جستجوی مقالات مرتبط با کلیدواژه « Reactive dye » در نشریات گروه « مهندسی شیمی، نفت و پلیمر »

The aim of this article was to compare of Reactive Dye adsorption isotherm of one- and two-factors on Cotton fabric. In this study, according to the type of fabric used and the two types of dyes used with chemical bases (MCT and MCT/VS), we investigated the effect of three cooperative substances dispersing, urea and penetrating. It should be noted that the Concentration and temperature were also variable. The results of the experiments showed that all three mentioned cooperative materials cause higher penetration and stabilization and improve the stability of both types of dyes mentioned on the tested fabric, in which the use of these materials for both types of dyes is investigated and the results Shown that the order of effect of these materials was different for the two types of dyes. To determine the type of adsorption isotherm, Nernest, Langmuir and Friendlich adsorption isotherms were used and the results indicated that the Langmuir adsorption isotherm is better suited to the test results. This means that the adsorption of RR and RGB Red Reactive dyes by the cellulosic product is superheated. Finally, the results of activation energy data shown that RR dye in the presence of urea and dispersants cooperatives has the lowest activation energy and Arrhenius prediction coefficient, while this has the highest value for RGB dye.

ZnO nanoparticles were synthesized from the purified solution form the residue of Zn melting factory in Bafgh. The synthesized nanoparticles were studied using TEM, XRD, FTIR and UV ray. The studied nanoparticles in comparison with the purchased one form Merck Company showed well photovoltaic properties in removal of NB21 reactive dye. In the color bleaching process, the dye solution was exposed to the UV rays for 5, 10 and 30 minutes by both purchased and synthesized nanoparticles. The results of this study indicated the crystalline and hexagonal structure of synthesized nanoparticles. Also, TEM results revealed that the fabricated nanoparticles have clear spherical shape and distinct hexagonal dimension in the range of 40-120 nm. The dye removal efficiency in the 30 minutes in B21 dye was 92% in synthesized nanoparticles in compassion with 89.21% for purchased one.

The treatment of simulated textile wastewater was examined by advanced oxidation processes based on ozonation and UV irradiation, as individual and combined methods. For this purpose, two ultraviolet light sources)i.e., low pressure UV-C 9 W and medium pressure UV-C 150 W lamps(were used and the effect of each one on wastewater treatment was determined individually and in combination with ozonation process. Three conventional commercial reactive dyes) Blue 4, Red 45, and Orange 14(were used in this study. The rates of color and COD removals by oxidation of the systems were studied at neutral and alkaline pH. The ozonation process was enhanced by UV irradiation using low-pressure or medium-pressure UV-C lamps and the removal efficiencies of COD and TOC were increased to some extent. Regardless of the dye chemical structures, complete color removal, 95% COD and 56% TOC were achieved by a combination of ozonation and UV irradiation.

One of the common problems encountered in dyeing textiles with reactive dyes is their weak adsorption and take up by the textiles. In this work، the adsorption behavior of reactive dyes on the cotton fabric treated with chitosan was investigated. Initially، the cotton fabrics were treated with potasium periodate as an oxidating agent; subsequently impregnated with chitosan and finally dyed with two reactive dyes، with MCT (Remazol deep RR gran) and MCT/VS (Remazol deep red RGB gran) mono- and bifunctional groups. The obtained results indicated that the chitosan treatment could increase the dye adsorption as well as its fixation to cellulose. The samples، treated with chitosan followed by reduction with potassium hydrosulphate، showed the best dye adsorption properties. Generally the fastness properties of chitosan-treated cotton fabrics were acceptable as compared to untreated samples. Based on the obtained results، treatment of cotton samples with chitosan can be used in order to increase the adsorption of reactive dyes.

Since 1956, the reactive dyes due to having covalent bonds with the fibre and possessing excellent fastness properties, have a wide textile industrial application. During this period, most of the investigations are focused on synthesis of reactive dyes with novel reactive groups which firstly, have sufficient reactivity to covalent bonding with the fibre and secondly, have not that high reactivity to hydrolyze the reactive dyes during the dyeing process. Since, hydrolyzed dye during the dyeing process in the house effluent causing environmental issues. Therefore, in order to balance the amount of reactive dyes reactivity to covalent bonding with fibre instead water, the structural modifications of reactive dye including change in the type of reactive groups (triazine, diazine, dichloroquinoxaline, phosphonic acid and sulphatoethylsulphone), the number of reactive groups (monofunctional and bifunctional) and the type of bridging groups which make the linkage between chromogen and reactive group, have been applied. Monochlrotriazine and vinylsulphone are most important reactive groups in reactive dyes and also commercial bi-functional and tri-functional reactive dyes with good dyeing properties have introduced to the textile industry. A comprehensive literature review on development of commercial and synthesis reactive dyes has been provided in this paper. This article concentrated on developments of reactive groups’ type. The evaluation of studied patents and papers prove that there is still room for progress in this type of dyes.

In this study، the photocatalytic ozonation of Reactive Red 2 (RR2) and Reactive Red 120 (RR120) in aqueous solutions under UV irradiation was investigated using ZnO as a photocatalyst. The effect of operating parameters such as catalyst dosage، pH،initial dye concentration and salt on the decolorization was studied. UV/vis spectrophotometric was used to assess dye decolorization. The results showed that the best pH value and ZnO dosage were 3 and 15 mmol/l، respectively. The dye decolorization enhanced with decreasing initial dye concentration. Sodium sulfate had no significant effect on dye decolorization process but sodium bicarbonate and sodium carbonate increased decolorization time. The results shown that the photocatalytic ozonation process was an effective method to degrade reactive dyes. J. Color Sci. Tech. 6 (2012), 19-25© Institute for Color Science and Technology.

In order to have the better properties of each component, the use of fabrics prepared from natural and synthetic fibres blends are common. The well known method for the dyeing of this kind of fabrics is either the use of reactive-disperse dye or reactive/disperse dyes blend. For the dyeing of cotton component of the substrate with reactive dyes, the use of alkali is necessary. Since the addition of alkali during the dyeing process could cause unlevel dyeing and also it is time consuming, the dyeing of cotton fabric with selected reactive dyes under neutral condition was investigated. In this method, a mild alkali pretreatment of a selected reactive dye is done before dyeing stage in which the sulphato ethyl sulphone group of the dye is converted to the vinyl sulphone group. So, the role of alkali during dyeing process is performed before the dyeing process starts.The results obtained from the measurement of exhaustion and fixation percentages in dyeing of cotton/polyester substrate with selected reactive dye pretreated in optimised condition/disperse dye showed E%=94%, F%=84% for C.I. Reactive Blue 21 / C.I.Disperse Red 167 and E%=89%, F%=81% for C.I. Reactive Black 5 / C.I. Disperse Red 167. J. Color Sci. Tech. 4(2010), 143- 149© Institute for Color Science and Technology.

In the present study the treatment efficiency of O3 and UV+O3 processes were compared for the oxidation of simulated dyebath effluent containing a mixture of C.I. Reactive Red 120 (RR-120) and various dye auxiliaries. The color, COD and TOC removalrates were assessed for different processes. The effects of solution pH, initial dye concentration and presence of sodium hydroxide and sodium carbonate on rates of decolorization were studied. The rate of decolorization decreased by increasing of the initial dye concentration and addition of sodium hydroxide. No change in decolorization was observed by addition of sodium carbonate. The experimental results showed that ozonation combined with UV irradiation (9-watt low-pressure mercury lamp) was slightly more efficient than ozonation alone in COD removal with no change in color removal kinetics. At an initial pH of 6.2, bulk temperature of 25°C, ozone dosage of 55 g/m3 and initial dye concentration of 800 mg/L, the TOC removal efficiency of RR-120 reached 27% and 36% after 90 min for O3 and UV+O3 processes respectively. J. Color Sci. Tech. 4(2010), 151-160© Institute for Color Science and Technology.

This study provides information on the application of the Fenton process as an advanced oxidation method for the treatment of wastewater containing an azo reactive dye (C.I. Reactive Red 120). To establish cost-efficient operating conditions for potential application of Fenton oxidation process, the influence of the main operating parameters such as iron sulfate and hydrogen peroxide doses, solution pH, temperature, initial dye concentration and presence different concentrations of sodium chloride and sodium sulfate have been studied systematically in a laboratory scale. The obtained results showed that the best pH value for decolorization of dye solution was 3. The decolorization of RR120 enhanced with the increasing of reaction temperature but decreased as a presence of chloride and sulfate ions. The increase of Fe2+ and H2O2 doses accelerated the color and COD removals until a point where further addition of Fe2+ or H2O2 became inefficient and unnecessary. The result indicated that over 99% color removal and up to 74% COD removal can be obtained by Fenton’s oxidation. J. Color Sci.Tech. 4(2010), 105-114© Institute for Color Science and Technology.

In this research the efficiency of electrochemical treatment process with iron electrodes for treatment of a colored wastewater containing Reactive Red 198 in laboratory scale was studied. The effect of operating parameters such as voltage, reaction time, electrolyte concentration, initial dye concentration and interelectrode distance on the dye removal efficiency have been investigated. The experiments were carried out in a plexiglass reactor. The results indicated that electrochemical process is veryefficient mothod for dye removal and in the operational condition able to remove color and COD as high as 99% and 66.6% respectively in 30 minutes at 40 volts and 1 cm interelectrode distance. This study revealed that when the voltage and reaction time increased and interelectrode distance decreased, energy consumption, final pH and dye removal, would be increased. Increasing electrolyte concentration, resulted in decreasing retention time for dye removal. J. Color Sci. Tech. 3(2009), 97- 105.© Institute for Color Science and Technology.

In this work, decolorization of a reactive dye (C.I. Reactive Black 5) by ozonation method was evaluated by UV-Vis spectrophotometry. The effective operational parameters such as ozonation dosages, stirring, pH, temperature, dye concentration, wastewater volume and the electrolytes were studied. Results showed that the ozonation was a very effective method for reactive dye decolorization. Complete decolorization was achived in different dye concentrations, wastewater volume and electrolytes. These parameters just had some effect on rate of decolorization and not the yield. The concentration of ozone stream and mixing rate were two important factors among all other factors. J. Color Sci. Tech. 2(2008), 67-75.© Institute for Colorants, Paint and Coatings.