Crystal Violet Dye Research Articles

Exploring the efficiency of sodium alginate beads and Cedrus deodara sawdust for adsorptive removal of crystal violet dye

Sodium alginate beads were explored as an adsorbent for exclusion of CV dye in batch mode by optimizing various parameters such as solution pH, effect of dye concentration, adsorbent’s dose, contact time, and temperature. Experimental results revealed that maximum sorption, i.e., 97% was obtained at pH 12 in 20 minutes of contact time, 0.4 g of beads for 10 mL of dye solution at 30 °C. Characterization of sodium alginate beads confirmed that hydroxyl, carboxyl, amine, and sulfate functional groups are involved in dye adsorption on heterogeneous and porous surface of adsorbent. Isotherm study shows that Freundlich model fits best to experimental data having highest possible adsorption capacity of 4.797 mg g − 1 . Further, kinetic study revealed that pseudo-second order model plays a significant role in adsorption mechanism with R 2 = 0.9996. Suitability of each model is also checked by five error analysis models namely Hybrid, MPSD, EABS, ERRSQ, and ARE. Thermodynamic studies implied that CV dye adsorption on sodium alginate beads was spontaneous and endothermic in nature as confirmed from Δ G = −7.8 to −5.8 kJ mol−1 and Δ H = 10.201 kJ mol−1, respectively. Results also show that 92% of dye adsorption take place with tap water. Based on experimental outcomes, it has been concluded that sodium alginate beads are an excellent adsorbent to remove the CV dye from the solution.

Biodegradable polymeric green adsorbent for the highly efficient removal of crystal violet dye from aqueous solution

In this study, we fabricated a novel membrane from breadfruit peel (Artocarpus altilis), a biowaste, to quickly and effectively remove the toxic crystal violet (CV) dye from aqueous solutions. The membrane was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), water contact angle, thermogravimetric analysis (TGA), and Fourier transform infrared spectra (FTIR) techniques. SEM results confirmed that the breadfruit peel particles are well dispersed on the membrane surface. Furthermore, the breadfruit peel improved the mechanical and thermal stability of the membrane. The membrane exhibited a maximum adsorption capacity of 176.25 mg/g at a pH of 11 and a contact time of 150 min. The adsorption capacity of the membrane could be tailored by operational parameters like initial concentration of CV, equilibrium time, adsorbent dosage, and temperature. The adsorption mechanisms responsible for the efficient elimination of CV dye is discussed in terms of electrostatic attraction. The adsorption kinetic results indicate that the adsorption of CV was more consistent with pseudo-second order model. Meanwhile, the adsorption data fitted to Freundlich model rather than Langmuir isotherm model. Furthermore, even after six adsorption-desorption cycles, no significant decrease in the removal efficiency was observed. The polymer membrane was therefore proposed as a potential candidate for water treatment.

Zingiber officinale rhizome extracts mediated ni nanoparticles and its promising biomedical and environmental applications

BackgroundZingiber officinale, generally known as ginger, contains bioactive phytochemicals, including gingerols and shogaols, that may function as reducing agents and stabilizers for the formation of nickel nanoparticles (Ni-NPs). Ginger extract-mediated nickel nanoparticles were synthesized using an eco-friendly method, and their antibacterial, antioxidant, antiparasitic, antidiabetic, anticancer, dye degrading, and biocompatibility properties were investigated.MethodsUV–visible spectroscopy, fourier transform infrared spectroscopy, X-ray powder diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy were used to validate and characterize the synthesis of Ni-NPs. Agar well diffusion assay, alpha-amylase and glucosidase inhibitory assay, free radical scavenging assay, biocompatibility assay, and MTT assay were used to analyse the biomedical importance of Ni-NPs.ResultsSEM micrograph examinations revealed almost aggregates of Ni-NPs; certain particles were monodispersed and spherical, with an average grain size of 74.85 ± 2.5 nm. Ni-NPs have successfully inhibited the growth of Pseudomonas aeruginosa, Escherichia coli, and Proteus vulgaris by inducing membrane damage, as shown by the absorbance at 260 nm (A260). DPPH (2,2-diphenyl-1-picrylhydrazyl) free radicals were successfully scavenged by Ni-NPs at an inhibition rate of 69.35 ± 0.81% at 800 µg/mL. A dose-dependent cytotoxicity of Ni-NPs was observed against amastigote and promastigote forms of Leishmania tropica, with significant mortality rates of 94.23 ± 1.10 and 92.27 ± 1.20% at 1.0 mg/mL, respectively. Biocompatibility studies revealed the biosafe nature of Ni-NPs by showing RBC hemolysis up to 1.53 ± 0.81% at 400 µg/mL, which is considered safe according to the American Society for Materials and Testing (ASTM). Furthermore, Ni-NPs showed antidiabetic activity by inhibiting α-amylase and α-glucosidase enzymes at an inhibition rate of 22.70 ± 0.16% and 31.23 ± 0.64% at 200 µg/mL, respectively. Ni-NPs have shown significant cytotoxic activity by inhibiting MCF-7 cancerous cells up to 68.82 ± 1.82% at a concentration of 400 µg/mL. The IC50 for Ni-NPs was almost 190 µg/mL. Ni-NPs also degraded crystal violet dye up to 86.1% at 2 h of exposure.ConclusionsIn conclusion, Zingiber officinale extract was found successful in producing stable nanoparticles. Ni-NPs have shown substantial biomedical activities, and as a result, we believe these nanoparticles have potential as a powerful therapeutic agent for use in nanomedicine.

Binary metal doped and graphene anchored LaCrO3 perovskite with boost light harvesting properties for environmental remediation

This study developed visible light-driven ABO3 type (perovskite) lanthanum chromite (LaCrO3) and Co–Ni co-doped (La1-xCoxCr1-yNiyO3; LCCNO) photocatalyst using a straightforward micro-emulsion process. Later, LCCNO nanoparticles were deposited on reduced graphene oxide (r-GO) utilizing an ultrasonication approach to form nanocomposite (LCCNO/r-GO). The investigation included structural, morphological, and elemental analyses, which were conducted using techniques such as x-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), and energy dispersive x-ray (EDX) analysis. The present study investigated the impact of Co–Ni co-doping and rGO reinforcement on the bandgap and electrical conductivity in the context of optical analysis and current-voltage (I–V) experimentation. The nanomaterial's photocatalytic activity (PCA) was evaluated using crystal violet (CV), a well-recognized commercial dye. The composite as a photocatalyst exhibits superior CV dye photodegradation efficiency (99.02%; 100 min) compared to pure LCO (36.44%; 100 min) and co-doped LCCNO (73.74%; 100 min) counterparts due to its low band gap (2.14 eV), high conductivity (6.4 × 105 Sm−1), and large surface area (123.7 m2/g). Furthermore, a series of studies were conducted to examine the primary active free radicals generated by the composite material and to evaluate its long-term viability as a photocatalyst. The present research investigates the beneficial effects of co-doping and the incorporation of carbonaceous materials on the photocatalytic performance of ABO3-type perovskite.

Integrating artificial neural networks and response surface methodology for predictive modeling and mechanistic insights into the detoxification of hazardous MB and CV dyes using Saccharum officinarum L. biomass

The presence of dye pollutants in industrial wastewater poses significant environmental and health risks, necessitating effective treatment methods. The optimal adsorption treatment of methylene blue (MB) and crystal violet (CV) dye-simulated wastewater utilising Saccharum officinarum L presents a key challenge in the selection of appropriate modelling approaches. While RSM and ANN models are frequently used, there is a noticeable knowledge gap when it comes to evaluating their relative strengths and weaknesses in this context. The study compared the predictive abilities of response surface methodology (RSM) and artificial neural network (ANN) for the adsorption treatment of MB and CV dye-simulated wastewater using Saccharum officinarum L. The process experimental variables were modelled and predicted using a three-layer artificial neural network trained using the Levenberg-Marquard backpropagation algorithm and 30 central composite designs (CCD). The adsorption study used a specific mechanism, which led to noteworthy maximum removals of 98.3% and 98.2% for dyes (MB and CV), respectively. The RSM model achieved an impressive R2 of 0.9417, while the ANN model achieved 0.9236 in MB. Adsorption is commonly used to remove colour from many different materials. Saccharum officinarum L., a byproduct of sugarcane processing, has shown potential as an efficient and ecological adsorbent in this environment. The purpose of this study is to evaluate sugarcane bagasse's potential as an adsorbent for the removal of dyes MB and CV from industrial wastewater, providing a long-term strategy for reducing dye pollution. Due to its beneficial economic and environmental characteristics, the Saccharum officinarum L. adsorbent has prompted research into sustainable resources with low pollutant indices.

Modulation of optical and structural properties of CoFe2O4/ZnO@CNTs for photocatalytic removal of crystal violet and phenol

Abstract Photo-catalysis is a versatile method that is used to remediate water pollution and other issues related to the environment. Metal ferrite with a spinel structure, which is frequently used as a photocatalyst, is another solution for the remediation of environmental pollution. In this work, nanoparticles of cobalt ferrite (CoFe2O4) and zinc oxide (ZnO) were prepared by sol-gel and co-precipitation methods, respectively. CoFe2O4/ZnO (CF/ZnO) and its ternary nanocomposite with CNTs (CF/ZnO@CNTs) were fabricated by a wet-chemical approach. The prepared materials were characterized by different characterization techniques, including X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), and UV–visible spectroscopy for the structural, functional group, and optical study respectively. Band gap values calculated for the prepared materials (CF, CF/ZnO, and CF/ZnO) were 2.45 eV, 3.37 eV, and 2.18 eV, respectively. Crystal violet and phenol were used for the evaluation of the photocatalytic efficiency of the prepared samples. In case of crystal violet photocatalytic degradation of the CF, ZnO and CF/ZnO was 21.43 %, 46.43 %, and 66.62 %, respectively. Whereas, CF/ZnO@CNTs outperformed all catalysts with 97.61 % degradation of crystal violet dye. The degradation of phenol by CF/ZnO and CF/ZnO@CNTs was 53.70 % and 83.33 %, respectively. The CF/ZnO@CNTs exhibit excellent photodegradation activity than other photocatalysts used. It is because of heterojunction fabrication and the presence of CNTs as they increase the life span of photo-generated species and enhance the surface area of the catalyst.

Catalytic oxidative degradation of crystal violet dye using NanoCopper oxide encapsulated zeolite catalyst

A new active zeolite supported copper catalyst was developed from coal fly ash (FA) by immobilization of copper nanoparticles. Zeolite (Zeo) was created by FA via acid and hydrothermal synthesis methods. The metal salt CuCl2 was reduced to copper nanoparticle by using (nithyakalyani) Catharanthus roseus leaf extract. The formed copper nanoparticle was encapsulated into the zeolite framework by mechanical stirring followed by calcination at 550 °C. The prepared CuO-Zeo catalyst has been defined by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscope (SEM) and Energy dispersive X-ray (EDX) techniques. Catalytic activity of the synthesized CuO-Zeo catalyst was investigated by crystal violet dye degradation by wet catalytic method in the presence of H2O2. Effect of catalyst dosage, catalyst variation, dye content, volume of H2O2 and pH were studied. It was observed that the catalytic activity of bare Zeo is negligible and is enhanced by copper encapsulation and also the efficiency of the catalyst is tested and 95% is maintained. The work highlights the design and development of green catalyst from waste material FA.

Fabrication of CN-HAp heterostructures from eggshells with improved photocatalytic performance in degrading of mixing dyes under sunlight

In this work, hydroxyapatite (HAp) and g-C3N4 (CN) heterostructures were synthesized by the microwave-assisted hydrothermal method (MAHM). The calcium precursor for HAp synthesis was obtained from white eggshells. The influence of increasing the CN mass percentage (60–95%) in the heterostructure was investigated through structural characterizations via XRD, morphological characterizations through FESEM, and optical properties by UV–Vis and PL. The XRD results indicated hydroxyapatite formation from the eggshells and the heterostructures showed high crystallinity. The morphological and optical characterizations indicate the interface region between the phases, leading to a decrease in the intensity of the photoluminescence (PL) of the heterostructures, as well as a widening of the wavelength absorption band in relation to the spectrum of emission from the CN evidencing the decrease in the recombination of the photogenerated charges. The photocatalytic performance of heterostructures was first studied in the degradation of crystal violet (CV) and methyl orange (MO) dyes under UV light irradiation, in which heterostructures containing 80% and 95% CN had better performance over a period of 120 min. The best heterostructures were tested in the degradation of CV, MO, and a mixture (MIX) of both dyes under sunlight irradiation. The results under solar irradiation showed that the heterostructures with 80% and 95% CN degraded the CV dye in more than 99%, the MO dye in more than 80% and the MIX in more than 80% in 120 min. Therefore, obtaining environmentally friendly and economically sustainable CN-HAp heterostructures is another interesting option for use in photocatalysis.

ZnO and C/ZnO Catalysts Synthesized via Plant Mediated Extracts for Photodegradation of Crystal Violet and Methyl Orange Dyes

In this study, aqueous Cystoseira crinite extract was used to successfully biosynthesize ZnO and C-doped ZnO samples. X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray (EDX), FTIR, and UV–vis techniques were used to characterize the biosynthesized samples. XRD technique confirmed the crystalline structure of ZnO and C-doped ZnO. EDX confirmed the formation of C-doped ZnO. SEM analysis revealed the spherical shape of the samples with agglomeration. FTIR spectra showed that phenolic compounds and protein molecules are present in the Cystoseira crinite extract. The photocatalytic activity of the prepared photocatalysts was investigated using crystal violet (CV) as a model of the cationic dyes and methyl orange (MO) as a model of the anionic dyes. 5%C-doped ZnO calcined at 500 °C showed an optimum photocatalytic efficiency of 92.7% and 87.8% for CV and MO dyes, respectively. The improved photocatalytic activity could be attributed to the narrower optical band gap of C doped ZnO than pure ZnO. The photocatalytic activity of CV and MO dyes follows the first-order kinetics with high correlation coefficient values.Graphical

Green Development of Titanium Dioxide Using Astragalus boeticus for the Degradation of Cationic and Anionic Dyes in an Aqueous Environment

Wastewater discharge from the textile industry poses significant health problems for humans. As a result, the effluent waters are often rich in dyes, whose low natural decomposition capacity makes their treatment complex, thus contributing to environmental degradation. It becomes imperative to implement effective solutions for treating these contaminated waters, with a primary goal: to make them fit for human consumption. The present study focuses on the development of green TiO2 nanoparticles (TiO2-NP) using titanium (IV) isopropoxide as a precursor, along with the extract of Astragalus boeticus (A.B). These green TiO2 nanoparticles have been developed for use as highly efficient photocatalysts for the degradation of two types of dyes: Reactive Yellow 161 (RY161), an anionic dye, and Crystal Violet (CV), a cationic dye. The structural, microstructural, and optical properties of the synthesized material were characterized using XRD, FTIR, SEM, EDX, and UV-Vis methods. The results of these analyses revealed that the nanoparticles have a size of approximately 68 nm, possess an anatase structure, exhibit a spherical surface morphology, and have a band gap of 3.22 eV. The photocatalytic activity of the synthesized material demonstrated a 94.06% degradation of CV dye in a basic environment (pH = 10) within 30 min, with an initial CV concentration of 10 mg/L and a catalyst mass of 1 g/L. Additionally, it achieved a 100% degradation of RY161 dye in an acidic environment (pH = 4) within 90 min, with an initial RY161 concentration of 30 mg/L and a catalyst mass of 1 g/L. Furthermore, the recycling study indicated that the green TiO2 NPs catalyst could be effectively reused for up to five cycles. These experimental findings suggest that the developed TiO2 catalyst holds significant potential as an eco-friendly solution for remediating aqueous media polluted by both anionic and cationic dyes.

Efficient photodegradation of fast sulphon black and crystal violet dyes from water systems using locust bean gum (LBG)-encapsulated zirconium-based nanoparticles and antibacterial activity

Efficient photodegradation of fast sulphon black and crystal violet dyes from water systems using locust bean gum (LBG)-encapsulated zirconium-based nanoparticles and antibacterial activity

Phyto-fabrication of zinc oxide nanoparticles using Ficus religiosa and its potential application in degradation of crystal violet dye

Herein zinc oxide (ZnO) nanoparticles have been synthesized via a facile, environment friendly, and low-cost green synthesis method. The prepared metal oxide was characterized using powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), SEM/EDX (scanning electron microscopy/energy dispersive X-ray), volumetric analysis, and zeta potential measurements. The photocatalyst was then employed for the degradation of crystal violet (CV) dye under UV illumination (high-pressure Hg lamp 125 W). It was observed that phyto-fabricated ZnO nanoparticles exhibited high degradation efficiency towards CV dye as 95% of dye was degraded in 60 min of irradiation. The study also implies that phyto-fabrication of ZnO nanoparticles resulted in enhanced degradation efficiency of the photocatalyst.

Utilizing Novel Lignocellulosic Material from Hart's-Tongue Fern (Asplenium scolopendrium) Leaves for Crystal Violet Adsorption: Characterization, Application, and Optimization.

In this work, a new lignocellulosic adsorbent was obtained and tested for crystal violet dye removal from water. The material was obtained from hart's-tongue fern (Asplenium scolopendrium) leaves after minimal processing, without chemical or thermal treatment. The surface of the material was characterized using a variety of techniques, including FTIR, SEM, and color analysis. The effect of various factors on the adsorption capacity was then investigated and discussed. The kinetic and equilibrium studies showed that the general-order kinetic model and the Sips isotherm are the most suitable to describe the adsorption process. The equilibrium time was reached after 20 min and the maximum calculated value of the adsorption capacity was 224.2 (mg g-1). The determined values for the thermodynamic parameters indicated physical adsorption as the main mechanism involved in the process. The Taguchi method was used to optimize the adsorption conditions and identify the most influential controllable factor, which was pH. ANOVA (general linear model) was used to calculate the percentage contribution of each controllable factor to dye removal efficiency. Analysis of all the results shows that hart's-tongue fern (Asplenium scolopendrium) leaves are a very inexpensive, readily available, and effective adsorbent for removing crystal violet dye from aqueous solutions.

Bioremediation of Triphenylmethane and Sulfonated Azo Dyes Using an Indigenous Strain of Trichoderma Asperellum: Mechanisms and Efficacy Assessment

This study aimed to isolate a native fungal strain that was potent enough to curb the toxicity of azo dyes in textile effluent drain sludge. The native fungus, which has the potential to degrade several azo dyes under ‘non-sterile’ conditions, was isolated and identified as Trichoderma asperellum (TA). It was observed that the isolated strain was capable of decolorizing up to 71.42 %, 60.19 %, and 89.65 % of azo dyes (methyl orange, malachite green, and crystal violet, respectively) within a span of 14 days with an extensive range of temperatures (15°C-40°C) and pH (5-8) before optimization. The targeted dyes at concentrations of 100 mg/L, 200 mg/L, 300 mg/L, 400 mg/L, and 500 mg/L were decolorized after optimization. The maximum decolorization of methyl orange (MO), malachite green (MG), and crystal violet (CV) was 88.89 %, 71.09 %, and 92.75 %, respectively, at a dye concentration of 100 mg/L, pH of 6.5, and temperature of 25°C. The fungal isolate Trichoderma asperellum frequently contains chitinases, cellulose, and laccases. The findings of this study validated the potential of TA as an effective biocatalyst for the remediation of methyl orange, malachite green, and crystal violet in textile wastewater. The degradation products showed decreased toxicity to sprout seeds, such as Cicer arietinum (chickpea) and Vigna radiata (mung seeds), when compared to untreated wastewater.

Enhanced photocatalytic degradation of crystal violet dye and high-performance electrochemical supercapacitor applications of hydrothermally synthesised magnetic bifunctional nanocomposite (Fe3O4/ZnO)

The present investigation employed a facile hydrothermal approach for the fabrication of Fe3O4/ZnO dual-functional magnetic nanocomposite. Supercapacitor and visible-light-driven photocatalytic applications of the material were explored. X-ray diffraction, Fourier transform infrared spectra, ultraviolet–visible diffuse reflectance spectra (UV–vis/DRS), field emission scanning electron microscopy (FE-SEM), energy dispersive x-ray spectroscopy, and vibrating sample magnetometer were used to analyse the nanocomposite’s structural, morphological, optical, and magnetic properties. The FE-SEM analysis demonstrated that the surface morphology of Fe3O4, ZnO, and the Fe3O4/ZnO nanocomposite consisted of nanoparticles, nanoflakes, and nanoparticles adhered to the nanoflakes, respectively. The maximum specific capacitance of the electrode based on the Fe3O4/ZnO nanocomposite was measured to be 736.36 Fg−1 at a scan rate of 5 mVs−1. The electrode also demonstrated remarkable cycling stability, retaining 86.5% of its capacitance even after 3000 cycles. The Fe3O4/ZnO nanocomposite was found to have an optical bandgap of 2.7 eV, an average particle size of 22.5 nm, and a saturation magnetization of 68.7 emu g−1. The photocatalysis experiment was conducted using the optimised settings, which included a pH of 7.0, a dye concentration of 30 mg l−1, a catalyst dose of 1 g l−1, and a contact time of 120 min. The Fe3O4/ZnO nanocomposite exhibited a notable degradation efficiency towards crystal violet dye upon exposure to visible light, achieving a degradation efficiency of 96.9%. This performance surpassed that of pure ZnO, which attained a degradation efficiency of 70.2%. The nanocomposite exhibited a rate constant of 2.80 × 10−2 min−1, which was found to be notably higher than that of pure ZnO (0.8 × 10−2 min−1), as determined through modelling (pseudo-first order linear fit). The radical scavenger experiments indicated that the superoxide radicals and hydroxyl radicals are the primary reactive species. The Fe3O4/ZnO photocatalyst can be effectively isolated using a bar magnet. Remarkably, the photocatalytic efficiency of the material remained almost entirely intact even after undergoing four cycles of recycling. In addition, this research opens up exciting new possibilities for use in fields like energy storage and pollution control.

Structural, optical, thermal, mechanical, SHG and antibacterial properties of organic dyes doped glycine potassium dihydrogen orthophosphate single crystals

The advanced electro-optical materials are highly demanded because of their various uses in recent years. Glycine potassium dihydrogen orthophosphate single crystals are grown using a slow solvent evaporation technique in order to investigate the effects of the organic dyes crystal violet, malachite green, chrysoidine y, alizarin red, and victoria blue on the structural, optical, mechanical, thermal, SHG, and antibacterial properties. The powder XRD study validates the 14-2d space group tetragonal crystal structure. The higher optical bandgap energy and increased optical transparency of the crystal violet and victoria blue dye doped crystals indicate that there are less defects in their crystal lattice. The elemental analysis confirmed the presence of different organic dyes in the GKDP crystal lattice. The dye doping has enhanced the mechanical and optical characteristics of the formed crystals, and are categorised as soft materials. It is found that all dye-doped crystals have improved thermal stability. Malachite green and crystal violet doped GKDP crystals have higher SHG efficiency.

Optimization and mechanistic approach for removal of crystal violet and methylene blue dyes via activated carbon from pyrolyzed-ZnCl2 bamboo waste

In this study, bamboo waste (BW) was subjected to pyrolysis-assisted ZnCl2 activation to produce mesoporous activated carbon (BW-AC), which was then evaluated for its ability to remove cationic dyes, specifically methylene blue (MB) and crystal violet (CV), from aqueous environments. The properties of BW-AC were characterized using various techniques, including potentiometric-based point of zero charge (pHpzc), scanning electron microscopy with energy dispersive X-rays (SEM-EDX), X-ray diffraction (XRD), gas adsorption with Brunauer–Emmett–Teller (BET) analysis, infrared (IR) spectroscopy. To optimize the adsorption characteristics (BW-AC dosage, pH, and contact time) of PBW, a Box-Behnken design (BBD) was employed. The BW-AC dose of 0.05 g, solution pH of 10, and time of 8 min are identified as optimal operational conditions for achieving maximum CV (89.8%) and MB (96.3%) adsorption according to the BBD model. The dye removal kinetics for CV and MB are described by the pseudo-second-order model. The dye adsorption isotherms revealed that adsorption of CV and MB onto BW-AC follow the Freundlich model. The maximum dye adsorption capacities (qmax ) of BW-AC for CV (530 mg/g) and MB (520 mg/g) are favorable, along with the thermodynamics of the adsorption process, which is characterized as endothermic and spontaneous. The adsorption mechanism of CV and MB dyes by BW-AC was attributed to multiple contributions: hydrogen bonding, electrostatic forces, π-π attraction, and pore filling. The findings of this study highlight the potential of BW-AC as an effective adsorbent in wastewater treatment applications, contributing to the overall goal of mitigating the environmental impact of cationic dyes and ensuring the quality of water resources.

Adsorptive exclusion of crystal violet dye using barium encapsulated alginate/carbon composites: characterization and adsorption modeling studies.

The present study is devoted to the removal of crystal violet dye using the synthesized barium alginate/carbon composites abbreviated as BA (barium alginate), BAAC (barium alginate/activated carbon), BASC (barium alginate/starch carbon), and BASSC (barium alginate/starch carbon modified with CTAB). The adsorptive removal of crystal violet as a function of contact time, pH of solution, composite dose, initial dye concentration, and temperature was studied. The uptake of crystal violet (CV) dye for the composites was recorded in the range of 36 mg g-1 to 50 mg g-1 at pH 8.03 ± 0.03 for an equilibrium time of 120 min. The adsorption kinetics and isotherms in compliance with the CV sorption onto BA/carbon composites corroborated the utmost fit of pseudo-second-order and Freundlich isotherm models, respectively. The recycling process was achieved using the barium alginate-treated bead carbons for different initial CV dye concentrations of 10-30 mg L-1 with a scope of zero disposal. The practicability of BA/carbon composites in a groundwater sample spiked with 30 mg L-1 of CV was successfully achieved with a removal efficiency of about 65-74%. Characterization studies for the composites using FTIR, SEM (with EDS), XRD, TGA, and BET were carried out and discussed in the paper.

Production of activated carbon from food wastes (chicken bones and rice waste) by microwave assisted ZnCl2 activation: an optimized process for crystal violet dye removal

A major worldwide challenge that presents significant economic, environmental, and social concerns is the rising generation of food waste. The current work used chicken bones (CB) and rice (R) food waste as alternate precursors for the production of activated carbon (CBRAC) by microwave radiation-assisted ZnCl2 activation. The adsorption characteristics of CBRAC were investigated in depth by removing an organic dye (crystal violet, CV) from an aquatic environment. To establish ideal conditions from the significant adsorption factors (A: CBRAC dosage (0.02–0.12 g/100 mL); B: pH (4–10); and C: duration (30–420), a numerical desirability function of Box-Behnken design (BBD) was utilized. The highest CV decolorization by CBRAC was reported to be 90.06% when the following conditions were met: dose = 0.118 g/100 mL, pH = 9.0, and time = 408 min. Adsorption kinetics revealed that the pseudo-first order (PFO) model best matches the data, whereas the Langmuir model was characterized by equilibrium adsorption, where the adsorption capacity of CBRAC for CV dye was calculated to be 57.9 mg/g. CV adsorption is accomplished by several processes, including electrostatic forces, pore diffusion, π-π stacking, and H-bonding. This study demonstrates the use of CB and R as biomass precursors for the efficient creation of CBRAC and their use in wastewater treatment, resulting in a greener environment.

Fabrication of nanofiltration membranes through the deposition of polyethyleneimine on SMA-polyethersulfone supports under acid catalysis for cationic dye/salt separation

Organic selective nanofiltration membranes, with high organic rejections and salt passages, have attracted extensive research attention, especially for dye/salt separations. In the present work, nanofiltration membranes with lower MWCO were prepared by depositing PEI aqueous on porous supports containing poly (styrene-maleic anhydride) (SMA), under the catalysis of sulfuric acid. The amines in PEI reacted with the anhydrides in SMA through electrophilic protonation–addition, forming a crosslinked dense layer. Under the optimal conditions, a nanofiltration membrane with a permeance of about 24.3 Lm−2h−1bar−1 and a MWCO of about 400 Da was obtained. The membrane was further evaluated by filtrating aqueous solutions of dye and/or salt. The rejections of cationic dyes (crystal violet and methylene blue) were as high as 99.9%. The rejection of Na2SO4 was only 3.6%. During the 24 h filtration process of the crystal violet and Na2SO4 mixed aqueous solution, the separation performance remained stable, indicating the PEI/SMA-PES nanofiltration membrane had excellent organic-water selectivity and organics-salts selectivity. The membrane may have good potential in positively charged dye desalination.