Dye Removal Research Articles

Greenly synthesised novel microporous ZnO/GO for adsorption of methyl orange and malachite green

ABSTRACT This study presents a greenly synthesised novel nanocomposite composed of Zinc Oxide (ZnO) and Graphene Oxide (GO) for the adsorption of dyes from aqueous solutions. The nanocomposite was synthesised using algae thus representing a green and eco-friendly method, ensuring minimal environmental impact. The physical characterisation of zinc oxide and graphene oxide nanocomposite (ZnO/GO) was done using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FT-IR), Zeta Potential, and Particle Size Analyzer (PSA). The pore diameter of the ZnO/GO was 1.801 nm, and its total surface area was 54.062 m2/g. The nanocomposite’s adsorption performance was systematically investigated through batch adsorption experiments. With an adsorption efficiency of 296.73 mg/g and 259.74 mg/g for MO and MG, the Langmuir isotherm model outperforms the Freundlich isotherm model in terms of adsorption. The pseudo-second-order model having an R2 value of 0.99 for both MO and MG, offers a more convincing explanation of adsorption than the pseudo-first-order model. The results demonstrated rapid adsorption kinetics and high adsorption capacities for both cationic and anionic dyes. Additionally, the ZnO/GO has a high reusability without significant degradation. The sustainable nature of the nanocomposite was emphasised by its efficient dye removal, reusability, and minimal secondary waste generation.

Discoloration of textile dyes by spent mushroom substrate of Agaricus bisporus

The textile industry discharges up to 5 % of their dyes in aqueous effluents. Here, use of spent mushroom substrate (SMS) of commercial white button mushroom production and its aqueous extract, SMS tea, was assessed to remove textile dyes from water. A total of 30–90 % and 5–85 % of the dyes was removed after a 24 h incubation in SMS and SMS tea, respectively. Removal of malachite green and remazol brilliant blue R was similar in SMS and its tea. In contrast, removal of crystal violet, orange G, and rose bengal was higher in SMS, explained by sorption to SMS and by the role of non-water-extractable SMS components in discoloration. Heat-treating SMS and its tea, thereby inactivating enzymes, reduced dye removal to 8–58 % and 0–31 %, respectively, indicating that dyes are removed by both enzymatic and non-enzymatic activities. Together, SMS of white button mushroom production has high potential to treat textile-dye-polluted aqueous effluents.

Achievements in Preparation of Cyclodextrin–Based Porous Materials for Removal of Pollutants

Cyclodextrin–based porous materials have been widely applied in removing various organic pollutants from water environments, due to their unique physical and chemical properties, like the size–matching effect and hydrophobic interaction. Large numbers of hydroxyl groups in its external structure give cyclodextrin a high solubility in water, but the existence of these hydroxyl groups also endows cyclodextrin with the ability to be chemically modified with various functional groups to reduce its solubility in water and, meanwhile, to develop some novel functionalized cyclodextrin–based porous materials for selective removal of the target organic pollutants. This review focuses on the recent development in the synthesis of cyclodextrin–based porous materials (crosslinked cyclodextrin polymers and immobilized cyclodextrins), as well as highlighting their applications and mechanisms in the removal of dyes, endocrine disruptors, and mixed pollutants from water. Finally, the challenges and future perspectives in related research fields are discussed.

Study on Preparation of Calcium-Based Modified Coal Gangue and Its Adsorption Dye Characteristics.

Efficient and thorough treatment of dye wastewater is essential to achieve ecological harmony. In this study, a new type of calcium-based modified coal gangue (Ca-CG) was prepared by using solid waste coal gangue as raw material and a CaCl2 modifier, which was used for the removal of malachite green, methylene blue, crystal violet, methyl violet and other dyes in water. When the dosage of Ca-CG was 1-5 g/L, the dosage of Ca-CG was the main factor affecting the dye adsorption effect. The adsorption effects of Ca-CG on four dyes were as follows: malachite green > crystal violet > methylene blue > methyl violet. Kinetics, isotherms and thermodynamic analysis showed that the adsorption of malachite green, methyl blue, crystal violet and methyl violet by Ca-CG fitted the second-order kinetic model, and adsorption with chemical reaction is the main process. The adsorption of four dyes by Ca-CG conformed to the Freundlich model, which is dominated by multi-molecular layer adsorption, and the adsorption was easy to carry out. The adsorption process of Ca-CG on the four dyes was spontaneous. The results of FTIR, XRD and SEM showed that the calcium-based materials such as lipscombite and dolomite were the key to the adsorption of malachite green by Ca-CG, and the main mechanisms for the adsorption of malachite green by Ca-CG are surface precipitation, electrostatic action, and chelation reaction. Ca-CG adsorption has great potential for the removal of dye wastewater.

A Sustainable Approach for Enhancing Cationic Dyes Adsorption in Single and Multiple Systems using Novel Nano Ferrites Modified with Walnut Shell

AbstractWalnut shell has been used in various experimental studies for different dyes removal, but it is exciting to study the adsorption behaviour of bio‐waste (walnut shell) in combination with spinel zinc ferrite which resulted in the formation of a novel material having magnetic properties and help in easy separation after the wastewater treatment. Novel magnetic walnut shell zinc ferrite (WSZF) composite has been synthesized and used to remove Malachite Green and Methylene Blue from aqueous solution in single and binary dye systems. Different techniques have been used to characterize the composite such as Fourier Transform Infrared Spectroscopy, X‐Ray Diffraction, Field Emission Scanning Electron Microscopy, Energy Dispersive Spectroscopy, Thermogravimetric Analysis and pHzpc. Adsorption of dyes were studied to see the effect of time, pH, adsorbent dose, dye concentration and temperature. The Lagergren pseudo second order model fitted well among various kinetic models employed. Langmuir adsorption isotherm best fitted with maximum adsorption capacities of 86.20 and 169.5 mg/g in single dye and 23.92 and 18 mg/g respectively in binary dye system for Malachite Green and Methylene Blue. Process was spontaneous and ΔH° were found positive, confirmed endothermic process of adsorption. The composite‘s regeneration capacity was studied for five cycles and at the end of five cycle the efficiency of the material was found to be around 80 % for both single as well as binary dye systems. It is concluded that the chosen WSZF will be the optimum solution for cationic dyes removal.

Recycling lithium-ion battery graphite: Synthesis of adsorbent materials for highly efficient removal of dye and metal ions from wastewater

The fate of residual graphite derived from hydrometallurgical treatment of spent Lithium-ion batteries remains uncertain. This study dwells on the aim of identifying the potentialities of recycling residual graphite for wastewater treatment. Graphite was recovered hydrometallurgically, and new adsorption materials: graphite oxide (GO) and graphene oxide (GrO) were synthesized from the residual graphite using the chemical oxidization method. Synthesized materials showed higher interlayer spacings (GO = 0.81 nm, GrO = 0.78 nm) than the commercially available similar materials. Adsorption studies revealed higher adsorption capacities for both dye (>550 mg/g in all cases) and metal ions (highest ∼93 mg/g for Ni2+ and lowest ∼68 mg/g for Zn2+). GrO showed superior results than GO due to its high surface area and porosity despite GO having more functional groups. Moreover, produced materials showed about 97 % removal of dye and about 94 % removal of contaminated metals which are higher performance than existing commercial or similar materials. These findings highlight the promising recycling capabilities of waste graphite and suggest its potential as a substitute for natural graphite.

Blended Nephelium lappaceum and Durio zibethinus wastes for activated carbon production via microwave-ZnCl2 activation: optimization for methylene blue dye removal

Herein, this work targets to employ the blended fruit wastes including rambutan (Nephelium lappaceum) peel and durian (Durio zibethinus) seed as a promising precursor to produce activated carbon (RPDSAC). The generation of RPDSAC was accomplished through a rapid and practical procedure (microwave-ZnCl2 activation). To evaluate the adsorptive capabilities of RPDSAC, its efficacy in eliminating methylene blue (MB), a simulated cationic dye, was measured. The Box–Behnken design (BBD) was utilized to optimize the crucial adsorption parameters, namely A: RPDSAC dose (0.02–01 g/100 mL), B: pH (4–10), and C: time (2–6 min). The BBD design determined that the highest level of MB removal (79.4%) was achieved with the condition dosage of RPDSAC at 0.1 g/100 mL, contact time (6 min), and pH (10). The adsorption isotherm data is consistent with the Freundlich concept, and the pseudo-second-order versions adequately describe the kinetic data. The monolayer adsorption capacity (qmax ) of RPDSAC reached 120.4 mg/g at 25 °C. Various adsorption mechanisms are involved in the adsorption of MB dye onto the surface of RPDSAC, including π–π stacking, H-bonding, pore filling, and electrostatic forces. This study exhibits the potential of the RPDSAC as an adsorbent for removal of toxic cationic dye (MB) from contaminated wastewater.

ADSORPTION OF CATION DYE USING ACTIVATED CARBON DERIVED FROM GOLDEN SHOWERSEED POD ( C ASSIA FISTULA)

ADSORPTION OF CATION DYE USING ACTIVATED CARBON DERIVED FROM GOLDEN SHOWERSEED POD ( C ASSIA FISTULA)

Constructing sustainable keratin/algae biohydrogels for efficient removal of aniline blue via a pre-extrusion induced self-crosslinking strategy

Two environmentally friendly hierarchical porous biohydrogels, honeycomb keratin hydrogel (HKH) and spongy keratin-algae hydrogel (SKAH), were fabricated using an extrusion approach by using extruded keratin with or without algae. The extruded keratin exhibits exceptional self-crosslinking properties, making the biohydrogels behave with excellent adsorption performance for aniline blue dye removal from wastewater. In addition, the SKAH demonstrated a significantly higher maximum uptake capacity of 442.56 mg/g, surpassing that of the HKH (134.63 mg/g). This enhancement can be attributed to the looser porous structure of the SKAH, which enables better exposure of active groups within the material, which indicates the introduction of algae led to noticeable variations in the microstructure and performance of the adsorbent. Systematic investigation on the adsorption performance of isotherm and kinetics analyses indicated that chemisorption played a predominant role in governing the overall rate of adsorption. Overall, this extrusion approach allows for a simplified and non-toxic method of synthesizing these biohydrogels without the need for additional chemical reagents or biocross-linkers, promoting their eco-friendliness and reducing potential environmental impacts. The unique feature presents significant opportunity to fabricate sustainable and eco-friendly biohydrogel adsorbent for wastewater treatment.

Supramolecular Gels Based on C3-Symmetric Amides: Application in Anion-Sensing and Removal of Dyes from Water.

We modified C3-symmetric benzene-1,3,5-tris-amide (BTA) by introducing flexible linkers in order to generate an N-centered BTA (N-BTA) molecule. The N-BTA compound formed gels in alcohols and aqueous mixtures of high-polar solvents. Rheological studies showed that the DMSO/water (1:1, v/v) gels were mechanically stronger compared to other gels, and a similar trend was observed for thermal stability. Powder X-ray analysis of the xerogel obtained from various aqueous gels revealed that the packing modes of the gelators in these systems were similar. The stimuli-responsive properties of the N-BTA towards sodium/potassium salts indicated that the gel network collapsed in the presence of more nucleophilic anions such as cyanide, fluoride, and chloride salts at the MGC, but the gel network was intact when in contact with nitrate, sulphate, acetate, bromide, and iodide salts, indicating the anion-responsive properties of N-BTA gels. Anion-induced gel formation was observed for less nucleophilic anions below the MGC of N-BTA. The ability of N-BTA gels to act as an adsorbent for hazardous anionic and cationic dyes in water was evaluated. The results indicated that the ethanolic gels of N-BTA successfully absorbed methylene blue and methyl orange dyes from water. This work demonstrates the potential of the N-BTA gelator to act as a stimuli-responsive material and a promising candidate for water purification.

Synthesis of new sustainable polyester‐type hydrogels from chemical recycled poly(ethylene terephthalate) products applied on the removal of indigo carmine dye

Synthesis of new sustainable polyester‐type hydrogels from chemical recycled poly(ethylene terephthalate) products applied on the removal of indigo carmine dye

NiO/MnFe2O4 Nanocomposite Photoluminescence, Structural, Morphological, Magnetic, and Optical Properties: Photocatalytic Removal of Cresol Red under Visible Light Irradiation.

In this study, pure nickel oxide (NiO), manganese ferrite (MnFe2O4 or MFO), and binary nickel oxide/manganese ferrite (NiO/MFO1-4) nanocomposites (NCs) were synthesized using the Sol-Gel method. A comprehensive investigation into their photoluminescence, structural, morphological, magnetic, optical, and photocatalytic properties was conducted. Raman analysis, UV-Vis spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction techniques were used to characterize the materials. The synthesized samples exhibited superparamagnetic behavior, as revealed by our analysis of their magnetic properties. A lower recombination rate was shown by the photoluminescence analysis, which is helpful for raising photocatalytic activity. The photocatalytic activity was evaluated for the degradation of Cresol Red (CR) dye. 91.6% of CR dye was degraded by NiO/MFO-4 nanocomposite, and the NC dosage as well as solution pH affected the photocatalytic performance significantly. In four sequential photocatalytic cycles, the magnetically separable NCs were stable and recyclable. The enhanced photocatalytic activity and magnetic separability revealed the potential application of NiO/MFO-4 as an efficient photocatalyst for the removal of dyes from industrial wastewater under solar light irradiation.

Synthesis and application of dual-functional sorbent SBA-15-Fe3O4-PDA-ODA for removing both water soluble and insoluble pollutants

In this study, inorganic-organic hybrid sorbent SBA-15-Fe3O4-PDA-ODA with functional groups having affinity for both water-soluble and insoluble pollutants was synthesized for treatment of wastewater where Malachite Green (MG) dye and motor oil coexist. In order to enhance the specific interactions between the sorbent and dye via functional groups of polydopamine (PDA), Fe3O4 nanoparticles were encapsulated with SBA-15 and surface functionalization with PDA was accomplished and then the surface of Fe3O4-SBA-15-PDA was modified with octadecylamine (ODA) to remove the oil present in the same environment with dye. While the SBA-15-Fe3O4-PDA-ODA directed to the aqueous phase by magnet provided MG removal thanks to the hydrophilic groups of PDA, it provided motor oil removal thanks to hydrophobicity of ODA when directed to the oil phase. 99.20 % dye removal and 9.24 g/g oil adsorption capacity were achieved from the environment where oil and dye were present together. Besides, the adsorption of MG on Fe3O4-SBA-15-PDA was searched at various pH, dye concentration, adsorbent dosage, and temperature in order to propose optimum experimental conditions for removal of dye and maximum adsorption capacity was determined as 95.83 mg g−1 at optimum conditions (10 mg adsorbent, 10 mg L−1 MG concentration, pH 9). Interaction mechanism between dye and Fe3O4-SBA-15-PDA was explained by studying the adsorption behavior of sorbent derived from the isotherm and kinetic results. The sorbents were characterized by FT-IR, XRD, SEM, N2-adsorption/desorption, water-contact-angle, and VSM measurements. SBA-15-Fe3O4-PDA-ODA sorbent was tested for three successive adsorption cycles for both dye and oil and eventuated insignificant loss in activity when they were recycled. Easy and low-cost fabrication protocol, controllable removal ability of dye and oil will facilitate its versatility in environmental cleanup process for water soluble and insoluble pollutants.

Reuse efficiency yellow phosphorus slag in a combination with Copper (I) Oxide as a novel antibacterial additive and adsorbent: Experimental consideration and modeling

The present study investigated the green synthesis of Cu2O on yellow phosphorus slag (YPS) in the presence of nonionic surfactant, Tween 80 and ascorbic acid. The weight ratio of YPS/Cu(NO3)2.3 H2O was varied to evaluate the effect of Cu2O nanoparticles content on the properties of hybrid YPS. The characteristics of the hybrid material were evaluated by FT-IR, SEM, HR-TEM, XRD, UV-Vis, EDX mapping and DLS methods. The obtained results indicate the successful synthesis of Cu2O nanoparticles (Cu2O-NPs) on the YPS surface, exhibiting a regular spherical shape and a particle size in the range of 10–50 nm. Both the calcium phosphate β crystals of YPS and cuprite crystals of Cu2O NPs were appeared on the XRD pattern of the hybrid YPS materials. The YPS and hybrid YPS materials was stable in water with a negative charge lower than −24 mV. The hybrid YPS materials exhibit a great bactericidal activity against both E. coli and S. aureus strains, especially at the ratio of 30% of Cu(NO3)2.3 H2O. The study also applied YPS-Cu2O for removal of anionic active dye Remazol midnight black (RGB) in water. Under optimal conditions by Box-Behnken model, including pH 6, adsorption time of 240 min and YPS-Cu30 mass of 0.04 g, the RGB adsorption efficiency using YPS-Cu30 reached the highest, with a RGB removal of 86.34 ± 0.34% and an adsorption capacity of 65.23 ± 0.25 mg.g−1. We indicate that the hybrid YPS/Cu2O is an excellent adsorbent for dye removal and antibacterial additive.

Facile and environmentally sustainable synthesis of bone waste derived biochar-based bimetallic-LDH nanocomposite for selected dyes removal from aqueous medium

Facile and environmentally sustainable synthesis of bone waste derived biochar-based bimetallic-LDH nanocomposite for selected dyes removal from aqueous medium

Effective removal of Rhodamine 6G (Basic Red-1) reactive dye using waxy corn starch in waste water of textile industry

The textile industry generates effluents containing toxic dyes, which have detrimental effects on the environment, including air, soil, and water contamination. These dyes also pose risks to human health and disrupt aquatic ecosystems. Developing ecological and cost-effective method to address this issue is a major challenge. This study focuses on utilizing waxy cornstarch, which exhibits unique properties such as high biodegradability, environmental compatibility, low sludge volume, small particle size, and high surface area (1.27 m2/g), for removing the reactive dye Rhodamine 6G (Basic Red-1) from textile wastewater. The composition of waxy cornstarch was analyzed, including determination of protein content using the Kjeldahl apparatus, as well as moisture content, ash content, and fine fiber content through experimental methods. The rate of dye removal from wastewater was assessed using a UV-spectrophotometer. The experimental design was selected, and trials were conducted using a glass testing apparatus. Dye removal rates were investigated at different dosages, temperatures, and pH ranges. The highest dye removal efficiency of 83.6% was achieved at a pH of 5, a temperature of 40 °C, and a coagulant dosage of 40 mg/l. These findings highlight the potential of waxy cornstarch as a natural coagulant for effective removal of Rhodamine 6G dye from textile wastewater.

A green and economic approach to synthesize magnetic Lagenaria siceraria biochar (γ-Fe2O3-LSB) for methylene blue removal from aqueous solution.

In the printing and textile industries, methylene blue (a cationic azo dye) is commonly used. MB is a well-known carcinogen, and another major issue is its high content in industrial discharge. There are numerous removal methodologies that have been employed to remove it from industrial discharge; however, these current modalities have one or more limitations. In this research, a novel magnetized biochar (γ-Fe2O3-LSB) was synthesized using Lagenaria siceraria peels which were further magnetized via the co-precipitation method. The synthesized γ-Fe2O3-LSB was characterized using FTIR, X-ray diffraction, Raman, SEM-EDX, BET, and vibrating sample magnetometry (VSM) for the analysis of magnetic properties. γ-Fe2O3-LSB showed a reversible type IV isotherm, which is a primary characteristic of mesoporous materials. γ-Fe2O3-LSB had a specific surface area (SBET = 135.30 m2/g) which is greater than that of LSB (SBET = 11.54 m2/g). γ-Fe2O3-LSB exhibits a saturation magnetization value (Ms) of 3.72emu/g which shows its superparamagnetic nature. The batch adsorption process was performed to analyze the adsorptive removal of MB dye using γ-Fe2O3-LSB. The adsorption efficiency of γ-Fe2O3-LSB for MB was analyzed by varying parameters like the initial concentration of adsorbate (MB), γ-Fe2O3-LSB dose, pH effect, contact time, and temperature. Adsorption isotherm, kinetic, and thermodynamics were also studied after optimizing the protocol. The non-linear Langmuir model fitted the best to explain the adsorption isotherm mechanism and resulting adsorption capacity ( =54.55mg/g). The thermodynamics study showed the spontaneous and endothermic nature, and pseudo-second-order rate kinetics was followed during the adsorption process. Regeneration study showed that γ-Fe2O3-LSB can be used up to four cycles. In laboratory setup, the cost of γ-Fe2O3-LSB synthesis comes out to be 162.75 INR/kg which is low as compared to commercially available adsorbents. The results obtained suggest that magnetic Lagenaria siceraria biochar, which is economical and efficient, can be used as a potential biochar material for industrial applications in the treatment of wastewater.

Preparation of TPPZn/Ag3PO4 Electrospun Fiber Material and Removal of Organic Dyes

Preparation of TPPZn/Ag3PO4 Electrospun Fiber Material and Removal of Organic Dyes

Preparation of novel green adsorbent (Tabernaemontana divaricata leaf powder) and evaluation of its dye (malachite green) removal capacity, mechanism, kinetics, and phytotoxicity

In this study, a novel green adsorbent, Tabernaemontana divaricata leaf powder (TD), was prepared, and its efficacy in removing malachite green (MG) dye from water, along with the associated mechanism and kinetics, was systematically evaluated for the first time. Characterization of TD was carried out using scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). Optimization of MG dye removal was conducted by varying parameters such as pH, initial dye concentration, contact time, and TD dosage. Results demonstrated that TD exhibited a high adsorption capacity for MG dye (5.2131 mg.g−1), achieving a maximum removal efficiency of 89.5 % under optimized conditions: pH 7.0, initial dye concentration of 20 ppm, contact time of 120 min, TD dosage of 4 g/L, and temperature of 28.1 °C. Kinetic and isotherm models were applied to analyze the experimental data, revealing that the adsorption process most accurately followed Ho's pseudo-second-order kinetic model (R2 = 0.999). The high heats of adsorption observed in the isotherm study suggest prominent electrostatic interactions between adsorbate molecules and the surface, governing the chemisorption mechanism that dominates at the solid-liquid interface. This study underscores the potential of Tabernaemontana divaricata (jasmine) leaf powder as a cost-effective, environmentally friendly, and efficient adsorbent for the remediation of MG dye-contaminated water.

Facile synthesis of TiO2@ZnO nanoparticles for enhanced removal of methyl orange and indigo carmine dyes: Adsorption, kinetics

Water pollution represents one of the most important problems affecting the health of living organisms, so it was necessary to work on the formation of active materials to get rid of pollutants. In this study, Titanium dioxide (TiO2) doping Zinc oxide (ZnO) nanocomposites were produced via simple sonication method at 500 Hz in ethanol medium. At different weight concentrations (2.5, 5, 7.5, and 10 %). The morphology, structure configuration, chemical bonding, crystalline phase, and surface properties of obtained nanocomposites were characterized via FESEM, BET, XRD, XPS, RAMAN and FTIR instrumentation. The nanocomposites were employed as an adsorbent to eliminate the methyl orange (MO) and Indigo Carmine (IC) dyes from an aqueous solution. Batch removal experiments revealed that the elimination of MO and IC dyes by the TiZnO surface was pH and doping Ti concentration-dependent, with maximum removal occurring at pH = 7 for MO and pH = 3 for IC contaminants at 10 % doping Ti concentration (Ti (10 %)@ZnO). Langmuir model fit the absorptive removal of MO and IC dyes into the Ti (10 %)@ZnO surface well. The maximal removal capacity of Ti (10 %)@ZnO nanocomposite was found to be 994.24 mg. g−1 for MO and 305.39 mg. g−1 for IC. The Ti (10 %)@ZnO nanocomposite showed remarkable high stability towards the removal of both dyes through consecutive four cycles.