• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.362-363
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• 2006

Ozonized DI water was supplied to make alkaline cleaning solutions to replace SCI chemicals in a bath with and without recirculation. With recirculation, low dissolved ozone and low pH cause lower particle removal efficiency (PRE) of 75%. However, direct supply of ozonized water with $NH_4OH$ to a bath without recirculation resulted in higher PRE over 93 %.

• Korean Journal of Materials Research
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• v.18 no.6
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• pp.307-312
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• 2008

In this study, a new cleaning process with a low cost of ownership (CoO) was developed with ozonated DI water ($DIO_3$). An ozone concentration of 40 ppm at room temperature was used to remove organic wax film and particles. Wax residues thicker than $200\;{\AA}$ remained after only a commercial dewaxer treatment. A $DIO_3$ treatment in place of a dewaxer showed a low removal rate on a thick wax layer of $8000\;{\AA}$ due to the diffusion-limited reaction of ozone. A dewaxer was combined with a $DIO_3$ rinse to reduce the wax removal time and remove wax residue completely. Replacing DI rinse with the $DIO_3$ rinse resulted in a surface with a contact angle of less than $5^{\circ}$, which indicates no further cleaning steps would be required. The particle removal efficiency (PRE) was further improved by combining a SC-1 cleaning step with the $DIO_3$ rinsing process. A reduction in the process time was obtained by introducing $DIO_3$ cleaning with a dewaxing process.

• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.109-115
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• 2018

This study was conducted to solve the water shortage problem by reclaiming urine from homes or public places and using it as cleaning water for toilets. The process used in this experiment is a chemical oxidation process combining ozone, hydrogen peroxide, and UV. We set the key substance that is to be removed as chromaticity and conducted the experiment to remove it. If the quantity or concentration of injected ozone, UV, and hydrogen peroxide is insufficient, then the chromaticity will initially increase due to low oxidizing power, and will later decrease. In addition, the efficiency of removing chromaticity appeared to be higher, depending on the quantity of ozone injected, for medium concentrated urine than highly concentrated urine. However, the absolute quantity of removed chromaticity was about 68% higher for highly concentrated urine, when 16 g/hr of ozone was injected. The higher the pH level, the reaction time and efficiency of removing chromaticity were higher, and in normal conditions, in reference to a pH of 8.55, there was a 6% difference in efficiency between a pH level of 5.05 and a pH level of 10.12. Finally, when processing urine through an ozone-only process, COD decreased steadily over time, but DOC did not decrease. This is because ozone reacts selectively with organic matter.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.12
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• pp.791-797
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• 1999

Recently the ozone generation system is well used for cleaning the contaminated water by using the strong oxidization effects of ozone. In this paper the concentration, yield and generation quantity of the ozone by the Surface-Silent Discharge According to the Length of Coaxial Electrode is described. The electrodes composed of 3 electrodes-2 gaps are coaxial type and the ozone generation tube were designed and fabricated from the point of view of the energy efficiency, stability and easy control. To investigate the ozone generation dependency on electrode length, a few discharge tubes with different lengths were fabricated. The experimental equipments were provided with cooling system and dehumidifier for the many testing conditions. The main results show that the concentration, yield and generation quantity of ozone are improved by decreasing gas temperatures and increasing electrode lengths.

• Clean Technology
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• v.10 no.2
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• pp.73-87
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• 2004

In most of industrial fields, cleaning is employed for removing soils on their products or parts. Halogenated cleaning agents such as CFC-113, 1,1,1-TCE(1,1,1-trichloroethane), MC(methylene chloride) and TCE (trichloroethylene) have been used as cleaning ones in most of companies in the world since their excellent performance of cleaning ability and good material compatibility. However, CFC-113 and 1,1,1-TCE which are ozone destruction substances are not used any more in the advanced countries because of the which are ozone destruction substances are not used any more in the advanced countries because of the Montreal protocol. MC and TCE are now used restrictively at small part of industrial fields in most of countries since they are known to be hazardous or carcinogenic materials. Thus, it is indispensible that the alternative cleaning agents which are environmental-friendly and safe, and show good cleaning ability should be developed or utilized for replacement of the halogenated cleaning agents. Aqueous/semi-aqueous cleaning agents are evaluated to be promising alternative ones among various alternatives in environmental and economical view point. In this study, commercially available 12 aqueous and 6 semi-aqueous cleaning agents were selected and their physical properties, cleaning abilities, rinsing abilities and recycling of contaminated rinse water were measured and analyzed. Aqueous cleaning agents with higher wetting index showed better cleaning ability compared with those with lower wetting index. However wetting index did not have any correlation with cleaning ability in semi-aqueous cleaning agents. It was observed that soil concentration in aqueous and semi-aqueous cleaning agents should be maintained below the certain concentrations which depend on types of clearing agents. More than 70% soils in contaminated rinse water by some of aqueous and semi-aqueous clearing agents could be separated by simple settling method. This means that some cleaning agents with high oil-water separation efficiency will be effiective for recycling oil-contaminated rinse water. It was found that contaminated rinse water with aqueous agents was purified easiy by ultrafiltration method with PAN membrane of 30 kDa.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.1063-1065
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• 1999

Recently the ozone generation system is well used for cleaning the contaminated water by using the strong oxidization effects. Accordingly, with the purpose of improving ozone yield at the peak of ozone concentration, this paper describes the stracture and characteristics of ozonizer, and focused on the development of a 3E-3G discharge tube.

• Proceedings of the Materials Research Society of Korea Conference
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• 2006.05a
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• pp.15.1-15.1
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• 2006

• Clean Technology
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• v.9 no.1
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• pp.9-21
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• 2003

CFC-113 and 1,1,1-TCE which are ozone destruction substances are not used any more in the advanced countries because of Montreal protocol. MC and TCE are now used restrictively at small part of industrial fields in most of countries since they are known to be hazardous or carcinogenic materials. Thus, it is indispensible that the alternative cleaning agents which are environmental-friendly and safe, and show good cleaning ability should be developed or utilized for replacement of the halogenated cleaning agents. Aqueous cleaning agents are evaluated to be promising alternative ones among various alternatives in environmental and economical view point. This study has been carried out as a part of development program of aqueous cleaning agent. First of all, several types of surfactants which are the most important component in aqueous cleaning agents were chosen, and the physical properties, foaming ability, cleaning ability and oil-water separation efficiency of their aqueous solutions were measured and compared for selection of proper type of surfactant in aqueous cleaning agents.

• Journal of Korean Society on Water Environment
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• v.37 no.6
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• pp.433-441
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• 2021

The aim of this study was to optimize the ozonation and ceramic membrane integrated process for greywater reclamation. The integrated process is a repeated sequential process of filtration and backwash with the same ceramic membrane. Also, this study used ozone and oxygen gas for the backwashing process to compare backwashing efficiency. The study results revealed that the optimum filtration and backwash time for the process was 10 minutes each when comparing the filtrate flow and membrane recovery rate. The integrated process was operated at three different operating conditions with i) 10 minutes for filtration and 10 minutes for ozonation, ii) 10 minutes for filtration and 10 minute for oxygen aeration, and iii) continuous filtration without any aeration for synthetic greywater. The integrated process with ozone backwashing could produce 0.55 L/min of filtrate with an average of 18.42% permeability recovery, while the oxygen backwashing produced 0.47 L/min and 6.26%, respectively. And without any backwashing, the integrated process could produce 0.29 L/min. This shows that the ozone backwash process is capable of periodically recovering from membrane fouling. The resistance of the fouled membrane was approximately 34.4% for the process with ozone backwashing, whereas the resistance was restored by 10.8% for the process with oxygen backwashing. Despite the periodical ozone backwashing and chemical cleaning, irreversible fouling gradually increased approximately 3 to 4%. Approximately 97.6% and 15% turbidity and TOC were removed by ceramic membrane filtration, respectively. Therefore, the integrated process with ozonation and ceramic membrane filtration is a potential greywater treatment process.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.2
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• pp.161-168
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• 2017

Microfiltration (MF) and Ultrafiltration (UF) membrane processes capable of producing highly purified water have been extensively applied as a pretreatment process in the wastewater reuse field with the improvement of membrane properties and resistance, development of operating protocols, and improvement of technologies of backwashing and physicochemical cleaning, and improvement of scale and antifoulants. However, despite of the development of membrane production and process technologies, fouling still remains unresolved. This study confirmed that foulants such as polysaccharides, proteins and humic substances existed in final treated effluent (secondary effluent) by fluorescence excitation emission matrix (FEEM) and fourier transform infrared spectroscopy (FTIR) analysis. In addition, when constructing ozone oxidation and coagulation processes as a hybrid process, the removal efficiency was 5.8%, 6.9%, 5.9%, and 28.2% higher than that of the single process using coagulation in turbidity, color, dissolved organic carbon (DOC), and UV254, respectively. The reversible and irreversible resistances in applying the hybrid process consisting of ozone oxidation and coagulation processes were lower than those in applying ozone oxidation and coagulation processes separately in UF membrane process. Therefore, it is considered possible to apply ozonation/coagulation as a pretreatment process for stable wastewater reuse by and then contributing to the reduction of fouling when calculating the optimal conditions for ozone oxidation and coagulation and then to applying them to membrane processes.