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Environmental remedy calls for scientific contributions with ever increasing urgency. This research aims to a circular economy look to deliver the concept of novel materials, created from renewable by-product waste feedstock and designed to be reused, recycled, then the feedstock renewed through wastewater treatment process. The use of alum sludge (AS) waste as a photocatalyst in the catalytic oxidation of wastewater to the potential capability of ˙OH radical use as a strong oxidant is explored. Investigation has performed using magnetite (M) augmented with alum sludge as a composite material formed as alum sludge/magnetite (ASM) at different proportions (1:1), (1:2), (1:3), (1:5) and (2:1) and the samples labelled as ASM-1, ASM-2, ASM-3, ASM-4 and ASM-5, respectively. The characterisation of such composite materials was explored by X-ray diffraction (XRD), Transmission electron Microscopy (TEM) and the composition of the composite material is attained by the Energy dispersive X-ray spectroscopy (EDX). The capabilities of these materials are tested for dye removal. Consequently, the corresponding photocatalytic performance was notably improved. The various operating conditions, initial dye concentration, initial pH value, catalyst and H2O2 concentrations on the oxidation efficiency of the dye were optimised at pH 2.0 and 800 mg/L and 2 g/L for H2O2 and ASM-1, respectively. Thermodynamic and kinetics were studies and the data revealed that the reaction is spontaneous and exothermic in nature and follows the first-order reaction kinetics. This assessment introduces the role of engineers and chemists in a world without waste. [ABSTRACT FROM AUTHOR]

In this study, a functionalized magnetic powder complex porous carbon derived from ZIF‐8 (ZIF‐8@Na‐Cit@Fe3O4NPs@AC(500°C)) was prepared and applied for the waste liquid containing MB, TC, and Cu2+ adsorption removal. The ZIF‐8@Na‐Cit@Fe3O4NPs@AC(500°C) perfectly inherited the feature of parent ZIF‐8, posed a high specific surface area (SBET = 812.73 m2 g−1), be rich in surface nitrogen functional groups, and resulting in a good dynamic adsorption of the MB, TC, and Cu2+. The ZIF‐8@Na‐Cit@Fe3O4NPs@AC(500°C) exhibited the best adsorption performance of high‐concentration waste liquid containing MB, TC, and Cu2+, with equilibrium adsorption capacity of MB (408 mg g−1), TC (417 mg g−1), and Cu2+ (386 mg g−1), respectively. The acetone and toluene adsorption were spontaneously and exothermic, given the negative values of free energy (ΔG) and enthalpy (ΔH). The difference of MB, TC, and Cu2+ adsorption on ZIF‐8@Na‐Cit@Fe3O4NPs@AC(500°C) attributed to the affinity difference (polarity and molecular diameter) and the nitrogen‐containing functional groups (π‐π interaction and electrostatic attraction). Therefore, it was found that ZIF‐8@Na‐Cit@Fe3O4NPs@AC(500°C) could effectively adsorb MB, TC, and Cu2+, and ZIF‐8@Na‐Cit@Fe3O4NPs@AC(500°C) could remove more than 70% of the above pollutants after repeated use for four times; it has a good application prospect. [ABSTRACT FROM AUTHOR]

This contribution describes the indirect electrochemical oxidation of wastewater laden with bromothymol blue and methyl red dyes using a laboratory-scale electrochemical reactor with a Ti/Ru0.3Ti0.7O2 anode and stainless-steel cathode. The influence of current density, pH, and electrolyte concentrations on the oxidative degradation pattern of the dyes in the wastewater was also investigated by coupling the electrochemical reactor with an Ultraviolet–Visible spectrometer. By indirect oxidation, 97% of the bromothymol blue at 10 mA cm–2 current density and pH 3.0 and 98% of the methyl red at 2 mA cm–2 current density at pH 3.0 were indirectly oxidized in 10 min Initial concentrations of each were 200 ppm. During the degradation of the dyes, electrochemically generated chlorine and hypochlorite ions (OCl)– played pivotal roles. Under the aforementioned ideal circumstances, the minimum energy consumption values for bromothymol blue and methyl red were 0.2025 and 0.0636 kW h m–3, respectively. The anode exhibited an excellent service life for treating dye wastewater, and repeated tests and surface analysis revealed no evident passivation. In this way, a variety of dyes in effluents can be cheaply degraded by electrolyzing with a Ti/Ru0.3Ti0.7O2 anode, utilizing readily available electrolytes and with minimal electricity requirements. [ABSTRACT FROM AUTHOR]

Wastewater pollution is a pressing environmental issue, necessitating effective remediation strategies to mitigate its impact. This study investigates the use of an efficient catalyst for degrading nitrophenols by converting them into useful aromatic amines, which are crucial building blocks for many pharma industries, and photodegradation of various dyes in their unitary solution as well as in mixture. The Cu-Co-Mn ferrite was synthesized using the sol-gel process and sintered at different temperatures. Structural analysis using XRD and Rietveld refinement revealed a crystal structure corresponding to the Fd 3 ‾ m space group having high purity in all the samples. Additionally, the impact of sintering temperature on the magnetic features of the phases were also studied and the findings suggest that all the phases exhibit ferromagnetic behaviour, which means they can be easily separated from reaction mixtures using an external magnetic field. It was also found that higher sintering temperatures lead to a rise in saturation magnetization and magnetic moment with decrease in coercivity (H c). Further, it was observed that Curie temperature (T c) increases with increase in sintering temperature with the exception of CFM400. The catalytic performance of all the catalysts, including CFM400, CFM500, CFM600, CFM800, and CFM1000, was evaluated and the results indicate that CFM400 exhibits the highest catalytic activity for nitrophenols reduction and photodegradation of dyes, which could be accredited to its larger BET surface area and lower PL intensity. Overall, the structural and magnetic features of the catalyst's sheds light on the underlying mechanisms governing their catalytic activity. These insights offer valuable guidance in the designing and development of effective catalysts for sustainable wastewater treatment practices, emphasizing the importance of considering both structural and magnetic features in catalyst design. [ABSTRACT FROM AUTHOR]

Heterogeneous photocatalysts based on polyoxovanadates with Keggin structure (POV) supported onto zeolite (NH4ZSM‐5) were developed. The amount of POV incorporated was varied from 5% to 30% wt. Catalysts were characterized by N2 adsorption–desorption isotherms, FT‐IR, XRD, DRS UV–vis, TGA, and 31P MAS‐NMR techniques; and the catalytic activity was evaluated in azo dye degradation. The specific surface area decreased as the POV content increased because of zeolite pore blocking. The XRD patters presented the characteristic peaks of NH4ZSM‐5 and POV, with no additional diffraction peaks, assigned to a well dispersed POV. FT‐IR and 31P MAS‐NMR results confirm that the Keggin structure of [PVW11O40]4− anions remain unaltered after their inclusion in the zeolite. The incorporation of POV generated a redshift at the absorption border, determined by DRS UV–vis, which promotes its activity in the visible range. Moreover, while POV content increase the bandgap energy diminishes and the photocatalytic activity increased. The higher photoactivity was 80% of discoloration when 30% wt of POV was incorporated. The characterization and catalytic evaluation indicated that these materials present suitable properties to be used as catalysts in the photocatalytic treatment of wastewater, being the main advantage their easy separation and reuse without significant decrease of the photoactivity. [ABSTRACT FROM AUTHOR]

Biomass has a wide range of uses due to its cost-effectiveness and enormous diversity of functional groups. This research investigates the production of an inexpensive and efficient adsorbent using the stem waste charcoal (FTCC) of Tinospora cordifolia and its use in water decontamination, with a focus on the elimination of metal ions and dyes. The study shows that chemically functionalizing the surface of charcoal with APTES (3-Aminopropyltriethoxysilane) improves adsorption capabilities. Various characterization techniques, such as FTIR, FESEM, TGA, and BET studies, were used to evaluate the efficiency of FTCC. The results showed a considerable improvement in surface qualities that are favourable for adsorption. BET evaluations indicate that functionalized carbon has a high surface area of 1.45766 m2.g−1 and a pore volume of 0.534772 cm3.g−1. Adsorption data fit well with Langmuir model and follow pseudo-second-order kinetics. Thermodynamic parameters reveal the endothermic adsorption of Congo red dye and exothermic adsorption of Cr (VI) metal ion. The batch adsorption experiments revealed that FTCC was capable of removing various dyes and metal ions from aqueous solution, with adsorption capacity 65.22 mg/g for Congo red and 56.61 mg/g for Cr (VI). The FTCC showed good reusability potential up to 6th cycle. Additionally, tests with water samples containing contaminants have been conducted to demonstrate the best adsorbent quality of FTCC. The study highlights the feasibility of using functionalized charcoal FTCC derived from agricultural debris as a renewable alternative for restoring the environment and water remediation. [ABSTRACT FROM AUTHOR]

This study investigates the adsorption behavior of anionic (Congo red, Eosin yellow) and cationic (Malachite green) dyes on synthesized TD polymer particles, highlighting the material's potential as an effective adsorbent for industrial wastewater treatment. Key operational parameters, including initial solution's pH, contact time, initial dye concentration, and temperature, were systematically evaluated to determine their influence on adsorption efficiency. The experimental data demonstrated that the Langmuir isotherm provided the best fit for all three dyes, indicating monolayer adsorption with maximum adsorption capacities of 153.8 mg/g for Malachite green, 49.36 mg/g for Congo red, and 227.9 mg/g for Eosin yellow. Kinetic analysis revealed that the adsorption of Malachite green and Congo red followed pseudo‐second‐order kinetics, while Eosin yellow adsorption was better described by the intra‐particle diffusion model. Thermodynamic assessments, including Gibbs free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°), confirmed the spontaneous and endothermic nature of the adsorption processes for Malachite green and Eosin yellow, contrasting with the exothermic behavior observed for Congo red. These findings underscore the versatility and effectiveness of TD polymer particles in removing both anionic and cationic dyes from aqueous solutions. Further research could explore material optimization and real‐world applications to broaden their utility in sustainable water treatment strategies. [ABSTRACT FROM AUTHOR]

Textile industries utilize a variety of dyes and chemicals, resulting in wastewater that contains numerous hazardous components. The release of these dyes into aquatic systems poses a serious environmental and harms human health due to their persistence, recalcitrance, and nonbiodegradability. To address this, microbial bioremediation and nano‐photocatalysts are commonly employed for the effective removal of dyes and toxic compounds from textile effluents. This review explores the ecofriendly and efficient use of microbes, such as fungi, yeast, bacteria, and algae, in dye treatment, emphasizing their role in decolorization and degradation. Additionally, microbial remediation is highlighted as a clean, effective, and safe technology for detoxifying azo dyes in wastewater. The review also compares microbial and nanoparticle methods for dye removal from textile wastewater, examining the environmental impact of each approach. Furthermore, we have highlighted challenges and prospects for the development direction and future of this field. [ABSTRACT FROM AUTHOR]

In this study, the activated carbon (AC) was prepared from Sesbania sesban plant stem. Boric acid (H3BO3) was used as an activating agent. During calcination, the optimized temperature was kept upto 500 °C for 2 h. The prepared adsorbents were characterized using various techniques such as FT‐IR, scanning electron microscopy, energy dispersive x‐ray spectroscopy, and thermogravimetric analyzer. The prepared adsorbents were used for the removal of methylene blue (MB) dye adsorption. The adsorption experiments were conducted at different pHs such as (2–11), doses (0.0025–0.020 mg), times (30–300 min), MB initial concentrations (100–600 mg L−1), and temperatures (298–318 K), respectively. The maximum MB uptake capacity of the prepared adsorbent was 1380 mg g−1 under optimized adsorption conditions. Furthermore, the kinetic study is well described by pseudo‐second order, whereas the isothermal study showed the Freundlich isotherm was better followed by the equilibrium data. Based on thermodynamic studies, the negative values of ΔG° and ΔH° revealed that the MB adsorption process is spontaneous and exothermic in nature. However, the negative ∆Sxg° value indicates that solid‐solute interaction decreased randomness in the adsorption systems. The overall studies of AC showed that it was better to remove MB from an aqueous solution. [ABSTRACT FROM AUTHOR]

This work presents a green synthesis route, which utilises extracts from an indigenous plant in South Africa, eastern and southern Africa that is understudied and underutilised, for preparing zinc oxide nanoparticles (ZnO NPs). This study involved optimisation of the green synthesis method using Leonotis ocymifolia (L.O.) extracts and performing comparative studies on the effects of using different zinc (Zn) salt precursors; zinc sulphate heptahydrate (Z001) and zinc acetate dihydrate (Z002) to synthesise the ZnO NPs. The comparative studies also compared the L.O-mediated ZnO NPs and chemical-mediated ZnO NPs (Z003). The as-prepared ZnO NPs were tested for their effectiveness in the photodegradation of methylene blue (MB) dye. Furthermore, antibacterial studies were conducted using the agar well diffusion method on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria. The structural, morphological, and optical characteristics of the synthesised ZnO NPs were analysed using XRD, FTIR, SEM, EDS, DRS, and BET techniques. The XRD results indicated that the L.O-mediated ZnO NPs had smaller crystallite sizes (18.24–19.32 nm) than their chemically synthesised counterparts (21.50 nm). FTIR confirmed the presence of biomolecules on the surface of the L.O-mediated NPs, and DRS analysis revealed bandgap energies between 3.07 and 3.18 eV. The EDS results confirmed the chemical composition of the synthesised ZnO NPs, which were made up of Zn and O atoms. Photocatalytic studies demonstrated that the L.O-mediated ZnO NPs (Z001) exhibited a superior degradation efficiency of the MB dye (89.81%) compared to chemically synthesised ZnO NPs (56.13%) under ultraviolet (UV) light for 240 min. Antibacterial tests showed that L.O-mediated ZnO NPs were more effective against S. aureus than E. coli. The enhanced photocatalytic and antibacterial properties of L.O-mediated ZnO NPs highlight their potential for environmental remediation and antimicrobial applications, thus supporting sustainable development goals. [ABSTRACT FROM AUTHOR]

Due to the versatile usage and applications of chromium compounds in the industry worldwide, the chromium ions are present in the major effluents from a broad range of industries. Cr(VI) which is highly hazardous and carcinogenic poses a serious threat to the our ecosystem and human health even at very low concentration limits. Cr(III) ions are also toxic to aquatic life, but they are less harmful than Cr(VI) ions. Therefore, detection and analysis of the toxic Cr(VI) and Cr(III) ionic species in waste water are an utmost important area of research. Various chemical reagents and the different methods which require expensive instrumentation used in the past for detection and determination of the non-biodegradable Cr(VI) ions suffer from serious limitations. The present review summarises the use of spectrophotometric methods of determination of Cr(VI) and Cr(III) ions from aqueous solutions with high sensitivity, selectivity, accuracy and at lesser costs. The use of chemical reagents such as diphenylcarbazide (DPC) and several other dye-based reagents for spectrophotometric determination of hazardous Cr ions in water samples is discussed. Additionally, the use of DPC reagent in developing advanced technologies such as microfluidic detection system, microfluidic paper-based analytical devices (µPADs) and 3D printed device with online spectrophotometric detection system for onsite monitoring of water samples is elucidated. Different methods for selective speciation and preconcentration of Cr(VI) ions prior to spectrophotometric determination in water samples with very low concentrations (as low as ppb) of Cr ions are also described. The emerging trends in detection and determination of carcinogenic Cr(VI) ions involving the use of novel and innovative technologies and different categories of nanomaterials are also elucidated in the present review. [ABSTRACT FROM AUTHOR]

The present research employed ethylenediaminetetraacetic (EDTA) modified cellulose to remove basic violet 10 (BV10) and reactive orange 16 (RO16) dyes. The cellulose was obtained from sago bark which was solid waste of sago starch industries. Sago bark contains 56.86% cellulose so that it can provide significant amount of active site. The optimum condition was examined using batch method investigating some parameters including pH, initial dye concentration, contact time, and thermodynamics. The adsorption capacity of cellulose (Cell) itself was also investigated for the comparison. The characterization of adsorbent showed the presence of ester bond, amine groups and escalating of surface area and pores after EDTA modification. The adsorption capacity of EDTA‐modified cellulose (Cell‐EDTA) was 73.53 mg/g for BV10 and 22.42 mg/g for RO16. The adsorption of both dyes onto Cell‐EDTA followed Langmuir isotherm model and pseudo‐second‐order kinetic model. Thermodynamic parameters indicated that the adsorption process was spontaneous, endothermic and feasible. Desorption studies proved that NaOH was an effective desorbing agent of BV10 and RO16. Based on research, Cell‐EDTA was more favorable in cationic dye, basic violet 10 than anionic dye, reactive orange 16. [ABSTRACT FROM AUTHOR]

In this paper, CuFe2O4/PS nanocomposite was synthesized via co-precipitation method and explored for the adsorption performance and proposing mechanism for crystal violet and Bismarck brown removal. The synthesized material was characterized using X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometery, scanning electron microscopy–energy-dispersive X-ray, and transmission electron microscopy analyses. The batch experimental studies revealed that the CuFe2O4/PS nanocomposite exhibited excellent adsorptive performance with maximum adsorption capacity of 7.81 mg/g and 32.25 mg/g for CV and BBR dye, respectively, when compared to pristine peanut shell powder. Furthermore, only 1.5 g/L dose of the adsorbent was able to clean water having 10 mg/L of CV and 30 mg/L of BBR dye concentration. The thermodynamic investigations demonstrated that CV dye adsorption was an endothermic process whereas it was found exothermic for BBR dye. Besides this, the study revealed that the adsorption process occurred spontaneously across all temperatures studied. Additionally, the pseudo-second-order kinetic model was found to determine the reaction rate. The adsorption equilibrium was achieved within 75 min of contact time for both dyes. The nanocomposite material was also easily regenerated using 0.1 M HCl, with a regeneration efficacy of 59.44% for CV and 49.33% for BBR, despite four consecutive adsorption–desorption cycles. [ABSTRACT FROM AUTHOR]

This study investigates the adsorption of methylene blue (MB) and methyl orange (MO) dyes from aqueous solutions using purified Moroccan bentonite, being mainly composed of silica and alumina, in the form of quartz and cristobalite. The temperature controls the adsorption capacity for the kinetics, increasing 5.08% (from 295.1 to 310.1 mg/g) for the MB and 55.47% (from 86.8 to 134.9 mg/g) for the MO. It was discovered that the pseudo-second-order model, with a low Bayesian criterion indicator of 12.72 and R2adj > 0.996, was the best suitable for explaining both systems. The adsorption isotherm, experimental data indicate that both systems follow the Langmuir isotherm. At lower temperatures, 298.15 K 1.22 molecules are adsorbed per site. However, at a higher temperature of 328.15 K, the number of molecules is less than a unit of 0.68. As for MO, the number of molecules remains above 1.4 per site for all the temperatures studied. The endothermic nature of the system is indicated by the observation that the adsorption energy tends to grow for both systems: for the MB, it increases from 18.85 to 21.26 kJ/mol, and for the MO, it increases from 14.83 to 19.01 kJ/mol. Last, thermodynamic functions indicate that maximum entropy is reached around the half-concentration saturation at 25 and 124 mg/L, which is the maximum energetic concentration of the system. The same results were obtained for Gibbs free energy, where the maximum energy found was − 5.39 × 10−18 kJ/mol for the MB and − 1.99 × 10−18 kJ/mol for the MO at 328.15 K. [ABSTRACT FROM AUTHOR]

Organic chromophores have been successfully implemented into supramolecular systems to bestow them with distinct photophysical properties for various applications, ranging from solar energy conversion, photochemical reactions or as receptors for guest molecules with optical readout. We had previously introduced first members of the large family of coal‐tar dyes (methylene blue, crystal violet and rhodamine) as integral components of coordination cages. Here, we add two new chromophores, malachite green (MGP) and a purple phenazinium dye (PHP), serving as backbones of bis‐monodentate banana‐shaped ligands with pyridine donors. We show the formation of corresponding green and purple coloured Pd2L4 coordination cages and investigate their interaction with chiral guest molecules via UV‐Vis and CD spectroscopy. The PHP cage can be used to recognize nucleoside triphosphates, based on chirality transfer from the guests to the structurally flexible helicate. In combination with the already known methylene blue cage MBP we could further differentiate between all four canonical NTPs through characteristic changes in the observed CD signatures. [ABSTRACT FROM AUTHOR]

Organic luminogens play an indispensable role in optoelectronic devices, yet there is a pressing need to address their aggregation‐caused quenching (ACQ) and stability. Here we designed and prepared multilayered boron nitride nanosheets/fluorescein isothiocyanate (MBNNSs/FITC) composite phosphors with tunable photoluminescence by controlling the FITC content and annealing temperature. The research results indicate that MBNNSs/FITC with low or high loading of FITC is not conducive to enhancing the emission intensity of FITC, which can be attributed to the fact that low loading leads to a decrease in the content of fluorescent groups, while high loading promotes intermolecular aggregation of FITC dyes. Interestingly, the emission intensity of FITC in MBNNSs/FITC‐6 composite phosphors can be further enhanced by annealing treatment (200 °C), which can be ascribed to the suppression of the ACQ and effective energy transfer from the MBNNSs to the FITC. Moreover, the resultant composite phosphor displays outstanding thermal stability, remarkable photo stability and exceptional water‐resistance. This work provides a new design space for the development of non‐rare‐earth fluorescent materials using organic fluorescent dyes. [ABSTRACT FROM AUTHOR]

Despite the excellent thermometric performance of many developed luminescent nanomaterials, their use has not gone beyond proof‐of‐concept in vivo experiments to date. An important issue that needs to be resolved before moving toward true biomedical applications of engineered nanothermometers is their potential toxicity and bioaccumulation in the human body considering the ultimate objective of clinical applications. Since most reported nanothermometers currently are not degradable materials and are mainly based on the incorporation of heavy metal ions, these aspects remain of genuine concern in the fields of nanomedicine, nanobiotechnology, nanotoxicology, and nanopharmacology. This work explores the possibility of designing visible, as well as near‐infrared, emitting luminescent ratiometric nanothermometers based on appropriate organic dye mixtures embedded in hollow disulfide‐bridged periodic mesoporous organosilica (PMO) particles. Such hybrid particles show excellent thermometric performance in the physiological temperature range (20–50 °C), favorable degradability in simulated physiological conditions, as well as no toxicity to healthy normal human dermal fibroblast (NHDF) cells in a wide concentration range. Considering the simplicity of the approach from the synthetic point of view, and the large available library of known fluorescent dyes emitting in various regions of the electromagnetic range, this motif renders a very promising approach to designing novel non‐toxic, decomposable, luminescent ratiometric thermometers. [ABSTRACT FROM AUTHOR]

This article reports the synthesis, along with structural and photophysical characterization of 2‐(2'‐hydroxyphenyl)benzazole derivatives functionalized with various azaheterocycles (pyridine, pyrimidine, terpyridine). These compounds show dual‐state emission properties, that is intense fluorescence both in solution and in the solid‐state with a range of fluorescent color going from blue to orange. Moreover, the nature of their excited state can be tuned by the presence of external stimuli such as protons or metal cations. In the absence of stimuli, these dyes show emission stemming from anionic species obtained after deprotonation (D* transition), whereas upon protonation or metal chelation, ESIPT process occurs leading to a stabilized and highly emissive K* transition. With the help of extensive ab initio calculations, we confirm that external stimuli can switch the nature of the transitions, making this series of dyes attractive candidates for the development of stimuli‐responsive fluorescent ratiometric probes. [ABSTRACT FROM AUTHOR]

Many organic dyes are fluorescent in solution. In the solid state, however, quenching processes often dominate, hampering material science applications such as light filters, light‐emitting devices, or coding tags. We show that the dimethylene‐cyclopropanide scaffold can be used to form two structurally different types of chromophores, which feature fluorescence quantum yields up to 0.66 in dimethyl sulfoxide and 0.53 in solids. The increased fluorescence in the solid state for compounds bearing malonate substituents instead of dicyanomethide ones is rationalized by the induced twist between the planes of the cyclopropanide core and a pyridine ligand. [ABSTRACT FROM AUTHOR]

Valorizing biodegradable raw materials derived from agri‐waste is ecologically beneficial. Employing such materials to produce adsorbents is a smart platform for applications in wastewater purification. Lignin is one of the most plentiful natural biopolymers in the world. Its macromolecular structure possesses phenolic and carboxyl groups that can capture heavy metals and dyes. Lignin can be chemically and physically modified to generate adsorbent materials with enhanced capacity to remove pollutants from wastewater. In this work, lignin has been used as a natural resource to synthesize metal oxide‐based nanoadsorbents. The synthesized lignin‐based green nanomaterials effectively removed common pollutants from wastewater including dyes, heavy metals, and bacteria. The lignin‐based water purification technique holds immense potential to effectively remove the most common pollutants from wastewater. [ABSTRACT FROM AUTHOR]

This study investigates the adsorption of pollutants with different chemical structures; organic Naphtol Green B (NGB) dye and copper on a nanocomposite material with a hexagonal structure of the SBA-15 type. This research is divided into two main parts: the first carries out the synthesis of SBA-15 (Santa Barbra Amourphous) and its derivatives phases functionalized by 3-aminopropyl-triethoxylane (APTES) and calcined at 823 K. The second part presents the influence of the adsorption conditions on the adsorption efficiency of NGB dye and copper. High-resolution X-ray diffractogram (XRD) showed three distinct peaks characteristic of highly ordered mesoporous material. Nitrogen adsorption–desorption isotherm of SBA-15 at 77 K° is type IV typical of mesoporous materials. In addition, Fourier transform infrared spectroscopy (FT-IR) was also used in the characterization before and after the adsorption of the selected pollutants. At optimal conditions of pH 5.2, initial concentration of 50 mg/L, adsorbent dosage of 20 mg, and at adsorption time of 90 min the maximum removal of pollutants reached 76% and the adsorption capacity was 227.25 mg/g for NGB dye and 221.006 mg/g for copper. Furthermore, the adsorption kinetics followed the pseudo-second-order model, indicating that chemisorption was the dominant mechanism and the Sips isotherm model best described the adsorption data. Our research demonstrates that the SBA-15 material after modification is an effective adsorbent for removing effluents regardless of their different chemical structure (organic and inorganic). [ABSTRACT FROM AUTHOR]

During the last decade, thermally activated delayed fluorescence has been the topic of intense research due to its great potential for highly efficient all organic light emitting devices. While the quinazoline heterocycle has been used for its electron withdrawing ability in various push‐pull dyes, quinazoline derivatives have been rarely considered for TADF emitters. Here we design and synthesize a new series of dyes with phenyl‐ or methoxy‐substituted quinazoline rings combined with 9,9‐dimethylacridan, phenoxazine or phenothiazine and either 1,4‐phenylene or 2,5‐thienylene as linker. Combining optical spectroscopy and theoretical investigations, we demonstrate that delayed fluorescence is observed in the solid state for the phenyl‐substituted quinazoline derivatives for which both quasi‐equatorial and quasi‐axial conformations are predicted to coexist. Calculations further suggest that the reversed intersystem crossing is likely to involve the second triplet state that shows small energy splitting with the first singlet state. These results prompt further investigations of phenyl‐substituted quinazoline based dyes for TADF. [ABSTRACT FROM AUTHOR]

The principal objective of this article is a thorough analysis of the usage of inexpensive adsorbents to eliminate dyes from different aquatic environments. Dyes, commonly employed in industries—textiles, pharmaceuticals, and food, pose a significant environmental concern due to their persistence and potential toxicity. In response, researchers have explored the efficacy of low‐cost adsorbents (LCAs) as sustainable and economical alternatives for dye elimination. An overview of the environmental effects of dye contamination and the difficulties in using traditional dye removal techniques is given at the outset of the paper. It then delves into the diverse range of LCAs, including agricultural by‐products, waste materials, and natural substances, that have shown promise in adsorbing and eliminating dye contaminants. Examples of such adsorbents include activated carbon (AC) derived from agricultural residues, bio‐adsorbents from various plant materials, and industrial by‐products with inherent adsorption properties. Key mechanisms involved in the adsorption process, such as surface chemistry, pore structure, and electrostatic interactions, are elucidated to offer a fundamental understanding of the sorption capabilities of these materials. This comprehensive review consolidates the current knowledge on dye removal utilizing LCAs, offering insights into the challenges, advancements, and future directions in this environmentally significant field. The findings underscore the potential of harnessing readily available, sustainable materials as effective sorbents for mitigating the adverse impacts of dye pollutants in aqueous systems. The adsorption capacity is comparable to supplementary adsorbents suggested for the removal of dyes. The widely accessible adsorption properties of basic and acidic dyes do not significantly differ from one another. [ABSTRACT FROM AUTHOR]

Nanotechnology has enormous, economic, social, and environmental ramifications. Due to their capacity to survive in complex processes, inorganic nanomaterials like metal/metal oxides have received substantial study during the past decade. Nanoparticles have antibacterial, magnetic, electrical, and catalytic characteristics due to their greater surface area. There are several methods to develop nanoparticles but environment friendly behavior with no toxic byproducts attracts researchers toward biological process of nanoparticles. This work synthesizes copper oxide (CuO) nanoparticles and zinc oxide (ZnO) with Aloebarbadensis (Aloe vera) leaves extract and successfully characterizes them with different analytical techniques. The catalytic activity of such nanoparticles tests over different cationic and anionic dyes like methylene blue (MB), methyl orange (MO), and methyl red (MR) for different intervals of time and reveals. The degradation efficiency of CuO nanoparticles for MB, MO, and MR dyes are 59.92%, 73.48%, and 73.10% respectively, and for ZnO nanoparticles it is 81.44%, 76.46%, and 63.30% for MB, MO, and MR dyes respectively under the exposure of sunlight for 8 h. The present work successfully develops an ecofriendly process of dye degradation by biologically synthesized nanoparticles. [ABSTRACT FROM AUTHOR]

ABSTRACT Nowadays, surface‐enhanced Raman spectroscopy (SERS) has become a powerful tool for rapidly detecting and analyzing textile cultural relics due to its ability to provide chemical information with single‐molecule sensitivity. However, preserving a high level of detection sensitivity while avoiding sample damage remains a persistent challenge. In this work, we developed a SERS approach with both microextraction and detection functions. The alcohol–water droplet with iodide‐modified Au nanoparticles (AuIMNPs) is directly dropped on the textile, where dyes strongly bound on textiles can be extracted by ethanol (EtOH). As a result, the sample can be well preserved from being damaged. In particular, the volatility of EtOH allows the molecules to be captured in the hot spots through the capillary effect during droplet evaporation, resulting in a dramatic increase in Raman signal intensity. This highly sensitive strategy can be used to measure dyes in plant extracts and mock‐up textiles. Furthermore, the capability of SERS to provide fingerprint information allows us to distinguish different dyes in overdyeing textiles. Eventually, this approach is successfully applied to identify dyes of authentic ancient Chinese textiles. This rapid, universal, and negligibly invasive approach provides a powerful way to study textile cultural relics. [ABSTRACT FROM AUTHOR]

Dyes are one of the most threatening toxins released from industry. Methylene blue (MB) is one of the extremely common dyes in the textile industry. Being complicated in structure and non-biodegradable in nature, removing MB from the aqueous environment is a great challenge. Elimination of dye is usually performed in two ways, degradation, and adsorption. Iron-based nanoparticles, being biocompatible and non-expensive, became a hot field of research in the context of the elimination of toxic dyes. In our review article, we consolidated the data about the synthesis, nature, state, and applications of iron-based nanoparticles to remove MB dye from aqueous solutions specifically via adsorption and degradation. We also reviewed the effect of doping on nanoparticles and their effects on dye removal capacity. Physiological factors such as pH, and temperature play an important role in iron-based nanoparticle synthesis as well as dye degradation and adsorption. A comparative account between adsorption and degradation was tried to depict the elimination of dye in various aspects including efficiency and mechanism. [ABSTRACT FROM AUTHOR]

The current study proposes an introduction of interfering ions to the reaction medium as a simple way for obtaining efficient visible-light driven photocatalysts with active surface based on ZnO nanosheets. 9 samples with different morphological and structural parameters were obtained via simple and inexpensive precipitation and hydrothermal methods. XRD, SEM, FTIR, SSA, XPS, Raman, absorption spectra and DLS methods were used for ZnO nanosheet characterisation. An original approach was used to determine the amount of defects by processing Raman spectra via software specially designed for this purpose. XPS was used to estimate an overall amount of oxygen vacancies in the samples, and the DFT method was employed to model oxygen vacancies in the crystal structure. The latter were verified via absorption spectra. The most effective sample showed a dye degradation efficiency of 94 % after 60 min of irradiating by a common LED lamp available in a local store. The kinetic studies showed that the rate of adsorption and photodegradation depends on the DFT-calculated "surface-dye" interaction energy. Consequently, by regulating the ratio of ZnO nanosheet surface parameters, adsorption and photodegradation efficiency against a particular dye can be improved. [Display omitted] [ABSTRACT FROM AUTHOR]

The decolourisation of Bismarck Brown dye by the newly isolated bacterial strain, Pseudomonas aeruginosa (JKAK), was studied at various parameters. Additionally, decolourisation of Bismarck Brown was studied using previously isolated strains; Bacillus sp. (AK1), Lysinibacillus sp. (AK2) and Kerstersia sp. (VKY1). The studies were carried out at temperature (35–50°C), dye concentration (200–800 mg/L), pH (5.5–10.5), metal ions (200–1000 mg/L) and NaCl (5–30 g/L). The optimum pH and temperature were 8.5 and 40°C, respectively. The strains decolourised over 53.75% of 800 mg/L Bismarck Brown after 24 h of incubation. The JKAK strain showed significant halotolerance and decolourised over 90% of the dye in the presence of 30 g/L NaCl. Further, JKAK decolourised over 86.4% of the dye in the presence of 1000 mg/L of Pb2+ and Zn2+ ions. The products of decolourisation were identified as aromatic amines and showed decreased phytotoxicity when compared to the untreated dye. [ABSTRACT FROM AUTHOR]

This research investigates methylene blue as a high-performance photocatalyst in the photo-oxidation conversion of alcohols to aldehydes. The present study investigates the optimal conditions for the solvent effect, catalyst, and oxidant amount. The objective is to identify the most practical combination of these factors to optimize the desired outcome of the experiment. The notable characteristics of this transformation include its gentle conditions, the use of a metal-free organic dye as a photocatalyst, and TBHP's dual function as both a radical initiator and a means for regenerating the photocatalyst. This research provides valuable insights into the potential of methylene blue as a high-performance photocatalyst in the photo-oxidation reaction of alcohols, paving the way for more efficient photocatalytic processes. [ABSTRACT FROM AUTHOR]

The transition from lab-scale studies to pilot-scale applications is a critical step in advancing water remediation technologies. While laboratory experiments provide valuable insights into the underlying mechanisms and method effectiveness, pilot-scale studies are essential for evaluating their practical feasibility and scalability. This progression addresses challenges related to operational conditions, effectiveness and energy requirements in real-world scenarios. In this study, the potential of nanopulsed plasma bubbles, when scaled up from a lab environment, was explored by investigating critical experimental parameters, such as plasma gas, pulse voltage, and pulse repetition rate, while also analyzing plasma-treated water composition. To validate the broad effectiveness of this method, various classes of highly toxic organic pollutants were examined in terms of pollutant degradation efficiency and energy requirements. The pilot-scale plasma bubble reactor generated a high concentration of short-lived reactive species with minimal production of long-lived species. Additionally, successful degradation of all pollutants was achieved in both lab- and pilot-scale setups, with even lower electrical energy-per-order (EEO) values at the pilot scale, 2–3 orders of magnitude lower compared to other advanced oxidation processes. This study aimed to bridge the gap between lab-scale plasma bubbles and upscaled systems, supporting the rapid, effective, and energy-efficient destruction of organic pollutants in water. [ABSTRACT FROM AUTHOR]

Currently, water pollution caused by dyes is a serious problem since they are toxic and carcinogenic to living beings. To reduce the presence of these contaminants, natural adsorbents have been considered as they are easy to obtain, inexpensive, and have high removal efficiency. In this work, the adsorption process using natural brushite (nDCPD) was studied for the removal of phenol red (PR), achieving a removal rate of 99.15% and an adsorption capacity of 82.24 mg/g, and gentian violet (GV), achieving a removal rate of 97.03% and an adsorption capacity of 74.22 mg/g. Equilibrium adsorption occurs for both dyes in multiple layers on the surface. The adsorption process is spontaneous for both dyes. The kinetics of the adsorption process involve using a single active site on the surface for PR adsorption, while for GV, two active sites on the surface are required. Analysis via FTIR, EDS, and XRD revealed various mechanisms that intervene in the adsorption process of both dyes on the surface of nDCPD, such as electrostatic forces, functional groups, physisorption, and ion exchange. [ABSTRACT FROM AUTHOR]

Sorption technologies have been proposed for the treatment of water containing methylene blue (MB), a toxic and persistent pollutant. Despite its environmental risks, the role of process variables in MB removal has not been fully explored through experimental design. The objective of this study is to assess the potential of bone meal powder (BMP), an underexplored agricultural byproduct, as an affordable adsorbent for the removal of MB from water. BMP was subjected to a series of analytical characterization techniques, and its adsorption capacity was evaluated through a comprehensive factorial design, which investigated the effects of biosorbent dosage, solution pH, and initial MB concentration. The study revealed that the highest adsorption level was 14.49 mg g-1, attained under the following conditions: 1 g L-1 BMP, pH 11, and 100 mg L-1 MB. The adsorption equilibrium was reached within 60 min, with a measured capacity (qexp) of 18 mg g-1. Theoretical adsorption isotherms indicated a capacity of 63 mg g-1, which aligned well with the Langmuir model. To predict adsorption outcomes, machine learning models were applied, with multiple linear regression performing best. Optimization of decision trees and neural networks improved accuracy but risked overfitting. FT-IR, XRD, and ICP analyses indicated ion exchange as a significant mechanism of adsorption. In desorption studies, H2SO4 was the most effective agent, achieving 68.72% desorption efficiency. BMP exhibited optimal recyclability for up to four cycles before efficiency declined. [ABSTRACT FROM AUTHOR]

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In this study, we developed TiO2-coated aluminum (TiO2/Al) surfaces using eco-friendly methods to create efficient and environmentally friendly photoactive materials with the potential to enhance water purification systems. TiO2 particles were deposited onto aluminum foil surfaces via a spray method, followed by heat treatment at 200 °C for 15 min. The morphology of the TiO2/Al surfaces, both before and after photocatalytic treatment, was characterized using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The photocatalytic properties of these modified surfaces were evaluated through the degradation of rhodamine B (RB), methylene blue (MB), and methyl orange (MO) under simulated solar and UV–LED irradiation. Among the dyes tested, MO exhibited the highest degradation, influenced by factors such as absorption maximum, molecular structure, charge, and the number of condensed rings. The computational study of interactions between dye molecules and the combined nanoparticle revealed that the binding was the strongest in the case of MO dye. This study also explored the influence of varying the number of TiO2/Al surfaces in solution (one, five, and ten) on the photodegradation efficiency. The solution with five TiO2/Al surfaces demonstrated optimal performance, achieving a 16% degradation of RB. The reusability of the TiO2/Al surfaces was confirmed through five successive runs of RB degradation. The results indicate that TiO2/Al surfaces are a promising solution for addressing water contamination challenges and advancing sustainable water treatment practices. [ABSTRACT FROM AUTHOR]

Pollutant removal from different sources, especially water pollutants, is a major concern in today's world. Various methodologies were being utilized to purify water resources because water scarcity is a major problem of the twenty-first century. In the current study, we searched and discovered novel green, renewable, cost-effective, environmentally benign, and readily available adsorbent Aerva Javanica (A. Javanica), for remediation of selected fourteen (14) dyes from aqueous media. A quantitative structure–property relationship model was developed to relate the structural properties of dyes with the percentage adsorption based on data and information which was collected by the adsorption study of these selected dyes. The structures of these dyes were optimized using MOPAC2016 and DRAGON software and further used for descriptors calculation. Initially, 1666 descriptors were calculated. The heuristic method was employed to select significant descriptors, and after pre-reducing steps, we left with 36 descriptors. Stepwise multiple linear regression (SMLR) analysis followed by artificial neural network (ANN) was employed on these descriptors for model generation. The SMLR-ANN model has shown better predictive ability (R2 = 0.9907) than only the SMLR model (R2 = 0.9778). Validation of the model was performed by internal validation by measuring cross-validation squared correlation coefficient (Q2 = 0.921) and external validation (predictive R2 = 0.9211). Significant descriptors calculated for modeling include Mor10e, HATS5p, nHAcc, E3m, and GATS5v. All these descriptors are built on basic molecular properties like molecular structure, electronegativity, and polarity. So the model is significant in this regard as it relates basic molecular properties with their adsorption potential. Generated models have shown good robustness, stability, and predictive ability. [ABSTRACT FROM AUTHOR]

Advances in green engineering and technology have revealed a number of environmentally acceptable alternatives for water purification. In line with this, recent advances in biosorption of pollutants from aqueous solutions using animal biowaste-based activated carbon (AC) are reported herein. Apart from the fish scale-derived AC which is extensively documented, animal bones, among the rest others, have been studied most widely, followed by hair and feathers. Out of the various target water pollutants, removal of heavy metals has been mostly studied. Majority of the reports showed the Freundlich isotherm and pseudo second order as the best fit. Few investigations on the thermodynamics of the adsorption studies and reports on the Gibbs free energy change (ΔG°), enthalpy change (ΔH°), and entropy change (ΔS°) have also been discussed in this report. It has been concluded that while plant-based AC has gained wide interest, the same is not true for the animal-based counterpart albeit the latter's potential for high sorption efficiency as seen in the present report. [ABSTRACT FROM AUTHOR]

The contamination of water by organic dye compounds are worldwide environmental problem due to their highly toxic nature. To address this environmental issue, a simple technique with highly efficient dye removal was developed to prepare pH‐ sensitive dual‐crosslinked anionic and amphoteric interpenetrating network (IPN) hydrogels based on Na‐carboxymethyl cellulose (Na‐CMC) using jute stick‐based cellulose. Crosslinked Na‐CMC and crosslinked κ‐carrageenan (KC) were interlaced by H‐bonding in anionic IPN hydrogel (An‐gel), but crosslinked Na‐CMC and crosslinked Chitosan (CS) were interlaced by electrostatic interaction in amphoteric IPN hydrogel (Am‐gel). In various operating conditions (pH, temperature, etc.) An‐gel displayed a higher number of swelling ratios of about 2560% at pH 7.2 and Am‐gel of about 1874% at pH 5.5. Based on the point of zero charge, An‐gel achieved the maximum removal efficiency of 81.62 % for methylene blue (MB) at pH 7.2, whereas Am‐gel achieved 85.38% removal efficiency for eosin yellow (EY) at pH 5.5. The adsorption kinetics of IPN hydrogels followed a pseudo‐second order model and best fitted by Langmuir isotherm model. The removal efficiency of MB and EY decreased slightly with increasing temperature. The values of ΔH°, ΔG°, and ΔS° indicated an exothermic, spontaneous, and disordered adsorption process. [ABSTRACT FROM AUTHOR]

This study focused on the development of an efficient preparation method of activated carbon for the removal of para-phenylenediamine (PPD) dye in an aqueous solution. Walnut shells, a readily accessible biomass source in northern Iraq, were processed into activated carbon (AC). Several techniques, such as FTIR, XRD, and SEM, were applied to describe and study the surface of AC. According to XRD analysis, all the reflection peaks with the relative intensities of various planes indicate that the obtained particle size was around 7.63 nm. The influences of contact time, adsorbent, and other variables (the thermodynamic parameters for the influence of temperature) were calculated after studying the dosage and initial concentration. The effects of the change in the acidity functions and the increasing temperature were also studied. The results found that the best adsorption occurred in 120 min, with a 0.1 g adsorbent substance weight and pH 5. The adsorption rate was at its best at a temperature of 318 K. The best-recorded adsorption rate was obtained when applying the Langmuir and Freundlich isotherms, and the adsorption processes were of a physical nature.

The printing and dyeing wastewater has high chromaticity, biorefractory properties, and significant toxicity. In this study, PVDF-PVA/GO was synthesized for dyes' adsorption with various chemical properties. Incorporating graphene oxide (GO) into the composite substantially enhanced the hydrophilicity and electronegativity of the PVDF membrane. Results indicated that the adsorption efficiencies for rhodamine B (RhB) and methylene blue (MB) are higher than those of methyl orange (MO) and bromocresol green (BCG). At an initial pH of 8, the maximum adsorption capacities for RhB and MB were 11.81 and 9.25 mg/g, respectively, while MO and BCG indicated considerably lower capacities of 0.59 and 0.63 mg/g, respectively. The cyclic utilization of the PVDF-PVA/GO revealed minimal degradation in adsorption efficiency. The adsorption kinetics of the four dyes primarily follow intra-particle diffusion mechanisms, resulting in the binding of dye molecules to the PVDF-PVA/GO membrane through electrostatic interactions. Notably, competitive adsorption phenomena were observed in mixed dye systems, especially between RhB and MB. Comparative analyses indicated an increased adsorption capacity for MB in the mixed dye system, accompanied by a notable reduction in the adsorption capacity of RhB. This study provides a theoretical foundation for the remediation of printing and dyeing wastewater. Highlights: PVDF-PVA/GO membrane was prepared for the printing and dyeing wastewater treatment. The loading of GO significantly improved the hydrophilicity of PVDF membranes. Anionic, cationic, and non-ionic dyes exhibited opposite adsorption. There are differences in adsorption between single-dye and mixed-dye systems. [ABSTRACT FROM AUTHOR]

Abstract To obtain high efficient elimination of ammonia (NH4 +) from wastewater, Cu(II), Ni(II), and Co(II)) were loaded on Dowex-50WX8 resin (D-H) and studied their removal efficiency towards NH4 + from aqueous solutions. The adsorption capacity of Cu(II)-loaded on D-H (D-Cu2+) towards NH4 + (qe = 95.58 mg/g) was the highest one compared with that of D-Ni2+ (qe = 57.29 mg/g) and D-Co2+ (qe = 43.43 mg/g). Detailed studies focused on the removal of NH4 + utilizing D-Cu2+ were accomplished under various experimental conditions. The pseudo-second-order kinetic model fitted well the adsorption data of NH4 + on D-Cu2+. The non-linear Langmuir model was the best model for the adsorption process, producing a maximum equilibrium adsorption capacity (qmax = 280.9 mg/g) at pH = 8.4, and 303 K in less than 20 min. The adsorption of NH4 + onto D-Cu2+ was an exothermic and spontaneous process. In a sustainable step, the resulting D-Cu(II)-ammine composite from the NH4 + adsorption process displayed excellent catalytic activity for the degradation of aniline blue (AB) and methyl violet 2B (MV 2B) dyes utilizing H2O2 as an eco-friendly oxidant.

In this review, topic modeling—an unsupervised machine learning tool—is employed to analyze research on pigments in cultural heritage published from 1999–2023. The review answers the following question: What are topics and time trends in the past three decades in the analytical study of pigments within cultural heritage (CH) assets? In total, 932 articles are reviewed, ten topics are identified and time trends in the share of these topics are revealed. Each topic is discussed in-depth to elucidate the community, purpose and tools involved in the topic. The time trend analysis shows that dominant topics over time include T1 (the spectroscopic and microscopic study of the stratigraphy of painted CH assets) and T5 (X-ray based techniques for CH, conservation science and archaeometry). However, both topics have experienced a decrease in attention in favor of other topics that more than doubled their topic share, enabled by new technologies and methods for imaging spectroscopy and imaging processing. These topics include T6 (spectral imaging techniques for chemical mapping of painting surfaces) and T10 (the technical study of the pigments and painting methods of historical and contemporary artists). Implications for the field are discussed in conclusion.

Activated carbon was prepared at 300 °C and 600 °C, characterized by SEM, EDX and XRD, and was then used as an adsorbent for the removal of acidic dyes; acid yellow 25 and acid red 4. The activated carbon prepared at high temperature (600 °C) due to its high carbon contents and surface area was subsequently used as adsorbent for the selected dyes adsorption using batch adsorption approaches to estimate different adsorption parameters. For the estimation of kinetics and equilibrium parameters a number of kinetics and isotherm models were employed. Dyes were adsorbed on activated carbon surface at a high rate for the first 15 min, after which it began to diffuse into the micro pores and thus the process became steady. The rate constant was estimated for first and second order kinetics models. The maximum adsorption capacities recorded were 526.32 mg g−1 for acid red 4 and 555.55 mg g−1 for acid yellow 25. The enthalpy change values recorded were; 19.44 kJ mol−1 for acid yellow 25 adsorption and 16 kJ mol−1 for acid red 4 adsorption, meant that the process is endothermic. The negative values of Gibbs free energy change (−393.28, −1,515.48, −2,634.68 J mol−1) of acid red 4 and acid yellow 25 (−251.72, −1,058.06, −2,367.84 J mol−1) at tested temperatures, confirmed the feasibility and spontaneity of the adsorption processes. The adsorption of dyes on the carbon surface was diffusion-controlled process, as demonstrated by the linear graph of intraparticle diffusion model. [ABSTRACT FROM AUTHOR]

One major environmental issue responsible for water pollution is the presence of dyes in the aquatic environment as a result of human activity, particularly the textile industry. Chitosan–Polyvinylpolypyrrolidone (PVPP) polymer composite beads were synthesized and explored for the adsorption of dyes (Bismarck brown (BB), orange G (OG), brilliant blue G (BBG), and indigo carmine (IC)) from dye solution. The CS-PVPP beads demonstrated high removal efficiency of BB (87%), OG (58%), BBG (42%), and IC (49%). The beads demonstrated a reasonable surface area of 2.203 m2/g and were negatively charged in the applicable operating pH ranges. TGA analysis showed that the polymer composite can withstand decomposition up to 400 °C, proving high stability in harsh conditions. FTIR analysis highlighted the presence of N-H amine, O-H alcohol, and S=O sulfo groups responsible for electrostatic interaction and hydrogen bonding with the dye molecules. A shift in the FTIR bands was observed on N-H and C-N stretching for the beads after dye adsorption, implying that adsorption was facilitated by hydrogen bonding and Van der Waals forces of attraction between the hydroxyl, amine, and carbonyl groups on the surface of the beads and the dye molecules. An increase in pH increased the adsorption capacity of the beads for BB while decreasing OG, BBG, and IC due to their cationic and anionic nature, respectively. While an increase in temperature did not affect the adsorption capacity of OG and BBG, it significantly improved the removal of BB and IC from the dye solution and the adsorption was thermodynamically favoured, as demonstrated by the negative Gibbs free energy at all temperatures. Adsorption of dye mixtures followed the characteristic adsorption nature of the individual dyes. The beads show great potential for applications in the treatment of dye wastewater. [ABSTRACT FROM AUTHOR]

The Dagulf Psalter is a precious Carolingian manuscript on calf parchment, dated to 793–795. Its unique and high historical value required a non-invasive, multi-analytical approach to gain insights into the material composition of gold and silver inks, pigments, and dyes used for writing and illuminations. Elemental mapping based on X-ray fluorescence analysis (XRF), Fibre Optics Reflectance Spectroscopy (FORS) measurements, and hyperspectral imaging (HSI) gave complementary information on colour media and their brilliant shades. Knowledge of the material composition of inks, dyes, and pigments is of crucial importance not only for art historical research, but also for the preservation of the manuscript, as it is known that among other factors, silver inks and some pigments can lead to deterioration of parchment supports. The purple dye orchil and blue indigo were used for painted backgrounds on the initial folios. Lapis lazuli was found in decorative frames on these folios. Orchil, indigo, and lapis lazuli also appear in decorations of small initials throughout the manuscript. Red lead, ochre, cinnabar, orpiment, and lead white were also found in various painted details. Gold and silver inks of high purity were identified. The proof of chlorine in the silver ink indicates the presence of corrosion products. [ABSTRACT FROM AUTHOR]

The lanasyn black is among the most often used in manufacturing and is challenging to take out during the treatment of wastewaters from textile industry. The cloud point extraction was used for their elimination from an aqueous solution. The multivariable process parameters have been independently optimized using the central composite design and the Levenberg-Marquardt algorithm-based artificial neural network for the highest yield of the extraction of lanasyn black via the cloud point extraction. The CCD forecasts the output maximum of 97.01 % under slightly altered process parameters. Still, the ANN-LMA model predicts the extraction yield (99.98 %) using 1.04 g of KNO3, the beginning pH of solution 8.99, the initial content of lanasyn black 24.57 ppm and 0.34 mass % of Triton X-100. With the coefficients of determination of 0.997 and 0.9777, the most recent empirical verification of the model mentioned above predictions using CCD and ANN-LMA is determined to be satisfactory. [ABSTRACT FROM AUTHOR]

Background: Strongyloidiasis, a parasitic infection, presents a significant public health challenge in tropical regions due to the limited repertoire of effective treatments. The screening of chemical libraries against the therapeutically relevant third-stage larvae (L3) of the model parasite Strongyloides venezuelensis yielded meager success rates. This situation is reminiscent of Gram-negative bacteria, where drug entry is a limiting factor. Methods: Here, we set out to determine whether similar barriers are in place and establish whether structural and property requirements exist for anti-strongyloides drug discovery. We focused on dyes as their uptake and effects on viability can be independently assessed in the multicellular parasite, thus providing a means to study the possibility of similar entry rules. We tested different dyes in in vitro assays on L3s. Results: We found that staining was necessary to reduce parasite viability, with some dyes achieving anti-strongyloides effects at concentrations similar to those of the reference drug, ivermectin (IV). Some dyes also showed activity against female adults at concentrations well below that of ivermectin. Unfortunately, the most potent dye, Methylene Blue, was unable to prevent the infection in a preliminary in vivo mouse model assay, presumably due to fast dye clearance. Structural analysis showed that positive charges facilitated the access of the compounds to the L3 tissue, thus providing a structural tool for the introduction of activity. For female adults, low globularity is additionally required. As a proof of concept, we added a positive charge to an inactive compound of one of our chemical libraries and re-determined the activity. Conclusions: These findings allow us to establish structural rules for parasite entry that could be of interest for future drug screening or drug development campaigns. These rules might also be applicable to other related parasites. [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]

Industrial wastewater discharge, tainted with hazardous substances, including dyes like methylene blue (MB) from the textile sector, further emphasizes the need for water treatment to produce safe drinking water. This study explores the potential of olive mill solid waste, an abundant and cost-effective agricultural waste in Mediterranean regions, to yield high-quality activated carbon (AC) with zinc chloride activation for MB adsorption. The activation process, carried out at a modest temperature of 500 °C without the need for an inert atmosphere, resulted in AC with remarkable characteristics, boasting a substantial surface area of 1184 cm2·g−1 and a total pore volume of 0.824 cm3·g−1. Extensive characterization of the AC was carried out through a large range of surface techniques. The pH of the solution had minimal influence on MB adsorption, the maximum removal was 95%, which was under slightly acidic pH conditions (5.8), and the adsorbent dose was 0.4 g·L−1 for a 50 mg·L−1 MB concentration. Equilibrium data pertaining to MB adsorption were subjected to fitting with different models, namely Langmuir, Freundlich, and Temkin. Notably, the Langmuir model exhibited the best fit, revealing a maximum monolayer adsorption capacity of 500 mg·g−1 at 25 °C, and the adsorption kinetics closely followed a pseudo-second-order model. [ABSTRACT FROM AUTHOR]