• Membrane and Water Treatment
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• v.9 no.2
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• pp.87-94
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• 2018

The interactions of water soluble polymers with dye are studied by ultrafiltration using a molecular weight cut off of 10 KDa regenerated cellulose ultrafiltration membrane. Two water-soluble polymers, namely Poly (Sodium-4 Styrenesulfonate) (PSS) and Poly (Vinyl Alcohol) (PVA) were selected for this study. The effects of process parameters, such as, polyelectrolyte concentrations, transmembrane pressure, ionic strength and pH of solution on dye retention and permeation flux were examined. PSS enhanced ultrafiltration achieved dye retention as high as 99% as a result of complexation between polyanion containing aromatic groups and cationic dye. This result was confirmed by the red shift. The retention of dye decreases as the salt concentration increases, a high retention was obtained at pH above 4. However, in case of PVA, relatively low retention (50%) was observed. Ionic strength and pH has no significant effect on the removal of MB. The permeate flux depended slightly on polyelectrolytes concentrations, transmembrane pressure, salt concentration and pH.

• Membrane and Water Treatment
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• v.5 no.4
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• pp.281-293
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• 2014

The present work aimed to study the decolorization kinetics and characteristics of a selected azo dye under the influence of two key operational parameters including hydraulic retention time (HRT) and solid retention time (SRT). The decolorization efficiency and the two important criteria of k and normalized k (k/MLSS) were evaluated in lab-scale membrane sequencing batch reactors (MSBRs) at various HRTs of 48, 24 and 16 h (with constant SRT) and in addition, at various SRTs of infinity, 40 and 10 d (with constant HRT). According to the obtained results, both zero and first-order kinetics were properly fitted the decolorization profiles of the selected azo dye in all of the applied HRTs and SRTs. Increase of both HRT and SRT positively affected the decolorization efficiency. More MLSS concentrations corresponded to the lower HRTs and the higher SRTs resulted in higher decolorization rate constants (k). However, the effect of reducing the HRT was not compensated by increase of the MLSS concentration in order to reach higher decolorization efficiency. In addition, increase of the decolorization efficiency, as a consequence of the higher MLSS concentrations at longer SRTs, was restrained by decrease of the time-limited decolorization capability of biomass (represented by normalized k). Evaluation of both k and normalized k is suggested in order to have a more precise study on the decolorization kinetics and characteristics.

• Journal of the Korean Wood Science and Technology
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• v.34 no.3
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• pp.64-72
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• 2006

Two compounds were isolated from the diethylether and ethyl acetate fraction of hot water extracts by TLC and column chromatography as dyeing components. The isolated compounds were characterized as H-dibenzoquinoline-2,10-diol,5,6,6a,7-tetrahydro-1,9-dimethoxy-6-methyl (compoundI) and lyoniresinol (compoundII) by NMR and Mass spectrophotometry. To investigate if the isolated compounds are involved in the dyeing process, HPLC analysis was used. The retention time of the components from dye used in the study and the dye decolorized from the dyed substrate, silk by ethyl acetate were compared to conform the identity of those compounds. The retention time of the components from the dye and decolorized solution were identical. As a results, those two compounds were considered as dye bound to the silk.

• Journal of Environmental Science International
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• v.7 no.2
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• pp.209-216
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• 1998

Nanofiltration[NF45] and reverse osmosis membrane(HR98PP) separation treatment of dyestuff wastewater was carried out In order to separate relatively pure water from synthetic dyestuff wastewater, which consists of reactive dye, acid dye, basic dye, direct dye, and disperse dye. The experiments were performed by using the plate and frame membrane module. In the nanofiltration and reverse osmosis membrane separation, When the NaCl concentration was 0.1, 5.0, and 20.091, retention was 63.0, 46.0, 0.9%, respectively. When permeate flux was 125.0, 67.5, and 45.0 L/$m^2$ h, the osmotic pressure increased with Increasing the NaCl concentration. Permeate flux of two membranes Increased as temperature Increased due to segmental movement of polymer of the membrane and the rejection rate of dyestuff was decreased gradually. It was found that the rejection rate was about 95% in the nanofiltratlon, while the reverse osmosis membrane showed a high rejection rate of 99% under all temperature and pressures conditions.

• Membrane and Water Treatment
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• v.15 no.1
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• pp.41-50
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• 2024

Presence of hazardous dyes in water cause considerable risks to the human health and environment due to their potential toxicity and ecological disruptions. Therefore, in the present research, to suggest an alternative method for the retention of toxic Azocarmine G (ACG) dye from aqueous media, natural and H₂SO₄-modified acacia sawdust were performed for the first time as low-cost and efficient adsorbents. Based on batch experiments, it was determined that the best conditions for the developed dye retention process were an initial pH of 2.0 and an equilibrium time of 240 min. Analysis of the data using both pseudo-first order and pseudo-second order kinetic models showed that the retention of ACG onto the adsorbents predominantly occurred through chemical adsorption. Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models were employed to provide insights into the interaction between the adsorbate and adsorbent and the mechanism of the adsorption process. Maximum monolayer adsorption capacities of natural and H₂SO₄-modified acacia sawdust were determined as 28.01 and 64.90 mg g^-1, respectively by Langmuir isotherm model. Results of the study clearly indicated that the modification of acacia sawdust with H₂SO₄ leads to a substantial increase in the adsorption performance of anionic dyes.

• Textile Coloration and Finishing
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• v.35 no.4
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• pp.206-213
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• 2023

This study attempted to investigate what color would fade more during hair bleaching and examine what should be done to make hair color last longer. For this, hair was colored differently in ash gray with permanent hair dyes and semi-permanent hair dyes each. Hair in multiple levels was created through such bleaching. Color retention was improved in consideration of the degree of color fading in sample hair. In terms of post-bleaching hair coloring, it was more efficient to color hair by eliminating redness without hair damage after shampooing with a permanent hair dye. Therefore, it is anticipated that the study results would be highly useful for beauty salons to find a base level in consideration of bleaching effects and make improve- ments according to hair retention and moisturizing effects.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.04a
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• pp.105-107
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• 2008

Dyeing properties of the colorants extracted from pomegranate hull on hair were investigated to study its efficay of natural hair coloring dye. Effect of dyeing condition and mordanting on dye uptake, color change and colorfastness were explored. In addition, tensile strength retention is measured and the surface of the hair was observed by SEM. The water extracted pomegranate hull was concentrated and freeze-dried for preparing colorant powders. It was considered that ionic bonding was involved in the adsorption of pomegranate colorants to hair. Pomegranate hull colorants produced greyish brown colors on hair and the hair mordanted with Fe showed dark brown color. Mordant except Fe did not significantly increased dye uptake. Mordant except Cu increased light fastness, mordant except Cr increased washing fastness. SEM to observe the hair is damaged by ultraviolet light and cleaning. This is consistent with the results of tensile strength retention. From the results of colorfastness th washing and light, it was concluded that colorants from pomegranate hull can be need as a semi-permanent natural hair coloring dye.

• Journal of the Korean Wood Science and Technology
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• v.48 no.5
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• pp.745-754
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• 2020

The dye marker Sudan Red 7B was tested as an effective and appropriate marking method for searching the territory of the termite, Reticulitermes speratus, in Korea. The sensitivity of termites to the dye marker was evaluated by measuring the feed consumption amount, survival rate, retention time, and transfer efficiency of R. speratus according to the concentration and feeding period of Sudan Red 7B. As the concentration conditions of dye marker increase, Sudan Red 7B remarkably reduced the feed consumption of the termites. The survival rate was not significantly different from that of the control group (more than 90%), except when feed containing 1% or 2% concentrations of the dye marker was given for five days. The duration of the marking effect persisted for seven days, even at a concentration of 2% dye marker in the feed. No dye transfer by trophallaxis occurred between termites marked with Sudan Red 7B and unmarked termites.

• Textile Coloration and Finishing
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• v.11 no.2
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• pp.19-26
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• 1999

Strains degrading and decolorizing acid dyes, Nylosan red E-BL 150%. were isolated from natural system, was named as ARK3. The optimal culture conditions of temperature and pH were $35^\circ{C}$, 7.0, respectively. Growth rate of cells in conditions of aerobic shaking more than standing culture conspicuously increased, and optical density of those to strain ARK3 were found as 1.38 and 0.25 after 42 hrs. Decolorization efficiency in batch culture which used as immobilization media to natural zeolite was 15% after 6 hrs, while suspension culture was 5%, also its of immobilization and suspension culture were 90% and 85% after 48 hrs, respectively. Decolorization efficiency of air-lift bioreactor was more than 90% to a dilution rate of $0.038hr^{-1}$, but that was decreased as 70%, when the dilution rate was $0.05hr^{-1}$. Even though at maximum dilution rate of this study, there was not appeared "wash out" phenomienon of biomass. Decolorization efficiency was 97.7% at a dilution rate of $0.025hr^{-1}$, when influent dye concentration was $100mg/\ell$. But if influent dye concentration increased as $150mg/\ell$, even though MLVSS increased, that of treatment water decreased as 93%. Also, when influent dye concentration increased as $200mg/\ell$ and $300mg/\ell$, decolorization efficiencies of treatment water abruptly decreased as 85% and 63%, respectively. Decolorization efficiency was more than 92% to the limit volumetric loading rate of $3.75mg/\ell\cdot{hr}$hr, without regard to variation of influent dye concentration or hydraulic retention time. if volumetric loading rate was more than $3.80mg/\ell\cdot{hr}$, at same condition, decolorization efficiency was lower decrease of retention time than increase of influent dye concentration.entration.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.3
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• pp.391-400
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• 2009

The purpose of this study is to investigate the efficacy of safflower yellow colorant as a natural dye for hair coloring. The dyeing properties of safflower yellow colorant on hair were explored to obtain optimum conditions. Also, the effect of mordant was studied in terms of dye uptake, colorfastness, and hair damage to better understand the characteristics of the colorant. Tensile strength measurement and SEM analysis were carried out for investigating hair damage to light exposure and washing. On the basis of obtained results considering possible hair damage, optimum dyeing conditions were set 100%(o.w.h.) colorant concentration, pH 5, $40^{\circ}C$, and 20min. Dye uptake was improved more effectively by repeated dyeing rather than by increasing concentration. Pre-mordanting method improved dye uptake slightly, irrespective of mordant type. The safflower yellow colorant produced Y colors on hair. Cu and Fe mordants improved washing and light fastness slightly. Better strength retention was obtained with the mordanted-dyed hair than the unmordanted-dyed hair after light irradiation for 40 hours and 10 repeated washing. The hair was more damaged by light exposure than by washing. It was concluded that the safflower yellow colorant can be used as a natural semi-permanent hair dye producing Y color without mordanting.