Adsorption Of Dyestuffs Research Articles

Enhanced catalytic reductive hydrogenation of an organic dye by Ag decorated graphitic carbon nitride modified MCM-41.

Utilization of efficient, stable and reusable catalysts for wastewater treatment and catalytic elimination of toxic pollutants is a challenge among researchers. This present work shows the synthesis of high-surface-activity Ag nanoparticle decorated gC3N4 modified MCM-41 and its efficiency towards catalytic hydrogenation of organic dye in the presence of reducing agent NaBH4. The proposed mechanism is based on the transfer of H+ and 2e- between the dye and the catalyst. Adsorption of dye stuff on the catalyst is a rate-determining step and is accelerated by the MCM-41 support which enhances the surface area. The catalytic efficiency and optimum time requirement were examined through the adsorption-desorption equilibrium, pseudo-first-order reaction kinetic model for the dye. The result obtained was 98% catalytic efficiency followed by the catalytic hydrogenation reaction.

Activated carbon synthesis and methylene blue adsorption from pepper stem using microwave assisted impregnation method: Isotherm and kinetics

BackgroundAdsorption is a potent technique used to separate hazardous compounds due to its practical, affordable, and ecologically benign uses. Activated carbons are often employed for better results in adsorption processes. Agricultural by-products and wastes have recently been used in the development of large-pored adsorbents. These adsorbents are gaining popularity as an alternative to commercial activated carbons. MethodsThis study integrated the known carbonization method with a microwave device, and waste pepper stalks (locally known as isot) activated with phosphoric acid were carbonized at 650 °C for 30 min. The activated carbon (BSAC) obtained was utilized in the adsorption of dyestuff (methylene blue MtB). The adsorption was investigated according to pH, concentration, and kinetic model. ResultsThe monolayer adsorption capacity (qmax) was 178.4121 mg g−1 based on Langmuir isotherm, which was the most appropriate match. Response surface methodology (RSM) was used to examine the removal of MtB. The central composite method was used in RSM. In experimental design, solution initial concentration (75–150 ppm), adsorption time (120–240 min) and activated carbon amount (50–100 mg) were selected and adsorption capacity (qe) was chosen as response parameter. The adsorption capacity was 75.0072 mg g−1 under optimum conditions (88 ppm solution initial concentration, 191 min, adsorption time and 95 mg activated carbon). ConclusionThe activated carbon obtained from pepper (isot) stems with microwave impregnation process integrated into the traditional method are a cheap and environmentally friendly adsorbent for MtB removal.

Adsorption of dyestuff by nano copper oxide coated alkali metakaoline geopolymer in monolith and powder forms: Kinetics, isotherms and microstructural analysis

To remove contaminants and pollutants from wastewater systems, adsorbents are widely used. Geopolymers offer a convenient alternative as adsorbents in the wastewater treatment system as they are low-cost, environmentally friendly, and safer. A new adsorbent material prepared by coating nano copper oxide on the surface of alkali-activated metakaolin showed a higher ability to remove methylene blue (MB) dye from wastewater, thus making them attractive in dye removal applications. First, nano copper oxide was prepared by sol gel method and metakaolin geopolymer was produced using sodium silicate solution having a Ms value of 1.1 (M). Afterwards, nano copper oxide (MC) was coated on the surface of the geopolymer. The ability of MB dye to bind to both pristine (Mp, MCp) and powder forms (Mpr, MCpr) of the geopolymer was evaluated. X-ray diffraction revealed that the halo found at 27.40°–31.077° (2θvalue) in both samples related to amorphous gel's composition and the major peaks of copper oxide in MCpr were sited at a 2θ value of 35.45° and 38.88°.The dye removal efficiency can be inferred from the increased adsorption capacity of 11.9 mg/g (Mp) and 14.4 mg/g (MCp) for the monolith form and 81.43 mg/g (Mpr) and 87.82 mg/g (MCpr) for the powder form. The adsorption of reused active sites was 73% for Mpr and 83% for MCpr up to the fifth cycle after regeneration by heat treatment at 400 °C. The models that best suited the adsorption data were pseudo-second-order and Freundlich isotherms, which indicated possible chemisorption with intra-particle diffusion. Furthermore, the binding energy is shifted to lower value in XPS spectra due to dye adsorption arising from electrostatic attraction. A higher electron density is formed due to interaction with an equal contribution of silanol Si–O–H and Si–O–Na/Cu(O1s). The adsorbents are effective over a wide pH range and their improved recycling capability increases their applications for a wide range of uses.

New optimization approach for amphoteric/magnetic ramie biosorbent in dyestuff adsorption

There is growing interest for the utilization of biomass for environmentally friendly adsorbents, and optimizing the complicated and multi-functional structure of biosorbents remains challenging. Herein, ramie waste biomass-based adsorbents with amphoteric/magnetic multi-structures via two different fabrication routes were constructed, studied and optimized to fill the gaps between multi-structure of biosorbent and performance requirements. The results show that the biosorbents exhibit excellent adsorption and magnetic recovery performance, while the biosorbent with amphiprotic-magnetic structure exhibits higher adsorption capacities for methylene blue and congo red with maximum 195.9 mg/g and 147.7 mg/g. These results are attributed to optimization of multi-structure by regulating the introduction strategy of amphiprotic groups and Fe3O4 magnetic nanoparticles. The adsorption processes of the biosorbents accord well with the pseudo-second-order kinetic model and Langmuir isotherm model, which suggests dyestuff are adsorbed via a monolayer spontaneous chemical reaction, and hydrogen bonding and electrostatic interaction are the dominant adsorption mechanisms. These demonstrate that the optimized preparation of the biosorbent improves the adsorption capacity, reusability, and stability, and provides a new perspective for the preparation of high-efficient biosorbents with multi-structures and the purification of dye-polluted wastewater.

Oyster shell derived hydroxyapatite microspheres as an effective adsorbent for remediation of Coomassie brilliant blue

Discharging of dyestuff is one of the most important causes of water pollution, which could cause severe threat to human health and environment. Hydroxyapatite (HA) is an effective and potential adsorbent to the adsorption of dyestuff. In this study, HA microspheres prepared from oyster shell wastes were used to simulate the removal of Coomassie brilliant blue (CBB) in wastewater. Several effects which can influence the adsorption capacity such as solution pH, initial CBB concentration and temperature were investigated. The maximum adsorption capacity of HA microspheres for CBB can reach 83.8169 mg/g. Thermodynamic analysis shows the adsorption process of CBB by HA microspheres is spontaneous and endothermic because of the negative △G0 and positive △H0. HA has also been proved to have good reusability. This study may provide an economical strategy for the control of oyster shell wastes and an excellent adsorbent for the adsorption of CBB in wastewater.

Preparation and Characterization of Adsorbent from Natural Zeolite Mixed Chicken Feather in Degradation of Batik Waste Dyes Based Green Chemistry

<p class="Standard">This research is the adsorption of dyestuffs from batik industry waste. The adsorption method was used chicken feather adsorbent with natural zeolite. Zeolite was activated by HF. Feather flour was activated with 0.2 M KOH. The main focus of this research is determine the potential for dye degradation with the batch method.Samples were analyzed by Atomic Absorption Spectroscopy (AAS), Fourier Transform Infra Red Spectrophotometer (FTIR), and Surface Area Analyzer (SAA). Measurement of dye degradation includes the effect of adsorbent concentration, pH, contact time and particle size of adsorbent. The results showed that the optimum pH in the degradation of dyestuffs from the batik industry waste was pH 8.5. The optimum contact times by activated and unactivated adsorbents were 65 minutes and 120 minutes, respectively. The reaction kinetics analysis showed the Freundlich adsorption model based on the experimental data. This indicates that the surface pores of the adsorbent are very influential in the degradation of the dye. Adsorption capacity of degradation dyestuffs with adsorbents has an efficiency of 94%. In the laboratory, it has been proven that adsorbents are able to degrade dyes in batik waste before being discharged into the water disposal system.</p>

Synthesis of a starch-based sulfonic ion exchange resin and adsorption of dyestuffs to the resin

A starch-based ion exchange resin (SIR) was synthesized by copolymerizing raw starch with sodium methallyl sulfonate and styrene. The structural and surface properties of the SIR were characterized by 13C nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, gel permeation chromatography, scanning electron microscopy, X-ray diffractometry, thermogravimetric analysis, Brunauer–Emmett–Teller surface area analysis, and laser particle size analysis. The SIR was physicochemically and thermally stable and resistant to acids, bases, and enzymes. In static adsorption tests, the SIR had decolorization ratios (DRs) for mixed dyestuffs in wastewater of up to 84.04%, which was higher than the DR for a synthetic ion exchange resin (001 × 7, DR 77.14%). In dynamic adsorption tests, the SIR bed had a DR of 99.85% and a wastewater handling capacity 25 times the column volume. After three adsorption–regeneration cycles, the DR of the resin bed had decreased by <7.5%. The properties of the SIR, particularly the adaptability of the SIR to continuous column adsorption, make the SIR suitable for removing dyestuffs from industrial wastewater and a potential substitute for traditional sorbents such as activated carbon and synthetic resins.

Study on the adsorption of dyestuffs with different properties by sludge-rice husk biochar: Adsorption capacity, isotherm, kinetic, thermodynamics and mechanism

The adsorption capacity, isotherm, kinetics, thermodynamics and mechanism of four dyes with different properties on a novel economical sludge-rice husk biochar (SRHB) were determined. The sludge and rice husk with ratio of 1:1 were pyrolyzed at 500 °C, for 2 h in a tubular furnace. The SRHB was characterized using an element analyzer, Brunauer-Emmett-Teller (BET) method, X-ray diffraction, Fourier transform infrared spectroscopy, zeta potential measurement and X-ray photoelectron spectroscopy. Results of the adsorption experiments revealed that the adsorption capacities of these dyes on the SRHB followed the order: Direct Red 4BS (DR) > Acid Orange II (AO) > React Blue 19 (RB) > Methylene Blue (MB). Adsorption data of DR, RB, AO, MB all fitted both the Langmuir isotherm and Freundlich isotherm well, Temkin and D-R isotherm models verified the result. Kinetic data of the four dyes showed good correlation with the pseudo-second-order model. The adsorption of DR and AO onto SRHB were exothermic, while that of RB and MB were endothermic. Dyestuffs sorption on the SRHB involved surface participation, electrostatic interaction, π-π interactions, hydrogen bond. However the main adsorption mechanisms of the different dyes onto the SRHB varied. Therefore, the SRHB could be an effective adsorbent for removing dyestuffs from wastewater, and it is most effectively for direct dye adsorption, followed by acid and reactive dyes. However, the SRHB was apparently not effective for cationic dyes.

Design of a Zwitter-Ionic Nanocomposite for Dyestuff Removal

Today, with the increasing awareness of environmental conservation, many scientists are directing their work on environmental improvements. In the textile industry, dyestuff load of wastewater increases, and improvements are made to reduce this load. As a contribution to these improvements, a nanocomposite is designed with clay, chitosan and its modifications, which are totally natural. As a preliminary study, the clay was modified and treated with dyestuff solutions to investigate the absorption properties of Methylene Blue with various clay types. According to the results obtained by UV visible spectrophotometer, Cloisite 30B, which is the clay with the best absorption property, has been determined as the reference material. With the lights of preliminary study, a nanocomposite was designed to adsorb dyestuffs from textile waste waters using modified clay and modified chitosan. With the anionic modification of chitosan, it can be converted into carboxymethylchitosan (CMCTS) and it can also have affinity to cationic structures. With this structure, colored composites are obtained while contributing to recycling and environment by providing adsorption of dyestuff. According to UV-vis and FT-IR results, CMCTS that is modified with Butanetetracarboxylic acid (BTCA) has better adsorption from textile wastewaters.

Adsorption of dyestuff in household-scale dyeing onto rice husk

As the direct discharge of dying wastewater into the environment has harmful effects, there is a growing interest in using low–cost and waste materials to adsorb dyes. The main objective of this study was to investigate the adsorption of a commercial synthetic dye in household–scale dyeing onto rice husk using batch process. The effects of adsorption such as contact time, initial dye concentration and temperature were evaluated. The rice husk was characterized by Fourier transform infrared spectrophotometer (FTIR), BET surface area and scanning electron microscopy (SEM). The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherm models. It was found that the Langmuir isotherm provided a good model and the maximum monolayer adsorption capacity values were 14.9, 15.6 and 16.9 mg/g at 20, 30 and 40°C, respectively. The kinetic experimental data were fitted well by pseudo–second order model at all temperatures. The thermodynamic investigation indicated that the adsorption of dye was spontaneous and endothermic.

Investigation of adsorption of Basic Blue 41, Acid Violet 17 and Reactive Red 23 dyestuffs on Çatalağzı Thermal Power Plant flyash

In this study the various dyestuffs in industrial wastewaters (Basic Blue 41, Acid Violet 17, Reactive Red 23) was investigated adsorption on fly ash whiche is a waste. Dyestuff adsorption on fly ash carried out in batch system has been investigated as a function of medium pH, temperature and the amount of adsorbent. In the other part of the study, fly ash samples treated using H 2 SO 4 and heat have been studied for dye adsorption. After acid and heat treatment, the specific surface area of the fly ash and the dye adsorption capacity increased. The results of adsorption equilibrium obtained by untreated of fly ash were examined for compliance of Langmuir and Freundlich isotherm models. Dye adsorption systems data were fitted better to the Langmuir izoterm. The Gibbs free energy of adsorption (ΔG 0 ), enthalpy (ΔH 0 ) and entropy (ΔS 0 ) were calculated using the adsorption isotherms obtained at different temperatures. Negative Gibbs free energy shows the dye adsorption onto flyash is spontaneous.

Adsorption of Methylene Blue, Bromophenol Blue, and Coomassie Brilliant Blue by α-chitin nanoparticles

Expelling of dyestuff into water resource system causes major thread to the environment. Adsorption is the cost effective and potential method to remove the dyes from the effluents. Therefore, an attempt was made to study the adsorption of dyestuff (Methylene Blue (MB), Bromophenol Blue (BPB) and Coomassie Brilliant Blue (CBB)) by α-chitin nanoparticles (CNP) prepared from Penaeus monodon (Fabricius, 1798) shell waste. On contrary to the most recognizable adsorption studies using chitin, this is the first study using unique nanoparticles of ⩽50nm used for the dye adsorption process. The results showed that the adsorption process increased with increase in the concentration of CNP, contact time and temperature with the dyestuff, whereas the adsorption process decreased with increase in the initial dye concentration and strong acidic pH. The results from Fourier transform infrared (FTIR) spectroscopy confirmed that the interaction between dyestuff and CNP involved physical adsorption. The adsorption process obeys Langmuir isotherm (R2 values were 0.992, 0.999 and 0.992 for MB, BPB and CBB, and RL value lies between 0 and 1 for all the three dyes) and pseudo second order kinetics (R2 values were 0.996, 0.999 and 0.996 for MB, BPB and CBB) more effectively. The isotherm and kinetic models confirmed that CNP can be used as a suitable adsorbent material for the removal of dyestuff from effluents.

Adsorption Behavior of Dyestuffs on Hollow Activated Carbon Fiber from Biomass

This study focuses on the adsorption behavior of typical dyestuffs (methylene blue and reactive black 5) on hollow activated carbon fibers (ACFs) obtained from Kapok- and Hasuo-seed based biomass. It was found that the adsorption of dyestuffs on ACFs increased with increasing pH and temperature. In addition, the Hasuo-seed based ACFs showed higher adsorption capacities than the Kapok-seed based ACFs for dyestuffs. It was also determined from the adsorption energy distribution results that the ACFs are having energetically heterogeneous surfaces. The results clearly indicated that the prepared ACF in this study could efficiently remove dyes dissolved in water.

Novel cotton cellulose by cationization during mercerization—part 2: the interface phenomena

Cationisation during the mercerisation process with an epihalohydrin results in novel cotton cellulose that gives a new dimension to cotton pre-treatment and finishing. The modified cotton retains all the beneficial properties of mercerised cotton with a change of the surface charge that ensures further quality improvement. The present paper deals with systematic investigations of the interface phenomena of cationised cotton fabric with an epihalohydrin; 2,3-epoxypropyl trimethyl ammonium chloride during and after mercerisation process. The water, ionic surfactant and dyestuff adsorption, as well as surface free energy, electrokinetic potential, isoelectric point and point of zero charge determined according to the streaming current/streaming potential method; and specific amount of surface charge of modified cotton fabrics are researched.

Adsorption of dyestuff from aqueous solutions through oxalic acid-modified swede rape straw: Adsorption process and disposal methodology of depleted bioadsorbents

Swede rape straw (Brassica napus L.) was modified by oxalic acid under mild conditions producing an efficient dye adsorbent (SRSOA). This low-cost and environmental friendly bioadsorbent was characterized by various techniques and then applied to purify dye-contaminated aqueous solutions. Equilibrium study showed that the Langmuir model demonstrated the best fit to the equilibrium data and the methylene blue (MB) adsorption capacity calculated by this model was 432mgg(-1). The adsorption process and mechanism is also discussed. To properly deal with the dye-loaded bioadsorbents, the disposal methodology is discussed and a biochar based on depleted bioadsorbents was for the first time produced and examined. This method both solved the disposal problem of contaminant-loaded bioadsorbents and produced an useful adsorbent thereafter. The study indicates that SRSOA is a promising substitute for ACs in purifying dye-contaminated wastewater and that producing biochars from contaminant-loaded bioadsorbents maybe a feasible disposal method.

Optimized Response Surface Methodology for Adsorption of Dyestuff from Aqueous Solution

Optimized Response Surface Methodology for Adsorption of Dyestuff from Aqueous Solution

Acid Green 25 removal from wastewater by organo-bentonite from Pacitan

The capability of surfactant modified-bentonite for adsorption of dyestuff from aqueous solution was investigated. The so-called “organo-bentonite” was obtained by modifying the raw bentonite obtained from Pacitan, Indonesia using cetyl trimethylammonium bromide (CTAB) and later employed as adsorbent for Acid Green 25 removal. Isotherm and kinetic experiments were carried out on three different temperatures (30, 40 and 50 °C). Langmuir and Freundlich models were chosen for isotherm equilibria data correlation, of which the former showed better suitability. On kinetic data representation, pseudo-first and second order models were used, with the last model gave better correlation.

Functional group analysis on oxidized surfaces of synthetic textile polymers

A comprehensive collection of wet-chemical analyses of functional groups on oxidatively treated surfaces of hydrophobic polymers like poly(ethylene terephthalate) or polyolefine is presented. New methods are introduced. Textiles and foils have been subjected to advanced oxidation processes and the different oxygen functions have been quantified. Analysis of surface functional groups includes radical site determination with radical scavengers like diphenylpicrylhydrazyl, reduction of peroxides determined iodometrically, cationic dyestuff adsorption, carbonyl binding to Girard reagent P and surface hydroxyl group determination by surface nitrosation and subsequent azo-dye formation photometrically determinable. Use of potential surface swelling agents has been excluded except for addition of wetting agent. Wet-chemical analyses on textile surfaces bear the benefit of integrating over (relatively) large sample areas, a point which is interesting when regarding inhomogenities of textile or other surface constructions. In addition examples for visualisation for the existence of surface groups are described.

Utilization of powdered waste sludge (PWS) for removal of textile dyestuffs from wastewater by adsorption

Acid pre-treated powdered waste sludge (PWS) was used for removal of textile dyestuffs from aqueous medium by adsorption as an alternative to the use of powdered activated carbon (PAC). The rate and extent of dysetuff removals were determined for four different dyestuffs at different PWS concentrations varying between 1 and 6 g l –1. Biosorbed dyestuff concentrations at equilibrium decreased with increasing PWS concentration for all dyestuffs tested. PWS was more effective for adsorption of Remazol red RR and Chrisofonia direct yellow 12 as compared to the other dyestuffs tested. More than 80% percent dyestuff removal was obtained for all dyestuffs at PWS concentrations above 4 g l −1 after 6 h of incubation. Similar to percent dyestuff removal, the rate of adsorption was maximum at a PWS concentration of 4 g l −1. Kinetics of adsorption of dyestuffs was investigated by using the first- and second-order kinetic models and the kinetic constants were determined. Second-order kinetics was found to fit the experimental data better than the first-order model for all dyestuffs tested. Adsorption isotherms were established for all dyestuffs used and the isotherm constants were determined by using the experimental data. Langmuir and the generalized adsorption isotherms were found to be more suitable than the Freundlich isotherm for correlation of equilibrium adsorption data. Acid pre-treated PWS was proven to be an effective adsorbent for dyestuff removal as compared to the other adsorbents reported in literature studies.

Coal-based bottom ash (CBBA) waste material as adsorbent for removal of textile dyestuffs from aqueous solution

A locally available CBBA waste material was used as adsorbent for removal of reactive dyes from synthetic textile wastewater. This study presents the results of our investigation on color removal from synthetic wastewater containing Vertigo Blue 49 (CI Blue 49) and Orange DNA13 (CI Orange 13) by adsorption onto CBBA waste material. The effectiveness of CBBA waste material in adsorbing reactive dyes from aqueous solutions was studied as a function of contact time, initial dye concentration and pH by batch experiments. Leachability of waste material was also evaluated using standard leaching test with deionized water (DIN38414-S4). pH 7 was more favorable for color removal from both Vertigo Blue 49 (CI Blue 49) and Orange DNA (CI Orange 13). Dyestuff adsorption capacities of CBBA for Vertigo Blue 49 and Orange DNA13 were 13.51 and 4.54 mg dye/g adsorbent, respectively. The adsorption isotherms for the CBBA can be better described by the Freundlich isotherm. The results showed that the dyestuff uptake process for both dyes followed the second-order kinetics. The bottom ash used in this study is not classified as ecotoxic/hazardous material according to the French proposal for a criterion and evaluation methods of waste ecotoxicity (CEMWE) and the German regulation on Hazardous Waste Classification (HWC).