Effective Removal Of Dyes Research Articles

Recyclable Copper -Decorated Magnetic Composites As Non-Precious Catalysts for Effective Removal of 4-Nitrophenol and Azo Dyes

Recyclable Copper -Decorated Magnetic Composites As Non-Precious Catalysts for Effective Removal of 4-Nitrophenol and Azo Dyes

Determination of Concentration of Various Phases in Activated and Dye Treated Sewage Sludge Samples using Synchrotron X-Ray Diffraction

Sludge sample collected from sewage treatment plant was used to develop an effective adsorbent for the removal of various dyes from wastewater. A quantitative estimation of major compounds in without activated (as collected), activated and various dyes treated sludge samples using synchrotron XRD technique is reported. Sewage sludge sample activated at 900 ºC for 30 min was found to have maximum adsorption efficiency (~ 95%) for the removal of different dyes (e.g. brilliant green, crystal violet and malachite green) from aqueous solution. The result shows that the adsorption using activated sewage sludge is the simplest and effective method for the removal of dyes from wastewater. As expected, the major compound in all the samples is SiO2 (~ 50 mol%). However, SiO2 was found in three different space groups. On activation at 900 ºC, a part of monoclinic SiO2 phase changes to the hexagonal phase. On the other hand, on various dyes adsorption such as brilliant green, crystal violet and malachite green, the monoclinic phase changes to the tetragonal phase.

Effective removal of industrial dye from aqueous solution using mesoporous nickel oxide: a complete batch system evaluation

Effective removal of industrial dye from aqueous solution using mesoporous nickel oxide: a complete batch system evaluation

Conversion of Waste Face Mask into Super Adsorbent by Polydopamine Assisted Coating for Effective Co2 Capture and Multiple Dye Removal

Conversion of Waste Face Mask into Super Adsorbent by Polydopamine Assisted Coating for Effective Co2 Capture and Multiple Dye Removal

Optimizing graphene oxide membranes for effective removal of dyes by modulating the reduction degree and doped nitrogen.

The excellent mechanical and chemical characteristics of graphene oxide (GO) enable their potential application in the realm of membrane separation. However, the expansion and instability of GO nanosheets in water limit its application. In this work, nitrogen-doped GO (NGO) was obtained by a harmless hydrothermal reduction method. The obtained NGO films were attached to a polyvinylidene fluoride support membrane by vacuum filtration. By changing the hydrothermal reaction temperature, the reduction degree of GO and doping amount of nitrogen was adjusted to control the inter-layer structure and permeability of NGO. The defect of NGO nanosheets and the reduction of oxygen-containing functional groups could accelerate the transportation of water molecules through the inter-layer space of the hydrophobic graphene sheets. Significantly, the polarization and high adsorption energy of pyridine-N serve as a supplement to the exclusion mechanism of the inter-layer spacing. NGO membranes have better permeability than the initial GO membranes without sacrificing the rejection rate. The optimized NGO film has a significant rejection rate of above 99% for various dyes, such as methylene blue, Congo red and methyl blue.

Recent Literature Review of Significance of Polypyrrole and Its Biocomposites in Adsorption of Dyes from Aqueous Solution

The usage of dyes has been tremendously augmented due to industrialization and human’s intrinsic fascination with colors. Owing to their excessive usage in industries like textiles, food, cosmetics, paints, printing etc., it is indisputably a contributing factor in aquatic pollution. Dyes effluents have emerged as a burgeoning challenge. Owing to issues such as toxicity, mutagenicity, and disturbed photosynthesis associated with dye contamination, it is crucial to look for an explication to deal with this challenge. Polypyrrole-based biocomposites have been reported as good adsorbents for textile wastewater treatment. In the last decade, numerous studies have stated the effective removal of dyes via Polypyrrole-based biocomposites. This review concentrates on the implication of different Polypyrrole-based biocomposites for decontamination of dyes and synthesis methods, characteristics, and mechanism of dyes degradation by these biocomposites from wastewater.

Effective Removal of Acid Dye in Synthetic and Silk Dyeing Effluent: Isotherm and Kinetic Studies.

Here, we propose a low-cost, sustainable, and viable adsorbent (pine tree-derived biochar) to remove acid dyes such as acid violet 17 (AV), which is used in the silk dyeing industry. As a case study, the AV removal process was demonstrated using synthetic effluent and further as a proof of concept using real dye effluent produced from the Sirumugai textile unit in India. The pine tree-derived biochar was selected for removal of aqueous AV dye in batch and fixed-bed column studies. The adsorbent material was characterized for crystallinity (XRD), surface area (BET), surface morphology and elemental compositions (SEM–EDX), thermal stability (TGA), weight loss (DGA), and functional groups (FTIR). Batch sorption studies were performed to evaluate (i) adsorption at various pH values (at pH 2 to 7), (ii) isotherms (at 10, 25, and 35 °C) to assess the temperature effect on the sorption efficiency, and (iii) kinetics to reveal the effect of time, adsorbent dose, and initial concentration on the reaction rate. After systematic evaluation, 2 g/L biochar, 25 mg/L AV, pH 3, 40 °C, and 40 and 360 min in a completely mixed batch study resulted in 50 and 90% dye removal, respectively. The isoelectric point at pH 3.7 ± 0.2 results in maximum dye removal, therefore suggesting that monitoring the ratio of different effluent (acid/wash/dye) can improve the colorant removal efficiency. The Langmuir isotherm best fits with the sorption of AV to biochar, provided a maximal dye uptake of 29 mg/g at 40 °C, showing that adsorption was endothermic. Fixed-bed studies were conducted at room temperature with an initial dye concentration of 25 and 50 mg/L. The glass columns were packed with biochar (bed depth 20 cm, pore volume = 14 mL) at an initial pH of 5.0 and a 10 mL/min flow rate for 120 min. Finally, the regeneration of the adsorbent was achieved using desorption studies conducted under the proposed experimental conditions resulted in 90–93% removal of AV even after five cycles of regeneration.

Preparation and Characterization of a Novel Activated Carbon@Polyindole Composite for the Effective Removal of Ionic Dye from Water.

The present study is aimed at the synthesis and exploring the efficiency of a novel activated carbon incorporated polyindole (AC@PIN) composite for adsorptive removal of Malachite Green (MG) dye from aqueous solution. An AC@PIN hybrid material was prepared by in situ chemical oxidative polymerization. The physico-chemical characteristics of the AC@PIN composite were assessed using Fourier-transform infrared spectrometer, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, ultraviolet visible spectroscopy, and determination of point of zero charge (pHPZC). A series of adsorption studies was conducted to evaluate the influence of operational parameters such as pH, contact time, initial dye concentration, AC@PIN dosage, and temperature on dye adsorption behavior of developed composite. A maximum dye removal percentage (97.3%) was achieved at the pH = 10, AC@PIN dosage = 6.0 mg, initial dye concentration 150 mg L−1, and temperature = 20 °C. The kinetic studies demonstrated that the adsorption of MG on AC@PIN followed pseudo-second-order model (R2 ≥ 0.99). Meanwhile, Langmuir isotherm model was founded to be the best isotherm model to describe the adsorption process. Finally, the recyclability test revealed that the composite exhibits good recycle efficiency and is stable after 5 cycles. The obtained results suggest that AC@PIN composite could be a potential candidate for the removal of MG from wastewater.

Effective removal of metal ions and cationic dyes from aqueous solution using different hydrazine–dopamine modified sodium alginate

In this paper, DSA-AAD-DA and DSA-TPDH-DA were prepared to effectively remove metal ions and cationic dyes from aqueous solution. The hydrazone structure was prepared by hydrazide-modified SA which captured metal ions selectively, and the remaining functional groups were used as active adsorption sites for cationic dyes. The thermodynamic parameter for the sorption demonstrated the process is endothermic and spontaneous. In single process, the adsorption of metal ions by DSA-AAD-DA and DSA-TPDH-DA correlated well with the Freundlich model through the hydrazone structure coordination and ion exchange which was mainly chemical adsorption, and cationic dyes adsorption correlated well with the Langmuir model which was shown monolayer adsorption was dominant by hydrogen bonding, electrostatic interaction, and π-π interaction. In binary system, the mixed adsorption shown significant antagonism effect in high concentration, but cationic dyes and metal ions in low concentration were efficiently and simultaneously removed, the adsorption ability of DSA-TPDH-DA was much better than DSA-AAD-DA. Moreover, adsorption efficiency can still maintain more than 80% after five times adsorption-desorption recycle. Therefore, DSA-AAD-DA and DSA-TPDH-DA possessed great potential for wastewater treatment.

Improved visible light photocatalytic degradation of yttrium doped NiMgAl layered triple hydroxides for the effective removal of methylene blue dye

Fabrication of layered triple hydroxides (LTH) is a typical and remarkable approach to produce new functionalities passionately investigated for photocatalytic removal of organic pollutants from industrial wastewater. The hydrothermal method was used to prepare different weight percentages of yttrium (Y) doped NiMgAl LTH. The structural, functional, optical, and morphological properties of the prepared samples were investigated using X-ray diffraction, Fourier transformed-infrared spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, and scanning electron microscopy. The photocatalytic degradation of the different percentages of Y-doped LTH samples were assessed through the photocatalytic degradation of methylene blue dye under the visible light irradiation. When compared to other lower concentrations of Y doping, the photocatalytic degradation efficiency of 1 wt.% Y-doped LTH was higher. Thus, the optimized LTH's improved photocatalytic performance was attributed to increased visible light absorption with low transmission and improved electron-hole separation.

Ag nanoparticles anchored on NiO octahedrons (Ag/NiO composite): An efficient catalyst for reduction of nitro substituted phenols and colouring dyes

The development of an efficient sustainable catalyst for effective removal of hazardous chemicals, viz. nitrophenols and organic dyes, from wastewater is a challenging task. Herein, facile synthesis of Ag/NiO composites by anchoring Ag nanoparticles (NPs) on NiO octahedrons with different amounts of Ag NPs (AN-5% (5% Ag), AN-10% (10% Ag) and AN-15% (15% Ag)) has been demonstrated. SEM (scanning electron microscopic) and TEM (transmission electron spectroscopic) images ensured the proper anchoring of spherical Ag NPs (particle size = 16.54 ± 1.88 nm) on octahedron particles of NiO, which was also ensured by XPS (X-ray photoelectron spectroscopy) analysis. Moreover, the resulting composites have an average surface area (49–52 m2g‒1) and pore size (2.39–2.26 nm). All three synthesized Ag/NiO composites (100 μL) catalyzed the complete reduction of para-np (4-nitrophenol: 0.1587 mM) within 2–3 min in the presence of 0.04 M NaBH4. Among them, AN-5% has been chosen because of the lowest anchored Ag (5%) to obtain the optimized catalyst's amount (50 μL) and concentration of para-np (0.1587 mM). AN-5% also exhibited excellent catalytic activity towards different nitro substituted phenols, viz. ortho-np (2-nitrophenol), meta-np (3-nitrophenol), para-np (4-nitrophenol) and tri-np (2,4,6-trinitrophenol). AN-5% displayed ∼100% catalytic efficiency for reducing meta-np in 2 min with the apparent first order rate constant (kapp) and normalized rate constant (Knor) as 1.99 s−1 and 398.14 s−1 g−1, respectively. Additionally, AN-5% (29.41 μg mL−1) reduced >95% of the colouring dyes (10 ppm) such as CONG-R (congo red: 95% in 6 min), METH-O (methyl orange: 97.5% in 7 min), METH-B (methylene blue: 98.3% in 10 min) and RHOD-B (rhodamine B: 99.2% in 5 min). AN-5% not only demonstrated catalytic reduction towards individual pollutants, but also showed excellent activity for reduction of the mixtures of nitrophenols/dyes and for treatment of simulated industrial effluent samples (EFF1, EFF2) and a real industrial sample (textile dye-bath effluent). AN-5% can also be reused up to several cycles with almost same efficiency and followed the Langmuir-Hinshelwood apparent first order kinetics model.

Fast decolorization of rhodamine-B dye using novel V2O5-rGO photocatalyst under solar irradiation

Degradation of dyes through Metal-oxide semiconductors using Advanced Oxidation Process (AOP) presents a unique opportunity for the development of advanced treatment techniques for effective removal of dyes from industrial wastewater. In this paper, an experimental study is being carried out by synthesizing the vanadium pentoxide–reduced graphene oxide (V2O5-rGO) nanocomposite for effective dye-degradation through photocatalysis under solar irradiation. V2O5-rGO nanocomposite is obtained by using an easy and efficient procedure of V2O5 nanowire in an rGO solution. V2O5 nanowires when bonded to rGO sheets (2D), serves as an excellent catalyst for the degradation of Rhodamine-B (RhB) dye. V2O5-rGO nanocomposites has been characterized using FESEM (Field Emission Scanning Electron Microscope), XRD (X-Ray Diffraction), and FTIR (Fourier Transform Infrared spectroscopy) techniques. V2O5-rGO is primarily used as a photocatalyst which utilizes sunlight for degradation of aqueous Rhodamine-B (RhB) dye through the principle of photoreaction. The nanocomposite shows ̴ 97% dye removal efficiency of RhB (20 mg/L) solution for a short processing time of 50 min. The study shows an increased generation of hydroxyl radicals (∙OH) in the presence of rGO sheets in the catalyst, which supports the photocatalytic process through suppression of electron (e-) and hole (h+) recombination causing the degradation of RhB dyes. Adding rGO shows ~84% faster decolorization in comparison to pure V2O5. The catalyst efficacy is further evaluated through varying pH of the RhB solution medium. A pH dependency of the reaction rate is observed with the fastest degradation time in the presence of V2O5-rGO nanocomposite being achieved at a pH of 9. Reusable catalytic properties for the suspended V2O5-rGO nanocomposite are studied for 6 cycles and the degradation efficiency of more than 90% is observed in 50 min. A brief study is performed to determine the decreased photocatalytic performance, which is fully reverted using simple chemical treatment by H2O2 and UV irradiation for further usage of the photocatalyst.

Highly enhanced dye adsorption of MoO3 nanoplates fabricated by hydrothermal-calcination approach in presence of chitosan and thiourea

Water pollution by organic dyes poses great challenge to the environment and living organism. Hence effective removal of organic dyes by cost effective methods have received significant attention in recent years. Herein, we report the complete removal of organic dyes (rhodamine B), methylene blue) and eosin yellow) from water via effective adsorption by MoO3 catalyst. Hydrothermally synthesised MoO2 (1) and amorphous MoSx (2) using ammonium molybdate without and with thiourea exhibited low dye adsorption. In contrast, crystalline micro/nanoplates of MoO3 (3 and 4) obtained from calcination of 1 and 2 showed highly enhanced dye adsorption. Particularly 4 showed higher dye adsorption compared to 3. UV–Visible absorption studies confirmed complete removal of organic dyes upon stirring with MoO3 catalyst. Dye removal studies further revealed that cationic dyes are adsorbed faster than anionic dye that could be attributed to the surface charge of MoO3. Interestingly, the adsorbed dyes were not released from MoO3 for more than 50 days. The exhausted MoO3 catalyst can be recovered by annealing at 400 °C. MoO3 catalyst has also been used as packing materials in dropper column and demonstrated effective removal of dyes by passing through dyes separately as well as mixture.

Wastewater treatment containing methylene blue dye as pollutant using adsorption by chitosan lignin membrane: Development of membrane, characterization and kinetics of adsorption

An influential subject of research is the use of lignin for effective removal of hazardous dyes from wastewater effluents utilizing green techniques. Lignin makes up to 10–25% of lignocellulosic biomass. In this study, a solvent evaporation approach was employed to construct a novel chitosan lignin membrane, which was then used to remove the methylene blue (MB) dye from water. The physicochemical, thermal, and morphological attributes were characterized by SEM, XRD, FTIR ATR, and TGA DSC. With higher lignin content in the membrane, its tensile strength was reduced. The dye was removed 95% of the time by the membrane, and the adsorption followed the Langmuir isotherm. The membranes could be recycled up to five times.

Effective removal of cationic dyes in water by polyacrylonitrile/silica aerogel/modified antibacterial starch particles/zinc oxide beaded fibers prepared by electrospinning

In this study, potassium persulfate, N,N′-methylene bisacrylamide (MBA), and soluble starch (ST) were in situ cross-linked into porous antimicrobial starch particles containing N-halamine functional groups (PST–MBA–Cl). Then, polyacrylonitrile (PAN)/silica aerogel (SA)/zinc oxide (ZnO) beaded fibers containing PST–MBA–Cl particles were prepared by electrospinning. Scanning electron microscopy results demonstrated the uniform dispersion of the PST–MBA–Cl particles and ZnO on the surface and interior of the beaded fiber when the concentration of the PST–MBA–Cl particles was 15%. The composite beaded fibers prepared after chlorination and soaking in zinc salt solutions of different pH values had a higher degree of interior fluffiness. For the analysis of the effectivity of the prepared particles using 108 CFU/mL gram-positive (S. aureus) and gram-negative (E. coli) bacterial human pathogens, the inhibition zone was 15.97 ± 0.12 and 17.81 ± 0.23 mm, respectively. Meanwhile, the degradation efficiency of PAN and SA for the cationic dye methylene blue (MB) was 88.00% ± 1.83%. The PAN/SA/PST–MBA–Cl/ZnO composite beaded fiber showed good antibacterial properties and a fast recovery rate, and its degradation efficiency for MB was retained at ~ 80% after five cycles. Thus, the PAN/SA/ PST–MBA–Cl/ZnO beaded fibers can be used as an environment-friendly and reusable adsorbing material for the removal of dyes from industrial wastewater.

Functionalized polymethyl methacrylate-modified dialdehyde guar gum containing hydrazide groups for effective removal and enrichment of dyes, ion, and oil/water separation

In the study, a novel polymethacryloyl hydrazone modified guar gum adsorption material (GSA) was prepared via condensation between polyhydrazide and dialdehyde guar gum. GSA exhibited an abundant porous structure, higher selectivity for cationic pollutants in high-concentration wastewater like methylene blue (MB), malachite green (MG) dyes, and Cu2+. Under optimized experimental conditions, the maximum equilibrium adsorption capacity of MB, MG, and Cu2+ were 1418.36 mg/g, 1375.58 mg/g, and 196 mg/g, respectively. Adsorption isotherms and kinetics were well fitted with the Langmuir isotherm model and pseudo-second-order kinetic model. The thermodynamic analysis demonstrated that the adsorption process was endothermic, feasible, and spontaneous. Correspondently, the adsorption mechanism was explored by FTIR, SEM-EDS and XPS. The adsorbent was employed in disposing of local sewage water. Additionally, GSA successfully achieves efficient water/oil separation in different salt concentrations with a separation efficiency exceeding 99%.

Development of a Novel Adsorbent Prepared from Dredging Sediment for Effective Removal of Dye in Aqueous Solutions

This study proposed a novel and low-cost adsorbent prepared from dredging sediment (DSD) for effective removal of dye in aqueous solutions. The adsorption efficiency and behavior of the DSD adsorbent toward the crystal violet (CV), a cationic dye, were investigated via batch experiments. The results showed that DSD samples contain mainly clay minerals (illite and kaolinite) and other mineral phases. In addition, DSD is a mesoporous material (Vmesopore = 94.4%), and it exhibits a relatively high surface area (~39.1 m2/g). Adsorption experiments showed that the solution’s pH slightly affects the adsorption process, and a pH of 11 gave a maximum capacity of 27.2 mg/g. The kinetic data of CV dye adsorption is well described by the pseudo–second-order and the Avrami models. The Langmuir and Liu isotherm models provide the best fit for the adsorption equilibrium data. The monolayer adsorption capacity of Langmuir reached 183.6, 198.0, and 243.6 mg/g at 293, 308, and 323 K, respectively. It was also found that the adsorption process was spontaneous (−ΔG°), exothermic (−∆H°), and increased the randomness (+∆S°) during the adsorption operation. The primary mechanisms in CV dye adsorption were ion exchange and pore filling, whereas electrostatic attraction was a minor contribution. In addition, three steps involving intraparticle diffusion occur at the same time to control the adsorption process. The results of this study highlight the excellent efficiency of DSD material as an ecofriendly sorbent for toxic dyes from water media.

Double Network Gelatin/Chitosan Hydrogel Effective Removal of Dyes from Aqueous Solutions

Double Network Gelatin/Chitosan Hydrogel Effective Removal of Dyes from Aqueous Solutions

Chitosan-Terephthalic Acid-Magnetic Composite Beads for Effective Removal of the Acid Blue Dye from Aqueous Solutions: Kinetics, Isotherm, and Statistical Modeling.

A terephthalic acid-modified chitosan–magnetic nanocomposite (Cs–Tp@Fe3O4) was synthesized and characterized. The synthesized Cs–Tp@Fe3O4 was used in a batch process for the adsorptive removal of the acid blue 25 (AB-25) dye in aqueous solutions. The kinetic data were subjected to the pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion models, while the equilibrium data were evaluated with the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models. The effects of the initial dye concentration, contact time, and adsorbent dosage, as well as their interactions, on the removal efficiency were investigated using the design of experiments based on a central composite design, and the resultant data were modeled with the response surface methodology (RSM), artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS), and multiple linear regression (MLR) approaches. The adsorption process followed pseudo-first-order with good agreement between the experimental Qe(exp) and calculated Qe(cal.) amounts of dye adsorbed, as well as the values of correlation coefficient, R2 (0.999) and percentage of sum square error, % SSE (0.640). All the investigated adsorption isotherms fitted all models well in the order of Dubinin–Radushkevich > Langmuir > Freundlich > Temkin with R2 > 0.9 with the monolayer maximum adsorption capacity of 440.24 mg/g obtained from the Langmuir isotherm. The RSM model predicted the maximum removal efficiency at an optimum initial dye concentration of 19.11 mg/L, a contact time of 95.3 min, and an adsorbent dosage of 0.18 g. Statistically, the models were fitted in the order of RSM > ANN > ANFIS > MLR. These results indicated that the prepared Cs–Tp@Fe3O4 is an efficient adsorbent for the AB-25 dye removal with excellent stability for water treatment applications.

Triple-functional lignocellulose/chitosan/Ag@TiO2 nanocomposite membrane for simultaneous sterilization, oil/water emulsion separation, and organic pollutant removal

As the significant differences in physicochemical properties, it is extremely difficult to deal with the complex polluted water containing multiple pollutants by the one-step procedure. High-performance functional materials capable of simultaneously killing bacteria, separating oil from water and removing emitted organic dyes are critically demanded for wastewater purification. Herein, we focused on the design and preparation of triple-functional lignocellulose/chitosan/Ag@TiO2 nanocomposite membrane for the disposal of complex wastewater bearing oil contaminations, synthetic organic dyes and biological contaminants. Owing to their special wetting properties, the as-prepared composite membranes can selectively separate water from oily emulsion wastewater with a high efficiency (∼ 98.5%). Moreover, benefiting from the catalytic and antibacterial activities of Ag@TiO2 NPs compounded with lignocellulosic nanofibrils (CNF) and chitosan (CS), the CNF/CS/Ag@TiO2 nanocomposite membrane effectively removed the MB and killed the E. coli, B. subtilis and S. aureus from the water during the treatment. Specifically, the membrane always showed the high MB degradation efficiency no matter under UV light (96.25%) or under visible light (96.33%); the antibacterial efficiencies of the membrane were 99.97%, 99.98% and 99.98% towards E. coli, S. aureus and B. subtilis, respectively. Such triple-functional nanocomposite membranes capable of effective removal of bacteria, insoluble oils and organic dyes from water offer a promising solution for the complex polluted-water purification.