• Korean Chemical Engineering Research
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• v.53 no.3
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• pp.327-332
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• 2015

A large amount of dye wastewater poses a threat to environmental safety. Disperse blue, an anthraquinone dye that is widely used in textile dyes, is difficult to degrade in wastewater. In this work, one fungus was screened according to the decolorization rate of disperse blue. The fungus was identified and named Aspergillus XJ-2 on the basis of its morphological characteristics and 18s rDNA. Response surface method was used to optimize culture conditions for A. XJ-2. The optimum values of obtained responses were as follows: temperature, $35^{\circ}C$; pH, 5.2; carbon-to-nitrogen ratio, 30:5.5; and rotation ratio, $175r{\cdot}min^{-1}$. Under optimized conditions, the decolorization rate of A. XJ-2 was up to 94.8% in 48 h.

• Textile Coloration and Finishing
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• v.9 no.6
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• pp.26-32
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• 1997

In order to remove the pollutants effectively in the dye-processing wastewater by chemical precipitation, coagulation and flocculation test was carried out using several coagulants on various reaction conditions. It was found that the Ferric sulfate was best coagulant for the treatment of mixed dye-processing wastewater. When the Ferric sulfate dosage was 1,100mg/$\ell$, the COD removal rate was very high(50%), and the color was removed very effectively. The COD was decreased relatively well up to 40%, when Alum was dosed as coagulant. But it was difficult to remove the color effectively. Test results about COD removal for the Ferrous sulfate and the Ferric chloride used were mostly same as those of the Alum used. However, the color removal by the Ferrous sulfate was much better than the case of the Alum or the Ferric chloride. It was found that the COD removal was increased and the sludge yield was decreased by pH control before polymer flocculant addition, during the jar test for the Ferrous sulfate and the Ferric sulfate as a coagulant.

• Textile Coloration and Finishing
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• v.16 no.2
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• pp.34-40
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• 2004

This study was conducted to remove the reactive dyes by the Ozone demand flask method 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, Trihalomethane formation potentials(THMFPs), 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. THMFPs per unit dye concentration were gradually increased with increase of ozone dosage. By the result of THMFPs change with reaction time, THMFPs were rapidly decreased within 1 minute in single-solute dye solutions. Dey were increased after 1 minute of reaction time, and then they were consistently decreased again after longer reaction time. Competition quotient values were calculated to investigate the preferential oxidation of individual dyes in multi-solute dye solutions. Competition quotients$(CQ_i)$ and values of the overall utilization efficiency, no$_3$, were increased at 40mg/1 of ozone dosage in multi-solute dye solutions.

• Membrane and Water Treatment
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• v.11 no.2
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• pp.123-130
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• 2020

Submerged Membrane bioreactor (SMBR) is one of the last techniques that allow a high quality of treated industrial effluents by coupling biological treatment and membrane separation. Thus, this research was an effort to evaluate performance of a SMBR treating a model textile wastewater (MTWW). Different SMBR operating parameters like mixed liquor suspended solids (MLSS) and Dissolved oxygen concentration, hydraulic retention time (HRT), and nutrients addition (N and P) have been investigated. MTWW (influent to the SMBR) was generated using the reactive azo-dye, Novacron blue FNG (100mg/L feed concentration). Results of MTWW treatment using SMBR under optimal operating conditions (MLSS, 4.2-13.3g/L; HRT, 4 days; pH, 6.9-7.2; conductivity, 400-900 μS/cm and temperature, 19.4-22.2 ℃) showed that COD and blue colour treatment performances are between 94-98% and 30-80%, respectively. It is concluded that SMBR can be used in large scale textile wastewater treatment plants to improve effluent quality in order to meet effluent discharge standards.

• Journal of Korean Society on Water Environment
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• v.35 no.5
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• pp.418-424
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• 2019

In this study, $TiO_2$ nanotubes with different morphologies were prepared in the electrolyte consisting of ethylene glycol, ammonium fluoride($NH_4F$), and deionized water($H_2O$) by controlling the voltage and time in the anodization method. Thicknesses and pore sizes of these $TiO_2$ nanotubes were measured to interpret the relationship between anodization conditions and $TiO_2$ nanotube morphologies. Element contents in the $TiO_2$ nanotubes were detected for further analysis of $TiO_2$ nanotube characteristics. Photoelectrolyticdecolorization efficiencies of the $TiO_2$ nanotube plates with various morphologies were tested to clarify the morphology that a highly active $TiO_2$ nanotube plate should have. Influences of applied voltage in photoelectrolysis processes and sodium sulfate($Na_2SO_4$) concentration in wastewater on the decolorization efficiency were also studied. To save the equipment investment cost in photoelectrolysis methods, a two-photoelectrode system that uses the $TiO_2$ nanotube plates as photoanode and photocathode instead of adding other counter electrodes was studied. Compared with single-photoelectrode system that uses the $TiO_2$ nanotube plate as photoanode and titanium plate as cathode on the view of the treatment of dye wastewater containing different amounts of salt. As a result, a considerably suitable voltage was strictly needed for enhancing the photoelectrolyticdecolorization effect of the two-photoelectrode system but if salts exist in wastewater, an excellent increase in the decolorization efficiency can be obtained.

• Membrane Journal
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• v.32 no.2
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• pp.100-108
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• 2022

Among various industries, the textile industry uses the largest amount of water for coloring textiles which leads to a large amount of wastewater containing various kinds of dye. There are various methods for the removal of dye such as flocculation, ozone treatment, adsorption, etc. But these processes are not much successful due to the issue of recycling which enhances the cost. Alternatively, the membrane separation process for the treatment of dye in wastewater is already documented as the best available technique. Polymeric membrane and ceramic membrane are two separate groups of separation membranes. Advantages of ceramic membranes include the ease of cleaning, long lifetime, good chemical and thermal resistance, and mechanical stability. Ceramic membranes can be prepared from various sources and natural materials like clay, zeolite, and fly ash are very cheap and easily available. In this review separation of wastewater is classified into mainly three groups: ultrafiltration (UF), microfiltration (MF), and nanofiltration (NF) process.

• Journal of Environmental Science International
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• v.8 no.4
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• pp.539-545
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• 1999

Dye wastewater was treated by using an electrochemical oxidation process. Various combinations of electrodes such as carbon, Al and Fe were investigated. In this study, electrode material, electrolyte concentration, electrode distance, current density, and pH value were found to have significant effect on both pollutant removal efficiency and current efficiency in electrochemical oxidation process. After electrolysis for 40min with carbon/Al, it was observed that COD, $T-N, NH_{4}^{+}-N$ and color of treated wastwater were reduced from 580mg/$\ell$ to 145mg/$\ell$, 67.2mg/$\ell$ to 26.8mg/$\ell$, 46.8mg/$\ell$ to 1.4mg/$\ell$, and 4200 Pt-Co units to 336 Pt-Co units, respectively. The optimal conditions of the electrooxidation process to treat the wastewater for this study were found to be such : current density ; 16.67mA/$cm^2$, electrode distance ; 2.5cm, pH value ; 5.0 and carbon/Al electrode.

• Journal of Environmental Health Sciences
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• v.32 no.4 s.91
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• pp.381-385
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• 2006

For decolorization of synthetic dyes, One fungus(HUE05-1) which was isolated from textile wastewater collected from industrial complex in Korea showed excellent ability of removing synthetic dyes. This fungus was identified as Basidiomycetes species by Internal Transcribed Spacers (ITS) sequence. Isolated fungi. HUE05-1 completely decolorized all dyes in both solid and liquid condition. The decolorization results were Reactive Orange-16, 97.12%; Reactive Blue-19, 92.09%; Reactive Blue-49, 97.04%; Reactive Yellow-145, 95.53%; Acid Orange-10, 99.18%; Acid Violet-43, 98.73%; Acid Blue-350, 94.71% and Disperse Blue-106, 90.07%.

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

• Carbon letters
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• v.15 no.2
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• pp.105-112
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• 2014

Wastewater from textile industries is a major cause of water pollution in most developing countries. In order to address the issues of water pollution and high cost for treatment processes, the use of an inexpensive and environmentally benign adsorbents has been studied. The objective was to find a better alternative to the conventional methods. Lemon grass waste (ash) collected from a lemon grass stream distillation subunit in Bhutan was tested for dye removal from aqueous solutions. The study investigated the removal of methylene blue using the following operational parameters: initial concentration (100-600 mg/L), contact time, adsorbent dose (0.1-0.55 gm/100 mL), and pH (3-10). It was found that the percentage removal of dye increased with a decrease of the initial concentration and increased contact time and dose of adsorbent. The basic pH solution of dye showed better adsorption capacity as compared to the acidic dye solution. Langmuir and Freundlich adsorption isotherms were fitted to the data well. Data fitted better to Lagergren pseudo 2nd order kinetics than a 1st order kinetic model. Surface morphology was also examined via scanning electron microscopy. An elemental analysis was also carried out and the chemical composition and functional groups were analyzed using energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy techniques, respectively. The obtained results indicate that lemon grass ash could be employed as a low cost alternative to commercial activated carbon in wastewater treatment for the removal of dyes.