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Recent advances in photocatalysis include the development of floating catalysts since they assure efficient and rapid recollection of the catalysts from the purified liquid, besides enhancing the availability of photons at the catalytic surface. Bismuth ferrite (BiFeO3 and BFO) is a multifunctional perovskite material renowned for its excellent photocatalytic properties. Since bandgap of BFO falls in the visible spectrum, BFO nanoparticles could be combined with a suitable floating substrate to develop efficient visible light photocatalysts. Here, we report the synthesis of BFO–polydimethylsiloxane (PDMS) hybrids for photocatalytic applications, where sol-gel–synthesized BFO nanoparticles are immobilized on a floating porous PDMS sponge. The successful incorporation of the nanoparticles on PDMS is confirmed using Raman spectroscopy, scanning electron microscopy, and energy dispersive x-ray spectroscopy. The photocatalytic activity of the floating catalysts was studied by monitoring the degradation of malachite green dye under visible light irradiation. The effect of the amount of BFO immobilized, and the area and thickness of the PDMS sponge on the photocatalytic activity of the floating catalysts were investigated. An efficiency of 80.5% was obtained when the weight of BFO immobilized on the PDMS sponge was 5 mg. The method yields degradation efficiencies comparable with or higher than that of conventional BFO powder catalysts, even with 6–18 times less catalyst loading. The method introduces the fabrication of recyclable floating photocatalysts of notable efficiency using significantly less amount of BFO nanoparticles, which could be further modified by approaches such as doping, functionalization, or composite formation. [ABSTRACT FROM AUTHOR]

Synthetic textile dye malachite green (MG) and heavy metals present in industrial wastewater are hazardous to the ecosystem. Bioremediation of dyes and heavy metals using dry-biomasses has advantages over chemical methods. This study screened an acclimatized, heavy metal-resistant, and dye-degrading Gram positive Bacillus licheniformis AG3 strain from the textile wastewater near Kolkata, West Bengal. The EDXRF analysis of this colored wastewater effluent showed 36.33 mg/L lead, significantly higher than the WHO recommendation. Previously, Bag et al. showed bioremediation of synthetic dyes using dry-biomass of Bacillus cereus M116 from an aqueous solution (Bag et al. Arch Microbiol 203(7):3811–3823, 2021). Here, a consortium of dry-biomasses of B.licheniformis AG3 and B. cereus M116 strains (1:1 w/w ratio) was prepared for the simultaneous removal of lead and MG from wastewater. Statistical optimization determines that the pH, initial concentration of contaminants, and dry-biomass concentrations are critical for bioremediation under batch procedures. Further, optimization using the response surface methodology showed that 0.01% consortium dry-biomasses eliminated a maximum of 99.35% MG and 96.01% lead (II) within 6 h. SEM–EDS and FTIR confirmed a strong surface biosorption. Furthermore, a fixed-bed biofilter column of the consortium dry-biomasses was prepared, which was able to remove 98.1% MG and 98.5% lead at the 0.5–1 mL/min flow rate. Together, this study developed a biofilter with a consortium dry biomasses of B. licheniformis AG3 and B. cereus M116 for the simultaneous removal of MG and lead from wastewater. [ABSTRACT FROM AUTHOR]

Synthetic textile dye malachite green (MG) and heavy metals present in industrial wastewater are hazardous to the ecosystem. Bioremediation of dyes and heavy metals using dry-biomasses has advantages over chemical methods. This study screened an acclimatized, heavy metal-resistant, and dye-degrading Gram positive Bacillus licheniformis AG3 strain from the textile wastewater near Kolkata, West Bengal. The EDXRF analysis of this colored wastewater effluent showed 36.33 mg/L lead, significantly higher than the WHO recommendation. Previously, Bag et al. showed bioremediation of synthetic dyes using dry-biomass of Bacillus cereus M116 from an aqueous solution (Bag et al. Arch Microbiol 203(7):3811–3823, 2021). Here, a consortium of dry-biomasses of B.licheniformis AG3 and B. cereus M116 strains (1:1 w/w ratio) was prepared for the simultaneous removal of lead and MG from wastewater. Statistical optimization determines that the pH, initial concentration of contaminants, and dry-biomass concentrations are critical for bioremediation under batch procedures. Further, optimization using the response surface methodology showed that 0.01% consortium dry-biomasses eliminated a maximum of 99.35% MG and 96.01% lead (II) within 6 h. SEM–EDS and FTIR confirmed a strong surface biosorption. Furthermore, a fixed-bed biofilter column of the consortium dry-biomasses was prepared, which was able to remove 98.1% MG and 98.5% lead at the 0.5–1 mL/min flow rate. Together, this study developed a biofilter with a consortium dry biomasses of B. licheniformis AG3 and B. cereus M116 for the simultaneous removal of MG and lead from wastewater. [ABSTRACT FROM AUTHOR]

The rise of antibiotic-resistant bacterial strains has become a critical health concern. According to the World Health Organization, the market introduction of new antibiotics is alarmingly sparse, underscoring the need for novel therapeutic targets. The LytR-CpsA-Psr (LCP) family of proteins, which facilitate the insertion of cell wall glycopolymers (CWGPs) like teichoic acids into peptidoglycan, has emerged as a promising target for antibiotic development. LCP proteins are crucial in bacterial adhesion and biofilm formation, making them attractive for disrupting these processes. This study investigated the structural and functional characteristics of the LCP domain of LytR from Streptococcus dysgalactiae subsp. dysgalactiae. The protein structure was solved by X-ray Crystallography at 2.80 A resolution. Small-angle X-ray scattering (SAXS) data were collected to examine potential conformational differences between the free and ligand-bound forms of the LytR LCP domain. Additionally, docking and molecular dynamics (MD) simulations were used to predict the interactions and conversion of ATP to ADP and AMP. Experimental validation of these predictions was performed using malachite green activity assays. The determined structure of the LCP domain revealed a fold highly similar to those of homologous proteins while SAXS data indicated potential conformational differences between the ligand-free and ligand-bound forms, suggesting a more compact conformation during catalysis, upon ligand binding. Docking and MD simulations predicted that the LytR LCP domain could interact with ADP and ATP and catalyze their conversion to AMP. These predictions were experimentally validated by malachite green activity assays, confirming the protein's functional versatility. The study provides significant insights into the structural features and functional capabilities of the LCP domain of LytR from S. dysgalactiae subsp. dysgalactiae. These findings pave the way for designing targeted therapies against antibiotic-resistant bacteria and offer strategies to disrupt bacterial biofilm formation. [ABSTRACT FROM AUTHOR]

In this study, catalytic-degradation of dyes such as methylene blue (MB) and malachite green (MG) was carried out by using silver nanoparticles (AgNPs), obtained by adopting the flower extract of Luffa acutangula (LA). The biogenic synthesised LA-AgNPs were characterised by using UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), DLS (dynamic light scattering) with zeta potential analysis, X-ray diffraction (XRD) and high-resolution transmission electron microscopic(HR-TEM) analyses. The typical surface plasmon resonance peak of LA-AgNPs was observed at 428 nm, as confirmed from UV-Vis spectrum. The formation of LA-AgNPs was observed through colour transformation from pale yellow to dark-brown due to the reduction of Ag+. Synthesised LA-AgNPs displayed spherical shape and face-centred cubic structure with an average size of 10–30 nm. The effects of various parameters such as initial extract concentration, time and time process were studied. The degradation reactions of MB and MG are found to follow the Langmuir–Hinshelwood mechanism with a pseudo-first-order kinetic model. Biogenic synthesised LA-AgNPs showed good degradation ability to reduce the MG and MB with NaBH4. [ABSTRACT FROM AUTHOR]

Contaminated waterways, particularly effluent from the dye industry, are one of the major issues today. Among various methods adsorption is the most straightforward, effective, and successful to treat such effluents. For this purpose Copper oxide nanoparticles (CuO) and Copper oxide nanoparticles embedded within Polyvinyl alcohol (PVA) and Polyvinyl pyrrolidone (PVP) mixed polymer (CuO/PVA-PVP) were synthesized using precipitation methods and different analytical techniques such as dynamic light scattering (DLS), UV-Vis, band gap measurement, powdered X-ray diffraction(XRD), Fourier-transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) were used to characterize morphology and size. Synthesized nanomaterials were used for the adsorption of malachite green (MG) dye in aqueous solution by the batch adsorption method. Various experimental conditions e.g. contact time, concentrations, pH, were optimized to obtain the best adsorption outcome. Adsorption kinetics and isotherm suggested that it follows the pseudo-second-order kinetic and Freundlich isotherm that have maximum adsorption capacity of 40 and 76.92 mg/g for CuO and CuO/PVA-PVP, respectively. The in vitro antibacterial activity was investigated using disk diffusion and minimum inhibitory concentration (MIC) test against Staphylococcus aureus (S.aureus), a gram-positive and Escherichia coli (E.coli), a gram-negative bacteria, where both the synthesized nanoparticles showed a decent antibacterial activity against both the bacterial strain. [ABSTRACT FROM AUTHOR]

Heterogeneous photocatalysis is a convenient and effective tool for eliminating toxic organic effluents from the textile and pharmaceutical industries. The analogous photocatalytic properties of polyoxometalates (POMs) with metal oxide-based semiconductors make them applicable for photocatalytic wastewater treatment applications. However, the high aqueous solubility and low coverage of the visible solar spectrum limit the wider applicability of traditional POMs as heterogeneous photocatalysts. Herein, we report, for the first time, the hydrothermal transformation of a UV-active polyoxometalate precursor, (C16H36N)4[Mo8O26] abbreviated as TBA-Mo8, into a visible light active photocatalytic carbon-doped Bi2MoO6 nanosheets (C-BMO) in the presence of a Bi3+ salt and studied its catalytic activities toward the degradation of a dye pollutant, malachite green (MG), and a pharmaceutical pollutant, ciprofloxacin (CF). For comparison purposes, an undoped Bi2MoO6 (U-BMO) nanosheet was also prepared under identical conditions starting from an in situ generated POM precursor H4[Mo8O26]. The successful transformation of TBA-Mo8 and H4[Mo8O26] into Bi2MoO6 photocatalysts under hydrothermal conditions was confirmed through a series of analytical and spectroscopic techniques, including Fourier transform infrared, Raman, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron spectroscopy, high-resolution transmission electron spectroscopy, and other analyses. The results of the photocatalytic experiments revealed superior catalytic activities of C-BMO compared to U-BMO and the parent cluster TBA-Mo8 under visible light irradiation. C-BMO achieved 70 and 87% degradation of MG and CF under visible light irradiation against the 29 and 35% degradation, respectively, shown by U-BMO. A plausible reason for the higher photocatalytic activity of C-BMO is its better charge separation due to the band gap modification resulting from carbon doping. The detailed pathways of MG and CF degradation have also been proposed based on scavenger studies and ESI-MS analyses of the photocatalytic degradation products. This work, therefore, summarizes how simple polyoxometalate can serve as precursors for developing better and more efficient visible light active photocatalysts under milder experimental procedures. [ABSTRACT FROM AUTHOR]

Introduction: In the past decade, the construction of ecological civilization has been a major national strategy in China. Since 2020, the Chinese government has officially proposed the goals of achieving peak carbon emissions by 2030 and carbon neutrality by 2060. As one of the key issues, promoting a green lifestyle is the fundamental means of achieving ecological civilization construction. It is an inevitable path to achieve the "carbon peak and carbon neutrality" goals. The current status of China's efforts in this area is undoubtedly worth paying attention to. The purpose of this study is to analyze this issue. Method: This study uses text analysis methods. From 92 policy documents issued by the Chinese government, we extracted effective text totaling 100,122 characters for analysis. Perform three-level coding on the above text, and analyze the policy tools of the Chinese government to promote green lifestyles from three dimensions: the categories of policy tools, the target groups targeted by policy tools, and the implementing entities of policy tools. Conclusion: The study found that the current promotion of a green lifestyle in China primarily relies on information-based policy tools and market-based policy tools, with mandatory tools as a supplement. Information-based policy tools are mainly used for the public, while a combination of market-based policy tools, information-based policy tools, and mandatory policy tools is used for enterprises. Local governments' attention to this issue is insufficient, manifested in the limited number of policy tools adopted, the single composition of these tools, and the lack of necessary constraints on enterprises. Discussion: Overall, the current policy tool selection is reasonable, but there are also problems such as over-reliance on information-based policy tools, overly simplistic market-based policy tools, insufficient market-based policy tools for the public, and the underuse of voluntary policy tools. [ABSTRACT FROM AUTHOR]

The precise quantitative analysis using surface-enhanced Raman spectroscopy (SERS) in an uncontrollable environment still faces a significant obstacle due to the poor reproducibility of Raman signals. Herein, we propose a facile method to fabricate a self-calibrating substrate based on a flexible polyvinyl alcohol (PVA) film comprising assemblies of Prussian blue (PB) and Au NPs (PB@Au) for reliable detection. PB cores were coated with an Au shell through simple electrostatic interaction, forming core–shell nanostructure PB@Au assemblies within the PVA film. The outer Au layer provided identical trends in enhancement for both the PB core and neighboring targets while PB cores served as an internal standard (IS) to correct signal fluctuations. The prevention of competitive adsorption on the metal surface between targets and ISs was achieved. The proposed PVA/PB@Au film exhibited enhanced stability of Raman signals after IS correction, resulting in improved spot-to-spot and batch-to-batch reproducibility with significantly reduced standard deviation (RSD) values from 11.42% and 25.02% to 4.43% and 9.39%, respectively. Simultaneously, a higher accuracy in the quantitative analysis of 4-mercaptobenzoic acid (4-MBA) and malachite green (MG) was achieved with fitting coefficient (R2) values improving from 0.9675 and 0.9418 to 0.9974 and 0.9832, respectively. Moreover, the PVA/PB@Au film was successfully applied to detect residual MG in real fish samples. This work opens up an avenue to improve the reproducibility of Raman signals for flexible SERS substrates in the detection of residues under various complex conditions. [ABSTRACT FROM AUTHOR]

Chemical, petroleum, and dyeing industries generate a wide variety of highly toxic organic wastes. The discharge of this wastewater into the river without treatment will spoil the entire aquatic system. The photocatalytic degradation of dyes/toxic chemicals is considered a favorable technology for industrial wastewater treatment. For this purpose, we have prepared an efficient nanocomposite material. The Gelatin assisted Cerium loaded CuS (Ge−Ce−CuS) nanocomposite was successfully synthesized by a simple hydrothermal method and characterized by BET, UV‐DRS, and PL measurements. The BET surface area of Ge−Ce−CuS (88.6 m2 g−1) is higher than bare CuS (66.0 m2 g‐1). DRS Confirms that the photo‐absorption of Ge−Ce−CuS nanocomposite significantly increases from the 570 nm range to the whole visible region. PL measurements confirm that the CuS loading suppresses electron‐hole recombination of Ge−Ce−CuS. The photocatalytic activity of Ge−Ce−CuS was investigated for the degradation of malachite green oxalate dye (MGO) in an aqueous solution using UV light. The influence of operational parameters such as the amount of photocatalyst, dye concentration, and initial pH on the photo mineralization of MGO dye has been analyzed and discussed. Slightly basic pH enhances the degradation. The mineralization of MGO dye has been confirmed by COD measurements. The intermediates formed during degradations were analyzed by GC‐MS, and a suitable degradation pathway was proposed. The catalyst is found to be reusable. The mechanism of degradation of MGO dye by Ge−Ce−CuS is also proposed. [ABSTRACT FROM AUTHOR]

In order to investigate the adsorption process of malachite green (MG) on gold nanoparticles, a simple gold nanoparticles‐assembled film was prepared as a substrate of surface‐enhanced Raman spectroscopy (SERS), and it was soaked in MG solutions of different concentrations. The kinetic adsorption process was investigated by SERS method and density functional theoretical calculations. When saturated adsorption was achieved, the relationship between the characteristic SERS band signal intensity and the logarithm of solution concentration of MG was consistent with Temkin adsorption isotherm model, where the R2 value was greater than 0.995, and the linear range was 1 × 10−3–1 × 10−7 M. Finally, a SERS quantitative analysis model of the relationship between the adsorption properties of surface species and the bulk concentration was established. According to the electrostatic interaction and co‐adsorption, we proposed the surface adsorption configurations and adsorption process of MG on the nanostructured gold films. [ABSTRACT FROM AUTHOR]

Malachite green (MG) dye and cadmium metal ion are toxic pollutants that should be removed from aqueous environment. The recent study aimed to examine the adsorption behavior of MG dye and Cd (II) from wastewater onto low-cost adsorbent prepared by activating corn silk with nitric acid (ACS) and characterized by SEM, FTIR, XRD, BET and TGA. The optimum MG and Cd (II) adsorption was observed at pH 7 and pH 9 and maximum uptake of both pollutants was at 0.5 g dosage, 60 mins contact time and 20 mg/L initial concentration. The retention of dye and metal ion by the studied adsorbent was best fit to Langmuir isotherm and Pseudo-second order kinetics. The maximum monolayer coverage capacity of ACS for MG dye and Cd (II) ion was 18.38 mg/g and 25.53 mg/g, respectively. Thermodynamic studies predicted a spontaneous reaction with exothermic process for MG dye whereas an endothermic and spontaneous process was confirmed for Cd ion based on estimated parameters. The adsorption mechanism of MG dye and Cd (II) uptake was by combination of electrostatic interaction, pore diffusion, ion exchange, pie-pie attraction, hydrogen bonding, and complexation. The adsorbed pollutants were effectively desorbed with significant regeneration efficiency after successive five cycles that proved the potential of low-cost biosorbent for selective sequestration of cationic dye and divalent metal ion from effluents. The use of nitric acid-modified corn silk has been reported to enhance its adsorption performance over the unmodified cob for pollutants such as cadmium ions and malachite green. Although there may be no recorded data on the adsorption efficiency of acid-treated corn silk for selected pollutants, it can be considered as a prospective bio-sorbent owing to its chemical composition and functional groups for exchange of hydrogen ions for other cations. [ABSTRACT FROM AUTHOR]

This present work was aimed at evaluating the adsorptive properties of banana peel adsorbents, namely chars, hydrochar, activated carbons, and hydrochar activated carbon. The adsorbents were characterized for textural properties, functional groups, and morphology, and the adsorption was performed at varying contact time, concentrations, and temperatures. Hydrochar activated carbon yields an 877 m2/g specific surface area with dye maximum capacity of 582 mg/g at equilibrium concentration of 446 mg/L. Its fragmented surface allows more dye molecules to lodge although the effective diffusion coefficient is small compared to the other banana peel adsorbents. The Langmuir–Freundlich model appeared to fit the equilibrium data well with R2 of 0.988, while the kinetic obeyed the pseudo-second-order model with R2 > 0.914. There is only a slight rise in adsorption with increasing temperature and regeneration using HCl was unable to reclaim the adsorbents' performance. [ABSTRACT FROM AUTHOR]

This study aimed to produce the cost-effective mesoporous material "aluminum-modified MCM-41" using local Saidite clay for efficient removal of Malachite Green (MG) dye from an aqueous solution. Characterization of the products involved the use of X-ray diffraction (XRD), N2 adsorption and desorption, and scanning electron microscopy (SEM). The X-ray diffraction analysis confirmed the successful synthesis of pure Al-MCM-41 without any impurities. The surface area of the sample was determined to be approximately 660 m2/g. Various parameters, including contact time, adsorbent dosage, initial pH of the solution, dye solution concentration, and temperature, were taken into account. At a temperature of 298 K, the maximum adsorption capacity for MG was found to be 55 mg/g. Both adsorption isotherm and kinetic models were examined, revealing that the Langmuir model best described the adsorption phenomenon. Furthermore, the adsorption kinetics followed the pseudo-second-order kinetic model, demonstrating a high correlation coefficient (R2 = 0.99). Additionally, the study discussed the mechanical interaction between the removal of MG and Al-MCM-41. [ABSTRACT FROM AUTHOR]

Dye contamination in printing and dyeing wastewater has long been a major concern due to its serious impact on both the environment and human health. In the quest for bioremediation of these hazardous dyes, biological resources such as biodegradation bacteria and enzymes have been investigated in severely polluted environments. In this context, the triphenylmethane transporter gene (tmt) was identified in six distinct clones from a metagenomic library of the printing and dyeing wastewater treatment system. Escherichia coli expressing tmt revealed 98.1% decolorization efficiency of triphenylmethane dye malachite green within 24 h under shaking culture condition. The tolerance to malachite green was improved over eightfold in the Tmt strain compared of the none-Tmt expressed strain. Similarly, the tolerance of Tmt strain to other triphenylmethane dyes like crystal violet and brilliant green, was improved by at least fourfold. Site-directed mutations, including A75G, A75S and V100G, were found to reinforce the tolerance of malachite green, and double mutations of these even further improve the tolerance. Therefore, the tmt has been demonstrated to be a specific efflux pump for triphenylmethane dyes, particularly the malachite green. By actively pumping out toxic triphenylmethane dyes, it significantly extends the cells tolerance in a triphenylmethane dye-rich environment, which may provide a promising strategy for bioremediation of triphenylmethane dye pollutants in the environments. [ABSTRACT FROM AUTHOR]

The one‐step green synthesis of wide band gap zinc oxide@zinc sulfide (ZnO@ZnS) core–shell nanostructures offers promising prospects in wastewater treatment. These nanostructures exhibit a porous nature crucial for effective dye adsorption, as evidenced by Brunauer‐Emmett‐Teller (BET) and microscopic characterization. The synthesized material demonstrates high stability and minimal agglomeration, verified through BET analysis and zeta potential measurements. X‐ray powder diffraction confirms the presence of ZnO and ZnS phases. Transmission electron microscopy reveals the development of porous nanorods on the core surface, maximizing the surface area for dye adsorption. In wastewater treatment, the nanostructures exhibit notable performance, degrading 90% of malachite green and 50% of rhodamine B dyes within 120 min under normal conditions. Detailed discussions delve into the degradation mechanism, elucidating the major species responsible for the process. This study underscores the potential of ZnO@ZnS nanostructures in efficient organic pollutant removal, marking a significant advancement in environmental remediation. [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]

This research introduces a novel approach using silver (Ag) nanostructures generated through electrochemical deposition and photo-reduction of Ag on fluorine-doped tin oxide glass substrates (denoted as X-Ag-AgyFTO, where 'X' and 'y' represent the type of light source and number of deposited cycles, respectively) for surface-enhanced Raman spectroscopy (SERS). This study used malachite green (MG) as a Raman probe to evaluate the enhancement factors (EFs) in SERS-active substrates under varied fabrication conditions. For the substrates produced via electrochemical deposition, we determined a Raman EF of 6.15 × 104 for the Ag2FTO substrate. In photo-reduction, the impact of reductant concentration, light source, and light exposure duration were examined on X-Ag nanoparticle formation to achieve superior Raman EFs. Under optimal conditions (9.0 mM sodium citrate, 460 nm blue-LED at 10 W for 90 min), the combination of blue-LED-reduced Ag (B-Ag) and an Ag2FTO substrate (denoted as B-Ag-Ag2FTO) exhibited the best Raman EF of 2.79 × 105. This substrate enabled MG detection within a linear range of 0.1 to 1.0 µM (R2 = 0.98) and a detection limit of 0.02 µM. Additionally, the spiked recoveries in aquaculture water samples were between 90.0% and 110.0%, with relative standard deviations between 3.9% and 6.3%, indicating the substrate's potential for fungicide detection in aquaculture. [ABSTRACT FROM AUTHOR]

Developing synthetic strategies for smart materials for the adsorption and separation of toxic chemicals is of great importance. Metal–organic frameworks (MOFs) have been proven to be outstanding adsorbent materials that possess excellent pollutant removal performances in wastewater treatment, including dye recycling. In this work, a neutral Cd(II) based 2D framework with a dual ligand strategy involving –OH functionalized 5-hydroxyisophthalic acid (5-OH-H2IPA) and the amide decorated Schiff base ligand (E)-N′-(pyridin-4-ylmethylene)isonicotinohydrazide (L) has been synthesized by different synthetic routes and characterized by various analytical methods. Thus, crystals of {[Cd(5-OH-IPA)(L)]·CH3OH}n synthesized via diffusion (ADES-7D) and the phase pure bulk product synthesized by conventional reflux (ADES-7C) and the mechanochemical grinding method (ADES-7M) have been established using PXRD data of the respective product showing identical simulated SXRD data to those of ADES-7D. The mechanochemically synthesized ADES-7M possesses a better surface area and CO2 adsorption capability compared to ADES-7C, which is also supported by electron microscopy and particle size measurements. Furthermore, ADES-7 can be used as an efficient adsorbent material for the reversible, selective adsorption (42–99%) and separation of the cationic dyes malachite green (MG), methyl violet (MV), methylene blue (MB), and rhodamine B (RhB) from the mixture of cationic/anionic dyes (methyl orange (MO) and bromocresol green (BCG)) in the aqueous phase. Specifically, ADES-7M possesses better dye capture capability compared to ADES-7C, even in the case of the bigger dye RhB with adsorption differences of 2.38 to 1.01 mg g−1, respectively. The dye adsorption kinetics follows pseudo-second-order kinetics, and the dye adsorption isotherm fits well with the Langmuir/Freundlich adsorption isotherm models. The probable mechanism of adsorption involving the supramolecular interaction between the host MOF and the guest dye has also been proposed. [ABSTRACT FROM AUTHOR]

AbstractThe biomass-based adsorbents offer a promising solution for wastewater decolorization owing to their superior specific surface area, low-budget, high adsorption capacities, and environmental sustainability. In this work, wheat bran (WB) was used as raw material for the production of in situ N-doped biochar through a molten salt template method, and the adsorption characteristics of Malachite Green (MG) onto biochars prepared from WB by immersing and non-immersing (BC–NaK and BC–NaK-n) in the mixed salt solution (NaCl and KCl) were investigated. The experimental results indicated that the adsorption capacity of MG onto the BC–NaK was significantly better than BC–NaK-n, which was attributed to the rich functional groups and well-developed pore structure of BC–NaK. The adsorption equilibrium data of MG onto the BC–NaK was fitted well to Sips and Koble-Corrigan isotherm models and adsorption process of MG was spontaneous and endothermic. Meanwhile, the pseudo-second-order model was successfully applied to depict the adsorption process of MG. Furthermore, the adsorption of MG onto BC–NaK was primarily regulated by H-bonding, π–π interaction, hydrophobic interaction, electrostatic interaction. The maximum saturated adsorption capacity of the BC–NaK was 880.14 ± 9.35 mg g−1 at 298 K, further demonstrating that biochar prepared from wheat bran provided a long-term development strategy for dye wastewater treatment. [ABSTRACT FROM AUTHOR]

AbstractIn this study, magnesium oxide (MgO) nanoparticles (NPs) tuned via doping with transition metal ions, Co2+/Cu2+/Zn2+ have been synthesized biologically using Aloe vera leaf extract as an encapsulating agent. These pure and doped MgO NPs have been characterized by using various physico-chemical characterization techniques. X-ray diffraction (XRD) analysis confirms the formation of face-centered cubic structures of pure and doped MgO NPs with their average crystallite sizes ranging from 8.11-17.83 nm. X-ray photoelectron spectroscopic (XPS) analysis confirmed the presence of doped element in their +2 oxidation state. UV-Visible spectral analysis revealed a significant reduction in band gap energies in nano-dimensions which further gets modified upon doping (1.76 − 4.9 eV). Our findings also demonstrated the engagement of phytochemicals as capping agents in Fourier transform infrared (FTIR) examination. Scanning electron microscopic (SEM) and Transmission electron microscopic (TEM) analysis provided insights into the morphologies and particle sizes. Elemental analysis by Energy dispersive X-ray (EDX) confirms the presence of Co, Cu, and Zn elements in doped MgO NPs. The photocatalytic degradation of dyes has confirmed that Co and Cu doping substantially enhance the photocatalytic activity compared to both undoped and Zn-doped MgO NPs. Furthermore, these nanoparticles demonstrate superior efficiency in degrading the cationic dye Malachite green (MG) compared to the anionic dye Methyl orange (MO). Regarding their antibacterial properties, only Cu doping induces a notable antibacterial effect in MgO NPs, particularly against gram-positive bacteria. Additionally, these nanoparticles exhibit substantial antioxidant activities. These tailored MgO nanoparticles exhibit potential for applications in wastewater treatment. [ABSTRACT FROM AUTHOR]

Aims This study aimed to explore potential synergistic effects of medicinal dyes with antimicrobials against pathogens responsible for skin infections. Methods and results Antimicrobial testing was conducted using minimum inhibitory concentrations and minimum bactericidal/fungicidal concentration assays. The fractional inhibitory index (ΣFIC) of combinations was calculated, and isobolograms were constructed on selected combinations. Toxicity studies were conducted using the brine-shrimp lethality assay. Combination (1:1 ratio) studies noted that 26% of dye-antibiotic combinations were synergistic against the Gram-positive strains, 15% against the Gram-negative strains, and 14% against the yeasts. The Mercurochrome: Betadine® combination noted synergy at ratios against all the Staphylococcus aureus strains with ΣFIC values ranging from 0.05 to 0.48. The combination of Gentian violet with Gentamycin noted a 15-fold decrease in toxicity, and a selectivity index of 977.50 against the Escherichia coli (DSM 22314) strain. Time-kill studies were conducted on the combinations with the highest safe selectivity index (SI) value and lowest safe SI value i.e. Gentian violet with Gentamycin and Malachite green with Neomycin. Both combinations demonstrated better antimicrobial activity in comparison to the independent values and the controls. Conclusion This study highlights the potential for medicinal dye combinations as a treatment for skin infections. [ABSTRACT FROM AUTHOR]

Dyes are widely used in manufacturing of various consumer products for their ability to impart characteristic color. However, dyes are also one of the most important hazardous pollutants in this present day. Presence of hydroxyl, phosphate, ether, carbonyl and alkyl groups also enable bacterial extracellular polymers to function as biosorbent. In this study, negatively charged biosorbent EP-C1 produced by Gram-negative bacterium Ochrobactrum pseudintermedium C1 utilizing waste mineral lubricating oil has given different decolorization percentages for triphenylmethane cationic Malachite Green and azoic anionic Congo Red at neutral pH. Time wise absorbances from Ultraviolet-Visible Spectrophotometry has estimated maximum biosorption of Malachite Green after 300 min. Biosorption capacities have differed with initial dye concentrations, biosorbent dosages and contact time. Time taken by each dye to reach saturation has depended upon their charged bearing groups of each dye and biosorbent. Kinetic (pseudo first and pseudo second order) and diffusion (intra particle and liquid film) parameters in presence of different dye concentrations and biosorbent dosages were studied for understanding the biosorption mechanism. Morphological differences in chemical structure, chemical functional groups of EP-C1 and EP-C1 loaded dye was studied by Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy and Zeta potential measurements. A compiled overview on comparative mechanistic biosorption of Malachite Green and Congo Red dyes by a bacterial extracellular polymer in miniature laboratory shake flask experiments was done in this study. Newer advents on biological remediation of dyes with mineral lubricating oil as sole carbon source can add a new feather to the already available bioremediation techniques in mitigation of hazardous wastes. [ABSTRACT FROM AUTHOR]

Dye releases from the textile industry disrupt the ecosystem by causing environmental pollution. Our study focused on the degradation of synthetic triphenyl methane, Malachite Green dye by isolating native microorganisms from textile effluents. Among 150 bacterial colonies, two dye-degrading bacteria were selected for the study. The selected bacteria were characterized using different techniques including morphology, biochemical tests, and antibiotic susceptibility testing and 16S rRNA sequence analysis. Based on all test results, the isolates were confirmed as Bacillus cereus and Bacillus licheniformis species. Bacillus cereus was selected for further study based on the percentage of dye decolorization assay. The optimal dye degradation parameters were determined by the Central Composite Design (CCD). Experimentally 99.35% of dye degradation was obtained for Bacillus cereus, at a dye concentration of 1500 mg/L at pH 7.5, temperature 40 °C and 300 mg/L of which is the optimal condition for effective dye degradation. [ABSTRACT FROM AUTHOR]

Context and results: A nanocomposite photocatalyst consisting of polyaniline (PANI) and copper oxide (CuO) was successfully synthesized through an in-situ polymerization approach using aniline as the precursor. The synthesized nanocomposite was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV–Vis), determination of the point of zero charge (pHPZC), and scanning electron microscopy (SEM). The photocatalytic efficiency of the PANI–CuO nanocomposite was evaluated in the context of photodegrading Malachite Green (MG) dye under visible light. Malachite Green, a synthetic dye commonly used in the textile and aquaculture industries, is a significant contaminant due to its toxic, mutagenic, and carcinogenic properties, making its removal from water resources crucial for environmental and human health. Distilled water artificially contaminated with MG dye was used as the medium for testing. The parameters influencing the photodegradation efficiency were comprehensively investigated. These parameters included catalyst dosage, reaction time, initial dye concentration, and pH. The results of this study indicate that the degradation efficiency of MG dye displayed an upward trend with time, catalyst dosage, and pH while exhibiting a converse relationship with the initial dye concentration. A degradation rate of 97% was achieved with an initial concentration of 20 mg L−1, employing a catalyst dose of 1.6 g L−1 at pH 6 for a reaction time of 180 min. Furthermore, the reusability of the catalyst was assessed, revealing consistent performance over five consecutive cycles. Computational and theoretical techniques: Density functional theory (DFT) was employed to optimize the structures of PANI, PANI–CuO, and their respective complexes formed through dye interaction, employing Gaussian software. These calculations employed the B3LYP/6–311G + + (d,p) basis set in an aqueous environment with water serving as the solvent. The kinetics of Malachite Green degradation were analyzed using both first and second-order kinetic models. [ABSTRACT FROM AUTHOR]

Sulfur-doped BCNO quantum dots (S-BCNO QDs) emitting green fluorescence were prepared by elemental doping method. The ratiometric fluorescence probe with dual emissions was simply established by mixed S-BCNO QDs with gold nanoclusters (GSH-Au NCs). Because the emission spectrum of Au NCs (donor) at 615 nm overlapped well with the ultraviolet absorption of malachite green (MG), fluorescence resonance energy transfer (FRET) can be achieved. When the concentration of MG increased, the fluorescence intensity (F495) of S-BCNO QDs decreased slowly, while the fluorescence intensity (F615) of Au NCs decreased sharply. The fluorescence intensity ratio of F615/F495 decreased with the increase of MG. By plotting the F615/F495 values against MG concentration, a sensitive and rapid detection of MG was possible with a wide detection range (0.1–50 µM) and a low detection limit of 10 nM. Due to the accompanying fluorescence color change from pink to blue-green, it can be used for visual detection. A three dimensional-printing device utilizing digital image colorimetry to capture color changes through the built-in camera, enables quantitative detection of MG with a good linearity between the values of red/green ratio and MG concentrations at the range 1–50 µM. This sensing platform had a range of advantages, including high cost-effectiveness, portability, ease of operation, and high sensitivity. Furthermore, the sensing platform was successfully applied to the detection of MG in real water sample and fish samples, thereby verifying the reliability and effectiveness of this sensing platform in water quality monitoring and food safety. [ABSTRACT FROM AUTHOR]

The improvement of biosorption efficiency for selective dye removal in a multi-dye aqueous system has become an increasingly significant research topic. However, the competitive effects of coexisting dyes and the target dye in such systems remain uncertain due to complex interactions between adsorbent and coexisting dyes. Therefore, in this research, response surface methodology (RSM) model was effectively employed to investigate the competitive effects of allura red (AR) and malachite green (MG) on methylene blue (MB) removal in a ternary dye aqueous system using three different parts of rape straw powders. In the current design of RSM, the initial concentrations of AR and MG dyes ranging from 0 mg·L−1 to 500 mg·L−1 were considered as influencing factors, while the removal rates of MB on adsorbents at an initial concentration of 500 mg·L−1 were established as response values. The RSM models exhibited high correlation coefficients with adjusted R2 values of 0.9908 (pith core), 0.9870 (seedpods), and 0.9902 (shells), respectively, indicating a close fitted between predicted and actual values. The proposed models indicated that the perturbation effects of initial AR and MG concentrations were observed on the removal rates of MB by three types of rape straw powders in a ternary dye aqueous system, resulting in a decrease in MB removal rates, particularly at higher initial AR concentration due to stronger competitive effects compared to initial MG concentration. The structures of rape straw powders, including pith core, seedpods and shell, were analyzed using scanning eletron microscoe (SEM), energy dispersive spectroscopy (EDS), N2 physisorption isotherm, frourier transform infared spectroscopy (FTIR), Zeta potential classes and fluorescence spectrum before and after adsorption of MB in various dye aqueous systems. The characteristics of rape straw powders suggested that similar adsorption mechanisms, such as electrostatic attraction, pore diffusion, and group complex formation for MB, AR, and MG, respectively, occurred on the surfaces of adsorbents during their respective adsorption processes. This leads to significant competitive effects on the removal rates of MB in a ternary dye aqueous system, which are particularly influenced by initial AR concentrations as confirmed through fluorescence spectrum analysis. Impact of AR and MG on MB removal was analyzed using simple methodologies. Competitive behaviors between AR, MG and MB were understood through RSM. Intense restrain effects on MB removal were revealed by AR concentration. [ABSTRACT FROM AUTHOR]

The heterogeneous Fenton-like degradation overcome the shortage of traditional Fenton system, which got the high catalytic efficiency, good stability, wide pH working range, and so on. However, it is still challenging to develop highly efficient and recyclable solid catalysts in wastewater treatment. Herein, we employed melamine sponge (MS) as a base material to fabricate heterogeneous Fe/Cu-tannic acid (TA) coated MS (MS-Fe/Cu-TA) through the dip-coating method. The porous 3D structure of MS can enhance the catalyst loading, and expose more active catalytic sites to absorb dyes from solution. The loaded Fe/Cu weight ratio, pH value, H2O2 dosage, and initial MB concentration on the catalytic activity were optimized to get highest methylene blue (MB) degradation efficiency. The MS survived five times of cyclic MB degradation, and degradation efficiency for other dyes (methyl orange, rhodamine B, malachite green) kept above 65%. This work brings potential insights for development of enhanced heterogeneous Fenton-like degradation for wastewater treatment. Herein, we employed melamine sponge (MS) as a base material to fabricate heterogeneous Fe/Cu-tannic acid (TA) coated MS (MS-Fe/Cu-TA) through the dip-coating method. The porous 3D structure of MS can enhance the catalyst loading, and expose more active catalytic sites to absorb dyes from solution. This work brings potential insights for development of enhanced heterogeneous Fenton-like degradation for wastewater treatment. [ABSTRACT FROM AUTHOR]

In this research, the alginate doped graphene oxide (GO)-Fe3O4-TiO2 photomagnetic nanocomposite was synthesised through a three-step method. For comparison, alginate-GO was also prepared. The synthesised materials were characterised through FTIR, XRD, TGA, SEM, EDX, and TEM techniques. The photomagnetic properties of the resultant nanocomposite were evaluated by VSM. Degradation of Malachite green as a dye pollutant was studied in the presence of alginate (Alg), Alg-GO, and Alg-GO-Fe3O4-TiO2 nanocomposite using a sonophotocatalysis technique. The results showed, that, Alg-GO-Fe3O4-TiO2 nanocomposite has high efficiency in the removal of Malachite green. Recycling experiments displayed that the degradation efficiency dropped only by 12%, after five successive runs. and makes it a promising catalyst for efficient degradation of dye pollutants in the practical applications. [ABSTRACT FROM AUTHOR]

In the present study, a composite material consisting of silica gel 60 supported iron-zinc bimetallic nanoparticles (Si/Fe-ZnNPs) was prepared and characterized by SEM, EDX, FTIR, and XRD analysis. The adsorbent properties of the synthesized composite material were evaluated with the removal of Malachite Green (MG). According to characterization results, the cubic structures and agglomerated nano-sized spherical particles (≈30 nm) were formed. The FT-IR spectrum confirms the formation of Fe-Zn NPs through the observation of the Fe-O stretches and metal-metal stretching vibrations of (Zn2+ - O²) adsorption bands. Additionally, the FT-IR revealed the presence of Si-O-Si, Si-O-H stretching, and O-Si-O bending vibrations attributed to silica gel 60. The optimal environmental conditions for adsorption were determined to be a natural pH of 3.3, an adsorption temperature of 50°C, and an adsorbent concentration of 1.0 g/L. An increase in equilibrium uptakes of MG was observed with a linear correlation to initial dye concentrations. Thermodynamic studies indicated that the adsorption process was endothermic, non-spontaneous, and increasing disorder at the solid-solution interface during adsorption with positive ΔH, ΔG, and ΔS values, respectively. The experimental results revealed that the Langmuir isotherm model provided the best fit for the equilibrium data. The maximum monolayer coverage capacity of Si/Fe-ZnNPs was 666.67 mg/g at an optimum temperature of 50°C. Further analysis displayed that the kinetic adsorption data adhere to the pseudo-second-order kinetic model. Additionally, Weber-Morris model results revealed the effectiveness of both the film and intra-particle diffusion in the adsorption. [ABSTRACT FROM AUTHOR]

This work intends to evaluate the feasibility of improving the adsorption performance of biomass by both hydrothermal carbonization (HTC) pretreatment and single-step NaOH and ethanol modification. Peanut shell (PS) and pine (PE) are utilized as parent materials to produce efficient adsorbents, and malachite green (MG) is regarded as contaminants to evaluate the adsorption capacity of prepared materials. Adsorption test was performed under various operating conditions, including pH, interfering ions and contact time. The adsorbents were characterized by N2 adsorption–desorption, SEM, FT-IR spectra and elemental analysis to explore the potential adsorption mechanism. Results show that single-step NaOH and ethanol modification is an effective chemical modification to improve the adsorption performance of adsorbents by increasing the surface hydroxyl functional groups. The adsorption performance of adsorbents prepared by HTC following with chemical modification is best; the qe of modified hydrochar from PS and PE (MPS-HC and MPE-HC) reach as high as 570.34 mg/g and 562.2 mg/g, respectively. According to adsorption isothermal and kinetics analysis, the adsorption process mainly occurs on the surface of adsorbents, and MG removal is dominant by chemical adsorption resulting from the increase of surface hydroxyl functional groups by chemical modification. HTC pretreatment could enhance the п–п bond interaction, thus further promoting MG removal by MPS-HC and MPE-HC because it increases the aromaticity of hydrochar evidenced by the H/C ratio decrease. This work indicates that the combination of HTC pretreatment and chemical modification is a feasible way to improve the adsorption performance of biomass. [ABSTRACT FROM AUTHOR]

In this study, triphenylaniline-based porous organic polymers (TPA-POPs) were successfully prepared by the Friedel–Crafts reaction and applied to adsorb malachite green (MG) dye from water. The TPA-POP was characterized using TEM, SEM, FTIR, 13C (CP/MAS) NMR, BET surface area, and XRD analysis. The results exhibited that the TPA-POP has a high surface area (1625.14 m2/g) with pore volume (0.353 cm3/g) and pore radius (1.57 nm) that reflect the high quantity of MG adsorbed on the TPA-POP. The polymer was evaluated as an excellent adsorbent for MG adsorption from water using the batch method. MG dye removal was optimized as 99.60% (at pH: 6.0, adsorbent dosage (m): 0.01 g, temperature (T): 45 °C, and contact time (t): 300 min). The kinetic data follow the Elovich model, while the isotherm data fit the Langmuir model well with uptake capacity (755.72 mg/g) at T: 45 °C. According to thermodynamic parameters, the adsorption process was endothermic and spontaneous. The adsorption of MG on the TPA-POP occurred via different mechanisms (π–π interaction, electrostatic attraction, and hydrogen bonding). Reusability experiments exhibited that the TPA-POP still maintained high removal efficiency (82.12%) after five cycles. In conclusion, the TPA-POP is a promising adsorbent owing to its cost-effectiveness, high adsorption capacity, high surface area, excellent reusability, and efficient MG removal from aqueous media. [ABSTRACT FROM AUTHOR]

The rising concern about the environmental pollution, particularly due to the setup of more industrial sectors has grabbed the attention of scientists and researchers. Many textile businesses emit Malachite Green and Methylene Blue (MG and MB) into the atmosphere, posing serious health risks. In this study, a copper metal-organic framework doped with iron nanoparticles (Cu-MOF@Fe3O4) was synthesized utilizing the slow evaporation approach, commencing with cuprous chloride and 2-mercaptobenzimidazole in a 1:2 ratio. Cu-MOF@Fe3O4 was characterized using a variety of techniques, including FTIR, SEM, and DRS analysis. The SEM analysis showed a rough and uneven morphology for the Cu-based MOFs. The XRD analysis confirmed the crystallinity of the products. The average crystallite size for Cu-MOF, Fe3O4 nanoparticles and Cu-MOF@Fe3O4 were found to be 0.22, 1.00, and 1.00 nm. While the surface area of Cu-MOF was found to be 213.192 m2g−1 while in Cu-MOF@Fe3O4 it shows an increase, i.e., 218.268 m2g−1 as calculated through the iodometric method. A series of experiments were conducted to assess the surface area, chemical oxygen demand (COD), limit of detection (LOD) (0.065559, 0.0136), limit of quantification (LOQ) (0.198662, 0.041312), point of zero charge (PZC) (5.2), pH levels (6, 7), contact times (10, 25 min), photocatalyst dosages (0.3, 0.05 g), dye concentrations (2, 10 µg/mL), and temperature effects (50°, 90°) on the adsorption and photocatalytic degradation of MG and MB, respectively. Photodegradation of both dyes followed pseudo-second order kinetics with R2 values of 0.9833 (MG) and 0.8875 (MB). The adsorption isotherms (Freundlich and Langmuir) for MG and MB dye were analyzed and the experimental data holds a good correlation with Freundlich isotherm. The sample application of Cu-MOF@Fe3O4 as a photocatalyst, has high efficiency, % photocatalysis (96.9 % MG, 99.4 % MB) with reusability (95–100 %) upto 10 cycles to photodegrade MG and MB dye in wastewater. To the best of our knowledge, this is the first report on the deployment of copper-based MOFs-doped with magnetite for the photocatalytic degradation of MG and MB dyes. [ABSTRACT FROM AUTHOR]

Simple and economical colorimetric strips for measuring manganese (Mn) in natural waters are described. For their construction, leucomalachite green (LMG) embedded in a Nafion® polymeric matrix was immobilized on a polyvinylchloride surface. Upon immersing the strips in the sample, any soluble manganese(II/III) present catalyzed the oxidation of the LMG base to malachite green by adding sodium periodate. The observed color change is related to the manganese concentration and can be quantified using a field device constructed using commercial red–green–blue sensors and an Arduino® board. A linear response from 0.1 to 0.6 μmol L−1 manganese (limit of detection: 0.1 μmol L−1) was observed. The signal for strips prepared on 7 d gave a relative standard deviation equal to 13%. The strips showed good agreement with results obtained by ICP‐MS in porewater collected on Spiekeroog Island (North Sea). Therefore, the method is a tool for rapid measurements of manganese in porewater samples offering new possibilities in understanding biogeochemistry for high temporal and spatial resolution manganese surveys and providing an analytical technique that provides field results comparable to laboratory systems. [ABSTRACT FROM AUTHOR]

Textile-toxic synthetic dyes, which possess complex aromatic structures, are emitted into wastewater from various branches. To address this issue, the adsorption process was applied as an attractive method for the removal of dye contaminants from water in this article. An unprecedented integrated experimental study has been carried out, accompanied by theoretical simulations at the DFT-B3LYP/6-31G (d,P) level of theory to investigate how single Maxilon Blue GRL (MxB) dye or and its mixture with MG (Malachite Green) dyes interact with the adsorbent and compare the obtained results with the data obtained through experimentation. The full geometry optimization revealed the physical adsorption of dyes on the Al2O3 surface. Non-linear optical properties (NLO) results emphasized that the complex MG-Al2O3-MxB is a highly promising material in photo-applications, and the adsorbed binary system is energetically more favorable compared to the adsorbed sole dye system. The experimental results for (MxB) dye adsorption onto γ-Al2O3 affirmed that the optimum conditions to get more than 98% uptake were at dye concentration 100 ppm, pH 10, adsorbent content 0.05 g, and equilibrium time only 20 min. The kinetic and isothermal studies revealed that the adsorption accepted with the pseudo-second-order and Freundlich isotherm model, respectively. The removal efficiency of the mixture of MxB and MG dyes was the highest but did not change clearly with increasing the % of any of them. The details of the interaction mechanisms of the sole and binary dyes were proven. [ABSTRACT FROM AUTHOR]

This research explores the feasibility of using date seeds (DS), an agricultural waste, for the adsorption of malachite green (MG) dye from synthesized wastewater. The characterization of the DS before and after adsorption was accomplished by FTIR, SEM, BET, and EDX measurements. Batch adsorption experiments were investigated for MG dye adsorption from aqueous solution onto the DS. The effect of different parameters such as solution pH, adsorbent dose, contact time, temperature, and the initial dye concentration were studied. The optimum pH, adsorbent dose, temperature, and contact time for the dye removal were found to be 5, 0.1 g, 25 °C, and 30 min, respectively. The equilibrium studies for the data with Langmuir, Freundlich, and Temkin isotherms showed that Freundlich isotherm is the best model to describe the adsorption of MG onto the DS particles which has a heterogeneous surface. It was found that the adsorption process follows a pseudo-second-order kinetic model which revealed that the intra-particle diffusion stage is the rate-controlling stage for the process. The thermodynamic parameters ΔG, ΔS, and ΔH suggest the possibility of chemisorption and physisorption simultaneously and indicate the exothermic and spontaneous characters of the adsorption of MG dye on DS with negative values of ΔH and ΔG. This study used agriculture waste (date seeds) which is proved to be an environmentally friendly and low-cost adsorbent. The date seeds were shown to be a promising adsorbent, demonstrating high surface area and well-developed porosity. The prepared adsorbent will have a great impact on wastewater treatment technology and possible applications at a large scale. Thus, widespread and great progress in this area can be expected in the future. [ABSTRACT FROM AUTHOR]

In this work, green method to synthesize chromium-doped zinc oxide (ZnO) nanorods (NRs) using an aqueous flower extract from Rhododendron arboretum is explored. Herein, chromium-doped ZnO NRs were prepared with different amount of chromium doping, varied as 2–10%. The green synthesized products underwent substantial analysis through X-ray diffraction (XRD), spectroscopic such as ultraviolet spectroscopy(UV-Vis) and scanning electron microscopy (SEM) methods. All samples were found to have hexagonal wurtzite ZnO, with average particle sizes of 52.41, 56.6, 54.44, 53.05, and 56.99 nm, respectively, for 2, 4, 6, 8, and 10% chromium doping in ZnO NRs. The Cr-doped ZnO NRs exhibited remarkable photocatalytic degradation activity of cationic dyes under UV-light, i.e., Malachite Green and Fuchsin Basic with degradation of 99.604 and 99.881%, respectively in 90 min. The reusability tests for these green synthesized Cr-doped ZnO NRs have also been carried out, showed 9–11 cycles with 85% of degradation efficiency. In addition, the Cr-doped ZnO NRs exhibited high selectivity for cationic dyes when experiments against mixture of dyes were performed. Photodegradation kinetics followed the pseudo-first-order model. The flower-extract-stabilized chromium-doped ZnO NRs demonstrated high photocatalytic activity toward malachite green and fuchsin basic dyes, potential material for pollution remediation. Cr-doped ZnO NRs by green method using flower extract of Rhododendon arboretum were prepared for the first time under ambient reaction conditions. Effect of Dopant i.e. Cr on Photocatalytic activity have been exploited. Selective photocatalytic degradation of cationic dyes i.e. MG, and FB has been achieved in 60–90 minutes. Optimization of reaction condition and various parameters has also been carried out. Recyclability of Cr-doped ZnO NRs was also evaluated and were found to be reusable for 11 cycles for degradation. [ABSTRACT FROM AUTHOR]

AbstractA key strategy in enhancing the efficacy of collagen-based hydrogels involves incorporating polysaccharides, which have shown great promise for wound healing. In this study, semi-interpenetrating polymeric network (semi-IPN) hydrogels comprised of collagen (Col) with the macrocyclic oligosaccharide β-cyclodextrin (β-CD) (20–80 wt.%) were synthesised. Fourier-transform infrared (FTIR) spectroscopy confirmed the successful fabrication of these Col/β-CD hydrogels, evidenced by the presence of characteristic absorption bands, including the urea bond band at ∼1740 cm−1, related with collagen crosslinking. Higher β-CD content was associated with increased crosslinking, higher swelling, and faster gelation. The β-CD content directly influenced the morphology and semi-crystallinity. All Col/β-CD hydrogels displayed superabsorbent properties, enhanced thermal stability, and exhibited slow degradation rates. Mechanical properties were significantly improved with contents higher than β-CD 40 wt.%. These hydrogels inhibited the growth of Escherichia coli bacteria and facilitated the controlled release of agents, such as malachite green, methylene blue, and ketorolac. The chemical composition of the Col/β-CD hydrogels did not induce cytotoxic effects on monocytes and fibroblast cells. Instead, they actively promoted cellular metabolic activity, encouraging cell growth and proliferation. Moreover, cell signalling modulation was observed, leading to changes in the expression of TNF-α and IL-10 cytokines. In summary, the results of this research indicate that these novel hydrogels possess multifunctional characteristics, including biocompatibility, super-swelling capacity, good thermal, hydrolytic, and enzymatic degradation resistance, antibacterial activity, inflammation modulation, and the ability to be used for controlled delivery of therapeutic agents, indicating high potential for application in advanced wound dressings. [ABSTRACT FROM AUTHOR]

Flexible and transparent surface-enhanced Raman scattering (SERS) substrates have attracted considerable attention for their ability to enable the direct in situ detection of analytes on curved surfaces. However, the curvature of an object can impact the signal enhancement of SERS during the measurement process. Herein, we propose a simple approach for fabricating a curvature-insensitive transparent SERS substrate by depositing silver nanoparticles (Ag NPs) onto a large-area wrinkled polystyrene/polydimethylsiloxane (Ag NP@W-PS/PDMS) bilayer film. Using rhodamine 6G (R6G) as a probe molecule, the optimized Ag NP@W-PS/PDMS film demonstrates a high analytical enhancement factor (AEF) of 4.83 × 105, excellent uniformity (RSD = 7.85%) and reproducibility (RSD = 3.09%), as well as superior mechanical flexibility. Additionally, in situ measurements of malachite green (MG) on objects with diverse curvatures, including fish, apple, and blueberry, are conducted using a portable Raman system, revealing a consistent SERS enhancement. Furthermore, a robust linear relationship (R2 ≥ 0.990) between Raman intensity and the logarithmic concentration of MG detected from these objects is achieved. These results demonstrate the tremendous potential of the developed curvature-insensitive SERS substrate as a point-of-care testing (POCT) platform for identifying analytes on irregular objects. [ABSTRACT FROM AUTHOR]

"Core/shell" composites are based on a ferrite core coated by two layers with different properties, one of them is an isolator, SiO2, and the other is a semiconductor, TiO2. These composites are attracting interest because of their structure, photocatalytic activity, and magnetic properties. Nanocomposites of the "core/shell" МFe2O4/SiO2/TiO2 (М = Zn(II), Co(II)) type are synthesized with a core of MFe2O4 produced by two different methods, namely the sol-gel method (SG) using propylene oxide as a gelling agent and the hydrothermal method (HT). SiO2 and TiO2 layer coating is performed by means of tetraethylorthosilicate, TEOS, Ti(IV) tetrabutoxide, and Ti(OBu)4, respectively. A combination of different experimental techniques is required to prove the structure and phase composition, such as XRD, UV-Vis, TEM with EDS, photoluminescence, and XPS. By Rietveld analysis of the XRD data unit cell parameters, the crystallite size and weight fraction of the polymorphs anatase and rutile of the shell TiO2 and of the ferrite core are determined. The magnetic properties of the samples, and their activity for the photodegradation of the synthetic industrial dyes Malachite Green and Rhodamine B are measured in model water solutions under UV light irradiation and simulated solar irradiation. The influence of the water matrix on the photocatalytic activity is determined using artificial seawater in addition to ultrapure water. The rate constants of the photocatalytic process are obtained along with the reaction mechanism, established using radical scavengers where the role of the radicals is elucidated. [ABSTRACT FROM AUTHOR]

The discharge of colored effluent into water bodies is a big concern; hence, the current work was designed to fabricate a superior nanocomposite (NBM) using the Newbouldia laevis husk (NB) and functionalized multiwalled carbon nanotubes (f-MWCNTs) for the adsorption of malachite green oxalate (MGO). Brunauer–Emmett–Teller (BET) surface analysis was used to assess the specific surface area of NB (0.7699 m2 g−1) and NBM (94.006 m2 g−1). Fourier transform infrared spectroscopy (FTIR) was employed to determine the chemical moieties on the surface of the adsorbent. Field emission scanning electron microscopy (FESEM) and thermogravimetric analysis (TGA) were used to analyze the surface morphology and the thermal behavior of the adsorbents. Essential factors of the adsorption process were investigated, and it was revealed that pH 6.0, adsorbent dose of 0.05 g, contact time 80 min, concentration of 100 mg dm−3 and maximum adsorption capacity of 35.78 mg g−1 (NB) and 69.97 mg g−1 (NBM) were the optimal parameters. The NB and NBM adsorption processes followed a pseudo-first-order kinetic model. The exothermic and endothermic adsorptive processes were noticed to be the best descriptions of MGO elimination by NB and NBM, respectively. The uptake of MGO by NB and NBM was best described by models of Freundlich and Langmuir isotherms. Besides, NBM demonstrated uptake efficiency that is >80% after the fourth adsorption/desorption cycle. As a result, NBM has a wide range of possible uses in environmental remediation. The husk of Newbouldia laevis is a frequent waste that must be managed properly. This paper describes the application of Newbouldia laevis husk as a value-added material for the design of a water treatment agent. The use of carbon nanotube in the modification of Newbouldia laevis husk would have a synergistic effect on the overall property of the nanocomposite. Nanocomposite synthesized from multiwalled carbon nanotubes (MWCNTs) and Newbouldia laevis husk were characterized and used for the sequestration of malachite green oxalate from contaminated water. Our primary goal is to optimize the nanocomposite by varying factors of adsorption such as solution pH, equilibrium, kinetic, thermodynamic, and regeneration studies. We believe that this study will contribute to the existing knowledge of Newbouldia laevis husk. Owing to the exceptional potential of the nanocomposite, this adsorbent can be extended to possible field applications. [ABSTRACT FROM AUTHOR]

The situation of discharging a large amount of dyes from the textile industries has caused many adverse effects on human health and the ecosystems. Emerging bio-nanomaterials represent a new trend in efficient dye removal in aqueous media. Herein, we mention that MgFe2O4 bioprepared using gerbera extract has been successfully used to adsorb malachite green (MG) in water. A comparison was made to determine the dye removal efficiency between biogenic MgFe2O4 (MFOB) and chemical MgFe2O4 (MFOC). The spherical MFOB material exhibited a large surface area of 85.0 m2 g–1 and high crystallinity. The obtained outcomes showed that the highest adsorption capacity of MG dye was 584.49 mg g–1 at a MFOB dose of 0.05 g L–1 and MG concentration of 10 mg L–1. Higher correlation coefficients in the Langmuir isotherm suggested monolayer adsorption of MG. The Box–Behnken design and response surface method were established to optimize MG removal percentage under the conditions, i.e., initial MG concentration (10–30 mg L–1), adsorbent dose (0.02–0.08 g L–1), and pH of dye solution (6–8). MFOB had good reusability with high removal efficiencies after three continuous cycles. Post reuse, this adsorbent still showed excellent stability through the verification of their structural properties in comparison with fresh MFOB, showing potential for practical applications. [ABSTRACT FROM AUTHOR]

Together with the rapid growth of technology, the discharge of wastewater from industry into environment had become a hot topic among society nowadays. More attention had been given to the development of water treatment techniques. In this study, sonocatalysis was proposed to degrade the organic pollutants using silver-doped zinc oxide (Ag-ZnO) nanoparticles which were synthesized via green synthesis process using Clitoria ternatea Linn (Asian Pigeonwings flower). The characterization results revealed that the incorporation of Ag into the ZnO lattice decreased the crystallite size and increased the specific surface area of ZnO nanoparticles. It is noteworthy that about 98% of sonocatalytic degradation efficiency of malachite green (MG) was successfully achieved within 30 min in the presence of 5 wt.% Ag-ZnO with 1.0 g/L of catalyst loading under 500 mg/L of initial dye concentration, 80 W of ultrasonic power, 45 kHz of ultrasound frequency, and 2.0 mM of oxidant concentration. The kinetic study showed that the sonocatalytic degradation of organic dye was fitted well into second-order kinetic model with high R2 value (0.9531). In the thermodynamic study, negative value of standard Gibbs free energy and low value of activation energy (+ 24.43 kJ/mol) were obtained in the sonocatalytic degradation of MG using the green-synthesized Ag-ZnO sample. Highlights: • Facile synthesis of silver-doped zinc oxide nanoparticles using plant extract which act as reducing and stabilizing agents • Optical, physical, and chemical characterization of green-synthesized nanomaterials were performed • Evaluation of sonocatalytic degradation of organic dye using green-synthesized nanomaterials • Sonocatalytic behavior, kinetic and thermodynamic studies of sonocatalytic reaction [ABSTRACT FROM AUTHOR]

AbstractFour empty fruit bunch hydrochars namely HC, HC-Acr, HC-APS, and HC-Acr-APS, were synthesized through one-step hydrothermal carbonization in the presence of acrylic acid (Acr) and/or ammonium persulphate (APS). This study aims to combine HTC with free radical graft copolymerization to produce hydrochar with enhanced functional groups and adsorption capabilities. The FTIR results show that the modified hydrochars contain more functional groups as compared to the unmodified hydrochar. The HC-Acr-APS demonstrates the highest MG capacity (qm = 72.86 mg/g). The kinetic data obeyed the pseudo-second order model (qe = 19.61 mg/g, k2 = 0.02 g/mg.h), while isotherm demonstrates a good fit with the Freundlich model. The positive enthalpy change (ΔH = 26.06 kJ/mol) indicates an endothermic adsorption process, while the positive entropy change (ΔS=77.15 J/mol.K) suggests increased molecular randomness during adsorption. The Gibbs free energy change (ΔG) is also assessed, indicating the thermodynamic favorability of the adsorption process. This study offers valuable insights into the potential of surface-modified EFB hydrochar as an efficient adsorbent for MG removal, providing a sustainable solution for environmental challenges. [ABSTRACT FROM AUTHOR]

The scientific community has preferred the photocatalysis process to remove organic pollutants from water. Many catalysts have been developed over the years, and one such catalyst is molybdenum disulfide (MoS2), which is a two-dimensional (2D) material with an energy bandgap in the visible spectrum. In this manuscript, the facile synthesis of MoS2 nanostructures in varying molybdenum (Mo) and sulphur (S), Mo/S ratios has been demonstrated through a single-pot hydrothermal route. The structural validation of the nanostructures was done using X-ray diffraction (XRD) patterns. Further, the morphological information about the MoS2 nanostructures was gathered using the Field Emission Scanning Electron Microscope (FE-SEM) and High-Resolution Transmission Electron Microscope (HR-TEM) analyses. The photodegradation process of the Malachite Green dye was analyzed by UV-visible absorption spectroscopy. The results showed that 1T/2H MoS2 nanoflowers degraded the malachite green dye with a degradation efficiency of 98.4%. The decomposition of this commonly used dye possesses great significance in industrial waste water treatment. [ABSTRACT FROM AUTHOR]

Bee-collected pollen (BCP) and bee bread (BB) are honey bee products known for their beneficial biological properties. The main goal of this study was to investigate BB microbiota and its contribution to bioactivity exerted by BB. The microbiota of BB samples collected at different maturation stages was investigated via culture-independent (Next Generation Sequencing, NGS) and culture-dependent methods. Microbial communities dynamically fluctuate during BB maturation, ending in a stable microbial community structure in mature BB. Bee bread bacterial isolates were tested for phenotypes and genes implicated in the production and secretion of enzymes as well as antibacterial activity. Out of 309 bacterial isolates, 41 secreted hemicellulases, 13 cellulases, 39 amylases, 132 proteinases, 85 Coomassie brilliant blue G or R dye-degrading enzymes and 72 Malachite Green dye-degrading enzymes. Furthermore, out of 309 bacterial isolates, 42 exhibited antibacterial activity against Staphylococcus aureus, 34 against Pseudomonas aeruginosa, 47 against Salmonella enterica ser. Typhimurium and 43 against Klebsiella pneumoniae. Artificially fermented samples exerted higher antibacterial activity compared to fresh BCP, strongly indicating that BB microbiota contribute to BB antibacterial activity. Our findings suggest that BB microbiota is an underexplored source of novel antimicrobial agents and enzymes that could lead to new applications in medicine and the food industry. [ABSTRACT FROM AUTHOR]

This work studies the synthesis, characterization, and application of CuFe2O4 nanoparticles for the removal of acid blue 113 and malachite green dyes from aqueous media. Utilizing the combustion procedure, CuFe2O4 nanoparticles were synthesized using two different fuels: L-alanine (CFA) and L-valine (CFV). Besides, the synthesized CuFe2O4 nanoparticles were characterized through some tools, including Fourier transform infrared (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and field emission scanning electron microscope (FE-SEM). XRD analysis verified the creation of a CuFe2O4 cubic spinel structure without any contaminants, revealing average crystallite sizes of 26.37 and 17.65 nm for the CFA and CFV samples, respectively. The FTIR spectra exhibited peaks indicative of metal-oxygen bond stretching, verifying the presence of a spinel formation. Elemental analysis via EDX confirmed the stoichiometric composition typical of copper ferrite. In addition, FE-SEM displayed that the CFA and CFV samples are composed of particles with spherical and irregular shapes, measuring average diameters of 188.35 and 132.78 nm, respectively. The maximum adsorption capabilities of the CFA and CFV samples towards acid blue 113 dyes are 281.69 and 297.62 mg/g, respectively. Also, the maximum adsorption capabilities of the CFA and CFV products towards malachite green dye are 280.11 and 294.99 mg/g, respectively. Kinetic and equilibrium studies revealed that the adsorption process of acid blue 113 and malachite green dyes onto the CFA and CFV samples followed the pseudo-second-order model and Langmuir isotherm. Thermodynamic analysis indicated that the adsorption process was physical, spontaneous, and exothermic. [ABSTRACT FROM AUTHOR]

Malachite green (MG), a triphenylmethane dye is often used as a fungicide and preservative in fisheries due to its effectiveness against water molds in fish and fish eggs. However, excessive inhalation can be hazardous to human health. To quantify the MG concentration, we created and evaluated a 96‐well plate‐based chemiluminescence immunoassay (CLIA). This method used provided readings in <30 min, with an optimal incubation time of 15 min and a limit of detection of 0.20 ng·ml−1. The strong correlation (R2 >0.99) between the measured values of real fish samples examined using the method and the high‐performance liquid chromatography results confirmed the accurate quantitative detection of MG. In this study, CLIA was also used in conjunction with point‐of‐care testing (POCT) to greatly improve the efficiency of the experiments. Thus, a quantitative detection method based on MG plate chemiluminescence was established herein, with performance indexes that meet the requirements of on‐site detection. This approach is also applicable to the detection of small molecule compounds such as chloramphenicol and sulfadiazine pyrimethamine, providing a new direction in the field of food safety detection. [ABSTRACT FROM AUTHOR]