Removal Of Direct Dye Research Articles

The effect of pH on bioremediation potential for the removal of direct violet textile dye by Aspergillus niger

Alkaline and acidic media have been used in the textile dye industry, depending on the fabric nature. The bioremoval of textile direct violet dye by Aspergillus niger fungal strain was studied. The effect of pH on dye bioremoval was investigated at a pH range from 2 to 11. The direct violet dye bioremoval reached maximum with 92.4%, 64.0%, 91.4%, and 62.3 % at pH values of 2, 3, 8, and 9, respectively, at 24 h of incubation. The percentages of removal rate after 72 h incubation were 98.9, 97.3, 94.0, 95.0, 97.0, and 97.3 at pH 2, 3, 6, 7, 8, and 9, respectively. The optimum pH values were 2, 3, 8, and 9 for direct dye removal. At the end of the experiments, the treatment with fungal strain could reduce COD value of synthetic dye solution by 76–91%. Pseudo first and second order kinetic models were applied to evaluate differences in the biosorption rates and uptakes of textile dye. Pre-equilibrium biosorption of direct violet dye onto fungus under different dye concentrations followed a pseudo second order kinetic model with a high degree of correlation coefficients ( R 2 > 0.99), and the calculated values of q e nearly matched the experimental values of textile dye during the biotreatment process.

Removal of direct dyes from textile wastewater by means of combined methods

then to realize combustion for their final destruction. Moreover, it is necessary at the primary stage of the purification to use electrocoagulation in the presence of electrogenerated aluminum, because of its chemical activity, compared with the coagulant, generated due to the hydrolysis of aluminum salts [14]. Due to the electrochemical treatment, one part of the dye molecules is decolored and the other is oxidized to elementary substances [15]. This work is devoted to the study of the removal process of textile dyes from model solutions at their electrochemical and catalytic treatment. Also, we investigated the dependence of the separation efficiency of water on the electrogenerated coagulant quantity, the initial concentration and nature of the dyes, the oxidizer consumption (H 2 O 2 ), and the process duration.

Removal of Direct N Blue-106 from artificial textile dye effluent using activated carbon from orange peel: Adsorption isotherm and kinetic studies

The purpose of this study is to suggest an efficient process, which does not require a huge investment for the removal of direct dye from wastewater. Activated carbon developed from agricultural waste material was characterized and utilized for the removal of Direct Navy Blue 106 (DNB-106) from wastewater. Systematic studies on DNB-106 adsorption equilibrium and kinetics by low-cost activated carbons were carried out. Adsorption studies were carried out at different initial concentrations of DNB-106 (50, 75, 100, 125 and 150 mg l −1), contact time (5–180 min), pH (2.0, 3.0, 4.7, 6.3, 7.2, 8.0, 10.3 and 12.7) and sorbent doses (2.0, 4.0 and 6.0 g l −1). Both Langmuir and Freundlich models fitted the adsorption data quite reasonably ( R 2 > 97). The maximum adsorption capacity was 107.53 mg g −1 for 150 mg l −1 of DNB-106 concentration and 2 g l −1 carbon concentration. Various mechanisms were established for DNB-106 adsorption on developed adsorbents. The kinetic studies were conducted to delineate the effect of initial dye concentration, contact time and solid to liquid concentration. The developed carbon might be successfully used for the removal of DNB-106 from liquid industrial wastes.

Some properties of a granular activated carbon-sequencing batch reactor (GAC-SBR) system for treatment of textile wastewater containing direct dyes

Resting (living) bio-sludge from a domestic wastewater treatment plant was used as an adsorbent of both direct dyes and organic matter in a sequencing batch reactor (SBR) system. The dye adsorption capacity of the bio-sludge was not increased by acclimatization with direct dyes. The adsorption of Direct Red 23 and Direct Blue 201 onto the bio-sludge was almost the same. The resting bio-sludge showed higher adsorption capacity than the autoclaved bio-sludge. The resting bio-sludge that was acclimatized with synthetic textile wastewater (STWW) without direct dyes showed the highest Direct Blue 201, COD, and BOD 5 removal capacities of 16.1±0.4, 453±7, and 293±9 mg/g of bio-sludge, respectively. After reuse, the dye adsorption ability of deteriorated bio-sludge was recovered by washing with 0.1% sodium dodecyl sulfate (SDS) solution. The direct dyes in the STWW were also easily removed by a GAC-SBR system. The dye removal efficiencies were higher than 80%, even when the system was operated under a high organic loading of 0.36 kg BOD 5/m 3-d. The GAC-SBR system, however, showed a low direct dye removal efficiency of only 57±2.1% with raw textile wastewater (TWW) even though the system was operated with an organic loading of only 0.083 kg BOD 5/m 3-d. The dyes, COD, BOD 5, and total kjeldalh nitrogen removal efficiencies increased up to 76.0±2.8%, 86.2±0.5%, 84.2±0.7%, and 68.2±2.1%, respectively, when 0.89 g/L glucose (organic loading of 0.17 kg BOD 5/m 3-d) was supplemented into the TWW.

Removal of direct dyes by coagulation: The performance of preformed polymeric aluminum species

Removal of three direct dyes (Direct Black 19, Direct Red 28, and Direct Blue 86) by coagulation with three different Al based coagulants was investigated. The main purpose of this paper is to examine the coagulation features of polymeric aluminum coagulants in treatment of dye-polluted waters and the emphasis was placed on the roles of preformed Al species, particularly Al 13. The performance of Al 13 in coagulation of dyes was observed through jar tests by comparing traditional Al salt, polyaluminum chloride (PACl), and purified Al 13. The results showed that under most cases Al 13 had significantly higher efficiency in removal of direct dyes than traditional Al salt and commercial PACl with the exception of Direct Red 28 removal under high pH range. The coagulation of direct dyes could be greatly affected by pH. Reducing pH was favorable for preformed Al species in a broad pH range. For traditional Al coagulant, efficient dye removal only occurred in a relatively narrow pH range of near 6.0. The outstanding coagulation behavior of Al 13 could be ascribed to its high charge neutralization ability, relative stability and potential self-assembly tendency.

Cellulosic Fabric Wastes Grafted with DMAEMA for the Removal of Direct Dyes

Dimethylaminoethyl methacrylate (DMAEMA) was grafted onto a cellulosic fabric waste via γ-irradiation (60Co). Factors affecting the grafting such as the radiation dose and monomer concentration were investigated. The grafted fabric waste was studied by infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA), as well as its surface morphology. The ability of the grafted fabric waste for removing Direct Violet 31 from its aqueous solution was studied by batch experiments. The adsorption data obeyed the Langmuir and Freundlich isotherms. It was found that 1 g of grafted fabric waste adsorbed 40 mg of Direct Violet 31 from its aqueous solution. The grafted fabric waste could be used as an adsorbent for water pollutants such as dyes, thereby solving one of the most important environmental problems of the textile industry.

Dye removal from wastewater using activated carbon developed from sawdust: adsorption equilibrium and kinetics

Mahogany sawdust was used to develop an effective carbon adsorbent. This adsorbent was employed for the removal of direct dyes from spent textile dyeing wastewater. The experimental data were analysed by the Langmuir and Freundlich models of adsorption. Equilibrium data fitted well with the Langmuir model. The rates of adsorption were found to conform to the pseudo-second-order kinetics with good correlation. The equilibrium adsorption capacity of the sawdust carbon was determined with the Langmuir equation as well as the pseudo-second-order rate equation and found to be >300 mg dye per gram of the adsorbent. The most ideal pH for adsorption of direct dyes onto sawdust carbon was found to be 3 and below. The results indicate that the Mahogany sawdust carbon could be employed as a low cost alternative to commercial activated carbon in the removal of dyes from wastewater.

The removal of color from effluents using polyamide‐epichlorohydrin‐cellulose polymer. I. Preparation and use in direct dye removal

AbstractA novel series of adsorbents have been prepared by reacting adipic acid, diethylenetriamine, epichlorohydrin, and cellulose. The structural features of these polyamide‐epichlorohydrin‐cellulose (PAE‐Cell) polymers have been confirmed by IR analysis. The ability of PAE‐Cell polymers to adsorb direct dyes from aqueous solution has been evaluated in a fixed bed column system. These PAE‐Cell polymers have been found to exhibit a better capacities for direct dye removal than some commercial activated carbons.© 1993 John Wiley & Sons, Inc.