• Journal of Electrochemical Science and Technology
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• v.12 no.1
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• pp.21-32
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• 2021

This study reports for the first time the application of electrocoagulation (EC) from laboratory to pilot scales for the treatment of printing wastewater, a hazardous waste whose treatment and disposal are strictly regulated. The wastewater was taken from three real printing companies with strongly varying characteristics. The treatment process was performed in the laboratory for operational optimization and then applied in the pilot scale. The weight loss of the electrode and the generation of sludge at both scales were compared. The results show that the raw wastewater should be diluted before EC treatment if its COD is higher than about 10,000 mg/L. Pilot scale removal efficiencies of COD and color were slightly lower compared to those obtained from the laboratory scale. At pilot scale, the effluent CODs removal efficiency was 81.9 - 88.9% (final concentration of 448 - 992 mg/L) and color removal efficiency was 95.8 - 98.6% (final level of 89 - 202 Pt-Co) which proved the feasibility of EC treatment as an effective pre-treatment method for printing wastewater as well as other high colored and hard-biodegradable wastewaters.

• Clean Technology
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• v.9 no.3
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• pp.107-113
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• 2003

Printing process generates a vast amount of toxical waste and wastewater by the development of printing and publishing industry. The regulations for various environmental pollution material, which were indispensably used in printing industries, were getting stronger. The printing industries should develop the cleaner technologies in order to avoid the regulations. In this paper, the separation characteristics of microfiltration, ultrafiltration, reverse osmosis were surveyed to make basic data for the optimization of process as cleaner technologies for printing industries. The $2kg/cm^2$ of operation pressure were suitable to the U/F System. Because of the permeate of U/F was below 3 NTU as turbidity, which was probed to be possible using the rinsing water in printing process. U/F System,

• Journal of Forest and Environmental Science
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• v.23 no.2
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• pp.119-122
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• 2007

Actually, about 45% of total costs for wastewater treatment in a papermaking mill is spent for sludge disposal and the cost of chemicals used to improve the dewaterability of sludge takes much part of it. In order to reduce sludge disposal cost and to improve the efficiency of sludge treatment, it is necessary to minimize the amount of water contained within the sludge and hence to improve the dewaterability of the sludge. The objective of this study was to elucidate the way of improving the dewaterability of sludge. Three types of wastewater from a tissue paper mill, a printing paper mill and a newsprint mill were used and two types of high molecular weight flocculants (anionic PAM and cationic PAM) were used to treat the wastewater. Dewaterability of sludge was evaluated by measuring floc strength.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.1
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• pp.41-46
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• 2008

In this study, dewaterability, one of the important properties of wastewater sludge, was investigated using a simple capillary suction time (CST) measurement method. It turned out that one could use the results of CST to find optimum flocculants ratio to improve drainage in wastewater treatment for the printing paper, tissue paper, and newsprint paper mill. Since the optimum ratio of flocculants could be determined with the value of CST, COD removal efficiency could be improved and optimum floc strength could be achieved with precise ratio of flocculants. It was thus that using CST for determining the optimum ratio of flocculants could be economical by reducing the amount of flocculants. Dewaterability could be measured within several seconds using the values of CST in a precise way. The dewaterability could also be useful in investigating the optimum ratio of flocculants.

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

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

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.580-581
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• 2006

본 연구의 목적은 DTP 폐수를 나노여과막으로 여과하여 처리하는 공정에서 발생하는 농축수를 처리하는 공정의 개발에 있다. 특히 DTP 장치의 특성상 발생 폐수를 별도의 폐수처리장으로 수집, 이동 하지 않고 현장에서 처리하는 소규모 패키지 시스템을 개발하고자 하였다. 아런 목표를 달성하기 위해 효율적인 여과공정인 나노여과를 적용하였고, 이 때 발생하는 농축수는 오존이나 과산화수소와 같은 산화제를 이용하여 일부 처리하고 나머지는 감압농축 및 감량화를 농한 농축수 관리 방안을 연구 하였다.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.10a
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• pp.115-116
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• 2008

The textile wastewater discharged from printing and dyeing processes is characterized by high chemical oxygen demand(COD), low biochemical oxygen demand(BOD), and heavy color. The release of dyes into the environment constitutes only small proportion of water pollution, but dyes are visible in small quantities due to their brilliance. In this study, We are investigated to optimization of Ozone Oxidation process for Decolorization.

• Journal of the Korean Society of Industry Convergence
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• v.5 no.3
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• pp.213-218
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• 2002

Total nitrogen is a major pollutant which mostly causes eutrophication and red tide. Wastewater effluent from printing of cotton-viscose rayon containing high concentrations of total nitrogen can not be effectively treated with a typical biological treatment process. This paper provides a new treatment process and experimental results for the removal of high strength nitrogen from dyeing wastewater. The optimum conditions of air stripping for the removal of total nitrogen include around pH 12, temperature $60^{\circ}C$ with 60 minutes of stripping time. In case of a filtration-air stripping process, an initial level ($500mg/{\ell}$) of total nitrogen was significantly reduced to below $60mg/{\ell}$. Deconite was synthesised for further decomposition of organic nitrogen. Thus, a filtration-decomposition-air stripping process was possibly achieved, by which a high level ($900mg/{\ell}$) of total nitrogen was effectively removed to below $60mg/{\ell}$ P. Finally, a continuous new process for the removal of total nitrogen is proposed and confirmed, based on batch experimental results, and its process validity is further discussed throughout.

• Membrane Journal
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• v.32 no.1
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• pp.33-42
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• 2022

Growing industrialization leads to severe water pollution. Organic effluents from pharmaceuticals and textile industries released in wastewater adversely affect the environment and human health. Presence of antibiotics used for antibacterial treatment in wastewater leads to the growth of drug resistance bacteria, which is very harmful for human being. Various small organic molecules are used for the preparation of organic dye molecules in the textile industries. These molecules hardly degrade, which is present in the wastewater effluents from printing and dyeing industries. In order to address these problems, photoactive catalyst is embedded in the membrane and wastewater are passed through it. Through this process, organic molecules are photodegraded and at the same time, the degraded compounds are separated by the membrane. Titanium dioxide (TiO₂) is a semiconductor which behave as excellent photocatalyst. Photocatalytic ability is enhanced by the making its composite with other transition metal oxide and incorporated into polymeric membrane. In this review, the degradation of dye and drug molecules by photocatalytic membrane are discussed.