• Journal of Korean Society on Water Environment
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• v.25 no.3
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• pp.370-374
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• 2009

Adsorption characteristics of glass fibers, obtained from the spent lithium primary batteries recycling process, were investigated for the removal of Acid Red 27 dye from aqueous solution. The batch data clearly showed that increasing the initial sorptive concentration apparently enhanced the amount adsorbed and the uptake process followed the pseudo-second order rate model. The equilibrium adsorption data at different initial sorptive concentrations were fitted well to Freundlich and Langmuir adsorption isotherms. Moreover, the increase in temperature, favored the uptake of dye on this solid, indicated the process was endothermic in nature. Further, using the temperature dependence sorption data obtained at different temperatures was used to estimate various thermodynamic parameters.

• Membrane and Water Treatment
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• v.11 no.2
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• pp.131-139
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• 2020

The current study focused on the preparation of low-cost PVC-based adsorbing membrane. Metakaolin, as available adsorbent, was embedded into the PVC matrix via solution blending method. The as-prepared PVC/metakaolin mixed matrix membranes were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, atomic force microscopy (AFM), pure water permeability and contact angle measurements. The results confirmed the improvement of PWP and hydrophilicity due to the presence of metakaolin in the PVC matrix. Additionally the structure of PVC membrane was changed due to the incorporation of metakaolin in the polymer matrix. The static adsorption capacity of all samples was determined through dye removal. The effect of metakaolin dosage (0-7%) and pH (4, 8, 12) on dye adsorption capacity was investigated. The results depicted that the highest adsorption capacity was achieved at pH of 4 for all samples. Additionally, adsorption data were fitted on Langmuir, Freundlich, and Temkin models to determine the appropriate governing isotherm model. Finally, the dynamic adsorption capacity of the optimum PVC/metakaolin membrane was studied using dead-end filtration cell. The dye removal efficiency was determined for pure PVC and PVC/metakaolin membrane. The results demonstrated that PVC/metakaolin mixed matrix membrane had a high adsorption capacity for dye removal from aqueous solution.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.481.1-481.1
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• 2014

Dye-sensitized solar cell (DSSC) has been extensively investigated as the next generation energy source. Despite attractive features of simple fabrication process and its economical efficiency, there are some problems such as low efficiency and low long-term stability. Many groups have attempted the proposed way to improve the cell efficiency and long-term stability such as low recombination rate between $TiO_2$ surface and electrolyte, the development of new dye molecules capable of light adsorption as broadly as possible, the fabrication of a solid-state DSSC by replacing the liquid electrolyte, and protective coating on glass. In this work, we confirmed new dye-coating conditions to maximize the dye adsorption between the dye and $TiO_2$ nanoparticle surface. The experiment results coating conditions with the coating temperature of $70^{\circ}C$, the dye concentration of 10 mM and the coating time of 3 min. Conditions have two times, three times cycle the experiment in progress efficiency rises.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.3
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• pp.577-585
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• 2001

Dyeing properties of the colorants extracted from pomegranate hull on cotton fabric were investigated. Effects of dyeing conditions and mordanting on dye uptake, color change and colorfastness were explored. Cationic agent treatment was done for cotton to improve low dyeability in natural dyeing. In addition antimicrobial activity of the cotton fabrics dyed with pomegranate colorants was examined by the shake flask method. Pomegranate colorants showed low affinity to cotton fiber and its adsorption isotherm was Freundlich type. Therefore, hydrogen bonding was involved in the adsorption of pomegranate colorants onto cotton fiber. Mordants did not significantly increase dye adsorption. Pomegranate colorants produced mainly yellow color on cotton fabric. In order to improve dye uptake, cotton was cationized by treating with Cationon UK(quarterly ammonium salt) and chitosan. The cationized cotton with Cationon UK showed higher dye uptake and shorter dyeing time, compared with the untreated cotton. Chitosan treated cotton also showed high dye uptake, but chitosan was less effective compared with Cationon UK. Fastness to washing, perspiration, and rubbing was not improved by mordanting and cationizing treatment, but light fastness was increased by all mordants and cationic agent. As dye concentration increased, bacterial reduction rate was increased and mordants did not significantly increase bacterial reduction rate.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.11
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• pp.929-934
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• 2011

The adsorption kinetic study of ruthenium complex, N3, onto nanoporous titanium dioxide ($TiO_2$) photoanodes has been carried out by measuring dye uptake in-situ. Three simplified kinetic models including a pseudo first-order equation, pseudo second-order equation and intraparticle diffusion equation were chosen to follow the adsorption process. Kinetic parameters, rate constant, equilibrium adsorption capacities and related coefficient coefficients for each kinetic model were calculated and discussed. It was shown that the adsorption kinetics of N3 dye molecules onto porous $TiO_2$ obeys pseudo second-order kinetics with chemisorption being the rate determining step. Additionally the heterogeneous surface and the pore size distribution of porous $TiO_2$ adsorbents were also discussed.

• Clean Technology
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• v.17 no.2
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• pp.97-102
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• 2011

The adsorption characteristics of amatanth dye by granular activated carbon were experimently investigated in the batch adsorption. Kinetic studies of adsorption of amaranth dye were carried out at 298, 308 and 318 K, using aqueous solutions with 100, 200 and 300 mg/L initial concentration of amatanth. It was established that the adsorption equilibrium of amaranth dye on granular activated carbon was successfully fitted by Langmuir isotherm equation at 298 K. The pseudo first order and pseudo second order models were used to evaluate the kinetic data and the pseudo second order kinetic model was the best with good correlation. Values of the rate constant ($k_2$) have been calculated as 0.1076, 0.0531, and 0.0309 g/mg h at 100, 200 and 300 mg/L initial concentration of amatanth, respectively. Thermodynamic parameter such as activation energy, standard enthalpy, standard entropy and standard free energy were evaluated. The estimated values for standard free energy were -5.08 - -8.10 kJ/mol over activated carbon at 200 mg/L, indicated toward a spontaneous process. The positive value for enthalpy, 38.89 kJ/mol indicates that adsorption interaction of amatanth dye on activated carbon is an endothermic process.

• Korean Chemical Engineering Research
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• v.55 no.6
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• pp.771-777
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• 2017

Adsorption characteristics of Eosin Y dye by carbon nano tubes (CNTs) were examined through batch experiments. CNTs used in the study had specific surface area of $106.9m^2/g$, porosity volume of $1.806cm^3/g$, and porosity diameter of $163.2{\AA}$, respectively. Adsorption experiments were carried out as function of contact time, initial solution pH (2~10), dye concentration (100, 150 and 200 mg/L), adsorbent dose (0.05~1.0 g) and temperature (293, 313 and 333 K). The adsorption was favoured at lower pHs and temperatures. Adsorption data were well described by the Langmuir model. The adsorption process followed the pseudo-second order kinetic model. The adsorption capacity decreased with increase in temperature. The results of the intraparticle diffusion model suggested that film diffusion and particle diffusion were simultaneously occured during the adsorption process. Thermodynamic studies suggested the spontaneous and endothermic nature of adsorption of Eosin Y dye onto CNTs.

• Textile Coloration and Finishing
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• v.13 no.1
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• pp.38-44
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• 2001

The adsorption ability of dyes on chitin, a natural polymer was investigated for decolorization of dye wastewater. Chitin was manufactured in lab by decalcification in dilute aqueous hydrochloric acid solution and deproteination in dilute aqueous sodium hydroxide solution with shrimp shells. Absorbance of residue solution of dyebaths after dye adsorptions of chtin were measured in varieties of dye concentration and dipping periods. Three kinds of Direct dyes -C.I. Direct Red 81 (red 81), C.I. Direct Brown l(brown 1) and C.I. Direct Green 26(green 26) - were used. Red 81 and brown 1 have smaller molecular weight than green 26. The results from experimentals were of]tamed as follows: 1) Adsorption of green 26 was improved in dyebath by addition of salt, but red 81 and brown 1 were not found any improvements. 2) Smaller size of chitin particles could be absorbed much more speedy. In this experiments, the smallest range of chitin particle size was $250\mu{m}$ and less. 3) The most efficient amount of chitin for 20m1 of dyebath was 0.2g, 4) Both of red 81 and brown 1 showed good and speedy adsorption abilities as dyestuffs of over 90 percent in just one minute in dyebath of 0.01% dye concentration. But green 26 was absorbed slowly because of its large molecular weight. It took 40minutes to absorb dyestuffs of over 90 percent in dyebath of 0.01% dye concentration.

• Membrane and Water Treatment
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• v.14 no.3
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• pp.121-128
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• 2023

This study introduces a NaOH/Zn-assisted hydrothermal method for the synthesis of zeolites derived from coal ash (CA). A zeolite/Zn adsorbent is successfully prepared by the activation of CA with NaOH and Zn; it is characterized by a high surface area and a negative surface charge.Methylene blue (MB) and methyl orange (MO) are selected as dye pollutants, and their adsorption onto the zeolite/Zn adsorbent is investigated. Results show the high adsorption capacities of MB and MO and that the negative surface charge facilitates electrostatic interactions between the adsorbates and adsorbents. The zeolite/Zn adsorbents shows the selective adsorption of positively charged dye MB via electrostatic interactions between the =NH+ group (positive dipole) and the oxygen functional group of the adsorbents (negative dipole). The selectivity for the positively charged dye is sufficiently high, with the removal efficiency reaching 99.41% within 10 min. By contrast, the negatively charged dye MO exhibits negligible absorption. These findings confirm the role of electrostatic interactions in the adsorption of MB, in addition to the effect of a large surface area. The results of this study are expected to facilitate the development of simple, eco-friendly, and cost-effective zeolite-based adsorptive composites from CA residuals for the selective removal of dye pollutants from CA waste.

• Carbon letters
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• v.11 no.1
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• pp.1-8
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• 2010

The adsorption of Acid Blue 92 onto three low cost and ecofriendly biosorbents viz., cow dung ash, mango stone ash and parthenium leaves ash and commercial activated carbon have discussed in this work. The ash of all the mentioned bio-wastes was prepared in the muffle furnace at $500^{\circ}C$ and all the adsorbents were stored in an air thermostat. Experiments at total dye concentrations of 10~100 mg/L were carried out with a synthetic effluent prepared in the laboratory. The parameters such as pH and dye concentration were varied. Equilibrium adsorption data followed both Langmuir and Freundlich isotherms. The results indicate that cow dung ash, mango stone ash and parthenium leaves ash could be employed as low-cost alternatives to commercial activated carbon in wastewater treatment for the removal of dye.