Acid Green Dye Research Articles

Synthesis, characterization, wastewater treatment & plant growth application of ZnFe2O4/Bi2O3 nanocomposite

Vital for the prospective and sustainable environment, Bi2O3, ZnFe2O4 and ZnFe2O4/Bi2O3 (BZF) nanocomposite was synthesized in the present study by utilizing conventional combustion technique by green approach fueling with Aloe vera extract. The crystallite size calculated using Debye-Scherrer formula from X-Ray Diffraction (XRD) spectrum of BZF nanocomposite is ∼27 nm validated by XRD spectrum. Band gap of the nanocomposite is estimated using UV-Vis Diffuse Reflectance Spectra (DRS) analysis and was found to be 2.73 eV. The findings of the investigations have been validated by applications in photocatalytic degradation of acid green dye. The usage of Bi2O3, ZnFe2O4 and BZF nanocomposite as a catalyst for the degradation of acid green (AG) dye being subjected to visible light at ambient temperature results in improved photocatalytic response for Bi2O3, ZnFe2O4 and BZF nanocomposite was 88 %, 93 % and 97 % for 120 min respectively. Notably, the environmental impact of the entire technique has been examined in terms of the development of green gram plants displaying effective plant growth using the treated dye wastewater.

An Eco-friendly Approach to ZnO NP Synthesis Using Citrus reticulata Blanco Peel/Extract: Characterization and Antibacterial and Photocatalytic Activity.

Emission of greenhouse gases and infectious diseases caused by improper agro-waste disposal has gained significant attention in recent years. To overcome these hurdles, agro-waste can be valorized into valuable bioactive compounds that act as reducing or stabilizing agents in the synthesis of nanomaterials. Herein, we report a simple circular approach using Citrus reticulata Blanco (C. reticulata) waste (peel powder/aqueous extract) as green reducing and capping/stabilizing agents and Zn nitrate/acetate precursors to synthesize ZnO nanoparticles (NPs) with efficient antimicrobial and photocatalytic activities. The obtained NPs crystallized in a hexagonal wurtzite structure and differed clearly in their morphology. UV-vis analysis of the nanoparticles showed a characteristic broad absorption band between 330 and 414 nm belonging to ZnO NPs. Fourier transform infrared (FTIR) spectroscopy of ZnO NPs exhibited a Zn-O band close to 450 cm-1. The band gap values were in the range of 2.84-3.14 eV depending on the precursor and agent used. The crystallite size obtained from size-strain plots from measured XRD patterns was between 7 and 26 nm, with strain between 16 and 4%. The highly crystalline nature of obtained ZnO NPs was confirmed by clear ring diffraction patterns and d-spacing values of the observed lattice fringes. ZnNPeelMan_400 and ZnNExtrMan showed good stability, as the zeta potential was found to be around -20 mV, and reduced particle aggregation. Photoluminescence analysis revealed different defects belonging to oxygen vacancies (VO+ and VO+2) and zinc interstitial (Zni) sites. The presence of oxygen vacancies on the surface of ZnAcExtrMan_400 and ZnAcPeelMan_400 increased antimicrobial activity, specifically against Gram-negative bacteria Escherichia coli (E. coli) and Salmonella enteritidis (S. enteritidis). ZnNExtrMan with a minimal inhibitory concentration of 0.156 mg/mL was more effective against Gram-positive bacteria Staphylococcus aureus (S. aureus), revealing a high influence of particle size and shape on antimicrobial activity. In addition, the photocatalytic activity of the ZnO NPs was examined by assessing the degradation of acid green dye in an aqueous solution under UV light irradiation. ZnAcPeelMan_400 exhibited excellent photocatalytic activity (94%) within 90 min after irradiation compared to other obtained ZnO NPs.

Nanocomposite materials for decontamination of highly toxic acid dye from aqueous streams

ABSTRACT The rising issue of water pollution, driven by industry, urbanisation, and population increase, needs urgent action to address the release of contaminants. This study tackles the critical need for a low-cost, highly efficient adsorbent to extract toxic dyes from aqueous streams. The innovation lies in the synthesis of Cu/TiO2-CWSP composite, and composites with varying percentages of copper doping and comparing Cu/TiO2-CWSP composites with other nanocomposites, such as Li/TiO2-CWSP, Na₂SiO₃-CWSP, and various CaO-Fe-based composites. The works thoroughly optimised important parameters, including adsorbent dosage, pH, initial dye concentration, and exposure period, demonstrating their major influence on dye removal efficiency. Furthermore, the study assessed the effect of beginning pH on the adjustment of final pH, demonstrating variable efficiency levels depending on initial conditions. Recent research has evaluated numerous adsorbents, analysed by SEM. The highest % removal of acid green dye using Cu/TiO2-CWSP composite was at pH 7, dose of 0.5 g/L with a value of 99.12% achieved after 60 minutes only. The removal effectiveness of acid green dye improved as the percentage of Cu/TiO2 in the composite increased. Cu/TiO2-CWSP composite showed the presence of very fine particles at the surface of composite in SEM micrograph having a zeta Potential value of −20.9 mV. In conclusion, this study presents an innovative approach for efficiently removing acid green dye from aqueous solutions through adsorption-photocatalysis synergy. The findings contribute to addressing the critical issue of water pollution, especially in the textile industry, offering a sustainable path towards cleaner water resources.

Synthesis and efficiency comparison of reed straw-based biochar as a mesoporous adsorbent for ionic dyes removal

The reed straw is assessed as a potential source of widely available renewable biomass for biochar production and compared with two other waste-based biomasses, namely fruit stones blend, and brewery spent grains. The biochars were activated via steam and CO2. While steam activation yielded 12 % carbon from reed biomass, CO2 activation resulted in biomass degradation. The characterization of reed biochar showed a mesoporous structure and a high surface area of 514 m2/g. The adsorption tests displayed a decent adsorption capacity of biochar, with values of 92.6 mg/g for methylene violet dye and 35.7 mg/g for acid green dye. Only 1 g/L dosage of reed biochar was able to remove 99 % of the 50 mg/L methylene violet solution in 15 min and 60 % of the 50 mg/L acid green solution in 10 min. The obtained results demonstrate reed biomass as a suitable source for biochar production as well as reed-based biochar as a promising dye adsorbent.

Acid green crystal-based in situ synthesis of polyaniline hollow nanotubes for the adsorption of anionic and cationic dyes.

In this article, acid green (AG) dye played a dual pivotal role. The first role is as a structure-guiding agent and a soft template for the acid-free synthesis of polyaniline hollow nanotubes (PANI-HNTs) while the second role is as a target dye to be removed as a model of anionic dyes, alongside methylene blue (MB) as a model of cationic dyes. After characterization using X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), nitrogen adsorption–desorption isotherms (BET), and UV-visible absorption spectroscopy techniques, the prepared PANI-HNTs were exploited for the adsorption of basic MB dye and acidic AG dye from aqueous media. To optimize the adsorption process, the effects of different variables, such as adsorbent dose, contact time and pH, were studied. Due to the structural differences between the MB and AG dyes, the obtained data revealed that the best pH for the medium for optimal adsorption was 9.0 and 3.0, respectively. The rapid sorption dynamics were found to proceed in a second-order kinetic model and the equilibrium data for the adsorption of MB and AG dyes were fitted well to the Langmuir isotherm. The maximum monolayer capacity, qmax, for MB and AG was calculated from the Langmuir model and equalled 69.4 and 57.8 mg g−1, respectively. A thermodynamic study revealed that the adsorption of MB by PANI-HNTs was a feasible, spontaneous, and exothermic process. Investigation of the substrate regeneration revealed that PANI-HNTs can be reused for dye adsorption several times. Therefore, the synthesized PANI-NTs are highly efficient for the dual removal of basic and acidic dyes. TEM images showed that PANI-HNTs were formed with an external and internal diameter of 50–60 nm and 5–10 nm, respectively.

Bio-mediated Sm doped nano cubic zirconia: Photoluminescent, Judd–Ofelt analysis, electrochemical impedance spectroscopy and photocatalytic performance

A series of Sm doped ZrO2 nanomaterials (NMs) were synthesized at relatively low temperature by bio-template method using Leucas aspera (LA) plant extract as a fuel. Rietveld refinement results verified that the compounds were crystallized in cubic structure with space group Fm-3m (225). The PL emission, CIE and CCT analysis confirm that, the present photocatalyst can serve as an excellent candidate for cool LEDs. The registered trend (Ω2 < Ω4) calculated using the Judd–Ofelt theory reveals the ionic character of the SmO bonds as well as a relatively high symmetry environment around the rare earth ion (RE) site in ZrO2. ZrO2:Sm3+ (11 mol%) photocatalyst has a long lifetime (s) and exhibits excellent Sunlight driven photocatalytic activity for the degradation of acid green dye. This could be attributed to surface defects, special electronic structure, decreased band gap, multichannel transitions, long life time and efficient electron−hole separation.

Banana Fibers as Sorbent for Removal of Acid Green Dye from Water

In this study, banana fibers extracted from banana leaves, stem, and stalk were used to remove acid green dye from aqueous solution. Three initial concentrations (750, 1000, and 1500 ppm) were chosen to determine the kinetic characteristics of the banana fiber sorbents at 25°C, agitation speed of 200 rpm, and total contact time of 3 hours. The pseudo-first-order, pseudo-second-order, and Dunwald-Wagner kinetic models were applied to the experimental kinetic data. For isotherm study, the batch experiments were performed at 25°C, initial pH 2, agitation speed of 200 rpm, and initial concentrations between 100 and 2000 ppm. The experimental data was fitted to the Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherms. The equilibrium was achieved in less than 90 minutes. The removal of the acid green dye was found to be following closely the pseudo-second-order kinetic model. For equilibrium study, the Freundlich isotherm was found to fit well with adsorption of acid green dye on the banana leaves, stem, and stalk sorbents. The calculated mean free energy of 4–11 J/mol indicated that the sorption process was mostly physical in nature. Experimental results also showed the adsorption performance is greatly affected by the initial solution pH.

16SrRNA sequencing of Dye decolorizing bacteria isolated from Soil.

Dye׳s residues in textile effluents are hazardous for humans and animals health. Such pollutants can be degraded into non-harmful molecules using biological approaches that are considered cheaper and ecologically safer. Isolated 15 bacterial cultures from soil that could be used in biological system were showed decolorization capacity for Acid Green dye (33.9% to 94.0%) using thin layer chromatography and broth culture method. The most promising cultures (AMC3) to decolorize Acid green Dye (94.6%) was re-coded as NSDSUAM for submitting at IMTECH, Chandigarh for sequencing. The 16SrRNA sequencing suggested that it can be a variant of Pseudomonas geniculata (99.85% identical similarity) with difference of 2 base pairs to reference strain Pseudomonas geniculata ATCC 19374(T). Thus present study proposed dye decolorizing efficiency of the isolated strain of Pseudomonas geniculata that was previously unnoticed. The sequence is deposited in NCBI GenBank with the accession number KP238100.

Removal of acid green dye 50 from wastewater by anodic oxidation and electrocoagulation—A comparative study

The present work represents a comparative study for removing acid green dye 50 by anodic oxidation and electrocoagulation using a new batch self gas stirred electrochemical cell. The effect of operating parameters such as current density, initial dye concentration, NaCl concentration and pH on the efficiency of colour removal has been examined. The chemical oxygen demand (COD) reduction under suitable operating conditions was also calculated and found to be reduced by 68% and 87% in case of electrochemical oxidation and electrocoagulation methods, respectively. The results indicate that electrocoagulation is more economic than anodic oxidation, energy consumption ranged from 2.8 to 12.8 kWh/kg dye removed in case of electrocoagulation while in case of anodic oxidation it ranged from 3.31 to 16.97 kWh/kg dye removed. Although the mechanisms of electrocoagulation and anodic oxidation are different, results show that the first-order rate equation provides the best correlation for the decolourization rate of acid green 50 by the two methods.

Effect of Biosorption Parameters Kinetics Isotherm and Thermodynamics for Acid Green Dye Biosorption from Aqueous Solution by Brewery Waste

Biosorption of Acid Green (AG 25) was investigated using Spent Brewery Grains (SBG) a brewing industry waste in abatch system with respect to initial pH, temperature, initial dye concentration, biosorbent dosage, and contact time. Thebiomass exhibited the highest dye uptake capacity at 303 K, initial pH value of 3, the initial dye concentration of90mg/L, biosorbent dosage of 0.2 g and contact time of 75 min. The extent of dye removal increased with increase intime, biosorbent dosage and decreased with increase in temperature. The equilibrium sorption capacity of the biomassincreased on increasing the initial dye concentration up to 90 mg/L and then started decreasing in the studiedconcentration up to 300 mg/L. The experimental result has shown that the acidic pH favours the biosorption. Langmuirand Freundlich adsorption model is used for the mathematical description of the biosorption equilibrium and isothermconstants are evaluated. Equilibrium data fitted very well to the Langmuir model. The pseudo first- and second-orderkinetic models were also applied to the experimental data. The results indicated that the dye uptake process followed thepseudo second-order rate expression and biosorption rate constants increased with increasing concentration.

Photo-degradation of acid green dye over Co–ZSM-5 catalysts prepared by incipient wetness impregnation technique

Co–ZSM-5 catalysts with different Co-loadings (2–30 wt.%) were prepared by incipient wetness impregnation method. The prepared solid catalysts were characterized by X-ray diffraction, FTIR, in situ FTIR of pyridine adsorption and surface area measurements. The XRD data presented disintegration in the zeolitic crystalline structure accompanied by an increase in particle size of the prepared solids. New phases, Co 3O 4 and Co 2SiO 4, were detected with increasing the Co-loading, which indicate the strong interaction of cobalt ions with the ZSM-5 zeolite. FTIR study proved the presence of Co ions in stabilized sites inside the ZSM-5 framework. The in situ FTIR of adsorbed pyridine determined the type and relative strength of acidity on the surface of the prepared solids. The acidity switched from B-acid sites to L-acid sites with impregnation of cobalt ions in ZSM-5 zeolite. The acidity decreased with increasing Co-loading, which might be due to the destruction of zeolite framework and presence of new phases such as cobalt silicate and cobalt oxide on the surface. The surface texture characteristics changed with the promotion of ZSM-5 by cobalt ions, since a decrease of surface area, mean pore radius and pore volume was observed. The assessment of the catalytic activity was performed by the use of the photo-degradation of acid green (AG) dye as a probe reaction in presence of H 2O 2 as an oxidant. The pH value controlled the degradation rate since a gradual increase of AG degradation rate was observed with increasing pH value and the optimum H 2O 2 concentration was 61.6 mmol/l. It was found that, the AG degradation rate increased until an optimum value of Co-loading ( ca. 10 wt.%), beyond which a monotonic decrease of reaction rate was recognized. The experimental data pointed to the importance of both the cobalt moieties and the zeolite framework structure in the AG degradation reaction.

Synthesis, structural and catalytic activity of binaphthyl macrocyclic complexes

The binaphthyl macrocyclic ligand, N,N′-diethyl-[3,3′-(2,2′-dihydroxy-1,1′-binaphthyl)carboxamide]-2,2′-dihydroxy-1,1′-binaphthyl-3,3′-dicarboxylic acid (DDCDB), has been synthesized and investigated. The ligand (DDCDB) and its metal complexes involving CuII, ZnII, UO2II, ThIV, CeIII, MoVI and WVI ions have been prepared and characterized by spectral (i.r., u.v.–vis.), elemental analyses, magnetic moments and thermal analyses measurements. DDCDB behaves as a tridentate ligand towards CuII, ZnII and UO2II ions coordinating via CO, NH and the deprotonated naphthyl OH groups in a ratio of 2:1 (M:L). On the other hand, DDCDB behaves in a bidentate manner coordinatingvia the NH and the deprotonated naphthyl OH groups only in case of the ThIV, CeIII, MoVI, and WIV ions and in ratio 1:1 (M:L). Results of thermal measurements confirm the existence of solvent molecules inside and outside the coordination sphere. ThVI complex has been applied for the hydrolysis of phosphodiester and the results show a significant rate enhancement of ~5.8 million fold with respect to the auto-hydrolysis of bis-(p-nitrophenyl) phosphate (BNPP) under the same conditions Also, CuII complex accelerates the photodegradation of the hazardous pollutant (acid green dye) in the presence of hydrogen peroxide by degrading 90% of the dye within 23 min.

Electrochemical degradation of acid green dye in aqueous wastewater dyestuff solutions using a lead oxide coated titanium electrode

A modified electrode, which can be used as an anode for electrocatalytic oxidation processes of dyestuff in aqueous solutions, was fabricated by the electrodeposition of a lead oxide layer on a titanium substrate. The modified electrode was used for the electrochemical degradation of an acid green dye. The results of the electrocatalytic oxidation process of the dyestuff solutions were expressed in terms of the remaining dye concentration and chemical oxygen demand (COD) values. The different operating conditions of the treatment process were studied. The optimum operating conditions for the dye and modified electrode were determined, where good results for complete removal of the dye and COD were achieved. The optimum conditions were applied to the treatment of a sulfur black dye in true wastewater solutions.

Microbial diversity and complexity in hypersaline environments: a preliminary assessment.

The microbial communities in solar salterns and a soda lake have been characterized using two techniques: BIOLOG, to estimate the metabolic potential, and amplicon length heterogeneity analysis, to estimate the molecular diversity of these communities. Both techniques demonstrated that the halophilic Bacteria and halophilic Archaea populations in the Eilat, Israel saltern are dynamic communities with extensive metabolic potentials and changing community structures. Halophilic Bacteria were detected in Mono Lake and the lower salinity ponds at the Shark Bay saltern in Western Australia, except when the crystallizer samples were stressed by exposure to Acid Green Dye #9899. At Shark Bay, halophilic Archaea were found only in the crystallizer samples. These data confirm both the metabolic diversity and the phylogenetic complexity of the microbial communities and assert the need to develop more versatile media for the cultivation of the diversity of bacteria in hypersaline environments.