• Textile Coloration and Finishing
• /
• v.8 no.5
• /
• pp.17-24
• /
• 1996

Dye solutions were tested in order to find the optimal condition of ozonation and determine the progress of degradation, i.e., change of the parameters characterizing the dye solutions. From the results of our experiment we can conclude that almost all of the color was removed within a 10 minute time period. An ozone oxidation results in the effective removal of COD(60%). but the elimination of the total organic carbon(TOC) was not successful, only about 15~40% of TOC was removed from dyeing wastewater in 30 minutes. The color removal is much effective in using ozonation method.

• Clean Technology
• /
• v.5 no.1
• /
• pp.49-61
• /
• 1999

Fenton's oxidation can improve the biodegradability of refractory organic wastewater by generating $OH{\cdot}$ which is one of the most reactive species. Fenton's reagent is used to treat a variety of industrial waste containing a range of toxic organic compounds. But this process cannot be economical because of high chemical cost of $H_2O_2$, ferrous ion solution and high sludge disposal cost. In this study, we proposed a modified Fenton's oxidation process which can reduce the reagent cost and obtain better removal efficiencies with less Fenton's reagents, and have a good potential of sludge recycling. In modified Fenton reaction, ferrous ion solution is adjusted to optimal pH with NaOH. Then it added to the sample and reacted to $H_2O_2$. For the experiment, synthetic wastewater made of phenol, which is one of the typical water pollutants, was used and the ionic strength of this wastewater was controlled by adding $NaHCO_3$. The effects of DO, ionic strength, and $H_2O_2$ dosing methods were investigated. As a result, modified Fenton's treatment efficiencies are better than conventional Fenton's reaction treating leachate and dyeing wastewater. And modified Fenton's treatment efficiencies combined to the sludge recycling for a half of Iron dosage are as good as the conventional Fenton's for a normal Iron dosage.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.7
• /
• pp.738-745
• /
• 2006

In this research, the decolorization mechanisms of dye wastewater were divided into two pathways, one was physicochemical sorption to biomass flocs and the other was biological removal by microbial metabolisms. Batch tests were conducted to examine the reaction conditions, anaerobic and aerobic conditions, types and dose of cosubstrates, and to confirm the mechanisms of decolorization through the biosorption tests using the activated sludge and the autoclaved deactivated sludge. From the tests, the decolorization efficiencies of dye wastewater were 102 ${\Delta}$unit/g MLSS under the aerobic condition and 123 ${\Delta}$unit/g MLSS under the anaerobic condition, and organic removals were 82 $mg{\Delta}$COD/gMLSS and 75 $mg{\Delta}$COD/gMLSS respectively. Acetate was the more efficient cosubstrate than the domestic wastewater in the decolorization step. In addition the removal of colors and organics was increased with cosubstrates dosage. And $20.3{\sim}37.3$ ${\Delta}$unit/g MLSS was removed by the autoclaved sludge and $102.0{\sim}159.0$ ${\Delta}$unit/g MLSS by the activated sludge. The physicochemical sorption was dominant in the beginning of biosorption tests, and the biological decolorization was increased with a cosubstrate in the course of time.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.3
• /
• pp.345-350
• /
• 2006

This study investigated the removal of recalcitrant organics in dyeing wastewater using a fluidized bed reactor(FBR) that contained cell-immobilized pellets. The pellets were manufactured and condensing the gel phase by mixing PEG-polymer and cells to form micro-porous PEG-polymer pellets whose size were ${\Phi}\;4mm{\times}H\;4mm$ on average. An industrial activated sludge without any pre-adaptation was used for the cell immobilization because it gave an equivalent removal efficiency to a pre-adapted sludges. The feed was obtained from an effluent of a biological treatment plant, which contained $SCOD_{Cr}$ of 330 mg/L and $SBOD_5$ of 20 mg/L. The $SCOD_{Cr}$ removal efficiency was over 45% and the effluent $COD_{Mn}$ concentration was less than 100 mg/L at HRTs from 6 to 24 hrs. The optimum HRT in the FBR was determined as 12 hrs considering the removal efficiency and cost. When a raw wastewater containing 768 mg/L of $COD_{Cr}$ was fed to the FBR, the effluent $COD_{Cr}$ concentration increased only slightly, giving a 70% of $COD_{Cr}$ removal or a 97% of $BCOD_5$ removal. This indicated that the FBR had an excellent capability of biodegradable organics removal also. In conclusion, the FBR could be applied to textile wastewater treatment in place of an activated sludge process.

• Textile Coloration and Finishing
• /
• v.33 no.4
• /
• pp.202-209
• /
• 2021

Natural dyes are more expensive than synthetic dyes and the dyeing process, which is mainly immersion of dye, is complicated. For this reason, relatively small-scale production methods were predominant. However, awareness and interest in environmental sustainability is rising globally, and the use of synthetic dyes causes various environmental problems such as wastewater and CO₂ emission, so the consumption of natural dyes is increasing. In addition, interest in digital textile printing, an eco-friendly dyeing method that can produce products of various designs and uses less water, is growing. In this study, natural indigo dye (Indigofera tinctoria) was used as a raw material for Digital Textile Printing ink, and ¹⁴C (Biocarbon) present in it was measured to confirm whether it was derived from natural ingredients. The performance was confirmed by testing the pH, viscosity, electrical conductivity, surface tension, and particle size analysis of natural indigo ink. In addition, the performance of natural indigo DTP ink and printing fabric was evaluated by inspecting the change in color fastness and corresponding index substances before and after digital printing with natural indigo DTP ink on textiles. Through this, the possibility of commercialization of DTP ink and printing fabric using natural indigo was confirmed.

• Resources Recycling
• /
• v.9 no.1
• /
• pp.36-43
• /
• 2000

This study was carried out for treatment and reuse of inorganic sludge from Fenton process at B dyeing wastewater treatment plant. The parameters for pilot-scale treatment system were derived from the results of this study. It was found that $COD_{cl}$ of the treated effluent became lower than 100 mg/l approximately on the optimal reaction condition. 2nd sludge which was generated after redissolving sludge was analyzed, and it showed that reduction ratio of ash in 2nd sludge and total dry sludge weight in comparison with current sludge were 85% and 65%. Also Fe salt in sludge was redissolved about 90~95% of initial Fe by weight. It was estimated almost ￦350,000,000 for sludge reuse process. It was estimated saving of about ￦1,300,000 per day (￦420,000,000 per year) in operating cost based on 30,000 $m^3$/d treatment, which these were about ￦430,000 per day in chemical, ￦1,100,000 per day in sludge transportation and ￦200,000 per day in equipment maintenance. Payback period with interest charge for investment cost was estimated about 10.5 months. Also, net present value (NPV) was ￦792,000,000 and internal rat of return (IRR) was about 110%.

• Korean Journal of Environmental Agriculture
• /
• v.22 no.3
• /
• pp.192-196
• /
• 2003

Objective of this study was to investigate the influences of harvest index and percolation water quality as irrigated the discharge waters from an industrial and a municipal wastewater treatment plants and seawater (1:5 seawater: tap water) as alternative water resources during tillering stage for drought stress. There were four different treatments such as the discharge water from an industrial (textile dyeing manufacture plant) wastewater treatment plant (DIWT), discharge water from the municipal wastewater treatment plant (DMWT), seawater (1:5) and groundwater as a control. For the initial chemical compositions of alternative waters, it appeared that higher concentrations of COD, $Mn^{2+}$, and $Ni^+$ in DIWT were observed than reused criteria of other country for irrigation, and concentrations of $EC_i$, Cl, and $SO_4$ in seawater were higher than that for irrigation. Harvest index was not significantly different between DIWT and DMWT with different irrigation periods in two soil types, but that of seawater (1:5) is decreased with irrigation periods in clay loam soil and not different between 10 days and 20 days of irrigation periods in sandy loam soil. For percolation water qualities, values of sodium adsorption ratio (SAR) are increased with prolonging the irrigation periods of seawater (1:5) and DIWT, but those of DMWT were almost constant through the cultivation periods regardless of the irrigation period in both soil types. EG of percolation waters is eventually increased with prolonging days after irrigation regardless of irrigation periods in both soil types. Therefore, it might be concluded that there was potentially safe to irrigate the discharge water from municipal wastewater treatment plant relative to harvest index, SAR and $EC_i$ values of the ground water through the rice cultivation period at tillering stage for drought period.

• Journal of Korean Society on Water Environment
• /
• v.18 no.3
• /
• pp.245-251
• /
• 2002

Reactive dyes waste water, a toxic and refractory pollutant, was treated by an electrochemical method using $Ti/IrO_2$ as anode and Stainless Steel 316 as cathode. In this technique, sodium chloride as an electrolyte was added. A number of experiments were run in a batch system. Artificial samples (reactive blue 19, red 195, yellow 145) were used. Operation parameters, such as supporting electrolyte concentration, current density, pH and sample concentration have been investigated for their influences on COD and color removal efficiencies during electrolysis. After 5 and 90 minites of eletrolysis, color was reduced by 51.5% and 98.9% respectively. Under the condition of current density $10A/dm^2$, NaCl concentration 12mg/l and pH 3, 62.9% of $COD_{Cr}$ was removed after electrolysis for 90 minites. The optimum condition of color removal and COD reduction in this work was found to be the following : pH 3, sodium chloride concentration 20g/l, current density $10A/dm^2$. As a result, we confirmed to be effective to color removal and reduction of refractory organic material.

• Journal of Korean Society for Atmospheric Environment
• /
• v.19 no.4
• /
• pp.363-376
• /
• 2003

In this study, the fugitive emission characteristics of airborne volatile organic compounds from different source categories were evaluated with respect to the concentrations measured in the vicinity of the sources. A total of 22 different sources were investigated, including gasoline storage and filling stations, painting spray booth, laundry, printing officer, textile industries, and a number of environmental sanitary facilities such as landfill, wastewater treatment and incineration plants. The target VOCs included 83 individual compounds, which were determined by adsorption sampling and thermal desorption coupled with GC/MS analysis. Overall, the aliphatic compounds appeared to be the most abundant class of compounds in terms of their concentrations, followed by aromatic, and halogenated hydrocarbons. As a single compound, however, toluene was the most abundant one, explaining 11% of the total VOC concentrations as an average of all the dataset. Among source categories, petroleum associated sources such as gasoline storage/filling stations, and laundry factory were identified as the most significant sources of aliphatic hydrocarbons, while aromatic VOCs were dominantly emitted from the sources handling organic solvents, such as painting booth, printing offices, and textile dyeing processes. However. there was no apparent pattern in terms of the contributions of eath group to the total VOCs concentrations in environmental sanitary facilities. It was also found that the activated carbon adsorption tower installed for the VOC emission control in some facilities do not show any effective performances, which may result in the increased VOC levels in the ambient atmosphere.

• Textile Coloration and Finishing
• /
• v.31 no.4
• /
• pp.233-240
• /
• 2019

Dyeing is an essential process for improving the value of textile products, but it is considered as one of industries causing pollution because of producing wastewater containing hazardous chemicals as well as using a large amount of water and energy. Global demand for greener technologies in textile field is getting much more attention and accordingly, the use of eco-friendly natural dyes is growing much larger. In textile printing, both dyes and pigments can be used. Pigment printing is more simple process and requires less water and less energy, compared to dye printing. In this study, the organic pigment was prepared from the marigold colorant. Samples were stencil printed, pressed(70℃, 3min) and then heat treated(150℃, 5min). The uptake of polyacrylic acid as a chemical binder was the lowest. In particular, marigold pigments were excellent in color and texture when Guar Gum and Sodium Alginate were used as binders. In addition, the light and washing fastness was rated very high as 4, 4/5 grades, and the rubbing fastness was also excellent as 3 and 4 grades.