Search

In this study, Zirconium‐modified Engelhard Titanium Silicate 4 (Na−K‐ETS‐4/xZr) catalysts were synthesized and evaluated for their photocatalytic efficiency in degrading crystal violet (CV) and methylene blue (MB) in aqueous solutions. The catalysts were characterized using XRD, FTIR, SEM, WDXRF, and nitrogen adsorption/desorption isotherms. The results confirmed the successful incorporation of Zr into the ETS‐4 framework, with the highest Zr content reaching 9.2 wt %. The photocatalytic performance under visible light irradiation was studied at varying pH levels. The Na−K‐ETS‐4/6.3Zr catalyst exhibited the highest photodegradation efficiency for CV (76.6 %), while Na−K‐ETS‐4/8.9Zr achieved 86.6 % efficiency for MB. A combination of Engelhard Titanium Silicate 10, Na−K‐ETS‐10/6.3Zr and Na−K‐ETS‐4/8.9Zr significantly enhanced dye degradation, achieving up to 96.5 % efficiency for MB. Kinetic studies indicated that the degradation process follows a non‐linear pseudo‐first‐order model. The catalysts also demonstrated excellent reusability, with minimal efficiency loss after five cycles, and full recovery after an ethanol wash. These findings suggest that Na−K‐ETS‐4/xZr is a promising candidate for environmental water treatment applications due to its efficient photodegradation performance and stability. [ABSTRACT FROM AUTHOR]

Releasing wastewater containing organic dyes into water bodies generates a variety of hazards for humans and marine life. Thus, developing effective adsorbents to remove organic dyes from wastewater is critical. Herein, a mixture of the orange peel (OP) and watermelon rind (WR) wastes was converted into a mesoporous activated carbon (OPWRAC) via microwave-induced ZnCl2. Several analytical techniques such as XRD, N2 adsorption–desorption isotherms, FTIR, pHpzc, and SEM–EDX were applied to characterize the physicochemical properties of OPWRAC. Subsequently, the adsorptive efficiency of OPWRAC was comprehensively explored towards the removal of two structurally different organic dyes, namely, crystal violet (CV) and methylene blue (MB). The operational adsorption conditions such as OPWRAC dose (0.04–0.1 g) coded as (A), solution pH (4–10) coded as (B), and contact time (10–60 min) coded as (C) were statistically optimized using the response surface methodology-Box-Behnken design (RSM-BBD). The adsorption isotherm data for CV and MB dyes agree with the Freundlich model, and the kinetic data can be explained by the pseudo-second-order model. Thus, OPWRAC displays remarkable adsorption capacity for capturing CV (137.8 mg/g) and MB (200.7 mg/g). The tailored adsorption mechanism of CV and MB by the OPWRAC indicates the involvement of several types of electrostatic forces, π-π stacking, pore filling, and H-bonding. The output of this research shows the feasibility of converting the mixture of OP and WR into promising activated carbon with potential application for capturing two structurally cationic dyes from an aqueous environment. [ABSTRACT FROM AUTHOR]

Abstract\nIn this research, a nanocomposite called AAZG-NCPs was synthesized and analyzed. The nanocomposite showed a surface area of 10.57 ± 0.31 m2/g, a pore size of 0.07299 ± 0.002 cm3/g, and ferromagnetic properties with a magnetization of 3.9 ± 0.12 emu/g. Its band gap energy was found to be 2 ± 0.1 eV. The surface charge of the synthesized AAZG-NCPs was determined to be −29 ± 0.6 mV. A pHZPC value of 6.6 ± 0.04 was calculated using the salt addition method. The photocatalytic activity and optimization of the Crystal violet (CV) photodegradation process using synthesized AAZG-NCPs was investigated using Box Behnken design and Design Expert software. A polynomial equation was obtained for the experimental data, with a calculated R2, Adj-R2, and Pred-R2 values in the model were 0.998, 0.9977, and 0.9947 respectively, indicating a strong proportion between the model fitting and experimental data. The photocatalytic degradation of CV achieved a maximum efficiency of 98.7 ± 1% under optimum conditions at pH = 9, CV concentration of 5.7 mg/L, AAZG-NCPs amount of 0.075 g/L, and temperature of 40 °C under visible light. The kinetics study indicated a pseudo-first-order kinetics model with a rate constant of 0.0441 ± 0.002 min−1.A novel magnetic photocatalyst Ag2CrO4/Ag/ZnFe2O4/g-C3N4 was used for Crystal Violet dye degradation under Visible light.The degradation of Crystal Violet dye (5.7 mg/L) is quasi-total after 90 minute.The Box-Behnken design was used for optimization of the process.Crystal Violet dye degradation obeys a pseudo-first-order kinetics. [ABSTRACT FROM AUTHOR]

In this study, chromium‐based metal–organic framework (MIL‐101(Cr)) was incorporated into polyvinyl alcohol nanofibers (PVA NFs) via green electrospinning followed by heat treatment to fabricate MIL‐101(Cr)@PVA NFs composite without the need for any organic solvent or other dispersants. The fabricated MIL‐101(Cr)@PVA NFs were comprehensively characterized using a suite of common techniques. Morphological characteristics of MIL‐101(Cr)@PVA NFs showed a fibrous structure with an average diameter of 228 ± 37 nm and decorated with MIL‐101(Cr) particles arranged in a nanoneedle‐like pattern. Subsequently, its adsorption efficiency towards the cationic crystal violet dye (CV) was evaluated through batch adsorption experiments. The influence of various experimental parameters on CV removal efficiency was systematically optimized using a factorial design approach. The Langmuir isotherm and kinetic pseudo‐second‐order (PSO) model provided an excellent fit to the adsorption equilibrium data, indicating a maximum adsorption capacity (qmax) of 344.18 mg/g for MIL‐101(Cr)@PVA NFs compared with 83.94 mg/g for pristine PVA NFs. Furthermore, the MIL‐101(Cr)@PVA NFs composite demonstrated excellent reusability and stability, maintaining a significant portion of its removal capacity even after six adsorption–desorption cycles. These findings highlight the potential of the fabricated composite as a highly efficient and reusable adsorbent for CV removal from wastewater treatment applications. Highlights: The MIL‐101(Cr)@PVA NFs nanocomposite fabricated by electrospinning technique.The MIL‐101(Cr) particle arranged in a nanoneedle‐like pattern in the PVA NFs.Incorporation of MIL‐101(Cr) improved qmax of PVA by 391.5%.The MIL‐101(Cr)@PVA NFs membrane has excellent stability and reusability. [ABSTRACT FROM AUTHOR]

ABSTRACT The rapid increase of water pollution globally is a vital environmental concern that requires the immediate attention of researchers to find new innovative ways to remove unwanted environmental pollutants from our water sources. With the advances in the field of sustainable engineering, there is a high demand for the effective utilization of biomass resources for the removal of aqueous environmental contaminants. Biochar is carbon carbon‐enriched substance obtained by biomass pyrolysis; it is inexpensive and has received wide attention in the field of wastewater treatment. Herein, we describe the synthesis of pea pod (PO) biochar‐reinforced zeolitic imidazolate framework (ZIF‐8) nanocomposite (PO@ZIF‐8) through the in situ precipitation of ZIF‐8 onto the biochar surface. The crystal growth, morphology, chemical composition, and optical characteristics of fabricated PO@ZIF‐8 nanocomposite were scrutinized through PXRD, SEM, TEM, UV‐DRS, PL, and XPS analysis. The dodecahedral‐shaped PO@ZIF‐8 particles have an average size between 140 and 160 nm. The biochar‐reinforced ZIF‐8 nanocomposite showed significantly higher photocatalytic activity than the pure ZIF‐8 for the degradation of two commonly found organic dyes crystal violet (CV) and Victoria Blue (VB) in the presence of direct sunlight irradiation. The PO@ZIF‐8 nanocomposite showed the highest degradation efficiency of ~87% and ~80% within 50 min of irradiation time at a catalyst dosage of 20 mg for 30 ppm CV and VB dye solutions at pH 8. First‐order kinetics were obeyed during the photodegradation with 0.041 and 0.030 min−1 as the constant of degradation for the removal of CV and VB. The radical scavenger experiment and the photoluminescence analysis confirm the active participation of ·OH radical in the degradation of both dyes. LC–MS and TOC analysis was also performed to determine the degradation products and for evaluation of the degradation progress. Moreover, the synthesized PO@ZIF‐8 composite also exhibit good stability till the fourth cycle with high degradation efficiency thus making it a good choice of catalyst in the field of environmental decontamination. [ABSTRACT FROM AUTHOR]

Herein, composite films were fabricated using the solution casting route, incorporating different weight percentages of crystal violet (CV) into polyvinyl alcohol (PVA). To examine the final composites, a series of characterization approaches were used. Fourier-transform infrared spectroscopy (FTIR) elucidated PVA/CV molecules' physicochemical interactions. The analysis through X-ray diffraction (XRD) pointed out a decrease in the semi-crystalline nature of the polymer matrix with a rise in the CV content, thereby enhancing transport mobility and electrical conductivity. The optical properties of PVA influenced by CV dopants were systematically studied in the range of 190–1400 nm. Notably, the PVA/CV composites exhibited improved UV-blocking capabilities in the 190–380 nm range, making them appropriate for uses including UV notch filters and laser hindering filters. An increase in CV doping percentage from 0.1 to 0.8 wt% resulted in a reduction of the indirect optical bandgap of PVA from 5.16 ± 0.013 eV to 4.77 ± 0.069 eV. Additionally, the Wemple-DiDomenico model revealed significant enhancements in the optical parameters. Specifically, the dispersion energy and oscillator energy of PVA/CV composites increased from 0.91 eV and 2.01 eV to 6.83 eV and 3.25 eV, respectively, along with an increase in the lattice dielectric constant (εL) from 1.71 to 3.47. These improvements in dispersion factors were attributed to the cross-linking of CV with the polymer matrix. Furthermore, the composite films demonstrated notable nonlinear optical properties, indicating their potential for practical applications in photonic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

In the present study, grafting of acrylic acid and itaconic acid copolymer onto carboxymethyl cellulose backbone was performed by a free radical polymerization approach to decontamination of crystal violet and malachite green from aqueous media. To promote removal efficiency, various amounts of Cloisite 30B nanoclay were integrated into the hydrogel matrix, and the optimum value based on the removal performance was obtained 6 wt.%. The optimum pH values, initial concentration, and contact time were determined to be 7, 30 mg/L, and 140 min. The kinetic and equilibrium data were well defined by quasi-second-order and Langmuir models. The maximum adsorption capacity of hydrogel and nanocomposite hydrogel from the Langmuir model was obtained at 45.87 and 58.48 mg/g for crystal violet and 25.51 and 36.36 mg/g for malachite green, respectively. The FTIR analysis before and after dye adsorption showed that electrostatic interaction is the main mechanism of the adsorption process. It can be concluded that synthesized adsorbents have high potential in wastewater treatment applications. [ABSTRACT FROM AUTHOR]

The use of magnetic nanomaterials (MNPs) as adsorbents to eliminate pollution causing dyes from water has attracted substantial attention in recent years because they can be easily isolated and reused. In this work, core–shell Fe3O4@SiO2 MNPs in which magnetic Fe3O4 NPs as a core enclosed with a thick SiO2 shell were successfully synthesized by chemical co–precipitation followed by hydrolysis and condensation of alkoxysilanes in a mixture of ammonia, ethanol and water. The formation of core–shell Fe3O4@SiO2 MNPs has been characterized by TEM, TEM-EDS, XRD, FT-IR and VSM. TEM characterization revealed that several Fe3O4 NPs (around 10 nm) aggregated to form a Fe3O4 magnetic core and surrounded by an uniform SiO2 shell of 40-50 nm thickness to obtain Fe3O4@SiO2 magnetic core–shell NPs. As synthesized core–shell NPs were employed as adsorbent for elimination of two cationic toxic dyes, crystal violet (CV) and malachite green (MG) from aqueous solutions. Further, different adsorption parameters such as pH, adsorbent dosage and contact times of the dyes were found to enhance the adsorption of cationic dyes. At neutral pH 7 the cationic dyes could be speedily removed from aqueous solution with high efficiency. It has been observed that 0.35 g of adsorbent dosage is sufficient for 95% of dye removal efficiency. The contact time is optimised for 20 min for both the dyes. The Langmuir model adsorption isotherm is best suitable which indicates that the cationic dyes adsorption behaviour of Fe3O4@SiO2 is a homogeneous monolayer chemisorption process. The adsorptive binding of CV/MG with Fe3O4@SiO2 was directed through electrostatic interactions. Moreover, the magnetic adsorbents could be easily reused and regenerated with almost no adsorption capability is significantly reduced up to 5 cycles. So, the Fe3O4@SiO2 is an efficient and reusable adsorbent for rapid and removal of cationic dyes from the aqueous solution. [ABSTRACT FROM AUTHOR]

Herein, a novel hydrogel (HG-cl-poly(AA)) was synthesized by grafting acrylic acid (AA) onto Hing gum (HG) using methylene-bis-acrylamide (MBA) as a cross-linker and ammonium persulfate (APS) as an initiator in a hot air oven. The percentage swelling of the hydrogel was examined by optimizing various reaction parameters to ensure its maximum swelling percentage. The formation of crosslinked networks was confirmed using Fourier-Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA) techniques. The surface area and hydrophilicity of the prepared hydrogel were determined using Brunauer–Emmett–Teller analyzer and wettability studies, demonstrating a clear correlation with adsorption. The adsorption of crystal violet (CV) dye on the prepared hydrogel was studied via a batch adsorption system based on the amount of adsorbent, immersion time, pH level, and initial dye concentration. The prepared hydrogel showed a 99% removal rate and an excellent adsorption capacity of 492.61mg/g due to the electrostatic, H-bonding, and dipole–dipole interactions between the adsorbent surface and dye molecules. The results were further analyzed using the Langmuir, Freundlich, and Tempkin isotherm models. The study suggests consistency with the pseudo-second-order kinetic model (R2=0.998), further supported by the best data fit with the Langmuir isotherm model (R2=0.991). The thermodynamic study results indicated that the adsorption process is endothermic and spontaneous. Regeneration (desorption) studies showed that the prepared hydrogel could remove CV dye from an aqueous solution and maintain the highest adsorption capacity even after multiple adsorption and desorption cycles. Therefore, the prepared HG-cl-poly(AA) hydrogel could be a potential adsorbent for dye removal and have an admirable capacity for cleaning the aquatic environment. [ABSTRACT FROM AUTHOR]

This study aims to elucidate the possible application of cobalt aluminate nanoparticles (CoAl 2 O 4) as a photocatalyst for the removal of organic dyes. The sol-gel method was employed to synthesise Nd x /CoAl 2 O 4 nanoparticles with varying weight percentages (x = 0.0, 0.2, 0.4, and 0.6 wt %). The experimental investigation focused on the photocatalytic destruction of colour, employing a visible light irradiation source. The structural and optical properties of the synthesised nanoparticle were examined through various analytical techniques, including X-Ray Diffraction (XRD), Ultra Violet-Diffuse Reflectance Spectroscopy (UV-DRS), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray spectroscopy (EDX), Tunnelling Electron Microscopy (TEM), and X-ray Photoelectron Spectroscopy (XPS). The cubic spinel structure was confirmed through the study of the X-ray diffraction (XRD) pattern of the Nd x /CoAl 2 O 4 nanoparticles. For the compositions x = 0.0, 0.2, 0.4, and 0.6, the nanoparticles exhibited average crystallite sizes of 23.73, 22.99, 21.69, and 21.65 nm, respectively. The synthesised nanoparticle exhibited heterogeneous photocatalytic potential when employed as a model pollutant for the oxidative destruction of crystal violet dye. The experimental findings validated that the CoAl 2 O 4 nanoparticle exhibited a dye degradation rate of 64 % during a 100-min timeframe. Additionally, the 0.6 wt % Nd CoAl 2 O 4 nanoparticle shows a quick dye degradation rate of 91 % for crystal violet dyes when exposed to visible light sources. Hence, the synthesised nanoparticle exhibits catalytic activity and holds potential for utilisation in the treatment of hazardous contaminants in industrial wastewater. [ABSTRACT FROM AUTHOR]

Synthesis of unique morphologies in photocatalytic materials, coupled with utilization of wide-spectrum solar energy through rare earth doping, holds significant promise to maximize the potential of photocatalysts. Herein in, cube-like Holmium (Ho) doped Bi 5 Nb 3 O 15 was synthesized by the hydrothermal method and integrated with reduced graphene oxide (rGO) sheets. As synthesized Ho–Bi 5 Nb 3 O 15 @rGO composite along its analogs i.e., Bi 5 Nb 3 O 15 and Ho–Bi 5 Nb 3 O 15 was characterized by XRD, SEM, FT-IR, TGA, I–V, EIS, Mott-Schottky and photo-current measurements. Phase studies showed that crystallite size for Bi 5 Nb 3 O 15 , Ho–Bi 5 Nb 3 O 15 , and Ho–Bi 5 Nb 3 O 15 @rGO was 27.4, 25.5, and 13.5 nm, respectively. Optical analysis exhibited a reduction in the band gap in consequent to Ho doping from 2.54 to 2.19 eV for Ho–Bi 5 Nb 3 O 15. Conductivity and photo-current measurements showed a remarkable increase in both electrical conductivity and photo-response of Ho–Bi 5 Nb 3 O 15 upon its incorporation into rGO matrix, reaching maximum values of 1.72 × 10−2 S/m and 0.66 μA, respectively. The enhanced photocatalytic activity of Ho–Bi 5 Nb 3 O 15 @rGO was ensured through the outstanding photo-degradation efficiency (96.5 %) against crystal violet (CV), greater than Bi 5 Nb 3 O 15 (49 %) and Ho–Bi 5 Nb 3 O 15 (63.4 %). Additionally, Ho–Bi 5 Nb 3 O 15 @rGO showed sufficient potential towards the degradation of acetylsalicylic acid (ASA) with 79.1 % photo-degradation. This elevated photocatalytic activity of Ho–Bi 5 Nb 3 O 15 @rGO is believed to be contributed by the collaborative outcomes aroused from the Ho-doping and heterojunction fabrication among cubical Ho–Bi 5 Nb 3 O 15 and rGO sheets. Hence, our work proposes an efficient strategy for the development of innovative photolytic materials for sustainable wastewater remediation. [ABSTRACT FROM AUTHOR]

Search for water-stable, low-cost materials for sustainable water treatment is on the rise. Recently, phyto-magnetic hybrid materials have been demonstrated as the promising ones, showcasing outstanding water treatment capability, albeit challenging to prepare. Herein, we report the synthesis of peanut shell-embedded magnetic ferrites (MPS) for the scintillating elimination of crystal violet (CV) dye from a series of simulated, spiked, and wastewater. FTIR, FESEM-EDX, VSM, PXRD, and pHZPC elucidate the material characteristics, and CV uptake was mapped concerning various physicochemical parameters like equilibration time (0–90 min), pH (3–11), temperature (298–328 K), ionic strength, and competitive inhibition thwarting from coexistent ions. FTIR suggests the presence of polyphenolic moiety (3428 cm−1) and carbonyl groups (1716 cm−1). FESEM reveals a porous structure with uneven fractures which upon CV uptake converts to a smoother one. Vibrating sample magnetism suggests a typical hysteresis for a soft magnetic material with a saturation magnetization value of 28.464 emu/g and coercivity of 35.240 Oe. The maximum intake capacity is 97.903 mg/g at 298 K, whereas the process follows pseudo-second-order kinetics (R2 = 0.999) and the Langmuir isotherm model (R2 = 0.996). Spontaneity and feasibility of the uptake process were identified from the negative free energy (ΔG = –2.073 kJ/mol), (ΔH = 9.078 kJ/mol), and (ΔS = 0.034 kJ/mol/K). MPS could be revived well using 1:1 MeOH/H2O in up to 91% and elegantly reused for six cycles without significant loss in activity. [ABSTRACT FROM AUTHOR]

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

FeS@Fuller's Earth (FeS@FE) was synthesized by borohydride reduction in presence of dithionite with a 10% w/w iron loading. FESEM analysis reveal immobilized FeS NPs (40–100 nm) on the surface of Fuller's Earth with agglomeration. The presence of sulfur as confirmed from XPS and EDX analysis of FeS@FE. Batch adsorption study of FeS@FE for crystal violet (CV) dye adsorption in aqueous solution yielded an optimized adsorption at pH 8, adsorbent dose 0.1 g/L, with a removal of upto 80% of the dye from a 20 mg/L CV solution. The CV adsorption on FeS@FE followed a good non-linear fit for Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm with R2 > 0.95. The maximum monolayer adsorption capacity of FeS@FE was found to be 601.2 mg/g for CV with a D-R Isotherm Free energy of 141.58 kJ/mol at optimum conditions of pH 8, 100 mg/L of CV, and 0.1 g/L of adsorbent dose. The non-linear kinetic fit for CV dye adsorption on FeS@FE fitted to the pseudo-second-order (PSO) and intraparticle diffusion (IPD) models, indicating a strong chemical interaction between CV and FeS@FE. The strong adsorption of CV using FeS@FE is attributed to the Fe-OOH surface formation by FeS immobilized on FE under alkaline conditions, leading to deprotonation and electrostatic adsorption of the dye. [ABSTRACT FROM AUTHOR]

The rapid development of the global production printing and dyeing industry has led to an increase in the demand for various dyes. Crystal violet (CV), a versatile dye, is widely used in the textile industry and other applications. The reason for its widespread use is its effectiveness and the vivid color it gives to fabrics.CV dye is a water-soluble, toxic, resistant organic dye that is quite dangerous for the ecosystem and causes environmental pollution. Therefore, it must be removed before being released into the recipient environment. This study synthesized selenium nanoparticles (Se NPs) from agricultural Prunus avium L. (PaL.) wastes and removed CV dye. In batch adsorption tests, the effects of pH, amount of adsorbent, time, initial concentration, and temperature were investigated. In this study, where 3 different kinetic and isotherm models were tested, it was determined that the most suitable kinetic and isotherm models for the removal of CV dye with PaL-Se NPs were Pseudo second order (R2:0.999) and Langmuir (R2:0.997), respectively. Additionally, the maximum adsorption capacity (qmax) was calculated as 142.61 mgCV/g PaL-Se NP. Accordingly, it can be said that low-cost PaL-Se NPs synthesized by environmentally friendly methods are a suitable alternative for the removal of CV dye. [ABSTRACT FROM AUTHOR]

A nanostructured material, ordered mesoporous carbon (OMC), was synthesised in metal- and halide-free form and its use for the sequestration of crystal violet, a hazardous triphenylmethane dye, is reported for the first time. The OMC material is characterised using scanning transmission electron microscopy with energy-dispersive spectroscopy for chemical analysis, by Fourier-transform infrared spectroscopy, and by nitrogen gas physisorption. The ideal conditions for the uptake of crystal violet dye were determined in batch experiments covering the standard parameters: pH, concentration, contact time, and adsorbent dosage. Experimental data are validated by applying Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin isotherms. The thermodynamic parameters, ΔH°, ΔG°, and ΔS°, are calculated and it has been found that the adsorption process is spontaneous and endothermic with increasing disorder. An in-depth analysis of the kinetics of the adsorption process, order of the reaction and corresponding values of the rate constants was performed. The adsorption of crystal violet over OMC has been found to follow pseudo-second-order kinetics through a film diffusion process at all temperatures studied. Continuous flow column operations were performed using fixed bed adsorption. Parameters including percentage saturation of the OMC bed are evaluated. The exhausted column was regenerated through a desorption process and column efficiency was determined. [ABSTRACT FROM AUTHOR]

Utilising the solution combustion technique, nanocrystalline photocatalysts that included both pristine TiO2 and doped TiO2 with various La (III) dopant percentages (1, 3, 5, and 7 mol%) were created. Different methods, including thermal analysis, high resolution-transmission electron microscopy (HR-TEM), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FT-IR), and field-emission scanning electron microscopy (FE-SEM), were used to investigate the prepared nanostructures. The XRD results indicated the anatase form and the crystalline nature of the products (pristine and doped TiO2) in the size range of a crystallite (5–16.5) nm. The photocatalytic assessment of the prepared nano-photocatalysts was carried out by crystal violet (CV) decolourisation under ultraviolet (UV) light. The findings revealed that 3% La-TiO2 showed the highest degradation efficiency (95.98%) in 70 min with a pseudo-first-rate constant of k = 4.73 × 10−2 min−1, compared to pristine TiO2 and the other TiO2 nanostructures with various La (III) dopant ratios. [ABSTRACT FROM AUTHOR]

Among the biggest issues facing the world now are fuel shortages and water contamination. Therefore, the goal of the current study was directed to produce bioethanol from Jatropha curcas leaves and use the residual wastes in the form of composite sheets for crystal violet (CV) removal. The leaves were collected from Jatropha curcas, irrigated by various irrigation sources; sewage-water (A), sewage-water-sludge (B), and tap water (C). The acid hydrolysis (4% H2SO4) of these leaves demonstrated that the hydrolysis of the Jatropha curcas leaves (A) produced higher values of total reducing sugars (≈ 21 g/l) than other leaves (B &C). Moreover, the bioethanol concentrations obtained from the fermentation of this hydrolysate (A) at the bioreactor scale using Candida tropicalis and Saccharomyces cerevisiae (≈10 and 7 ml/l, respectively) were relatively increased compared to the flask level (≈7 and 5 ml/l, respectively). Afterwards, the unhydrolyzed wastes were dried, grinded, and embedded in polyvinyl chloride (PVC) polymer forming sheets. The sheets were characterized using FT-IR, SEM, swelling, and porosity. The highest CV removal percent of 95.39%, after optimization, was achieved at 100 ppm crystal violet concentration using 2.5 g/l from PVC-A composite sheet after 180-min contact time. [ABSTRACT FROM AUTHOR]

Copper is known to have toxic effects on bacterial growth. This study aimed to determine the influence of copper ions on Oleidesulfovibrio alaskensis G20 biofilm formation in a lactate-C medium supplemented with variable copper ion concentrations. OA G20, when grown in media supplemented with high copper ion concentrations of 5, 15, and 30 µM, exhibited inhibited growth in its planktonic state. Conversely, under similar copper concentrations, OA G20 demonstrated enhanced biofilm formation on glass coupons. Microscopic studies revealed that biofilms exposed to copper stress demonstrated a change in cellular morphology and more accumulation of carbohydrates and proteins than controls. Consistent with these findings, sulfur (dsrA, dsrB, sat, aprA) and electron transport (NiFeSe, NiFe, ldh, cyt3) genes, polysaccharide synthesis (poI), and genes involved in stress response (sodB) were significantly upregulated in copper-induced biofilms, while genes (ftsZ, ftsA, ftsQ) related to cellular division were negatively regulated compared to controls. These results indicate that the presence of copper ions triggers alterations in cellular morphology and gene expression levels in OA G20, impacting cell attachment and EPS production. This adaptation, characterized by increased biofilm formation, represents a crucial strategy employed by OA G20 to resist metal ion stress. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biowaste cinnamon stick was assessed as a sustainable sorbent. • MIL-125 and CMC were utilized for successfully enhancing CV adsorption. • Equilibrium studies were conducted 3 different temperatures. • q max of CMC/MIL-125@CS was calculated as 6750.58 mg/g. • CMC/MIL-125@CS reached equilibrium the fastest with minimum adsorbent dosage. In the current study, a biowaste cinnamon stick (CS) was used as an adsorbent and modified via in-situ techniques with titanium-based metal organic framework (MIL-125@CS) and carboxymethyl cellulose (CMC/MIL-125@CS). The prepared samples were characterized by various techniques, then utilized for toxic crystal violet (CV) dye removal. CV adsorption was examined for the effects of adsorbent dosage, solution pH, contact time, initial concentration, temperature and anion/cation/natural organic material (NOM). CV removal rate remarkably decreased at low pHs due to the degradation of CV and wavelength shift in the strongly acidic region. The kinetic and isotherm results showed that CMC/MIL-125@CS reached equilibrium much faster (30 min) and much higher adsorption capacity (6750.58 mg/g) than CS and MIL-125@CS. Furthermore, the samples were efficiently regenerated and reusable over five cycles, demonstrating significant adsorption rates. Functional material design approaches yielded superior CV adsorption performance. [ABSTRACT FROM AUTHOR]

Copper oxide nanoparticles incorporated-zeolite supported-graphitic carbon nitride (CuO/g–C3N4/Zeolite Y) catalyst was fabricated through a facile hydrothermal method, in which CuO nanoparticles were produced via precipitation. The synthesized CuO/g–C3N4/Zeolite Y was examined using characterization techniques such as FT-IR, XRD, XPS, TEM, SEM, EDX, TG, BET, DRS, and PL. BET analysis revealed that integrating zeolite and CuO has increased the surface area of graphitic carbon nitride. Increased separation efficiency and reduced recombination rates of photogenerated electrons and holes in CuO/g–C3N4/Zeolite Y were confirmed by photoluminescence studies. The CuO/g–C3N4/Zeolite Y catalyst exhibits enhanced efficiency for degrading MB and CV dyes compared to pristine g-C3N4 under sunlight exposure. The active species studies demonstrated that hydroxyl radicals, superoxide anion radicals and holes involve in the photocatalytic destruction of pollutants. Additionally, the CuO/g–C3N4/Zeolite Y composite efficiently degraded the antibiotic ceftazidime. Intermediates generated during the degradation process were identified, and plausible degradation pathways for ceftazidime were proposed through LC–MS analysis. This study implies that the synthesized catalyst can be used in the wastewater cleanup process to eliminate persistent organic contaminants and pharmaceutical pollutants under sunlight irradiation. [ABSTRACT FROM AUTHOR]

This research demonstrates the ability of cubic Ia3d aluminosilica (CAS) adsorbent prepared using a simple and repeatable one-pot synthesis technique to remove the cationic dye, such as Gentian violet (GV) from aqueous solutions. The prepared CAS adsorbent nanoarchitectonics appeared with 573 m2 g−1 as a BET surface area. The adsorption behaviour of GV on CAS adsorbent was investigated using the thermodynamics, kinetics, and isotherm models. According to the results, the CAS adsorbent indicated a high ability to absorb GV from an aqueous solution, and their kinetic behaviour follows a pseudo-second-order kinetic. In addition, the equilibrium study revealed that the GV adsorption by the CAS adsorbent followed the Langmuir model. Additionally, the outcomes obtained revealed adsorption of GV onto CAS adsorbent was dominated by electrostatic attraction forces, hydrogen bonding, ion-exchange, and pore filling, The maximum adsorption efficiency of GV onto CAS adsorbent was instituted to be 1.36 mmol g−1 (i.e. 554.85 mg g−1). The enthalpy (ΔHo), entropy (ΔGo), and Gibbs free energy (ΔSo) parameters revealed that the extraction of GV dye using CAS adsorbent was endothermic and spontaneous. The synthesised CAS adsorbent shows significant recyclability and characteristics of re-generability up to five adsorption-desorption cycles. As a proof of concept, the performance of the prepared adsorbent was evaluated for laboratory-scale purification of wastewater samples. [ABSTRACT FROM AUTHOR]

In this work, the Washingtonia palm stems were used as a novel precursor to product biochar (BCW) and activated carbon (CAW). The resulting CAW and BCW samples were characterized by N2 adsorption−desorption, scanning electron microscopy (SEM) and pH of zero-charge point (pHPZC). The results show a very large specific surface area and pore volume for CAW (SBET = 1032 m2/g, V = 1.1 cm3/g) compared to BCW (SBET = 357 m2/g, V = 0.27 cm3/g). The SEM images show a more or less regular porous shape for both samples. The obtained values of pHPZC were 5.2 and 6 for CAW and BCW samples, respectively. The ionic strength from 0 to 1.0 M greatly affects the adsorption capacity of Crystal Violet (CV) on BCW unlike that for CAW. The adsorption process occurred quickly and the kinetic data were well described by the pseudo first order (PFO), pseudo second order (PSO), Elovich and Avrami models. The maximum adsorption capacity of CV on CAW and BCW calculated from the Langmuir model was 328 and 93 mg/g respectively at 35°C. The values of the average free energy determined by the Dubinin–Radushkevich model are less than 8 kJ/mol, indicative of physisorption. The thermodynamic study at different solution temperatures (15, 25, and 35°C) shows that the adsorption process occurred spontaneously (∆G° < 0) and was exothermic for CAW and BCW (∆H° = –28.66 and –38.46 kJ/mol, respectively). [ABSTRACT FROM AUTHOR]

Activated carbon prepared from sawdust, magnetized by magnetite nanoparticles, was used for the adsorption of crystal violet dye (CV) from an aqueous solution. The nanocomposite Fe3O4/AC was characterized by means of XRD, FTIR, SEM, and BET analyses, along with size distribution and zeta potential assessments. The pHPZC and BET surface area of Fe3O4/AC were 6.05 and 160 m2/g, respectively. The study identified the optimum pH condition as pH 9.0, with a maximum removal efficiency of 100%. Kinetic studies were conducted, and the data fitted well with the pseudo-second order equation. The synthesized Fe3O4/AC exhibits a maximum uptake capacity of 76.0 mg/g. Overall, this nanocomposite provides an effective type of adsorbent for removing CV dye. Its primary advantage lies in its simple synthesis compared to other magnetic materials, along with its economic viability, rapid preparation, and environmental friendliness. [ABSTRACT FROM AUTHOR]

In this work, we report a facile fabrication of an interface-induced piezoelectric PVDF-ZnSnO3-MoS2 (PZM) device for the rapid degradation of organic dyes, namely, crystal violet (CV) and methylene blue (MB) in wastewater. The piezocatalyst composite mold is fabricated with PVDF as a binder matrix and ZnSnO3/MoS2 as piezoelectric cocatalysts to increase the selectivity and efficiency of the device. SEM micrographs display the formation of aggregated nanoparticle structures with a large number of active sites for superior catalytic activity. The structural studies reveal the increase in the β-phase of PVDF with the increased concentration of ZnSnO3 and MoS2 nanoparticles in the PZM mold. The optimized composite mold displays the superior performance of both CV and MB with 100% degradation in 14 and 6 min, respectively. Further, the superior performance of alkaline pH solution with an ultrasonic power of 50 W and a weight percentage of 20% was optimized to achieve maximum catalytic efficiency, selectivity, and stability to minimize the environmental impact. The fabricated piezocatalyst is found to be efficient and reusable after 7 degradation studies displaying high repeatability. The approach presented in this work can inspire a new strategy for designing efficient and scalable piezocatalytic materials for sustainable wastewater treatment. [ABSTRACT FROM AUTHOR]

With the increase in the use of paint in industrial areas, the rate of dye in wastewater is also increasing. Therefore, the adsorbents used to remove the dye in wastewater are gaining considerable importance. The potential of duckweed (DW) in adsorption of crystal violet (CV), a water-soluble and toxic organic dye, was investigated. Characterization of the adsorbent was made by FTIR, SEM and pHzpc (zero charge point) analyses, and the pHzpc value was 7.75 pH. The effects of temperature, contact time, initial dye concentration, adsorbent dose and solution pH on CV removal were determined. According to the results obtained, the optimum pH, initial dye concentration, adsorbent dose, temperature and contact time were 6 pH, 30 mg L−1, 0.5 g, 30 ºC and 60 min, respectively. The adsorption data were best fitted with Freundlich isotherm (R2 = 0.9714) and maximum adsorption capacity of 61.06 mg g−1 was determined from the Langmuir isotherm. Adsorption of CV by carbonized duckweed (cDW) follows the pseudo-second-order kinetic model (R2 ≥ 0.999). Thermodynamic results of the adsorption process show that adsorption can occur spontaneously (ΔG0 ≤ -5.302 kJ mol−1) and that the process is endothermic (ΔHº = 5.92 kJ mol−1). The results of this study showed that cDWs are cost-effective adsorbent for effective removal of crystal violet dye. [ABSTRACT FROM AUTHOR]

Solar light-induced aqueous crystal violet (CV) dye degradation was carried out on α-zirconium phosphate/graphitic carbon nitride (α-ZrP/g-C3N4) nanocomposite. α-ZrP was synthesized by direct precipitation of zirconium oxychloride with phosphoric acid. g-C3N4 was prepared by thermal decomposition of melamine. α-ZrP/g-C3N4 nanocomposite was synthesized by the direct precipitation of zirconium phosphate on the surface of g-C3N4. Powder X-ray diffraction pattern confirmed the formation of pure α-ZrP, g-C3N4, and α-ZrP/g-C3N4 nanocomposites with crystallite sizes of 51.3 nm, 8.9 nm, and 46.4 nm, respectively. SEM images of α-ZrP showed plate-like morphology and g-C3N4 showed a layered structure with buckled and backfolded edges. XPS and EDX spectrum of the α-ZrP/g-C3N4 nanocomposite shows the presence of Zr, P, N, C, and O elements. The optical absorption wavelength/band gap of the α-ZrP, g-C3N4, and α-ZrP/g-C3N4 nanocomposites were 394.7 nm/3.33 eV, 494.3 nm/2.66 eV, and 457.5 nm/2.85 eV, respectively. The degradation efficiency toward CV dye was found in the order of α-ZrP < g-C3N4 < α-ZrP/g-C3N4 nanocomposite. The degradation efficiency increases with an increase in time, and the pseudo-first-order kinetics model was fitted well. The rate constant of the α-ZrP/g-C3N4 nanocomposite was found four times higher than that of g-C3N4 and ten times of the α-ZrP. The photocatalytic degradation of CV dye under solar light occurred via oxidation by hydroxyl radical and was maximum at pH 6. The photocatalytic degradation efficiency decreases in the presence of anions. α-ZrP/g-C3N4 nanocomposite is easy to synthesize, low-cost, and has high degradation efficiency, making it a promising photocatalyst to clean water containing CV dye under solar light. [ABSTRACT FROM AUTHOR]

Uropathogenic Escherichia coli, the most common cause for urinary tract infections, forms biofilm enhancing its antibiotic resistance. To assess the effects of compounds on biofilm formation of uropathogenic Escherichia coli UMN026 strain, a high-throughput combination assay using resazurin followed by crystal violet staining was optimized for 384-well microplate. Optimized assay parameters included, for example, resazurin and crystal violet concentrations, and incubation time for readouts. For the assay validation, quality parameters Z′ factor, coefficient of variation, signal-to-noise, and signal-to-background were calculated. Microplate uniformity, signal variability, edge well effects, and fold shift were also assessed. Finally, a screening with known antibacterial compounds was conducted to evaluate the assay performance. The best conditions found were achieved by using 12 µg/mL resazurin for 150 min and 0.023% crystal violet. This assay was able to detect compounds displaying antibiofilm activity against UMN026 strain at sub-inhibitory concentrations, in terms of metabolic activity and/or biomass. [ABSTRACT FROM AUTHOR]

Synthetic dyes are prevalent in aquatic environments, they have high toxicities, are non-degradable, and accumulate in the water. The removal of Crystal violet (CV) is carried out using batch experiments on the Salsola Tetragona (ST) plant as a novel adsorbent. The prepared adsorbent was analyzed by various methods (MEB, EDX, IRTF and PZC), to support its applicability as adsorbent. The adsorption study of CV is performed by optimizing the parameters affecting the adsorption process. The adsorption kinetics study is represented by pseudo-second-order (R2 = 0.999) and the adsorption process is limited by external mass transport. In addition, the isotherm results demonstrate that the Langmuir model interprets better the adsorption isotherm. The thermodynamic parameters suggest that the adsorption phenomena are spontaneous and exothermic. Furthermore, the adsorption reactions involved are of physisorption type, which facilitates the desorption of pollutants from the surface of the adsorbent. The results show that ST adsorbent effectively removes CV in an aqueous solution, which is demonstrated by the maximum amount adsorption of 246.7 mg.g−1 at optimum adsorption conditions: pH = 6, adsorbent dose of 0.5 g.L−1, initial CV concentration of 10 mg.L−1, and adsorption time of 30 min at 298 K. Finally, these results can be considered as a useful reference for wastewater treatment using ST. The novelty of our work, entitled "Salsola Tetragona as a New Low-Cost Adsorbent for Water Treatment: Highly Effective Adsorption of Crystal Violet", lies in the utilization of a new biomass abundant in the southwestern region of Morocco. This plant as a novel material is used in its raw state as an adsorbent for removing a cationic dye. According to the literature, this material has not been previously employed in water treatment. Hence, to fill the gap in the literature, we examined its in-batch adsorption to remove crystal violet from the aqueous solution. The results show a high adsorption capacity compared to other natural biomass. [ABSTRACT FROM AUTHOR]

This study investigates the potential of using Ficus religiosa inflorescence (peepal tree) as an efficient solution for removing crystal violet from simulated and industrial wastewater. Various analyses were conducted to understand the adsorbent's structure, including particle morphology, BET surface area, FTIR, and pHZPC. The adsorption process was studied under different physicochemical factors such as temperature, concentration, contact time, and pH. Results revealed rapid adsorption, with 94.15% removal efficiency within the first 15 min at neutral pH. The highest observed adsorption capacity was 198.03 mg g−1, following pseudo-second-order kinetics (R2 = 0.99), indicating chemisorption. The Langmuir model accurately described the adsorption pathway (R2 = 0.99), showing monolayer adsorption. Thermodynamic analysis indicated an exothermic, feasible, and spontaneous process with increased entropy. The adsorbent could be easily regenerated using a 1:1 MeOH/H2O mixture for up to three cycles, yielding up to 73.86%. Real-time application with industrial effluent containing crystal violet showed up to 44.70% adsorption. The experiments demonstrated reliability with evaluated standard deviations (0.017935–0.000577) and relative standard deviations (0.439–0.673%), confirming statistical reliability. In conclusion, it presents a sustainable and eco-friendly approach for removing crystal violet dye from diverse wastewater sources. [ABSTRACT FROM AUTHOR]

Gac fruit (Momordica cochinchinensis Spreng.) is a prominent source of carotenoids, renowned for its exceptional concentration of these compounds. This study focuses on optimizing the extraction of active components from the aril of gac fruit by evaluating the effects of extraction temperature, solid–liquid ratio, and extraction time. The primary objective is to maximize the yield of gac oil while assessing its antioxidant capacity. To analyze the kinetics of the solid–liquid extraction process, both first-order and second-order kinetic models were employed, with the second-order model providing the best fit for the experimental data. In addition, the potential of gac fruit peel as a precursor for biochar production was investigated through carbonization. The resultant biochars were evaluated for their efficacy in adsorbing crystal violet (CV) dye from aqueous solutions. The adsorption efficiency of the biochars was found to be dependent on the carbonization temperature, with the highest efficiency observed for BCMC550 (91.72%), followed by BCM450 (81.35%), BCMC350 (78.35%), and BCMC250 (54.43%). The adsorption isotherm data conformed well to the Langmuir isotherm model, indicating monolayer adsorption behavior. Moreover, the adsorption kinetics were best described by the pseudo-second-order model. These findings underscore the potential of gac fruit and its byproducts for diverse industrial and environmental applications, highlighting the dual benefits of optimizing gac oil extraction and utilizing the peel for effective dye removal. [ABSTRACT FROM AUTHOR]

Electrochemical oxidation is an efficient and pollution-free technology that belongs to the advanced oxidation process. The anode with excellent characteristics is a key factor that affects the electrocatalytic oxidation system. To explore the difference of performance between the PbO2 electrode and RuO2-IrO2 electrode, the morphology, microstructure, and other electrochemical properties were tested respectively. The scanning electron microscopy (SEM) shows that the PbO2 film is a typical pyramid shape with a compact structure while many cracks appear on RuO2-IrO2 film. The PbO2 and RuO2-IrO2 crystallize sizes are 22.7 nm and 31.3 nm, respectively. The oxygen evolution overpotential of the PbO2 electrode is 1.33 V (vs. SCE) a little lower than the RuO2-IrO2 electrode of 1.41 V (vs. SCE). The phenol and crystal violet (CV) are applied as the target contaminants to check the electrocatalytic performance of the two electrodes. The experiment results show that the RuO2-IrO2 electrode is fit for the degradation of crystal violet and the PbO2 electrode is fit for the degradation of phenol. The better electrocatalytic performance on the degradation of crystal violet by RuO2-IrO2 electrode can be attributed to the higher oxygen evolution overpotential. [ABSTRACT FROM AUTHOR]

The crystal violet (CV) staining technique represents a prevalent approach for the development of latent fingerprints, especially on adhesive tape surfaces. Nevertheless, the technique necessitates intricate formulations to augment its performance. In this investigation, an optimized CV staining protocol was developed, characterized by the absence of residual dye on the target substrates and the capability of facilitating fingerprint visualization under ambient light conditions. Four donors, comprising two males and two females, deposited natural fingerprints on various substrates, including glass microscope slides, aluminum foil, and 115 g glossy coated paper, without any specific guidelines. Fingerprints developed using cyanoacrylate fuming served as benchmarks and were contrasted with those generated through alternative methods: CV, ardrox, rhodamine 6G, powdering, and the optimized CV staining protocol. The fingerprint development experiment was replicated at seven distinct time intervals, encompassing 1 day, 1 week, 1, 3, 6, 9, and 12 months, resulting in a dataset of 420 fingerprints. The evaluation of fingerprint identifiability employed a scoring system established by the Home Office Centre for Applied Science and Technology. The results indicated that the optimized CV staining technique demonstrated superior performance, boasting a 92.9% rate of identifiable fingerprint development in contrast to other employed methodologies. Consequently, this optimized CV staining approach is recommended as an efficient, rapid, and straightforward critical dyeing method, applicable to a wide array of substrates in forensic investigations. [ABSTRACT FROM AUTHOR]

The employment of green synthesized nanomaterials for water pollution prevention is increasing nowadays. Herein, Mn-doped ZnO nanoparticles were synthesized using Peganum Harmala seed extract and subsequently used for crystal violet (CV) dye removal from aqueous solutions. The first part of the study describes the preparation of the adsorbent (Mn-ZnO NPs) using a simple coprecipitation method. The surface properties of the material were characterized by Fourier transform infrared spectra (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The second part investigates the adsorption of CV dye onto the surface of the prepared Mn-ZnO NPs. Additionally, the isotherm, kinetics, and thermodynamics of the adsorption process were studied in detail. Batch adsorption analysis was carried out by evaluating different parameters, such as the amount of the adsorbent (0.01g to 0.04 g), CV concentration (20 to 80 mg/L), adsorption time (30 to 120 min), and temperature (35 to 65 ⁰C). The maximum CV dye adsorption capacity of the Mn-ZnO NPs was 45.60 mg/g. The thermodynamic study revealed the spontaneous, exothermic, and feasible nature of the adsorption process, primarily driven by physical forces. Kinetic and isotherm analyses indicated that the adsorption of the dye best fit the Freundlich isotherm and pseudo-second-order models, respectively. Mn-doped ZnO is considered an effective adsorbent for CV, benefiting from its rapid and easy preparation, non-toxic nature, and 94 % adsorption efficiency. The material holds potential for future applications in the removal of organic dyes from wastewater.. [ABSTRACT FROM AUTHOR]

Copyright of China Rural Water & Hydropower is the property of China Rural Water & Hydropower Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cactus cladodes have been emerged as one of the most popular plant-based flocculants. They have been listed as a promising natural alternative to the noxious synthetic flocculants. However, practical application of this bio-flocculant is still hampered by some questions concerning their formulations' stability, active agents therein and their flocculating performance. Thus, in this study, three cactus formulations, namely, cactus juice (CJ), cactus lyophilized powder (CLP) and oven-dried powder (CDP) were subjected to a physicochemical characterization to provide an in-depth understanding of the main flocculation active agents and distinguish the suitable preparation method promoting bio-flocculants' stability and effectiveness. Therefore, their flocculating activity was evaluated in treating a model-colored effluent, a crystal violet (CV) dye solution. The obtained results show that the three cactus formulations exhibit a significant sugars content with considerable calcium amounts. The highest sugars content was registered for CLP thanks to the efficacy of lyophilization method to maintain their stability. Furthermore, the main flocculating active compound was identified as an arabinogalactan composed of long polygalacturonic acid chain backbones with branches of neutral sugar residues involving mostly the arabinose. As for the color removal performance, an outstanding CV removal exceeding 99% was found using CLP under alkaline pH. It was occurred through charge neutralization and bridging mechanisms. Hence, based on these groundbreaking results, the application of cactus formulation-based flocculants, especially the lyophilized one is highly recommended to ensure a clean, eco-friendly and sustainable wastewater treatment approach. [ABSTRACT FROM AUTHOR]

In this study, geopolymer composites, GP0, GPC2.5, GPC5, GPC7.5 and GPC10 were synthesized from pozzolan, a naturally occurring, abundant and inexpensive precursor, substituted with varying proportions of 0, 2.5, 5, 7.5, and 10% content by weight of charcoal powder (CP), an industrial waste product, respectively. The geocomposites were characterized by Fourier Transformed Infrared Spectroscopy (FTIR), BET (Bruamer Emmet Teller) method, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), methylene blue and iodine indices. The adsorption performances for the removal of crystal violet, a toxic dye, from water in batch mode were evaluated. Incorporation of charcoal powder improved the functional group density, the microporous structure and the specific surface areas (SSA) of the pozzolan-based geopolymers resulting in increased adsorption efficacy. Langmuir, Freundlich, Temkin, Dubin-Radushkevich-Kaganer and Flory Huggins isotherms were applied to model the equilibrium data. The GPC7.5 composite (7.5% wt CP), with SSA 15.93 m2 g−1, exhibited an unprecedented ultrahigh maximum monolayer adsorption density of 2803 mg g−1, a new benchmark value for adsorption of crystal violet. The adsorption rate was best described by the pseudo-first order kinetic model with an invariable adsorption rate constant (k1). The Gibbs free energy (ΔG < 0) signify a spontaneous and feasible adsorption process while the magnitude of the adsorption energies corresponded to a physisorption mechanism. The GPC7.5 composite is a novel inexpensive superadsorbent for the abatement of crystal violet dye in aqueous media with about 1000 mg g−1 higher adsorption capacity than pristine pozzolan-based geopolymer (GP0). The synthesis adopted minimal and abundant precursors producing a material that is techno-economical and reproducible in many countries, especially emerging economies. [ABSTRACT FROM AUTHOR]

CdO nanoparticles codoped with Ni, Zn have been produced through co-precipitation. The study of structural properties is performed using X-ray diffraction (XRD) as well as field emission scanning electron microscopy (FESEM). Energy-dispersive X-ray spectroscopy (EDX) is utilised to examine the compositional properties of Ni and Zn doped CdO nanoparticles. Ni and Zn doped CdO nanoparticles exhibited a pure cubic phase, as revealed by XRD. The X-ray photoelectron spectroscopy (XPS) method is used to evaluate the chemical and electronic states of the atoms. Codoping caused a redshift in the band gap of the CdO, which was determined by Diffused reflectance spectroscopy (DRS). In a study of their photocatalytic activity, Crystal Violet (CV) dye degradation under sun light exposure was compared with pristine CdO activity. A significant improvement in photocatalytic activity was observed in the degradation of CV due to codoping. Within exposure of 180 min, degradation of CV took place upto 99% by highly doped CdO (NZC3). [ABSTRACT FROM AUTHOR]

The present study uses a bio-waste, i.e., skin of Allium cepa, for green synthesis of zinc oxide nanoparticles. The nanoparticles A. cepa-ZnONP were tested for their photo catalytic degradation efficacy toward harmful dyes. Additionally, the anti-bacterial properties of A. cepa-ZnONP were evaluated against four organisms, namely Escherichia coli (EC), Pseudomonas aeruginosa (PA), Bacillus cereus (BC), and Staphylococcus aureus (SA). The synthesized A. cepa-ZnONP was characterized with scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM–EDX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) methods. The A. cepa-ZnONP demonstrated efficient degradation of Crystal Violet (CV), Rhodamine B (RB), and Methylene blue (MB) dyes, achieving maximum degradation percentages of 99.21%, 95.63%, and 92.34%, respectively, while operating under optimal process conditions. The rate constant values for CV, RB, and MB dyes at a temperature of 328 K were determined to be 0.1063, 0.0758, and 0.0447 min−1, respectively. The activation energy values for CV, RB, and MB dyes were determined to be 12.28, 18.437, and 50.623 kJ/mol, respectively. The successful regeneration of photo catalytic material A. cepa-ZnONP is a crucial milestone in guaranteeing their long-term effectiveness and practical usability. This work also emphasizes the possible uses of A. cepa-ZnONP in environmental remediation. This demonstrates the wide range of applications and importance of this substance in addressing current problems. [ABSTRACT FROM AUTHOR]

The potential of biochar derived from water hyacinth (Eichhornia carassipes)—an invasive aquatic weed capable of producing high biomass—for the adsorptive removal of organic dyes like methylene blue (MB) and crystalvViolet (CV) from the aqueous medium was studied. The properties of the resultant Eichhornia biochar (ECBC) were studied using SEM–EDS, ICP-MS, FTIR, TGA, and Brunauer–Emmett–Teller (BET). The adsorption capacities of the dyes were obtained under batch adsorption experiment conditions. Adsorption isotherms and kinetic models were used to analyze the experimental data. Adsorption of dyes increased with solution pH, biochar dosage, contact time, initial dye concentration, and temperature, whereas the presence of a monovalent NaCl salt system decreased the adsorption process. The biosorption was found to follow the pseudo-second-order kinetic model. The Langmuir monolayer biosorption capacity of the biochar was estimated as 362.4 and 346.9 mg/g−1 for MB and CV, respectively. The resultant biochar showcased high reusability. The appreciable level of dye adsorption capacity of ECBC could be ascribed to the basic properties of the Eichhornia-derived biochar. Physical and electrostatic attraction, intermolecular hydrogen bonding and n-interactions, surface precipitation, and cation exchange are proposed as the combined mechanisms that result in MB and CV adsorption onto ECBC. The results suggest that the conversion of the aquatic weed Eichhornia to biochar as an effective eco-friendly adsorbent for the removal of toxic dyes from wastewater is a viable and environmentally sustainable option. [ABSTRACT FROM AUTHOR]

In this research, activated carbon was obtained from rubber fruit shells (ACRPs). The obtained activated carbon (ACRPs) was modified by magnetite particle coating and silanization with triethoxyiphenylsilane (TEPS) to produce a new magnetic adsorbent (ACRPs-MS). The affinity of as-prepared adsorbent (ACRPs-MS) toward methylene blue (MB) and crystal violet (CV) dyes was tested in mono-component and bi-component solutions. Structural characterization proves the success of the magnetite coating process and the silanization of ACRPs. In the infrared (IR) spectroscopy spectrum of ACRPs-MS, Si–O-Fe and Si–O-Si bonds were identified, which indicated the presence of magnetite and silane. This is also supported by the elemental composition contained in the energy-dispersive X-ray (EDX) diffractogram. In addition, the presence of the porous structure of the surface of the material and the increase in the specific surface area increase the accessibility of contaminants such as MB and CV dyes to be adsorbed to the ACRPs-MS adsorption site effectively. The experimental results showed that the adsorption of mono-component MB and CV dyes by ACRPs-MS was optimum at pH 8 and an interaction time of 60 min. The adsorption kinetics of mono-component MB and CV dyes by ACRPs-MS tended to follow pseudo-second-order kinetics (PSO) models with PSO rate constant (k2) values of 0.198 and 0.993 g mg−1 min−1, respectively. The adsorption of MB and CV dyes by ACRPs-MS in a bi-component mixture tends to follow the Langmuir isotherm model with adsorption capacity (qm) values of 85.060 and 90.504 mg g−1, respectively. Analysis of adsorption data on the bi-component mixture between MB and CV by ACRPs-MS with the Langmuir isotherm equation for a binary mixture resulted in qm of 22.645 × 10–3 mmol equiv g−1. ACRPs-MS material can be used repeatedly five times with adsorption ability > 80%. Desorption of MB and CV dyes was carried out using 0.05 M HCl solution. ACRPs-MS material was able to adsorb MB and CV dyes with a large adsorption capacity and could be used in repeated adsorption. Thus, it can be stated that ACRPs-MS can be used as an effective adsorbent for MB and CV dyes, either singly or in a bi-component mixture. [ABSTRACT FROM AUTHOR]

Deposition of extracellular Amyloid Beta (Aβ) and intracellular tau fibrils in post-mortem brains remains the only way to conclusively confirm cases of Alzheimer's Disease (AD). Substantial evidence, though, implicates small globular oligomers instead of fibrils as relevant biomarkers of, and critical contributors to, the clinical symptoms of AD. Efforts to verify and utilize amyloid oligomers as AD biomarkers in vivo have been limited by the near-exclusive dependence on conformation-selective antibodies for oligomer detection. While antibodies have yielded critical evidence for the role of both Aβ and tau oligomers in AD, they are not suitable for imaging amyloid oligomers in vivo. Therefore, it would be desirable to identify a set of oligomer-selective small molecules for subsequent development into Positron Emission Tomography (PET) probes. Using a kinetics-based screening assay, we confirm that the triarylmethane dye Crystal Violet (CV) is oligomer-selective for Aβ42 oligomers (AβOs) grown under near-physiological solution conditions in vitro. In postmortem brains of an AD mouse model and human AD patients, we demonstrate that A11 antibody-positive oligomers but not Thioflavin S (ThioS)-positive fibrils colocalize with CV staining, confirming in vitro results. Therefore, our kinetic screen represents a robust approach for identifying new classes of small molecules as candidates for oligomer-selective dyes (OSDs). Such OSDs, in turn, provide promising starting points for the development of PET probes for pre-mortem imaging of oligomer deposits in humans. [ABSTRACT FROM AUTHOR]

A significant variation in the relative representation of copies of bacterial genes of dye-decolorizing DyP peroxidases typical for the genus Shewanella and a number of other microorganisms was found in the bottom sediments of freshwater reservoirs. It was found that the specific rate of decolorization of crystal violet in a laboratory bioelectrochemical system by a mixed culture of bottom sediments, which showed the highest representation of DyP genes, depended on the method of electrical stimulation of the external circuit and the concentration of the dye. After an increase in the concentration of more than 20 microns, the maximum speed was achieved in the presence of an ionistor polarly connected to the external electrical circuit of the bioelectrochemical system and amounted to 3.23 ± 0.11 μM/h, while with the opposite polarity connection, a minimum value of 2.07 ± 0.08 μM/h was observed. In the case of an open circuit and a resistor, similar indicators occurred with 2.88 ± 0.09 and 2.67 ± 0.12 μM/h, respectively. When analyzing the decolorization products, a consistent decrease in the maxima of the absorption bands of the dye was noted, indicating its more complete degradation by the mixed culture. The results may be of interest for the development of methods to improve the efficiency of bioelectrochemical methods of environmental biotechnology by electrostimulation of the external circuit. [ABSTRACT FROM AUTHOR]

Crystal violet (CV) is an organic chloride salt and a triphenylmethane dye commonly used in the textile processing industry, also being used as a disinfectant and a biomedical stain. Although CV is widely used, it is carcinogenic to humans and is retained by industrial-produced effluent for an extended period. The different types of metal oxide (MOx) have impressive photocatalytic properties, allowing them to be utilized for pollutant degradation. The role of the photocatalyst is to facilitate oxidation and reduction processes by trapping light energy. In this study, we investigated different types of metal oxides, such as titanium dioxide (TiO2), zinc oxide (ZnO), zirconium dioxide (ZrO2), iron (III) oxide (Fe2O3), copper (II) oxide (CuO), copper (I) oxide (Cu2O), and niobium pentoxide (Nb2O5) for the CV decomposition reaction at ambient conditions. For characterization, BET and Raman spectroscopy were applied, providing findings showing that the surface area of the anatase TiO2 and ZnO were 5 m2/g and 12.1 m2/g, respectively. The activity tests over TiO2 and ZnO catalysts revealed that up to ~98% of the dye could be decomposed under UV irradiation in <2 h. The decomposition of CV is directly influenced by various factors, such as the types of MOx, the band gap–water splitting relationship, and the recombination rate of electron holes. [ABSTRACT FROM AUTHOR]

In this study, monodisperse, uniform, and spherical covalent organic frameworks (COFs) were synthesized using 1,3,5‐tris (4‐aminophenyl) benzene and 1,3,5‐tricarboxaldehyde benzene at room temperature. Post‐modification of 6‐aminocaproic acid on the COFs yielded carboxyl‐modified COFs (COFs‐COOH). The modification enhanced the hydrophilicity and adsorption efficiencies of COFs‐COOH for malachite green (MG) and crystal violet (CV). A COFs‐COOH‐based dispersive solid‐phase extraction coupled with high‐performance liquid chromatography was developed for the analysis of MG and CV. The method showed a linear range from 10 to 1000 ng/mL with detection limits of 1.82 and 0.70 ng/mL for MG and CV detection, respectively. The recoveries of MG and CV from water samples collected from fish farms and markets ranged from 91.63% to 107.10% with relative standard deviations below 5%. Reproducibility tests demonstrated that the adsorption efficiencies of COFs‐COOH were maintained at above 85.86% over 15 cycles. The study verified the potential of COFs‐COOH as sorbents for the enrichment and separation of triphenylmethane dyes from complex samples. [ABSTRACT FROM AUTHOR]

Dyes can be determined as a substance that creates many environmental issues leading to the death of aquatic life, plants and all living organisms. Dye removal can be done by several physical, chemical and biological methods, including the photocatalytic method. Photocatalysis is a method in which light energy is used to degrade the dye. This technique is low-cost and eco-friendly, and it degrades many harmful substances from organic dyes compared to other techniques. The prime aim of the present work is to degrade the largely used organic dyes such as methylene blue, malachite green and crystal violet using EDTA-doped FeZnS2 and Leishman stain-doped FeZnS2 thin films. The doped FeZnS2 thin films were fabricated using the co-precipitation method. Thin fabricated films are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and UV–Visible spectroscopy (UV). These characterization studies show an active photo response indicating effective dye degradation. Based on the absorption studies of UV spectroscopy measurements after 60 min, the degradation efficiency of methylene blue, crystal violet and malachite green using EDTA-doped FeZnS2 are 76, 85 and 90, respectively. Similarly, the degradation efficiency after 60 min of methylene blue, crystal violet and malachite green using Leishman stain-doped FeZnS2 are 82, 79 and 89, respectively. [ABSTRACT FROM AUTHOR]

A composite photocatalyst, denoted as rGO/NiIn2S4 (rGO/NIS), was created to facilitate the efficient destruction of crystal violet (CV) dye under visible radiation. This composite photocatalyst consists of NiIn2S4 (NIS) and reduced graphene oxide (rGO). The photocatalytic behavior of pristine NiIn2S4 for the breakdown of crystal violet (CV) in the presence of visible light was found to be significant. However, the experimental findings indicated that the material experienced substantial breakdown upon exposure to visible light. The rGO/NIS contains significantly improved visible light photocatalytic behavior compared to the hybrid material (NIS). The data on characterization indicates that there exists a chemical interaction between NiIn2S4 nanosheets and rGO sheets, resulting in the development of a band structure that may be adjusted and in an enhancement in photocatalytic performance. Significantly, the establishment of covalent bonds between NiIn2S4 and rGO holds promise for enhancing the structural integrity of the composite, thus augmenting its resistance to photocorrosion. The finding of this study has the potential to contribute to the formulation of an innovative strategy in the creation of photocatalysts that are active under visible light and resistant to degradation by sunlight. These photocatalysts can be utilized in the field of environmental remediation. [ABSTRACT FROM AUTHOR]

In this study, the reuse of Citrus fortunella (CF) plant waste, an agricultural product, was evaluated within the scope of sustainability. In this context, selenium nanoparticles (CF‐Se NPs) were synthesized from CF waste extracts and crystal violet (CV) dye was removed. The characteristic structure of the synthesized CF‐Se NPs was determined by X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray (EDX), Fourier transform infrared spectroscopy (FTIR), UV–vis spectroscopy, and point of zero charge (pHpzc). Batch adsorption tests were applied to determine the effect of the synthesized CF‐Se NPs on CV removal. Four different kinetic and isotherm models were examined using error analysis functions. While the particle size of CF‐Se NPs was determined as 27.58 nm, the pHpzc value was calculated as 9.40, the average surface charge distribution was −24.1 mV, and mass losses were 9.03% and 13.42% at 334.99 and 739.21°C, respectively. The most suitable kinetic and isotherm model for CV removal with CF‐Se NPs was determined to be pseudo‐second‐order with a R2‐value of 0.999 and Freundlich with R2‐value of 0.993, and the qmax was calculated as 23.55 mgCV/gCF‐SeNPs. The effectiveness of CF‐Se NPs synthesized from waste in CV removal is a remarkable issue in terms of sustainable production. [ABSTRACT FROM AUTHOR]

Nanomaterials are widely employed in wastewater treatment, among which nanoferrites and their composites hold significant prominence. This study adopts a green approach to synthesize zinc ferrite nanoparticles, subsequently integrating them with polyaniline (PANI) to fabricate the ZnFe2O4-PANI nanocomposite. Characterization of the prepared ZnFe2O4-PANI nanocomposite was conducted using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopic (SEM) techniques. Using Scherrer's equation, the crystallite size of the synthesized zinc ferrite nanoparticles was found to be 17.67 nm. SEM micrographs of the ZnFe2O4-PANI nanocomposite revealed that in situ polymerization of ZnFe2O4 with polyaniline transforms the amorphous surface morphology of the polymer into a homogeneous nanoparticle structure. The adsorption of crystal violet (CV) dye onto the surface of the ZnFe2O4-PANI nanocomposite depends on pH, adsorbent dosage, temperature, concentration levels and duration. The Langmuir adsorption model fitted the data well, indicating adherence to a pseudo-second-order kinetic pattern. Thermodynamic values ΔG°, ΔH° and ΔS° indicated that the adsorption process occurred spontaneously. Advantages and disadvantages of the technique have also been highlighted. Mechanism of adsorption is discussed. From the obtained results, it is evident that the ZnFe2O4-PANI nanocomposite holds promise as a sorbent for the removal of dye from wastewater. [ABSTRACT FROM AUTHOR]