Purification Of Dyes Research Articles

Assessment of a novel aminated magnetic adsorbent with excellent adsorption capacity for dyes and drugs

Dyes and drugs with high toxicity and low biodegradability pose risk to human health and ecological security, and should be purified efficiently from effluents before discharge. Traditional adsorbents are limited by the insufficient active adsorption sites and low stability. In this study, a novel aminated magnetic adsorbent (MCTs) was fabricated via two cross-linking steps using chitosan and triethylenetetramine to fill the gaps between current adsorbent and performance requirements. The morphological and physicochemical characteristics of the as-prepared MCTs were determined and identified with the aid of several characterization techniques. The adsorption performance of dyes and drugs was also investigated and represented by their adsorption capacities. In particular, the adsorption capacities of Congo Red, Chicago Sky Blue, Reactive Brilliant Red, and Ibuprofen were 583.11, 465.01, 403.12, and 291.71 mg/g, respectively. They also remained at around 80% after four reuse cycles. MCTs were adsorbed via a monolayer spontaneous chemical reaction, and hydrogen bonding and electrostatic interaction were the dominant adsorption mechanisms. These results demonstrated that the preparation of MCTs via two cross-linking steps enhanced the adsorbents’ adsorption capacity, reusability, and stability. They provided a new perspective for the preparation of high-efficient adsorbents and the purification of dye- and drug-polluted wastewater.

Biochar supported CuFe layered double hydroxide composite as a sustainable adsorbent for efficient removal of anionic azo dye from water

This study reports the synthesis of date palm waste-derived biochar (B) supported CuFe layered double hydroxides (CuFe LDH) composite by facile co-precipitation method. The adsorption performance of B-CuFe composite was evaluated for the removal of Eriochrome black T (EBT), as a model anionic azo dye, from the aqueous phase. The B-CuFe composites were characterized by FTIR, XRD, TGA, SEM-EDX and BET techniques. Characterization results revealed the synergistic effect of biochar and CuFe LDH has resulted in substantial improvement in physicochemical characteristics (i.e. surface functionality, surface area and surface morphology) of B-CuFe composite, which promotes rapid and improved adsorption of (EBT) from the solution. The B-CuFe composite with 2.5 g loading of biochar onto CuFe LDH - showed better adsorption performance than that of other B-CuFe composites. The adsorption process of EBT onto B-CuFe composite was well described by the RSM models (with R 2 = 0 . 964 – 0 . 999 ). Acidic pH (2–5) and higher temperature favored the adsorption of EBT onto B-CuFe composite, and almost (70–85%) of EBT was removed from the water within the first 15 min. The highest adsorption capacity, 565.32 mg/g of EBT onto B-CuFe composite, was obtained at pH 2.5 and 45 °C. The adsorption mechanism associated with the strong electrostatic and chemical interactions of EBT sulfonated anions (SO 3 − ) with protonated hydroxyl surface groups ( OH 2 + ) of B-CuFe composite. The B-CuFe composite exhibited better EBT removal in the presence of co-existing anions and demonstrated excellent reusability performance (11% reduction) after five successive cycles. The results demonstrated that the B-CuFe composite has a great potential to be employed as a sustainable and cost-effective adsorbent for the purification of dye contaminated water bodies. • Sustainable biochar-CuFe composite was fabricated by the coprecipitation method. • B-CuFe exhibited improved physicochemical properties than pure biochar and CuFe. • B-CuFe removed 85% of Eriochrome black T dye from the water in 15 min. • The maximum adsorption capacity of B-CuFe was 565.32 mg/g at 45 °C. • B-CuFe composite exhibited excellent reusability performance.

In situ biogenic synthesis of CuO nanoparticles over graphene oxide: A potential nanohybrid for water treatment

The development of environmental friendly and benign strategies for the purification of dye polluted water is a growing challenge. To this end, Solanum americanum functionalized copper oxide-graphene oxide (CuOSA/GO) nanohybrid were prepared by an efficient, eco-friendly, and economical green procedure by using Solanum americanum leaf extract as a reducing agent (i.e., for the reduction of metal salt) as well as the stabilizing agent. The formation of CuOSA/GO nanohybrid was confirmed by using various spectroscopic and microscopic techniques. Microsphere shaped clusters of CuOSA were shown to be coated over GO surface confirmed via SEM while the crystallite size of 5.48 nm was calculated from powder x-ray diffraction data., i.e., Methyl blue (MB) (98% ± 6.9 removals in 60 min), Methyl green (MG) (87% ± 6.62 removals in 60 min), Methyl orange (MO) (69% ± 7.02 removal in 60 min), Methyl violet (MV) (63% ± 6.97 removals in 60 min) and Rhodamine B (RB) (36% ± 6.98 removals in 60 min) with apparent rate constants of 0.038, 0.034, 0.019, 0.016 and 0.007 min−1 respectively. The enhanced rate was obtained due to the large surface area provided by the GO and the synergetic effect. The green synthesis approach and photocatalytic efficiency make the CuOSA/GO nanohybrid a promising candidate for the purification of dye polluted water via photocatalytic oxidation method.

Novelties Filtration Theory of Liquid Chromatography-Mass Spectrometry in Volume Nanotube of Cotton Filament of Layers Woven Fabrics

Objectives of the research to present a modern theory of water purification for multiple purposes entitled “a novelties filtration theory of liquid chromatography-mass spectrometry” is an exceedingly sensitive and specific analytical technique in volume layers woven fabrics that can precisely determine the identities and quantities of compounds within volume Nanotube of cotton filament of layers woven fabrics. The problems are that the filters in the local and international markets have increased complications in configuration, installation and cost without reaching the efficiency that humanity hopes. Throw materials and methods the chromatography-mass spectrometry in layers woven fabrics, and throw the nanotube of cotton filament for purification of water dyes and smells. Industry, in which mass spectrometry is a convenient, versatile method for characterization and identification of process throw the Nanotube of cotton filament for purification of water dyes and smells. Results came up with a theme “innovations in textiles”, and also, for characterization of fibers and contaminants of the fabrics. Additive manufacturing in layers woven fabrics, are the processes used to synthesize a volume object under computer control with successive material layers that have been used and highlighted. The conclusions has included chromatography-mass spectrometry drop, physico-chemical, biological, combined physical-biological and chemical-biological treatment processes recently being developed to meet Jet-filtration, the strict discharging limits set by ASTM standards. Some important aspects of both qualitative and quantitative data analysis have been described and the power of using mass profiles to enhance selectivity and sensitivity has been demonstrated.

ЗАСТОСУВАННЯ КИСЛОТНО АКТИВОВАНОГО ЦЕОЛІТУ В ТЕХНОЛОГІЇ ОЧИЩЕННЯ СТІЧНИХ ВОД ВІД БАРВНИКІВ

The work aims to study the process of activation of natural zeolite by inorganic acids, in particular, HNO3and H3PO4to verify their effectiveness when extracting dyes from aqueous media in batch mode.It is proposed to use the method of purification with sorbents modified with mineral acids nitric, hydrochloric, and ortho-phosphate to increase the absorption capacity concerning water-soluble dyes. The analysis of the process of purification and neutralization of dyes in water systems with the help of zeolite of the Sokernyanskoye deposit was carried out experimentally. Chemical activation, which was carried out by the impregnation method, was used to improve the sorption properties. Samples of chemically activated zeolite were obtained. Due toacid activation, Al, K, Na, Ca, Mg, Fe ions are released, which release micro-and mesopores in the sorbent, which increases its porosity and improves sorption properties. The composition of activated natural mineral zeolite with HNO3, HCl, H3PO4acids were characterized. The chemical composition of activated zeolite was determined by X-ray fluorescence.The efficiency of acid-activated zeolite for the extraction of dyes from wastewater was tested. The dependences of the dye extraction process from model solutions using ordinary and acid-activated zeolite have been established. The dye content in the treated wastewater was determined by the photometric method. The kinetic regularities of the dye adsorption process during contact of natural and activated zeolite samples in the time interval every 6 h for 24 h have been established. It was found that the concentration of pollutants varies and depends on the type of acid and has a decisive influence on the obtained chemical properties of the modified samples.It is recommended to use zeolite activated with hydrochloric acid asa natural adsorbent at a dose of 4 g/dm3with a contact time of 24 hours. According to these technological parameters, the dye content in water decreases from 117 mg/dm3to 41 mg/dm3.The obtained results allow to significantly expand the knowledge about the areas of application of natural sorbents in various technological processes.

Activated carbon of Lignite loaded –Al2O3-Cu2O nanocomposite material purification of dye and high power electrochemical applications

The prepared nanocomposite material is one of most interesting and well-technologies. Activated Lignite loaded –Al2O3-Cu2O nanocomposite was synthesized by the self-assembly surfactant based sol–gel method its characterized by the Surface morphological study, Structural characterization; Optical Properties study and surface analysis were discussed. The First application of Prepared nanocomposite phocatalytic activity study were discussed by UV-Light irradiation, Influence of outfitted parameters in [effect of temperature, effect of pH] and reusability of photocatalytic activity for industrial application, photocatalytic oxidation and reduction of COD was inverstigated. The results indicated photodegradation is explained by pseudo-first order kinetics based by Langmuir-Hinshelwood model and electrochemical study of Cyclic Voltammetry (CV) was discussed.

Nanostructured polyethersulfone nanocomposite membranes for dual protein and dye separation: Lower antifouling with lanthanum (III) vanadate nanosheets as a novel nanofiller

A novel polyethersulfone (PES) nanocomposite membrane incorporated with lanthanum vanadate (LaVO3) nanosheets was fabricated based on phase inversion approach. The morphology and the performance of the fabricated nanocomposite membranes were systematically studied by ATR-FTIR, SEM, AFM, porosity, water contact angle, antifouling and rejection measurements. The resulting membranes showed an asymmetric structure with finger-like pores in which the surface roughness declined by adding different dosages of LaVO3 nanosheets. Contact angle measurements proved that the hydrophilicity of the nanocomposite membranes significantly increased. Furthermore, the water flux of the resulting nanocomposite membranes markedly enhanced due to the nanosheets incorporation. Moreover, nanocomposite membranes showed remarkable antifouling properties (flux recovery ratio ~85%) in contrast with the bare PES (flux recovery ratio ~60%). The high retention of Solazol Red SP-3B (~99%) and Bovine serum albumin (BSA) (~99%) as well as the high permeation flux of the fabricated membrane unveiled the multifunctional character of the nanocomposite membrane for purification of dyes and proteins.

Built-in piezoelectric field improved photocatalytic performance of nanoflower-like Bi2WO6 using low-power white LEDs

Photocatalysis technology has been proved to be a potential strategy for removal of organic dyes, however high-power light sources are generally necessary to initiate photocatalytic reaction. In this work, we employed an excellent photocatalyst of Bi2WO6 with visible light harvest and meanwhile an intrinsic ferroelectricity, which realized the efficient degradation of organic dye via the synergetic photopiezocatalysis. Through coupling the illumination by a low-power (9W) LED and the ultrasonic vibration (120W) by an ultrasonic cleaner, the nanoflower-like Bi2WO6 composed of ultrathin nanosheets showed a much more enhanced photopiezocatalysis performance for purification of organic dye than the individual photocatalysis and piezocatalysis. Furthermore, the high mineralization efficiency and the good durability of the Bi2WO6 catalyst were demonstrated. The possible mechanism of photopiezocatalysis was finally proposed, where the ultrasound-induced piezoelectric field in Bi2WO6 drove photo-generated electrons and holes to diffuse along opposite directions, consequently promoting the separation efficiency of charge carriers. This work indicates that the synergetic photopiezocatalysis by coupling irradiation and ultrasonic vibration is a promising strategy to purify organic pollutants in wastewater.

Fe-Rich Aragonite Concretion Applied to Industrial Dye Purification Using Fenton and Photo-Fenton Technologies

For a low cost and efficient oxidation process of industrial textile dye, this investigation described an economic process for the Indigo Carmine (IC) dye degradation from aqueous solution. Our study used a novel natural carbonated concretion catalyst, aragonite, which was collected from the thermal station waste located in El Hamma, Southwestern Tunisia, as an advanced oxidation process. This new studied ferrous sample Fe-rich aragonite (Fe–Ar) was characterized using various techniques, such as X-ray diffraction (XRD), Specific Surface Area (BET) and Infrared Spectroscopy (FTIR). The textural, structural and chemical characterizations confirmed the presence of Aragonite phases with a high amount of iron (almost 30%) on the surface material. The new catalyst activity was evaluated in the oxidation of IC dye in an aqueous solution by Fenton and photo-Fenton process. The test results show that the Fe-rich aragonite exhibited higher photocatalytic oxidation activity at pH 3. In addition, the IC dye could effectively be removed from the aqueous solution by photo-Fenton process in the existence of the used material as catalyst. Based on this work, the importance of this material in the purification of industrial effluents loaded with dyes is confirmed proving that this material can replace a very expensive commercial catalyst materials used in fenton and photo-Fenton technologies.

Microwave-assisted synthesis of carbon powder for rapid dye removal

Adsorption is generally considered a facile way for the water treatment, the importance of which is to be more and more noticeable when it comes to the purification of dyes which are very harmful to human life. At the present work, the mixture of glucose dissolved in water and polyethylene glycol (PEG) was irradiated with microwave to form the stable dispersed carbon particles. Then, NaCl played a key role in precipitating the stable dispersed carbon particles. Having full characterization, the synthesized carbon particles (CPs) was applied to adsorption of two cationic dyes, methyl violet (MV) and cationic blue (CB). The equilibrium and kinetics adsorption of MV and CB onto the CPs were studied. The kinetics investigations indicated that the adsorption rate of both dyes onto the obtained CPs was fast (few seconds). In addition, the studied temperature effect on CB and MV revealed that the adsorption of these dyes is dependent on temperature. Finally, the kinetics studies of mixed cationic and anionic dye solution were followed showing that the prepared CPs adsorb cationic dye selectively.

Development of antifouling nanofiltration membrane with zwitterionic functionalized monomer for efficient dye/salt selective separation

Nanofiltration (NF) membranes offer advantages to address enormous demands for textile water treatment. To meet omnipresent challenges of dye/salt selectively and antifouling performance, an efficient dye desalting and antifouling NF membrane was developed by virtue of zwitterionic functionalized monomer (zwitterionic N,N-Bis(3-aminopropyl)methylamine, ZDNMA). The structures of zwitterionic membranes can be tailored to suit the separation performance and antifouling property. The prepared zwitterionic NF membrane shows superior removal performance of methyl blue and penetration capacity of NaCl due to zwitterion desirable features of accelerating NaCl transportation. Thus, the membrane selectivity factor for NaCl/methyl blue can be as high as 857.0, accompanied by pure water flux of 10.67 L m-2 h-1 bar-1. When dealing with 0.3 g L-1 MYB and 4 g L-1 NaCl mixture solution, a high NaCl removal was achieved in 75.8% with about 8.1% dye loss after dye purification process. Furthermore, the membrane revealed antifouling performance with a 94.9% flux recovery ratio. The zwitterionic NF membrane highlights more exceptional dye desalination performance, which renders a vast potential for practical textile effluent.

Preparation of nanofibrous metal-organic framework filter for rapid adsorption and selective separation of cationic dye from aqueous solution

A nanofibrous metal-organic framework (MOF) filter was successfully fabricated via co-electrospinning of anionic bio-MOF-1 (Zn8(Ad)4(BPDC)6O·2(NH2(CH3)2)+, 8DMF, 11H2O) and polyacrylonitrile (PAN) for adsorption and selective separation of cationic dyes from aqueous solution. Characterization with FT-IR, EDS and PXRD confirmed that bio-MOF-1 crystals were effectively encapsulated into PAN nanofibrous matrix and their crystallinity maintained well. Due to the free NH2 (CH3)2+ cations in the channel of bio-MOF-1 and nucleophilic group CN in PAN, both bio-MOF-1 crystals and PAN nanofibers were only capable of adsorbing cationic dyes and could not adsorb neutral and anionic dyes. Benefiting from the synergistic effect of bio-MOF-1 and PAN, the bio-MOF/PAN filter exhibited rapid adsorption rate towards positively charged dye methylene blue (MB+), and realized the fast selective separation of MB+ from mixed dyes solution. More importantly, the bio-MOF/PAN filter can be effectively regenerated through ion-exchange process. The adsorption capacities of the filter towards MB+ kept relatively stable values within the five cycles of filtration-regeneration, indicating that bio-MOF/PAN filter can meet the requirement of long service life. This work may provide a new insight into the development of electrospun MOF nanofibrous membrane as a filter for rapid separation and purification of organic dyes from practical wastewater.

Sustainable scientific advancements modified Ag2O-ZnO thin films characterization and application of photocatalytic purification of carcinogenic dye in deionizer water and contaminated sea water solutions and synthetic, natural based dye-sensitized solar cells

The manuscript studied the preparation of ZnO as well as Ag2O-ZnO thin films deposited on glass substrates by spray pyrolysis approach at 500 °C. The photocatalytic activity of Ag2O-ZnO nanocomposite material was studied via the Photodegradation reaction of Rhodamine B (Rh B) dye under UV-light irradiation in Deionizer water which shows high activity as compared by Contamination of sea water. The Zinc was Zincacetylacetonate (ZnC10H14O5) at the atomic concentration and then dissolved in the ethanol and Ag NO3 (0.1 M) dissolved in ethanol. The effect of silver Oxide-Zinc Oxide Nanocomposite material on the structural, surface morphological, electrical and optical properties of Ag2O-ZnO thin films were studied. HR-SEM and HR-TEM image shows exposed that the surface morphology of the films nanoflower shaped structure. The presence of Silver, Zinc and Oxygen are confirmed the presence of peaks, using EDS analysis. X-ray diffraction (XRD) patterns accepted the successful growth of high quality thin films which is polycrystalline nature. The PL analysis shows in Ag2O-ZnO is certified to the low recombination of electron-hole pairs by transfer of electrons and holes between ZnO and UV–Vis DRS analysis. The photocatalytic activity of Ag2O-ZnO nanocomposite material was studied from Photodegradation study of Rhodamine B (Rh B) dye under UV-light irradiation of Deionizer water was high activity that Contamination of sea water. As a reaction of this the material was found to be stable and reusable, which extends to a high antibacterial activity and the electrochemical study from synthetic based and Natural based.DSSCS analysis showed increased current is short circuit by Ag2O-ZnO thin film nanocomposite material was industrial applications.

A low-cost and eco-friendly biosorbent material for effective synthetic dye removal from aquatic environment: characterization, optimization, kinetic, isotherm and thermodynamic studies

A novel biosorbent was prepared by the surface modification of Zostera marina L. bioresidues and used for the removal of model synthetic dye, methylene blue from aqueous medium in this study. Taguchi design of experiment (DoE) methodology was employed to investigate the influence of significant operational parameters (reaction time, pH of medium and dye concentration) on the biosorption process and to develop a mathematical model for the estimation of biosorption potential of biosorbent. The percentage contribution of each of these process variables on the dye biosorption was found to be 9.03%, 1.95% and 88.84%, respectively. The dye biosorption capacity under the obtained optimum environmental conditions (reaction time of 120 min, pH of 8 and dye concentration of 15 mg L−1) was estimated to be 140.154 mg g−1 (R2: 99.83). This value was very close to the experimentally obtained dye removal performance value (140.299 mg g−1). These findings indicated the high ability of Taguchi DoE technique in the optimization and simulation of dye biosorption system. The kinetic and equilibrium modeling studies showed that the pseudo-second-order and Langmuir models were the best models for the elucidation of dye removal behavior of biosorbent. Besides, the performance of dye decontamination system was evaluated using the pseudo-second-order kinetic parameters. The thermodynamic analyses displayed that the dye biosorption was a feasible, spontaneous and exothermic process. For large scale dye purification applications, a single-stage batch biosorption system was also designed using the mathematical modeling data. All these results revealed that Z. marina L. bioresidues could be used as a promising alternative biosorbent material for the effective and eco-friendly dye biosorption systems.

Impact of solvents on the extraction and purification of vegetable dyes onto the efficiency for dye-sensitized solar cells

Eight vegetable dyes extracted from flowers, fruits and leaves abundant in the wide biodiversity of the Andes region of South America were extracted with ethanol without purification to explore as vegetable photosensitizers in dye-sensitized solar cells (DSSCs). The absorbance spectra were measured by UV–visible spectroscopy and the photoelectrical performance of the DSSCs based on these dyes with a homemade solar simulator, constructed only for educational purposes under 1 sun of illumination. The open-circuit voltages (Voc) and the short-circuit photocurrent densities (Jsc) varied from 0.39 to 0.48 V and from 0.04 to 0.56 mA cm−2, and the power conversion efficiency (PCE) ranged from 0.01 to 0.18%. Particularly, the highest Voc and PCE values of the DSSCs sensitized by the ethanol extracts of Mortiño fruit (Vaccinium floribundum) and Jamaica flowers (Hibiscus sabdariffa) without purification were presumably associated with anthocyanin, the most effective component present in both vegetable photosensitizers. Hence, various components of the ethanol extracts obtained from these two vegetable dyes were purified by liquid–liquid extraction using different organic solvents of different polarity, namely petroleum ether, chloroform, ethyl acetate, n-butanol, and distilled water. Ethyl acetate resulted as the most favorable solvent for purification of ethanol extracts from Mortiño fruit and Jamaica flowers to use as vegetable photosensitizers in DSSCs. The PCE of the DSSC fabricated with the dye extracted in ethyl acetate from Mortiño fruit achieved 0.33%, with Voc of 0.520 V and Jsc of 1.014 mA cm−2, whereas the corresponding values obtained from the dye extracted from Jamaica flowers reached 0.22% with Voc of 0.541 V and Jsc of 0.678 mA cm−2. Thus, the purification of vegetable dyes used as photosensitizer impacts the photoelectrochemical performance of DSSCs.

Preparation of stable and superior flux GO/LDH/PDA‐based nanofiltration membranes through electrostatic self‐assembly for dye purification

Graphene oxide (GO) has triggered significant attention as a new type of self‐assembly membrane material. However, the low filtration flux and unstable performance of GO membrane limit its practical application. Hence, in this work, layered double hydroxides (LDHs), as a 2D material with double‐layer channel structure and positive electricity, were self‐assembled with GO at weight ratio of 7:3 by electrostatic interaction. Then, the GO/LDH hybrids combined with polydopamine (PDA) to obtain stable and high‐flux GO‐based membranes through vacuum filtration and the structure and morphology of as‐prepared samples were characterized by FT‐IR, XRD, XPS, and SEM. Furthermore, the separation performance and surface electronegativity of membranes were tested via pure water flux, rejection efficiency, recycle experiments, and zeta potential. Results revealed that the stability and flux of composite membrane were enhanced significantly compared with neat GO‐based membrane. Further, the dye rejection rate of methylene blue (MB) is higher than Congo red (CR) and rhodamine B (Rh B) and reached to 99.8%.

WITHDRAWN: A combinatorial bioinnovative approach integrating synthetic dye bioremediation and bioenergy production using waste pepper seed biomass

A combinatorial study integrating synthetic dye bioremediation and biodiesel production using discarded pepper seed biomass was performed for a cleaner and more sustainable environment/energy in the present work. The vegetal oil was extracted from the pepper seed biomass and the defatted residual biomass was mainly investigated as a sustainable green generation alternative biosorbent source for the treatment of colored aqueous effluents. To test the wastewater cleaning ability of biosorbent, basic red 46 was selected as a common harmful model synthetic dye. The kinetic, equilibrium and thermodynamic modeling studies were performed to elucidate the dye biosorption behavior of biosorbent. Besides, the performance of dye bioremediation system was evaluated using the kinetic modeling parameters, and for large scale dye purification applications, a single-stage batch bioreactor system was designed using the mathematical modeling data. The operating conditions significantly affected the biosorption process. The pseudo-second-order and Freundlich models provided the best fit to the kinetic and isotherm data, respectively. The thermodynamic studies showed that the dye biosorption was a feasible and spontaneous process. The maximum dye biosorption capacity of biosorbent based on Langmuir model was predicted as 82.019 mg g-1. As compared many other biosorbents reported in literature for the same contaminant, this high value revealed a great potential of biosorbent for the dye removal from aqueous medium. Thus, the present study showed that the discarded pepper seed biomass could be employed as a highly efficient as well as cost-effective material for both dye bioremediation and biodiesel production in a sustainable manner.

Fabrication of phosphonium bamboo cellulose by triphenylphosphine: preparation, characterization, and adsorption of Acid Black 24.

Cellulose from bamboo shavings (BC) separated and modified by grafting triphenylphosphine, which was used as an adsorbent for the removal of Acid Black 24 from aqueous solution. The quaternary phosphonium-based bamboo cellulose (PBC) was characterized by FTIR and SEM measurements. The FTIR studies showed that the quaternary phosphonium group was successfully grafted onto the BC molecular structure. The effects of PBC dosage, contact time, initial dye concentration, temperature, and pH on the adsorption performance were studied. The nonlinear fitting kinetics and isotherms models were also conducted. The pseudo-second-order, intra-particle diffusion and Langmuir models were more suitable for analyzing the adsorption behavior of PBC for Acid Black 24 dye. The adsorption activation energy was lower than 40kJmol-1, and the ΔH0 value was in the range of 20~80kJmol-1, indicating that PBC played a dominant role in the physical purification of dye. The results of thermodynamic analysis indicated that the adsorption was a spontaneous endothermic purification process. Adsorbents had a good reusability and high adsorption performance for dye removal. The adsorbents PBC had a good reusability and could effectively remove residual Acid Black 24 dye with good development prospects in the field of biomass adsorbent materials.

Efficient removal of Pb(II), Cr(VI) and organic dyes by polydopamine modified chitosan aerogels

Chitosan is highly suitable for removing metal ions and dyes from water; however, the sorption performance, stability and recycling are still critical issues in practical applications. Herein, polydopamine-modified-chitosan (CS-PDA) aerogels were synthesized through dopamine self-polymerization and glutaraldehyde cross-linking reactions to enhance the adsorption capacity and acid resistance of chitosan. The self-polymerization of dopamine and gelation of chitosan were accomplished simultaneously, simplifying the synthesis process of CS-PDA aerogels, which is meaningful for the popularization and industrial application of adsorbent. CS-PDA exhibited superior adsorption performances in the removal of Cr(VI), Pb(II) and organic dyes. Adsorption isotherms and kinetic data were well fitted by Langmuir and pseudo-second-order kinetic models. The maximum adsorption capacities of CS-PDA for Cr(VI) and Pb(II) were 374.4 and 441.2 mg g−1, respectively. After eight cycles, adsorption capacity of CS-PDA showed no obvious decline. These superiorities make CS-PDA a promising multifunctional adsorbent for the purification of metal ions and dyes.

Synthesis and Characterization of Silver Coated Multi Walled Carbon Nanotubes for Dye Degradation in Textile Waste Water

The most important challenge across the globe in recent years is to meet the sufficient supply of drinking water and to reduce water pollution, one of the major problems is the waste water from the textile industry and the purification of dye based water is a challenge for many years. In this paper we report dye degradation in textile waste water using Ag coated MWCNTs. Multi walled carbon nanotubes were synthesized using chemical vapor deposition method, using powder catalyst and the coating of Silver in MWCNTs was done by wet chemical method. Three Different silver concentrations were taken for coating the MWCNT. These Ag coated Multiwall carbon nanotubes were characterized by X-ray Diffraction, Field Emission Scanning Electron Microscopy (FESEM) and UV spectroscopy, Field Emission Scanning Electron Microscopy (FESEM) was used to study the morphology of the sample and Energy dispersive X-ray analysis (EDAX) characterization was done to study the chemical composition. The multiwalled carbon nanotubes act like a absorbent which helps in dye degradation and silver has antibacterial properties which help in removing the bacteria and viruses in water. The adsorption was tested for three different samples of Ag coated MWCNT’s using photocatalytic study. The UV intensity peaks showing the observable shift in intensity. Adsorption column test was done, using the Ag coated MWCNTs, using dye based water appears clear after the test.