• Journal of Environmental Science International
• /
• v.14 no.12
• /
• pp.1195-1201
• /
• 2005

In order to develop a dye coloring technology on Conchiolin layer in cultured pearls, appropriate dyes were selected, their solubilities in various solvents were studied, and adsorption and desorption experiments were performed. Solubilities of several basic dyes known to suitable for the pearl coloring, i.e., Rhodamine 6G(R6), Rhodamine B(RB) and Methylene Blue(MB), in several solvents (distilled water, methanol, ethanol, and acetone) were investigated. Among these dyes, R6 was chosen as a dye for single component adsorption and desorption experiment due to the relatively good solubility in various solvents tested. Solubilities of dyes were judged to be enough to color the pearls since dye concentrations in pearl coloring are, in general, not so high. The internal surface area of the pearl layer is believed to be directly related to the dye adsorption, the single-point internal surface area of the pearl layer measured at the nitrogen relative pressure of 0.3 was found to be $0.913m^2/g$, and the BET internal surface area, $1.01m^2/g$ The most probable diameters of micropores and macropores were found to be $40{\AA}$and $5000{\AA}$ respectively, from the pore size distribution data. Adsorption isotherm was well fitted to the Langmuir isotherm model, resulting in q=$\frac{1.62C}{1+1.09C^{.}}$

• Applied Biological Chemistry
• /
• v.38 no.5
• /
• pp.447-451
• /
• 1995

Chitosan, a deacetylated polymer of chitin, was applied and characterized as an adsorbent for a dye Toluidine Blue O. The adsorption of Toluidine Blue O by chitosan was affected by the particle sire and mass of chitosan, initial dye concentration, reaction time, and solution pH. More dye was adsorbed the smaller the chitosan particles. When initial ratio of dye to chitosan was over 1 : 500, the adsorption of dye was rapidly declined. Adsorption rate of dye to chitosan showed 2 phases, rapidly occurred one at the beginning within 3 min and thereafter very slowly occurred one. The amount of dye adsorbed was increased with increase in pH.

• Fashion & Textile Research Journal
• /
• v.10 no.5
• /
• pp.779-783
• /
• 2008

The main colorant of Morus alba L. fruit is anthocyanin which is a kind of flavonoid group. In this article, the dyeing properties of colorant extracted from Morus alba L. fruit were investigated on some silk fabrics. The results were as follows: The maximum absorbance of Morus alba L. fruit showed at 284 nm, and 516 nm by UV-VIS spectrophotometer. The dye adsorption increased according as dye concentration. The optimal dyeing temperature was $60^{\circ}C$ and the dye equilibrium was reached 40 minutes after dyeing. The highest K/S value of the colorant obtained at bath ratio 40:1. The effect of pH of dye solution showed higher K/S value at acidic than alkaline condition. Almost Mordants except pre-Fe and Sn did not significantly increased dye adsorption. The pre mordanted silk fabrics showed RP, P, and post mordanted ones showed PB, GY. The color fastnesses to light, washing, and perspiration were modified at pre-Sn mordanted samples.

• Membrane and Water Treatment
• /
• v.7 no.1
• /
• pp.23-38
• /
• 2016

Batch adsorption of methyl orange (MO) from aqueous solution using three kinds of anion exchange membranes BI, BIII and DF-120B having different ion exchange capacities (IECs) and water uptakes ($W_R$) was investigated at room temperature. The FTIR spectra of anion exchange membranes was analysed before and after the adsorption of MO dye to investigate the intractions between dye molecules and anion exchange membranes. The effect of various parameters such as contact time, initial dye concentration and molarity of NaCl on the adsorption capacity was studied. The adsorption capacity found to be increased with contact time and initial dye concentration but decreased with ionic strength. The adsorption of MO on BI, BIII and DF-120B followed pseudo-first-order kinetics and the nonlinear forms of Freundlich and Langmuir were used to predict the isotherm parameters. This study demonstrates that anion exchange membranes could be used as useful adsorbents for removal of MO dye from wastewater.

• Membrane and Water Treatment
• /
• v.11 no.4
• /
• pp.275-282
• /
• 2020

Hranfa's marl, a local natural mineral, is selected for the decontamination by adsorption of aqueous effluents in textile industry. Its physicochemical characterization is first performed. It is composed mainly of Calcite, Quartz, Ankerite and Muscovite. Its specific surface area is 40 ㎡ g^-1. Its adsorption performance is then tested in batch conditions using an industrial organic dye, Bemacid Red E-TL, as a model pollutant. The measured adsorption capacity of Hranfa's marl is 16 mg g^-1 which is comparable to that of other types of natural adsorbents. A hybrid process is tested coupling adsorption of the dye on marl in suspension and microfiltration. An adsorption reactor is inserted into the circulation loop of a microfiltration pilot using ceramic membranes. This makes possible a continuous extraction of the treated water provided that a periodic replacement of the saturated adsorbent is done. The breakthrough curve obtained by analyzing the dye concentration in the permeate is close to the ideal one considering that no dye will cross the membrane as long as the adsorbent load is not saturated. These first experimental data provide proof of concept for such a hybrid process.

• Advances in environmental research
• /
• v.3 no.3
• /
• pp.217-230
• /
• 2014

The large quantity of green cull bananas has the potential of being used industrially and, thereby, to improve banana economics and eliminate the large environmental problem presented by banana waste. Wastewaters from textile, cosmetics, printing, dying, food colouring, and paper-making industries are polluted by dyes. The adsorption of basic dye by waste banana pith was investigated by varying dye concentrations, adsorbent dose, particle size and agitation rate. The adsorption capacity was found to be maximum value of removal by using 0.1 g of sorbent with particle size 1mm at mixing speed 200 rpm for initial concentration 25 mg/l to reach value of approximate 89%. The Langmuir, Temkin and Freundlich adsorption models were used for mathematical description of the adsorption equilibrium and it was found that experimental data fitted very well to these models except Langmuir model. Adsorption of dye was applied on (pseudo-first and pseudo-second-order kinetics), and the experimental data was more fitted to pseudo second order. The results of this study showed that banana pith could be employed as effective and low-cost materials for the removal of dyes from aqueous solutions.

• Textile Coloration and Finishing
• /
• v.19 no.3
• /
• pp.26-36
• /
• 2007

This study was carried out to treat the aqueous solutions containing reactive dyes(RB19, RR120 and RY179) by the Ozone demand flask method and adsorption process using activated carbon fiber(ACF) which are one of the main pollutants in dye wastewater. Ozone oxidation of three kinds of the reactive dyes was examined to investigate the reactivity of dyes with ozone, competition reaction and ozone utilization on various conditions for single- and multi-solute dye solution. Concentration of dyes was decreased continuously with increasing ozone dosage in the single-solute dye solutions. Competition quotient values were calculated to investigate the preferential oxidation of individual dyes in multi-solute dye solutions. Competition quotients(CQi) and values of the overall utilization efficiency, ${\eta}O_3$, were increased at 40mg/l of ozone dosage in multi-solute dye solutions. ACF(A-15) has much larger specific surface area$(1,584m^2/g-ACF)$ in comparison with granular activated carbon adsorbent (F400, $1,125m^2/g-GAC$), which is commonly used, and most of pores were found to be micropores with pore radius of 2nm and below. It was found that RB19 was most easily adsorbed among the dyes in this study. In the case of PCP (p-chlorophenol) and sucrose, which are single component adsorbate, adsorption capacities of ACF(A-15) were in good agreement with the batch adsorption measurement, and saturation time predicted of ACF columns for these components was also well agreed with practically measured time. But in the case of reactive dyes, which have relatively high molecular weight and aggregated with multi-components, adsorption capacities or saturation time predicted were not agreed with practically measured values.

• Journal of Environmental Science International
• /
• v.14 no.12
• /
• pp.1203-1209
• /
• 2005

Basic dyes, Rhodamine 6G(R6G), Rhodamine B(RB), and Methylene Blue(MB), dissolved in water were used to investigate single-component adsorption affinity to the pearl layer fractionated according to the size. Unfractionated pearl layers were also used as adsorbents for the R6G and RB. The Langmuir and the Redlich-Peterson(RP) models were used to fit the adsorption data, and the goodness of fit was examined by using determination coefficient($R^2$) and standard deviation(SSE). The 3-parameter RP model was found to be better in describing the dye adsorption data than the 2 parameter Langmuir model, as can be expected from the number of parameters involved in the model. The adsorption affinity to the fractionated pearl layer was higher than that to the unfractionated layer The affinity order to the fractionated Conchiolin layer was found to be R6G > MB > RB. Furthermore, the dye adsorption capacity of the various types of pearl layer was found to be in the order, the fractionated pearl > powdered pearl > unfractionated pearl, exhibiting different adsorption isotherms according to the types of layer used in the study.

• Textile Coloration and Finishing
• /
• v.26 no.4
• /
• pp.297-304
• /
• 2014

In this study, we investigated the relationship between the adsorption property of Methyl violet or Tartrazine dye onto silica sol surface and surface charge density of the sol. The adsorption ratio of Methyl violet dye on silica sol decreased to 74% and 92% for the 68nm and 94nm silica sol, respectively, at dye concentration of $175{\mu}g/m^2$. However, the adsorption ratio of Tartrazine dye on 68nm and 94nm silica sol was about 0% for both of them. The surface charge density is $-0.40C/m^2$, $-0.26C/m^2$ for 68nm and 94nm silica sol, respectively. The amount of Methyl violet dye adsorbed on silica sol increased with an increase of surface charge density of particle at the same concentration of the dye. The adsorbed amount of the silica having high surface charge density is larger at high pH domain. But adsorbed amount of the silica having low surface charge density is larger at low pH domain.

• Textile Coloration and Finishing
• /
• v.14 no.2
• /
• pp.85-85
• /
• 2002

The interaction between berberine and tannin in aqueous solution was investigated spectrophotometerically. The dyeing mechanism of silk fabrics (control and tannin treated silk fabrics) with berberine was based on thermodynamic parameters obtained from equilibrium adsorption experiments. In adsorption spectra of aqueous solution of berberine and tannin mixture two isosbestic points (328nm, 357nm) were found and the mole fraction of reaction of components was 1:1. Initial dyeing rates were increased and the diffusion of dye was more effective by tannin treatment. Without regard to tannin treatment the adsorption isotherm of berberine was the langmuir type except high temperature, 80℃. By tannin treatment the saturation dye uptake was increased, the increase of dye uptake appeared to be a result of entropy change rather than enthalpy change. All these results can be interpreted by the hydrophobic interaction between berberine and silk treated with tannin and it is reasonable to conclude that not only the ionic force, but also the hydrophobic interaction contributes to the binding of berberine and tannin treated silk treated with tannin.