the banana peel adsorbent with hydrogen peroxide (H2O2), which significantly enhanced its performance when compared to untreated banana peel powder. By eliminating organic contaminants, discoloring the sample, inhibiting the growth of bacteria or fungi, and raising the quantity of active sites accessible for dye adsorption, the H2O2 treatment increases efficiency. The results indicated that optimal conditions for CR dye removal with physio-chemically processed Musa paradisiaca biowaste were: pH 3, adsorbent dose 0.4 g, temperature 30 °C, and contact time 25 min. Equilibrium data were evaluated with isothermal and kinetic models, indicating that the data followed second-order kinetics with a correlation coefficient of R2 = 0.995 with a maximum dye removal of 8.577 mg/g. Furthermore, the study found that CR dye removal was physiochemical and exothermic process, as confirmed by the experimental data, with a ΔGo of −6.992 kJ/mol. The results of this study suggest that this fabricated material of Musa paradisiaca biowaste could be a potential alternative for large-scale Congo red dye elimination from industrial effluents. This is both a sustainable and cost-effective solution. [ABSTRACT FROM AUTHOR]

An effective and easily regenerated adsorbent is the one for which scientists are making an effort to explore. In this study, copper oxide nanoparticles (CuO NPs) were synthesized in a green manner from a leaf extract of Moringa stenopetala and used for dye adsorption. XRD, FTIR, and SEM were employed for the characterization of CuO NPs. The crystallite size of the CuO NPs was calculated via Debye–Scherrer equation from the XRD data and was found to be 8.33 nm. The Cu–O bonding bending vibration at 1116 cm− 1 and stretching vibration at 1649 cm− 1 observed from the FTIR data strongly confirmed the formation of CuO NPs. SEM morphology analysis confirmed the formation of nanoparticles with a plate-like morphology and a spherically random orientation. The zero-point charge of CuO NPs was investigated and reported to be at pH 7. The adsorption of dyes on the greenly produced CuO NPs was studied by optimizing different adsorption parameters. The removal efficiencies of the green CuO NPs adsorbent were 99.54% at the optimum conditions (pH, 4; dye concentration, 30 mg/L; amount of adsorbent, 0.25 g; and contact time, 80 min) and 98.33% at the optimum conditions (pH, 11; dye concentration, 20 mg/L; amount of adsorbent, 0.4 g; and contact time, 80 min) for congo red and malachite green, respectively. The adsorption efficiency of the biosynthesized CuO NPs for the mixture of the two dyes was 92.3%. The green synthesized adsorbent was regenerated and able to work effectively for four cycles for the two dyes. The results of the kinetics-type investigation indicate that the adsorption of both dyes by the CuO NPs adsorbent best fits a pseudo-second-order model. The isotherm model-type investigation resulted in the fitting of the Langmuir adsorption isotherm for both the congo red and malachite green dyes. [ABSTRACT FROM AUTHOR]

Treating dye-containing wastewater poses numerous challenges due to its high chemical complexity and its persistent nature. Thus, the present study aims to synthesize biochar derived from banana peel (BC) and its nanocomposites with copper oxide nanoparticles (CuOx/BC1-x) for the purpose of adsorptive removing Congo red (CR) dye from water. Several analytical methods were utilized to describe the physicochemical features of the CuOx/BC1-x nanocomposites. It was found that the crystallinity of the nanocomposites gradually improved, while the specific surface area and the surface electronegativity were reduced with increasing x value. The effects of x values (0–0.5), interaction time (10–120 min), adsorbent dose (0.01–0.05 g), initial CR concentration (20–200 mg/L), and the solution temperature (20–60 °C) were evaluated on CR removal. The obtained results revealed that the CuO0.5/BC0.5 nanocomposite showed the highest adsorption efficiency with a maximum adsorption capacity of 233.6 mgg−1. Analysis of the equilibrium experimental data revealed that the Langmuir and the pseudo-2nd-order models were the most proper to describe the current adsorption process. Moreover, the thermodynamics studies demonstrated that the adsorption process was spontaneous, endothermic, and random. [ABSTRACT FROM AUTHOR]

In this study, it was aimed to remove Congo Red (CR) dye in aqueous solution by biosynthesized Selenium Nanoparticles from Prunus armeniaca L. (PAL‐SeNPs) leaf wastes by green synthesis method. The characteristic structure of PAL‐SeNPs was determined by UV‐vis spectroscopy, X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscope (SEM), energy dispersive X‐ray (EDX), fourier transform infrared spectroscopy (FTIR), thermogravimetry‐differential thermal analysis (TGA‐DTA), dynamic light scattering (DLS), zetasizer, and point of zero charge (pHpzc). The effects of pH, adsorbent amount, time, initial concentration, and temperature were investigated by batch adsorption studies. 2 different kinetic and 4 isotherm models were tested and error analysis functions were determined for the most suitable model. Accordingly, the particle size, crystallinity, pHpzc value and average surface charge of PAL‐SeNPs were determined as 9.969 nm, 48.50 %, 3.47, and −23.6 mV, respectively. Also, the most suitable kinetic and isotherm models for the removal of CR dye with PAL‐SeNPs were found as Pseudo‐second‐order and Freundlich, with R2 values of 0.996, respectively. Also, where the optimum pH was 7.00, the maximum adsorption capacity was calculated as 96.59 mgCR/gPAL‐SeNPs. The results obtained show that environmentally friendly and low‐cost PAL‐SeNPs produced by the green synthesis method are a suitable alternative for the removal of CR dye. [ABSTRACT FROM AUTHOR]

The utilization of electroplating sludge (ES) to derive metal oxide functional materials is a key strategy, as it enables the recycling of valuable elements, mitigates environmental risks, and aligns with green, low-carbon development strategies. Nevertheless, the development of metal oxide composite functional materials with distinctive structures and properties derived from ES continues to present several challenges. Herein, we synthesized CuFe2O4/MgFe2O4 metal oxide composites from ES by one-step hydrothermal method. As-obtained CuFe2O4/MgFe2O4 metal oxide composites (MMOs) have a unique layered structure, richer mesoporous and microporous structures, activity sites. When evaluated as an adsorbent for Congo red (CR), as-synthesized CuFe2O4/MgFe2O4 with layered structure composite exhibited excellent adsorption capacity (1039.1 mg/g) and reusability (85.55% after five cycles), which was superior to most similar adsorbents reported till date. Such improvement is explored to mainly originate from two respects: the physical adsorption facilitated by the abundant pores formed through the stacking and growth of CuFe2O4 and MgFe2O4, and the chemisorption resulting from surface complexation and hydrogen bonding between the MMOs and CR. This strategy to directly transform ES into functional materials shows great promise both in waste management and preparation of robust adsorbents for wastewater treatment. [ABSTRACT FROM AUTHOR]

A global water crisis is emerging due to increasing levels of contaminated water and decreasing clean water supply on Earth. This study aims to address the removal of azo dye from wastewater to enable its reuse. Recently, utilizing microorganisms has been proven to be a practical choice for the remediation of azo dyes in wastewater. Hence, in this study, we employed a preformed biofilm of Pseudomonas aeruginosa on a solid support (called substrate) to degrade azo dyes. This process offers several advantages, such as stability, substrate portability, more biofilm production in less time, and efficient utilization of enzymes for remediation. From 50 ppm of initial Congo Red concentration, 75.74% decolorization was achieved within ten h using a preformed biofilm on a coverslip. A maximum of 52.27% decolorization was achieved using biofilm during its formation after 72 h of incubation. The Fourier-transform infrared (FTIR) spectroscopic analysis of Congo Red dye before and after remediation revealed a significant change in peak intensity, indicating dye degradation. Phytotoxicity studies performed by seed germination with Vigna radiata revealed that, after 5–7 days, almost 40% more seeds with longer root and shoot lengths were germinated in the presence of treated dye compared to the untreated one. This data indicated that the harmful Congo Red was successfully degraded to a non-toxic product by Pseudomonas aeruginosa biofilm grown on a glass substrate. [ABSTRACT FROM AUTHOR]

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Two polyurethane polyaniline nanocomposites have been synthesized using two in situ polymerization routes of dried and wet bases to valorize the polyurethane waste. The physical and chemical properties of polyurethane-based nanocomposites were compared using SEM, XRD, FTIR, and Zeta potential. SEM images showed that the average particle size of the dried-based composite was 56 nm, while the wet-based composite had an average size of 75 nm. The separation efficiency for methylene blue (MB) and Congo red (CR) dyes was evaluated against free polyurethane foam waste. It was evident that pure polyurethane (PPU) achieved only 4.79% and 16.71% removal for MB and CR, respectively. These dye decontamination efficiencies were enhanced after nano polyaniline decoration of polyurethane foam either through dried base polymerization (DPUP) or wet base polymerization (WPUP). WPUP composite records 11.23% and 85.99% for MB and CR removal, respectively, improved to 26.69% and 90.07% removal using DPUP composite for the respective dyes. The adsorption kinetics, isotherms, and thermodynamics were investigated. The experimental results revealed the pseudo-second-order kinetic model as the most accurately described kinetics model for both CR and MB adsorption. The Langmuir model provided the best fit for the data, with maximum adsorption capacities of 110.98 mg/g for CR and 26.86 mg/g for MB, with corresponding R-squared values of 0.9974 and 0.9608, respectively. Regeneration and reusability studies of PPU, WPUP, and DPUP showed effective reusability, with DPUP displaying the highest adsorption capacity. These results aid in creating eco-friendly and cost-efficient adsorbents for dye removal in environmental sanitation. [ABSTRACT FROM AUTHOR]

In this work, we aimed to demonstrate new polyoxoniobate containing surface peroxo groups obtained after the treatment of niobic acid with hydrogen peroxide and lyophilization process. Raman and diffuse reflectance measurements confirm the presence of peroxo groups in the new polyoxometalate. Isotherms from N2 adsorption/desorption have evidenced a drastic change in specific surface area after treatment with hydrogen peroxide, from 195 m2.g−1 for Nb1 to 4 m2.g−1 for Nb3. Catalytic studies were performed for Congo red (CR) oxidation using H2O2 as oxidizing promoter. The results showed a new material with larger specific area, smaller particle size and an increase in peroxo groups, thus leading to higher catalytic response of discoloration of the Congo red (about 70% for Nb3 and close to 20% for the other catalysts) as compared with the raw material, without previous treatment. [ABSTRACT FROM AUTHOR]

The present study uses Adenanthera pavonina L. plant extract to synthesize Y/Fe2O3 nanoparticles in a sustainable and efficient manner. Several physicochemical investigations were performed on the synthesized Y/Fe2O3 to evaluate its structure and morphological characteristics. The high crystallinity of Fe2O3 and decreased crystal size of Y/Fe2O3 were revealed by the XRD study. The formulated Y/Fe2O3 was spherical in shape. Y/Fe2O3 has shown potential photocatalytic activity in the degradation of congo red and brilliant green dyes in the presence of visible light. Degradation efficiency is higher than 90% for both dyes. In addition, the antibacterial activity of Y/Fe2O3 was measured against pathogenic strains of Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Micrococcus luteus, Proteus mirabilis, Pseudomonas putida, Shigella dysenteriae, and Staphylococcus aureus. Y/Fe2O3 showed promising antibacterial activity against all microorganisms. Micrococcus luteus showed a higher zone of inhibition (equal to 35 mm in diameter) than other microorganisms using Y/Fe2O3. Thus, it is established that the green synthesized Y/Fe2O3 nanoparticles are active catalysts for the photocatalytic degradation of hazardous dyes and have antibacterial properties against different bacterial stains. [ABSTRACT FROM AUTHOR]

[Display omitted] • Red emissive fluorescent amphiphilic carbon dots (CL-9) were designed. • The ternary carbon source was used. • CL-9 exerted turn-on red fluorescence towards α-synuclein fibrils. • CL-9 possessed good anti-photobleaching resistance, biocompatibility and high sensitivity. • CL-9 succeeded in imaging α-synuclein fibrils in vivo. The misfolding and aggregation of α -synuclein monomers usually cause the occurrence and development of Parkinson's disease (PD). It is important to develop effective methods for detection of α -synuclein aggregates. Carbon dots (CDs) could be the potential fluorescence probe for this purpose owing to their appreciated optical properties. However, undefined structure of CDs and complicated three-dimensional structure of protein severely hindered the design of fluorescence probe towards protein aggregates. Herein, a red emissive fluorescent amphiphilic CD, named as CL-9, was designed with a high sensitivity to α -synuclein fibrils by a one-step heating process, using the ternary carbon source, including Congo red, l -tryptophan and urea. The CL-9 exhibited turn-on red emissive fluorescence towards α -synuclein fibril, but remained no change towards its monomer. Compared with the original Congo red dye, CL-9 exhibited stronger turn-on red fluorescence towards α -synuclein fibrils with better anti-photobleaching resistance, biocompatibility and signal-to-noise ratio. The CL-9 was successful as a fluorescent probe to image α -synuclein fibrils in NL-5901 C. elegans. The present study provided a feasible approach using the multiple carbon sources to construct the CDs based fluorescence probe targeting amyloid proteins. [ABSTRACT FROM AUTHOR]

The removal of Congo red (CR) and heavy metal ion nickel (Ni(II)) from wastewater is a critical concern for safeguarding the aquatic environment and promoting sustainable development. Herein, a novel citric acid steam-assisted decomposition method is applied to form meso-macroporous magnesium oxide (MgO) with rich oxygen defects. As the gelation process of xerogel precursor could be significantly promoted by the steam-assisted process with citric acid solution as steam source, the morphology structure of MgO changes into loose aggregates with sharp edges and is covered by a layer of MgO nanoparticles. The synthesized MgO, with a high surface area (103.60 m2 g−1), meso-macroporous structure and abundant oxygen defects, exhibits super adsorption capacities for CR (7109.85 mg g−1) and Ni(II) (1405.88 mg g−1). The MgO (0.4 g L−1) could completely remove CR (200 mg L−1) in 30 min, while 10 min for Ni(II) (200 mg L−1) adsorption. The adsorption mechanism of MgO for CR and Ni(II), including electrostatic interaction, oxygen vacancy capture, hydrogen bonding and ion exchange, is effectively enhanced due to the appearance of meso-macroporous structure and oxide defects, such as 5-coordinated oxygen anion (O 5C 2−) for terrace, 4-coordinated oxygen anion (O 4C 2−) for edge and 3-coordinated oxygen anion (O 3C 2−) for corner. The easy calcination is applied to recycle MgO after CR adsorption and the CR removal efficiencies are above 98 % after five cycles. Meanwhile, a nickel chelator (Na 2 EDTA) and calcination are used to regenerate the MgO after Ni(II) adsorption and the adsorbent shows an insignificant removal efficiency loss after three cycles. The meso-macroporous MgO with rich oxygen defects has the characteristics of high adsorption speed, high adsorption capacity and convenient recovery property, and is expected to become an ideal material for the rapid treatment of high concentration wastewater. [ABSTRACT FROM AUTHOR]

In this study, Trametes trogii‐loaded poly(2‐ hydroxyethyl methacrylate) cryogel (Tt‐PHEMA) was prepared and used as a biosorbent to remove Congo Red (CR), from aqueous solutions. The biomass and Tt‐PHEMA cryogel were characterized with scanning electron microscopy and Fourier Transform infrared spectroscopy. Macroporosity degree (%) and swelling ratio (%) of the Tt‐PHEMA cryogel were determined as 78.3% and 61.04%, respectively. The effect of loaded biomass amount, pH, initial CR concentration, temperature, and contact time were investigated detailedly. The maximum biosorption capacity of Tt‐PHEMA cryogel was 156.71 ± 1.22 mg g−1 at pH 6.0 at 45°C. Biosorption capacity was increased from 125.92 ± 1.524 mg g−1 to 156.71 ± 1.22 mg g−1 with increasing temperature from 25 to 45°C, demonstrating that the biosorption process was endothermic. The biosorption data were well fitted to the Freundlich isotherm and pseudo‐second‐order kinetic models. The negative Gibbs free energy change values showed favorable biosorption. The Tt‐PHEMA cryogel was easily regenerated with ethanol and used repeatedly five times without a significant change in the biosorption capacity. As a result, Trametes trogii‐loaded PHEMA cryogel has an application potential for CR removal from wastewater, taking advantage of interconnected macroporous structure cryogels. [ABSTRACT FROM AUTHOR]

This study used lemon peel and Fe3O4 nanocomposite (LE-Fe3O4) to remove Congo red (CR) from the aqueous solution in batch adsorption techniques. The main factors influencing the adsorption process studied were pH, dose, contact time, and initial concentration. The results have shown the optimum conditions for making LE-Fe3O4 a suitable adsorbent were pH 6, 25 mg/50 mL dose, 90 ppm initial CR concentration, and 30-min contact time. The experimental data best fit with the Langmuir isotherm model with 16.28 mg/g max adsorption capacity and pseudo-second-order kinetic model, which indicates the monolayer chemisorption adsorption process. The properties of the nanocomposite adsorbent were established through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), and Barrett-Joyner-Halenda (BJH). [ABSTRACT FROM AUTHOR]

In this work, two iron oxide nanoparticles are synthesized in an environmentally friendly way using two aqueous extracts of Artemisia herba-alba.(L) and Rosmarinus Officinalis.(L) to be used in the removal of Congo red dye. The synthesized iron oxide NPs are characterized by XRD, ATR-FTIR, SEM, and UV-Vis techniques. The analysis showed the formation of A R M - F e 0.8319 O / F e 3 O 4 and R O S - F e 0.9060 O / F e 3 O 4 phases. This work is founded on the demonstration of the impact of the plant's mediator on the activities of the iron oxide surfaces against Congo red (CR) adsorption. This activity is translated by the investigation of the effect of the density of hydroxyl groups (act as active sites) located on the surface on CR adsorption capacity and yield. For this purpose, the total contents of polyphenols, flavonoids, and condensed tannins in the aqueous extracts of Artemisia herba-alba.(L) and Rosmarinus officinalis.(L) are calculated. Similarly, the densities of hydroxyl groups located on iron oxide surfaces are analyzed by FTIR spectroscopy. The calculated total contents of polyphenols, flavonoids, and condensed tannins of Artemisia herba-alba.(L) and Rosmarinus officinalis.(L) aqueous extracts are found to be, respectively, 310.84 mg ACE/g and 237.94 mg ACE/g dry plant extract (DPE), 209.52 mg AGE/g DPE and 153.75 mg AGE/g DPE, and 853.04 mg CE/g DPE and 666.00 mg CE/g DPE. The obtained results showed that ARM-Fe NPs showed a higher CR adsorption capacity and yield (90.66 mg/g and 72.52%) compared to those of ROS-Fe NPs (77.10 mg/g and 61.68%). The increase in the total contents of polyphenols, flavonoids, and condensed tannins in Artemisia herba-alba.(L) extract leads to an increase in the density of hydroxyl groups located on the surface of ARM-Fe NPs, and hence an increase in their activity against CR adsorption. The linear pseudo-first-order and pseudo-second-order kinetics of CR adsorption and the intra-particle diffusion mechanisms were analyzed. The results obtained indicate that, in CR adsorption processes on ARM-Fe and ROS-Fe surfaces, the kinetics followed a linear pseudo-second-order model, and intra-particles diffusion is the step that governed CR adsorption mechanisms on ARM-Fe and ROS-Fe surfaces in ambient conditions, which is in accord with the pseudo-second-order kinetic model. [ABSTRACT FROM AUTHOR]

This research investigates the synthesis of a hybrid nanomaterial, denoted as Ni‐Zn−S@Cyclodextrine, through a cost‐effective and easy co‐precipitation method. The resulting nanomaterial has been thoroughly characterized and applied for the adsorptive removal of Crystal violet and Congo red dyes from their solutions. The study delves into the thermodynamics and kinetics of the sorption process, as well as helps to propose adsorption mechanism for both the dyes onto the Ni‐Zn−S@Cyclodextrine surface. A comprehensive analysis, encompassing techniques, such as XRD, FTIR, SEM‐EDX, TEM, TGA, Zeta potential, and XPS, have been conducted to explore the structural and morphological attributes of the prepared nanomaterial. Furthermore, key sorption parameters, including adsorbent's dosage, temperature, contact time, and solution pH, have been systematically optimized to achieve maximum efficiency. The TEM images of prepared nanomaterial indicated the particle size ranging between 60–80 nm. Moreover, it exhibited a strong affinity for both the dyes, with a maximum adsorption capacity of 138.20 mgg−1 for Congo red and 129.95 mgg−1 for Crystal violet dyes at 303 K. The thermodynamics of the adsorption process indicated an endothermic and spontaneous nature. Isotherm studies revealed that the data best aligned with the Freundlich isotherm, while the kinetics of the reaction adhered to a pseudo‐second order within the investigated temperature range. [ABSTRACT FROM AUTHOR]

Background: Methotrexate (MTX), a drug utilized in cancer and rheumatoid arthritis treatment, is associated with acute and chronic neurodegenerative alterations. Spirulina platensis (SP) has several important phytochemical substances that act as free radical scavengers or natural antioxidants. The current study investigated the possible effects of the blue-green alga Spirulina platensis on cerebellar damage in male rats exposed to methotrexate. Forty (40) adult male albino rats were randomly divided into 4 groups (n = 10) and treated for one week: GI, the control group; GII was orally given 1000 mg SP/kg/daily, GIII was given a single intraperitoneal injection of MTX 75 mg/kg at the first day, and continued under the normal condition without other treatment till the end of the experiment, and GIV received both SP and MTX together with the same previous doses and duration. Neurobehavioral, histopathological, histochemical, immunohistochemical, ultrastructural, molecular, and biochemical data were recorded. Results: MTX caused severe cerebellar degeneration in 3 cortical layers, especially the Purkinje layer. The Purkinje layer displayed a disrupted monolayer arrangement with pyknotic nuclei, a significant decrease in cell number, and shrunken cells surrounded by empty spaces. The molecular and granular layers are degenerated with elevated immunoreactions and gene expression of the glial fibrillary acidic protein (GFAP), ionized calcium-binding adapter molecule 1 (Iba-1), and neurofilament light chain antibody (NFL). Moreover, MTX significantly increased malondialdehyde (MDA) and myeloperoxidase (MPO) while decreasing the levels of reduced glutathione (GSH), serotonin, superoxide dismutase (SOD), acetylcholinesterase (ACHE), norepinephrine, and dopamine. These insults were noticeably mitigated by concomitant treatment with spirulina. Conclusion: Spirulina improves neurological function by modulating the cerebellar damage elicited by MTX. This improvement may be attributed to the anti-inflammatory and antioxidant properties of spirulina. [ABSTRACT FROM AUTHOR]

Water remediation has become a hot subject of study due to textile, pharmaceutical, and agricultural discharge to the water bodies. Photocatalysis with photocatalyst having favorable structure, reduced charge carrier recombination and ability to harness UV–Visible spectrum has emerged as efficient way to completely mineralize the persistent organic pollutants (POPs) (Sharma et al. in J Environ Chem Eng 9(5):105812, 2021; Chawla et al. in Coord Chem Rev 491:215246, 2023). In this research, we reported the synthesis of SnO2/Fe2O3/MoS2 ternary composite. The motive of the composite formation is to harvest the entire solar spectrum with prolonged electron–hole recombination. The band gap has reduced from 3.46 to 2.30 eV with the formation of SnO2/Fe2O3/MoS2 ternary composite. The ternary composite exhibited an excellent photocatalytic activity of 95% against Congo red after 80 min at a rate constant of 0.018 min−1. Moreover, the composite showed a photocatalytic activity of 85% and 93% against diclofenac sodium and pendimethalin at a rate constant of 0.017 min−1 and 0.02 min−1 respectively. Through trapping experiments, we determined that hydroxyl radicals scavenging had reduced the photocatalytic degradation of Congo red, diclofenac sodium and pendimethalin to 25%, 22%, and 15% respectively. Beyond its exceptional photocatalytic degradation capabilities, the SnO2/Fe2O3/MoS2 ternary composite also ushered in new possibilities for utilizing wide band gap materials reinforced with visible light active materials along with 2-D materials. [ABSTRACT FROM AUTHOR]

In this work, bismuth sulfide (Bi2S3) thin films were deposited by a chemical bath deposition (CBD) technique (called soft chemistry), while titanium dioxide (TiO2) nanoparticles were synthesized by sol–gel and zinc oxide (ZnO) nanoparticles were extracted from alkaline batteries. The resulting nanoparticles were then deposited on the Bi2S3 thin films by spin coating at 1000 rpm for 60 s each layer to create heterojunctions of Bi2S3/ZnO and Bi2S3/TiO2. These materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). The optical and contact angle analyses were undertaken by UV–Vis spectroscopy and a contact microscopy angle meter, respectively. The calculated band gap values were found to be between 1.9 eV and 2.45 eV. The Bi2S3 presented an orthorhombic structure, the TiO2 nanoparticles presented an anatase structure, and the ZnO nanoparticles presented a wurtzite hexagonal crystal structure. Furthermore, heterogeneous solar photocatalysis was performed using the Bi2S3, Bi2S3/ZnO, and Bi2S3/TiO2 thin film combinations, which resulted in the degradation of Congo red increasing from 8.89% to 30.80% after a 30 min exposure to sunlight. [ABSTRACT FROM AUTHOR]

The adsorption properties of microporous carbon materials modified with iron citrate were investigated. The carbon materials were produced based on resorcinol-formaldehyde resin, treated in a microwave assisted solvothermal reactor, and next carbonized in the tube furnace at a temperature of 700 °C under argon atmosphere. Iron citrate was applied as a modifier, added to the material precursor before the synthesis in the reactor, in the quantity enabling to obtain the nanocomposites with C:Fe mass ratio equal to 10:1. Some samples were additionally activated using potassium oxalate or potassium hydroxide. The phase composition of the produced nanocomposites was determined using the X-ray diffraction method. Scanning and transmission electron microscopy was applied to characterize the changes in samples' morphology resulting from the activation process and/or the introduction of iron into the carbon matrix. The adsorption of nitrogen from gas phase and dyes (methylene blue and congo red) from water solution on the obtained materials was investigated. In the case of methylene blue, the adsorption equilibrium isotherms followed the Langmuir isotherm model. However, in the case of congo red, a linear dependency of adsorption and concentration in a broad equilibrium concentration range was found and well-described using the Henry equation. The most efficient adsorption of methylene blue was noticed for the sample activated with potassium hydroxide and modified with iron citrate, and a maximum adsorption capacity of 696 mg/g was achieved. The highest congo red adsorption was noticed for the non-activated sample modified with iron citrate, and the partition coefficient for this material equaled 171 dm3/g. [ABSTRACT FROM AUTHOR]

Abstract An effective and easily regenerated adsorbent is the one for which scientists are making an effort to explore. In this study, copper oxide nanoparticles (CuO NPs) were synthesized in a green manner from a leaf extract of Moringa stenopetala and used for dye adsorption. XRD, FTIR, and SEM were employed for the characterization of CuO NPs. The crystallite size of the CuO NPs was calculated via Debye–Scherrer equation from the XRD data and was found to be 8.33 nm. The Cu–O bonding bending vibration at 1116 cm− 1 and stretching vibration at 1649 cm− 1 observed from the FTIR data strongly confirmed the formation of CuO NPs. SEM morphology analysis confirmed the formation of nanoparticles with a plate-like morphology and a spherically random orientation. The zero-point charge of CuO NPs was investigated and reported to be at pH 7. The adsorption of dyes on the greenly produced CuO NPs was studied by optimizing different adsorption parameters. The removal efficiencies of the green CuO NPs adsorbent were 99.54% at the optimum conditions (pH, 4; dye concentration, 30 mg/L; amount of adsorbent, 0.25 g; and contact time, 80 min) and 98.33% at the optimum conditions (pH, 11; dye concentration, 20 mg/L; amount of adsorbent, 0.4 g; and contact time, 80 min) for congo red and malachite green, respectively. The adsorption efficiency of the biosynthesized CuO NPs for the mixture of the two dyes was 92.3%. The green synthesized adsorbent was regenerated and able to work effectively for four cycles for the two dyes. The results of the kinetics-type investigation indicate that the adsorption of both dyes by the CuO NPs adsorbent best fits a pseudo-second-order model. The isotherm model-type investigation resulted in the fitting of the Langmuir adsorption isotherm for both the congo red and malachite green dyes.

Abstract Background Methotrexate (MTX), a drug utilized in cancer and rheumatoid arthritis treatment, is associated with acute and chronic neurodegenerative alterations. Spirulina platensis (SP) has several important phytochemical substances that act as free radical scavengers or natural antioxidants. The current study investigated the possible effects of the blue-green alga Spirulina platensis on cerebellar damage in male rats exposed to methotrexate. Forty (40) adult male albino rats were randomly divided into 4 groups (n = 10) and treated for one week: GI, the control group; GII was orally given 1000 mg SP/kg/daily, GIII was given a single intraperitoneal injection of MTX 75 mg/kg at the first day, and continued under the normal condition without other treatment till the end of the experiment, and GIV received both SP and MTX together with the same previous doses and duration. Neurobehavioral, histopathological, histochemical, immunohistochemical, ultrastructural, molecular, and biochemical data were recorded. Results MTX caused severe cerebellar degeneration in 3 cortical layers, especially the Purkinje layer. The Purkinje layer displayed a disrupted monolayer arrangement with pyknotic nuclei, a significant decrease in cell number, and shrunken cells surrounded by empty spaces. The molecular and granular layers are degenerated with elevated immunoreactions and gene expression of the glial fibrillary acidic protein (GFAP), ionized calcium-binding adapter molecule 1 (Iba-1), and neurofilament light chain antibody (NFL). Moreover, MTX significantly increased malondialdehyde (MDA) and myeloperoxidase (MPO) while decreasing the levels of reduced glutathione (GSH), serotonin, superoxide dismutase (SOD), acetylcholinesterase (ACHE), norepinephrine, and dopamine. These insults were noticeably mitigated by concomitant treatment with spirulina. Conclusion Spirulina improves neurological function by modulating the cerebellar damage elicited by MTX. This improvement may be attributed to the anti-inflammatory and antioxidant properties of spirulina.

Calcifications on mammography from systemic disease at times meet diagnostic criteria for histologic sampling to exclude malignancy. We present a case of bilateral groups of new calcifications on mammography that yielded amyloidosis on core biopsy. Awareness of our patient's known diagnosis of systemic light chain amyloidosis (AL) prompted use of Congo red staining to confirm the histologic diagnosis. Knowledge of systemic diseases with possible manifestations on mammography can facilitate cogent and clinically relevant radiology-pathology correlation.

[Display omitted] • Gelatin/carboxymethyl cellulose cryogels with Fe 3 O 4 NPs enhanced CR adsorption. • Pseudo-second-order kinetics and Freundlich model fitted CR adsorption. • The maximum adsorption capacity of CR by cryogel reached 698.19 mg/g. • Key mechanisms included hydrogen bonding, electrostatics, and π–π interactions. • XGB model had the highest predictive accuracy (R2 = 0.9862) for CR adsorption. To achieve highly efficient and environmentally degradable adsorbents for Congo red (CR) removal, we synthesized a dual-network nanocomposite cryogel composed of gelatin/carboxymethyl cellulose, loaded with Fe 3 O 4 nanoparticles. Gelatin and sodium carboxymethylcellulose were cross-linked using transglutaminase and calcium chloride, respectively. The cross-linking process enhanced the thermal stability of the composite cryogels. The CR adsorption process exhibited a better fit to the pseudo-second-order model and Langmuir model, with maximum adsorption capacity of 698.19 mg/g at pH of 7, temperature of 318 K, and initial CR concentration of 500 mg/L. Thermodynamic results indicated that the CR adsorption process was both spontaneous and endothermic. The performance of machine learning model showed that the Extreme Gradient Boosting model had the highest test determination coefficient (R 2 = 0.9862) and the lowest root mean square error (RMSE = 10.3901 mg/g) among the 6 models. Feature importance analysis using SHapley Additive exPlanations (SHAP) revealed that the initial concentration had the greatest influence on the model's prediction of adsorption capacity. Density functional theory calculations indicated that there were active sites on the CR molecule that can undergo electrostatic interactions with the adsorbent. Thus, the synthesized cryogels demonstrate promising potential as adsorbents for dye removal from wastewater. [ABSTRACT FROM AUTHOR]

Polymethyl methacrylate (PMMA)/Congo Red (CR) and polyvinyl chloride (PVC)/CR composite films were prepared on optical glass by the drop method for optical measurements and also prepared as tablets under pressure for dielectrical measurements. The optical transmission spectra measurements for PMMA and PVC film doped with CR showed a highly absorption in the ultraviolet-visible (UV-Vis) optical range (at 353 nm and 518 nm) and considerably blocking in broad visible range (190 nm–640 nm). PMMA/CR and PVC/CR composite films containing congo red at a concentration of 1 wt% showed maximum absorption bands at 290 nm and 416 nm, but their transmittance percentages were reasonably reduced compared to those of pure PMMA and PVC. Both of composites indicated high transmittances between 640 nm and 800 nm. The optical constants of the PMMA/CR and PVC/CR composite films such as optical band energy gaps (Eg) estimated using Tauc's model, refractive index and reflectance (%) were calculated. UV–Vis, Fourier transform infrared spectroscopy (FTIR) and Thermogravimetry Analysis (TGA) measurements were used to confirm the breakdown of the -N = N- azo group bonds attached to the aromatic ring as a result of thermal decomposition of CR at 500 °C, and it was suggested that N2 gas was eliminated from the CR above 360 °C. The dielectric plots showed that the dielectric constant increased when the CR is doped up to 70 wt% in the polymer matrices. A further increase in the doping concentration of CR resulted in an increase of the dielectric constant. The dielectric constant decreased with an increase in the frequency for all of the samples. The ac (alternating current) conductivity values of PMMA and PVC showed an increase with increasing CR dopant in the polymer composites, while the ac conductivity values were found to be values between those of the pure polymers and CR. [ABSTRACT FROM AUTHOR]

This study aims to synthesize silver-palm kernel expeller ash (PKE) composites using in-situ combustion at 600 °C. Compared to previous methods, the novel in-situ combustion was developed to easily obtain composites in the laboratory using simple procedures. The products obtained were characterized with X-ray diffraction (XRD) analysis. The results showed that the composites contained silver metal peaks and some peaks of a mixture of compounds predicted to be calcium phosphate, calcium hypophosphate, and other undetermined metal oxides. In addition, X-ray fluorescence (XRF) analysis showed the presence of several important minerals derived from PKE combustion. Composites obtained in this study showed better activity as catalysts in the removal of congo-red under sunlight irradiation compared to only PKE ash. Based on these results, the by-products of palm oil processing had the potential to be used for advanced materials preparation.

Advanced Oxidation Processes (AOP), such as persulfate oxidation is a promising contaminant removal agent for treating wastewater. In this study, Sidoarjo volcanic mud (VM) was applied as heterogeneous catalyst to support the persulfate oxidation process for Congo Red (CR) dye removal. The Sidoarjo volcanic mud is known to have a high iron content, making it a potential catalyst in AOP. This study was conducted under conditions of pH 2, CR 50 mg/L, and catalyst dosage 0.5 g/L and effective reaction volume of 300 mL. This experiment was conducted by comparing three types of catalysts: unmodified volcanic mud (UVM), impregnated volcanic mud (Fe-IVM), and calcined volcanic mud (CVM). The methods were carried out by comparing two methods, namely simultaneous and sequential. The obtained CR removal values for UVM, Fe-IVM, and CVM catalysts were 83.73%, 78.86%, 51.96% for simultaneous and 84.75%, 81.72%, and 87.69% for sequential method. Whereas the UVM catalyst has the highest CR removal value with a lower adsorption value of 16.89%. The production of sulfate radical analyzed by comparing the oxidation process of homogeneous and heterogeneous catalysts. It was shown that the application of VM catalyst as heterogeneous catalyst is very promising for dye removal in wastewater treatment.

The synthesis of Cu(II)-doped ZIF-8/Chitosan by means of the one-pot method at room temperature was successfully carried out. The synthesized materials exhibit enhanced adsorption properties for the removal of Congo red (CR) dye. The structural and morphological properties of Cu(II)-doped ZIF-8/Chitosan were characterized. Cu(II)-doped ZIF-8/Chitosan achieved the most optimal CR removal efficiency and CR adsorption capacity (153.85 mg/g) due to its higher specific surface area (522.776 m2/g) compared to ZIF-8/Chitosan (514.882 m2/g). Electrostatic attraction, hydrogen bonding, and π-π interaction are the main interactions for the higher adsorption performance. The CR adsorption process followed pseudo-second-order kinetic model and Langmuir isotherm model. The results of the thermodynamic adsorption indicated that the process of CR adsorption by Cu-doped ZIF-8/Chitosan was an endothermic reaction. The experimental results indicate that the Cu(II)-doped ZIF-8/Chitosan material has the potential to be used in wastewater treatment for the removal of anionic dyes.

The removal of Congo red (CR) is a critical issue in contemporary textile industry wastewater treatment. The current study introduces a combined electrochemical process of electrocoagulation (EC) and electro-oxidation (EO) to address the elimination of this dye. Moreover, it discusses the formation of a triple composite of (Co), (Mn), and (Ni) oxides by depositing fixed salt ratios (1:1:1) of these oxides in an electrolysis cell at a constant current density of 25 mA/cm2. The deposition ended within 3 hours at room temperature. X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and energy dispersive X-ray (EDX) characterized the structural and surface morphology of the multi-oxide sediment. Marvelously, the deposition has simultaneously occurred on both anodic and cathodic graphite electrodes. These electrodes besides Aluminum (Al) are employed as anodes in the EC-EO system, and the results were optimized by response surface methodology (RSM). The optimum operating conditions were a current density of 6 mA/cm2, pH =7, and NaCl of 0.26 g/L. The results showed that the combined system eliminated more than 99.91% of the Congo red dye with a removal of Chemical Oxygen Demand (COD) of around 97% with 1.64 kWh/kg of dye of the consumed energy. At low current density, the current delivered for the composite anode was more than for the Al anode with the same surface area. On top of this superiority, the EC-EO scenario is a practical hybrid process to remove CR in an environmentally friendly pathway.

Background: Congo red (CR), a harmful dye present in water, requires effective removal methods. This study investigated the utilization of dry green pea husk (DGPH) and its charcoal (CGPH) as economical and eco-friendly adsorbents. Methods: Various factors, including contact time, pH, adsorbent dosage, initial concentration, and temperature, were investigated to assess their impact on the adsorption process. Also, different models (isotherms, kinetics, and thermodynamics) were compared to describe the adsorption phenomenon. Results: Equilibrium adsorption was achieved within 30 minutes for both adsorbents. The optimum pH for CR removal was determined to be 2. The adsorption capacity decreased by increasing the adsorbent dosage, whereas it increased by increasing the initial dye concentration. The Langmuir isotherm model demonstrated the best fit for DGPH, while the Freundlich model exhibited the best fit for CGPH. The pseudo-second-order model displayed a superior fit for both adsorbents. To assess the spontaneity and feasibility of the adsorption process, thermodynamic parameters including enthalpy, entropy, and Gibbs free energy were computed. The results indicated that the adsorption of CR on DGPH was endothermic and favorable at lower temperatures, whereas the adsorption on CGPH was exothermic and favorable at higher temperatures. The negative values of Gibbs free energy for the CGPH adsorbent confirmed the spontaneous nature of the adsorption process. Conclusion: The study establishes that green pea husk and its charcoal are effective and environmentally friendly alternatives for the removal of CR from water.

Green synthesis of nanoparticles (NPs) is considered a highly promising technology for materials. The use of plant-based NPs is the simplest with high reproducibility. Iron nanoparticles (Fe-NPs) were synthesized by pruned tea leaf extract and FeSO4 and were analyzed by XRD, FTIR, XPS, and TEM. The catalytic activity of the Fe-NPs was evaluated for dye degradation under different operating parameters. Kinetc and thermodynamic tests were also conducted to study the reaction behavior. Results showed that the Fe-NPs had an average pore size of 17.9 nm with a surface area of 2.54 m2 g−1. The Fe-NPs contained Fe–O bonds and bioactive substances. The crystalline Fe-NPs were composed of FeOOH, Fe2O3, and α-Fe forms. XPS showed the presence of Fe3+ and Fe2+ in a ratio of 1.78, with Fe2+ accounting for over 64%. TEM revealed the spherical structure with particle size around 34–52 nm. The degradation efficiency of Congo red (CR) surpassed 95% within 30 min for the Fenton-like system, while sole adsorption only achieved 50%. Increasing the solution pH had a significant negative effect. Pseudo-second-order model provided the best fit. Thermodynamic calculations revealed that the catalytic degradation is favorable, spontaneous, and endothermic. Reusability demonstrated that over 95% retention was achieved after five cycles. HIGHLIGHTS Fe-nanoparticles were synthesized using pruned tea leaf extract.; Fe-nanoparticles exhibited superior catalytic activity in a Fenton-like system.; More than 95% degradation efficiency was achieved after five cycles.; The pseudo-second-order kinetic model provided the best fit for the experimental data.; The reaction was spontaneous endothermic and increased disorder.;

Abstract 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.

TiO2@BiOCl‐BiOI heterostructure photocatalyst with high photocatalytic activity was prepared by the composite modification and sol‐gel procedure. TiO2 nanoparticles highly dispersed on the surface of TiO2@BiOCl‐BiOI, which provides sufficient active sites for the photocatalytic degradation process. The photodegradation performance of the photocatalyst was evaluated by the removal rate of Congo Red. The researches showed that the degradation effect of TiO2@BiOCl‐BiOI for Congo Red is significantly stronger than that of TiO2 and BiOCl‐BiOI, which is mainly due to the type‐II heterojunction structure of TiO2@BiOCl‐BiOI and its enhanced visible‐light response. The experiments of free radical capture indicated that ⋅O2- ${{{\rm O}}_{2}^{-}}$ and h+ ${{{\rm h}}^{+}}$ are the main active species in the photocatalytic degradation system. This study showed that TiO2@BiOCl‐BiOI can almost completely degrade Congo Red under simulated sunlight, making it the harmless substances such as H2O and CO2. [ABSTRACT FROM AUTHOR]

This study focuses on developing copper oxide-based nanocomposites using plant extracts for photocatalytic applications. Curcuma amada leaf and Alysicarpus vaginalis leaf extracts were utilized alongside recycled copper precursors to synthesize photocatalysts via a green synthesis approach. Structural characterization through X-ray diffraction confirmed the formation of monoclinic CuO with reduced crystallite sizes due to plant extract incorporation. Fourier-transform infrared spectroscopy identified additional functional groups from the plant extracts, enhancing the material's properties. UV–Vis spectroscopy demonstrated increased light absorption and narrowed bandgaps in the nanocomposites, crucial for efficient photocatalysis under visible light. Morphological studies using FESEM revealed unique leaf-like structures in nanocomposites, indicative of the plant extract's influence on morphology. Photocatalytic degradation of methylene blue, rhodamine B, Congo red, and reactive blue 171 dyes showed enhanced performance of plant extract-modified CuO compared to without plant extract mediated CuO, attributed to improved charge carrier separation and extended lifetime. The effects of pH, catalyst dosage, and dye concentration on degradation efficiency were systematically investigated, highlighting optimal conditions for each dye type. Radical scavenger studies confirmed the roles of holes and hydroxyl radicals in the degradation process. Kinetic analysis revealed pseudo-second-order kinetics for dye degradation, underscoring the effectiveness of the nanocomposites. Overall, this research provides insights into sustainable photocatalytic materials using plant extracts and recycled copper, showcasing their potential for environmental remediation applications. [ABSTRACT FROM AUTHOR]

Organic azo-dyes, including Congo Red, present a significant environmental concern due to their widespread industrial usage and resistance to biodegradation, leading to severe contamination of effluents. This study explores the efficacy of two basic perovskites (MSnO3, where M = Ca and Sr) in removing Congo Red by adsorption, offering a potential solution for wastewater treatment. The synthesis of the adsorbents was performed by a coprecipitation technique, an effective and no-waste producing method. By adjusting reaction conditions, the physical-chemical characteristics of the perovskites, including crystallinity, morphological features, surface area and porosity, were controlled. Adsorption studies conducted across a range of Congo Red concentrations (10–100 mg L− 1) at pH 10 revealed MSnO3 to possess exceptional adsorption capacity exceeding 100 mg per gram. The results indicate irreversible adsorption and potential adsorbent regeneration by thermal treatment. Slow kinetics also suggest strong binding forces aligned with the fundamentals of pseudo-second-order adsorption kinetic model. Regarding the impact of the synthesis parameters, while the precipitation conditions may not significantly influence adsorption performance, perovskite samples synthesized at higher temperatures are considered more suitable for this application due to their enhanced stability and regenerative capabilities for repeated use. Estimated correlations between sample parameters and adsorption efficiency provide a valuable insight for the practical application of oxide perovskites in addressing dye contamination issues. Highlights: MSnO3 with tuneable properties can be obtained via MSn(OH)6 as an intermediate. CaSnO3 consistently demonstrates high adsorption capacities of 98–105 mg g− 1. SrSnO3 adsorption performance is significantly influenced by experimental conditions. Desorption experiments indicate irreversibility, suggesting strong binding forces. Both perovskites exhibit successful regeneration capabilities by thermal treatment. [ABSTRACT FROM AUTHOR]

The removal of congo red (CR) is a critical issue in contemporary textile industry wastewater treatment. The current study introduces a combined electrochemical process of electrocoagulation (EC) and electro-oxidation (EO) to address the elimination of this dye. Moreover, it discusses the formation of a triple composite of Co, Mn, and Ni oxides by depositing fixed salt ratios (1:1:1) of these oxides in an electrolysis cell at a constant current density of 25 mA/cm2. The deposition ended within 3 hours at room temperature. X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and energy dispersive X-ray (EDX) characterized the structural and surface morphology of the multi-oxide sediment. Marvelously, the deposition has simultaneously occurred on both anodic and cathodic graphite electrodes. These electrodes besides aluminum (Al) are employed as anodes in the EC-EO system, and the results were optimized by response surface methodology (RSM). The optimum operating conditions were a current density of 6 mA/cm2, pH = 7, and NaCl of 0.26 g/L. The results showed that the combined system eliminated more than 99.91% of the congo red dye with a removal of chemical oxygen demand (COD) of around 97% with 1.64 kWh/kg of dye of the consumed energy. At low current density, the current delivered for the composite anode was more than for the Al anode with the same surface area. On top of this superiority, the EC-EO scenario is a practical hybrid process to remove CR in an environmentally friendly pathway. [ABSTRACT FROM AUTHOR]

Seven bacterial strains, isolated from various Tunisian biotopes, were investigated for Congo Red (CR) and Malachite Green (MG) decolorization. The isolated strains underwent morphological and biochemical tests, including assessments for antibiotic sensitivity as well as biofilm formation. One selected strain, ST11, was partially identified as Paenibacillus sp. strain ST11. The newly isolated crude bacterial filtrates (NICBFs) effectively decolorized CR and MG. Specifically, six and seven NICBFs were found to be effective for degrading CR (150 mg l−1) and MG (50 mg l−1), respectively. Under non-optimized conditions, CR and MG could be decolorized up to 80% within 6–12 h. The degradation products of CR and MG, characterized by UV–visible and FT-IR techniques, demonstrated both decolorization and transformation, highlighting the role of enzymes in dye degradation. Phytotoxicity and cytotoxicity studies evaluated the impact of treated and untreated CR and MG. Some NICBFs showed promise as powerful biological tools, reducing and sometimes detoxifying CR and MG, commonly used as fertilizers. The potential applications of these NICBFs in decolorization and bioremediation of dye-rich textile effluents were explored. The screening also identified environmentally friendly, cost-effective bacterial strains adaptable to various conditions through phytotoxicity and cytotoxicity studies. [ABSTRACT FROM AUTHOR]

In order to reduce the enormous costs of photocatalytic processes, the development of new photocatalysts sensitive to visible light constitutes a promising strategy to boost the efficiency of this method in water treatment. In this paper, strontium cobaltite nanoparticles (SrCo2O4 NPs) were shaped by simple, ecological and economical methods using cobalt and strontium nitrates as precursor and freshly isolated chicken egg white as capping agents. The crystalline product SrCo2O4 NPs was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Ultraviolet–Visible (UV–Vis) spectroscopy studies. The SrCo2O4-catalyzed Congo red (CR) degradation under visible light is investigated. XRD analysis showed that the sample was indeed crystallized in the cubic spinel structure (space group Fd3m). The average size of the nanoparticles was estimated to be ∼28nm. The FT-IR spectrum shows two bands at 620 and 573cm−1, which are characteristic of the spinel strontium cobaltite crystalline structure. The two optical band gap energy of synthesized photocatalyst estimated from UV–Visible spectrum is 2.07 and 3.48eV. The developed photocatalyst exhibits significant photocatalytic degradation of RC in an acidic medium with 97% of the dye mineralized after 5h. [ABSTRACT FROM AUTHOR]

The present work is an attempt to address the feasibility of sewage sludge as a cost-effective adsorbent for the Congo Red (CR) elimination from a wastewater sample. The physicochemical properties of treated sewage sludge SS40 were identified by using several techniques, such as Thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), zeta potential, and Fourier transform infrared spectroscopy (FTIR), Furthermore, to describe the adsorption balance, the experimental results were analyzed using the Langmuir, Freundlich, and Sips isotherms. The equilibrium was perfectly described by the Langmuir model, and the peak adsorption capacity in the monolayer was 25.10 mg. g−1 at 40 °C. The kinetic data of adsorption were analyzed by the Pseudo-First Order (PFO), Pseudo-Second Order (PSO), and Elovich models. The results indicated that both Elovich and PSO models were the most appropriate for describing the adsorption of CR onto (SS40) for all initial CR concentrations, indicating that the chemisorption controlled the dye retention by SS40. The determination of thermodynamic parameters showed that ΔG0 was − 9.42 kJ.mol−1 at 40 °C, ΔH0 was 10.64 kJ.mol−1, and ΔS0 was 30.14 J.mol−1. K−1. The adsorption of CR on SS40 was found to be feasible, spontaneous, and endothermic. The results of this study demonstrate that sewage sludge from the domestic wastewater treatment plant can be used advantageously as an economical, easy-to-handle, and eco-friendly sorbent for the elimination of CR as an emerging pollutant from aqueous solutions. [ABSTRACT FROM AUTHOR]

Water pollution is a pressing global concern due to the uncontrolled discharge of organic pollutants into aquatic environments without adequate treatment. One significant contributor is the release of organic dyes, notably Congo red (CR) dye, from industrial effluents, posing environmental and health risks. In response, a highly effective 2D porous material, the PEG-ZnO/rGO composite, has been developed for the removal of CR dye from water systems. The composite was thoroughly characterized using XRD, FTIR, SEM, AFM and EDX analytical techniques to assess its crystalline nature, functionalities, surface morphology, 3D structure and elemental composition. Under optimized conditions (pH 3, 3 mg adsorbent dose and 0.5 mM CR dye concentration), the PEG-ZnO/rGO composite demonstrated a remarkable 94% removal efficiency of CR dye from aqueous solutions, with an adsorption capacity of 97.462 mg/g. Various isotherm models, including Langmuir, Freundlich, D-R, and Temkin, were applied to determine the adsorption capacity, with the Langmuir model showing the best fit (R2 = 0.9809), indicating a homogeneous surface for CR dye adsorption. The practical utility of the composite was validated through testing in both river and synthetic water samples, yielding recovery values within acceptable limits, affirming its potential for commercial-scale application in CR dye removal. [ABSTRACT FROM AUTHOR]

Against the backdrop of “carbon neutrality”, the green treatment of dye wastewater is particularly important. Currently, the adsorption method shows strong application prospects. Therefore, selecting efficient and recyclable adsorbents is of significant importance. TiO2 is an excellent adsorbent, but its difficult recovery often leads to secondary pollution. γ-Fe2O3-modified coal-series kaolin exhibits both excellent adsorption properties and rapid separation through magnetic separation technology. By utilizing the synergistic effects of both, TiO2/-γFe2O3 coal-series kaolin, magnetic adsorbent regeneration materials were prepared using coprecipitation method and characterized. The influencing factors of this functional material on the adsorption of Congo red dye and its regeneration performance are discussed. The experimental results indicated that the specific surface area, pore volume and Ms value of this functional material are 127.5 m2/g, 0.38 cm3/g, and 13.4 emu/g, respectively. It exhibits excellent adsorption characteristics towards Congo red, with an adsorption rate reaching 96.8% within 10 min, conforming to the pseudo-second-order kinetic model, and demonstrating Langmuir IV-type monolayer adsorption. After the adsorption of Congo red, magnetic separation shows superior efficiency. Furthermore, treatment of the adsorbed composite with EDTA allows for recycling, with adsorption rates still above 91% after three cycles, indicating an excellent regeneration capability. [ABSTRACT FROM AUTHOR]

In this study, ethylenediamine (EDA)-modified wheat straw (EMWS) was prepared and used as an efficient adsorbent for removing Congo red (CR) from aqueous solutions. Adsorption of CR by EMWS was examined through static adsorption experiments to determine the effect of contact time, initial pH values, particle size of the adsorbent, solution concentration, and temperature. As pH ranged from 4.0 to 10.0, CR adsorption by the EMWS remained considerably elevated. The equilibrium adsorption capacity was determined to be 97.92 mg·g−1 for a CR concentration of 400 mg·L−1, pH of 4.0, temperature of 318 K, and EMWS dose of 2 g·L−1, which was found to be comparable to other materials used for CR adsorption. Following that, optimal conditions were used to conduct isothermal, kinetic, and thermodynamic studies. In the adsorption process of CR, the Freundlich isotherm model and the pseudo-second-order (PSO) kinetics provided the best fit, indicating the presence of both physisorption and chemisorption mechanisms. Electrostatic attraction and hydrogen bonding were primarily responsible for CR adsorption onto the EMWS. Based on thermodynamic investigations, the adsorption of CR on EMWS is determined to be spontaneous (ΔG < 0) and endothermic (ΔH = 60.83 kJ·mol−1), while also exhibiting an increase in disorder (ΔS = 289.9 J·mol−1·K−1). The elution was carried out using 0.20 M HCl, followed by washing the EMWS with water, resulting in no loss of functionality. This study suggests that EMWS possesses the potential to serve as a feasible and efficient adsorbent for CR removal in wastewater. [ABSTRACT FROM AUTHOR]

In this study, the efficiency of poly(ethylene glycol dimethacrylate-N-methacryloyl-amido-l-tryptophan methyl ester) [PEDMT] microbeads (in the diameter range of 106–180 µm) as a support material for HRP immobilization was evaluated and the immobilized-HRP enzyme was used for decolorization of Congo Red (CR) and Reactive Black 5 (RB5) dyes. The specific surface area of the PEDMT microbeads was 1103 m2 g−1, which is very high. The PEDMT microbeads had a pore volume and pore size of 1.94 cm3 g−1 and 9.99–55.3 Å, respectively. The chemical compositions of the PEDMT and PEDMT–HRP microbead surfaces were analyzed using X-ray photoelectron spectroscopy (XPS). Immobilization yield, activity yield, and immobilization efficiency were 84.9 ± 2.1, 73.8 ± 5.9%, and 86.9 ± 6.9%, respectively. Optimum pH (6.0), temperature (45 °C and 50 °C for free and immobilized enzyme), H2O2 concentration (3% v/v) were investigated in detail. Thermal and storage stability was increased after immobilization and immobilized enzyme preserved more than 55% of its initial activity even after 10 consecutive uses. Decolorization studies were also performed by investigating the effects of pH, CR, and RB5 concentration, enzyme amount, H2O2 concentration, contact time on decolorization efficiency. The decolorization efficiency for CR and RB5 by PEDMT–HRP was 98.20% and 47.99% after 30 min at pH 6.0 and 45 °C. The immobilized-HRP retained 89% and 27% of its initial activity after three repeated cycles with CR and RB5, respectively. The PEDMT microbeads with high surface area, porosity, durability, and reusability exactly met the requirements for HRP immobilization and dye decolorization. [ABSTRACT FROM AUTHOR]

Background: Nasopharyngeal amyloidoma is a rare, locally aggressive tumor that has been reported in the English literature in only 38 cases to date, most of which were in the form of case reports. The present study was aimed to summarize the characteristics of this rare tumor, with the goal of providing new insights for diagnosis and treatment. Materials and methods: We report three cases of nasopharyngeal amyloidoma diagnosed in our hospital following comprehensive medical examination and review the current literature on all cases of nasopharyngeal amyloidoma from PubMed. The journey of nasopharyngeal amyloidoma, including presentation, diagnostics, surgeries, and follow-up was outlined. Results: None of the three patients had systemic amyloidosis. CT and nasal endoscopy showed irregular masses obstructing the nasopharyngeal cavity. Congo red staining confirmed the deposition of amyloid, and immunohistochemical analysis showed that the amyloid deposition was the AL light chain type. Through literature review, we found that nasopharyngeal amyloidoma most commonly occurred in individuals over the age of 40, patients usually had a good prognosis after complete tumor resection; however, there were still cases of recurrence, and unresected patients were at risk of progression to systemic amyloidosis. The efficacy of radiotherapy and chemotherapy was currently uncertain. Conclusion: Early clinical and pathological diagnosis is crucial, and surgical intervention is the primary treatment option for this disease. Although patients usually have a favorable prognosis, long-term monitoring is necessary to detect potential relapses and initiate timely intervention. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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BACKGROUND: The encapsulation technique was applied to efficiently eliminate Congo red (CR) from aqueous solutions. During the ionotropic gelation between calcium (Ca2+) ions and alginate (AL), CR was effectively entrapped within the AL nanocapsules in a one‐step process. Suitable conditions for efficient CR removal via encapsulation were revealed by the systematic optimization of parameters including pH, time and stirring speed, etc. RESULTS: According to the experimental observations, the stirring rate and temperature were found to have an insignificant effect on the encapsulation of CR molecules. When the pH value of the medium was 3, the highest level of encapsulation efficiency was achieved in a period of 15 min. At a preliminary CR concentration of 2000 mg L−1 and pH 3, the encapsulation efficiency was calculated at ≈98.9%, with an encapsulation capacity of 2800 mg dye g−1 AL. The zeta potential values of AL and CR/AL nanocapsules were determined to be +7.05 eV and −14.9 eV, respectively, and the results showed that the particles tended to agglomerate. TEM micrographs also showed that the nanocapsules were nanosized and agglomerated. Soil and UV degradation studies showed that the dye‐entrapped nanocapsules degraded remarkably. These results highlighted the great potential of encapsulation for dye removal in economical and practical applications. CONCLUSION: Encapsulation was confirmed to be an economical and practical technique for effectively eliminating CR from aqueous solutions. Under UV light irradiation, the dye molecules entrapped within alginate nanocapsules displayed photodegradation. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The release of industrial wastewater has adverse effects on both aquatic ecosystems and the environment. Discharging untreated organic dyes into aquatic environments significantly amplifies pollution levels in these ecosystems. Ensuring the appropriate disposal of organic colorants and their derivatives before introducing them into wastewater streams is essential to prevent environmental contamination. This study aimed to develop an eco-friendly and sustainable approach to synthesize a chitosan-functionalized silver (Ag) nanocomposite using Solanum trilobatum for color pollutant mitigation. The synthesized CS-Ag nanocomposite was analyzed using various techniques such as UV–visible, FTIR, TEM, and EDS. TEM analysis revealed that the CS-Ag nanocomposite had a spherical nanostructure, with diameters ranging from 17.4 to 43.9 nm. These nanocomposites were tested under visible light irradiation to analyze their photocatalytic character against Congo red (CR). The nanocomposite exhibited a remarkable dye removal efficiency of over 93.6% within 105 min under irradiation. In the experimental recycling study, the CS-Ag nanocomposites demonstrated remarkable stability and reusability. Furthermore, the CS-Ag nanocomposite exhibited promising inhibition activity against bacterial pathogens. Our research revealed that the synthesized nanocomposite has the potential to act as a highly effective photocatalyst and bactericidal agent in various industrial and clinical applications. [ABSTRACT FROM AUTHOR]

The removal of pollutants from water bodies is crucial for the well-being of humanity and is a topic of global research. Researchers have turned their attention to green synthesized nanoparticles for wastewater treatment due to their eco-friendly nature, biocompatibility, and cost-effectiveness. This work demonstrates the efficient removal of organic dye and both gram-positive and gram-negative bacteria from water bodies using copper-doped cerium oxide nanoparticles synthesized with Murraya Koenigii extract. Characterized via various methods, the 15% copper doped cerium oxide nanoparticles (Cu 15% NPs) exhibited maximum Congo red dye adsorption (98% degradation in 35 min). Kinetic analysis favoured a pseudo-second-order model, indicating the chemical nature of adsorption. Equilibrium adsorption isotherms aligned with the Langmuir model, indicating homogenous monolayer dye adsorption on the doped adsorbent. The maximum uptake of adsorbate, Q m obtained from Langmuir model for Cu 15% NPs was 193 mg g−1. The study also showed enhanced antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa for Cu-doped ceria, attributed to generation of reactive oxygen species (ROS) induced by the redox cycling between Ce3+ and Ce4+. This substantiated that the green synthesized copper doped cerium oxide nanoparticles are potential candidates for adsorptive removal of Congo red dye and as antibacterial agents. [ABSTRACT FROM AUTHOR]