• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.610-614
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• 2004

The objective of this study was to remove organics and color in livestock wastewater using coagulation and Fenton oxidation process. After coagulation process as $1^{st}$ treatment, organics in $1^{st}$ treatment water were removed by using OH radical produced in Fenton oxidation process. Removal efficiencies of $COD_{Mn}$ and color were 87.2% and 95.7% separately. At that time, the ratio of $Fe^{2+}/H_2O_2$ was 0.8~1.0, and range of reaction pH was effective at the pH of 3.5~3.8. The Reaction time of 120min more than 60min or 90min was sufficient in Fenton process. Removal efficiency of organics was higher two- or multi-stage treatment than one-stage treatment.

• 수도
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• s.28
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• pp.27-36
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• 1983

Oxidation process constitute an important and often indispensable measure in the reliable production of safe drinking water. Optimal introduction of oxidation processes into the treatment of drinking water requires an exact knowledge of the reactions taking place and of their interrelationships. It is the aim of this paper to review the necessary knowledge in summarized form.

• Journal of the Korean Ceramic Society
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• v.43 no.10 s.293
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• pp.613-618
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• 2006

Graphite is suitable materials as a moderator, reflector, and supporter of a nuclear reactor because of high tolerance to the high temperature and neutron irradiations. Because graphite is so weak to the oxidation, its oxidation study is essentially demanded for the operation and design of the nuclear reactor. This work focuses on the effect of the surface oxidation of graphite according to the surface treatment. With thermogravimeter (TG), oxidation characteristics of the isotropic graphite are measured at the three temperature areas, and oxidation ratio and amounts are estimated as changing the surface roughness. Furthermore, the polished graphite surface produced fom the surface treatment is investigated with the Raman spectroscopic study. Oxidation behaviors of the surface are also evaluated as elimination the polished layer by washing with strong sonication.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.4
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• pp.55-63
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• 1996

This research was based on comparing ozonation with combined ozone/ultraviolet oxidation through the methods of reducing THM produced during water treatment. The results were as follows ; 1. The decline of THM concentration was appeared according as ozone dosage increases with ozonation and combined ozone/ultraviolet oxidation. The more effective method was the treatment of irradiating UV then ozonation. In the beginning of reaction the decline rate of THM formation potential was low, I thought it was because that the reaction of ozone and humic acid needed times to be steady state, or that THM formation potential existed according to humic acid. 2. The effect of combined ozone/ultraviolet oxidation when ozone dosage was 4.2mg/L min was almost the same that of ozonation when ozone dosage was 8.6mg/L min. 3. In experiment of TOC decline through ozonation and combined ozone/ultraviolet oxidation, TOC concentration was also dropped according to increasing ozone dosage and the more effective results were showed in treatment of irradiating UV than ozonation. But the similar TOC remove rates were showed in experiment of changing with ozone dosage during combined ozone/ultraviolet oxidation TOC remove rates were low in proportion to the remove rates of THM formation potential, it was considered that humic acid was made low molecule itself though ozonation and ozone/ultraviolet oxidation. Moreover, the high degree of remove efficiency will be get though the treatment of activated carbon of GAC treatment after combined ozone/ultravilet oxidation.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.29-37
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• 2000

Fenton’s oxidation process is one of the most commonly applied processes to the wastewater which cannot be treated by conventional biological treatment processes. However, it is necessary to minimize the cost of Fenton’s oxidation treatment by modifying the treatment processes or other means of chemical treatment. So, as a method for the chemical oxidation of biorefractory or nonbiodegradable organic pollutants, the Photo-Fenton-Reaction which utilizes iron(11)salt. $H_2O$$_2$ and UV-light simultaneously has been proprosed. Therfore, the purpose of this study is to test a removal efficiency of dye-wastewater and treatment cost with Fenton’s and Photo-Fenton’s oxidation process. The Fe(11)/$H_2O$$_2$ reagent is referred to as the fenton’s reagent. which produces hydroxy radicals by the interaction of Fe(11) with $H_2O$$_2$. In this exoeriment, the main results are as followed; 1. The Fenton oxidation was most efficient in the pH range of 3-5. The optimal condition for initial reaction pH was 3.5 for the high CO $D_{Cr}$ & TOC-removal efficiency. 2. The removal efficiency of TOC and CO $D_{Cr}$ increased up to the molar ration between ferrate and hydrogen peroxide 0.2:1, but above that ratio removal efficiency hardly increased. 3. The highest removal efficiency of TOC and CO $D_{Cr}$ were showed when the mole ration of ferrate to hydrogen peroxide was 0.2:3.4. 4. Without pretreatment process, photo-fenton oxidation which was not absorbed UV light was not different to fenton oxidation. 5. And Fenton oxidtion with pretreatment process was similar to Fenton oxidation in the absence of coagulation, the proper dosage of F $e^{2+}$: $H_2O$$_2$ was 0.2:1 for the optimal removal efficiency of TOC or CO $D_{Cr}$ .6. Also, TOC & CO $D_{Cr}$ removal efficiency in the photo-fenton oxidation with pretreatment was increased when UV light intensity enhanced.7. Optimum light intensity in the range from 0 to 1200 W/$m^2$ showed that UV-intensity with 1200W/$m^2$ was the optimum condition, when F $e_{2+}$:$H_2O$$_2$ ratio for the highest decomposition was 0.2:2.5.EX>$_2$ ratio for the highest decomposition was 0.2:2.5.

• Journal of the Korean Society for Heat Treatment
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• v.12 no.1
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• pp.31-39
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• 1999

In the present study, oxidation behavior of 304 and 316 stainless steels was investigated. After solution treatment, specimens were polished up to $1{\mu}m$ $Al_2O_3$ grade and then subjected to oxidation treatment in dry air. The range of temperature was used for oxidation treatment at $300^{\circ}C{\sim}500^{\circ}C$ and TEM was used for analyzing the components and structure of oxide film. Also, these results were compared with the results of ESCA and TG. According to the results of TEM analysis, it was found that Cr oxide film was formed on top of the surface after room temperature oxidation but amorphous Fe oxide was formed on top of the surface and polycrystalline $(Cr,Fe)_2O_3$ was formed below the amorphous Fe oxide layer after $500^{\circ}C$ oxidation treatment. The oxidized specimens at $500^{\circ}C$ showed that 316 stainless steel resists more strongly to grain and grain boundary oxidation than 304 stainless steel. These results suggested that Mo component resolved in 316 stainless steel matrix suppressed the formation of Cr carbide which may results in local Cr deplete area.

• Journal of the Korean Society for Heat Treatment
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• v.22 no.1
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• pp.3-7
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• 2009

Variation in oxidation behavior with heat treatment temperature is investigated for a Ni-Ti alloy using X-ray diffraction, DSC (differential scanning calorimetry) and Auger electron spectroscopy. And the effect of oxidation on transformation behavior and superelasticity is characterized. A cold-worked 50.6Ni-Ti alloy is oxidized at 300-$700^{\circ}C$ for 1 hr in the air atmosphere. With an increase in heating temperature, the structure of $TiO_2$ changes from amorphous (300 and $400^{\circ}C$) to anatase ($500^{\circ}C$), and to rutile ($700^{\circ}C$). Activation energy of oxidation for NiTi is measured to be 51 Kcal/mol when heating temperature is $500^{\circ}C$ or above. Since Ti reacts preferably with oxygen, Ni content increases between matrix and oxide, forming $Ni_{3}Ti$ compounds. The resultant of oxidation decreases significantly $M_s$ and $A_s$ temperature in the specimen oxidized at $900^{\circ}C$ with $B_2{\rightarrow}M$ transformation path. An extra is found on cooling between two peaks in the specimen with $B_2{\rightarrow}R{\rightarrow}M$ one which is oxidized at $900^{\circ}C$ and aged at $500^{\circ}C$. Oxidation deteriorates superelasticity due to formation of Ni-rich compound.

• Journal of the Korean Applied Science and Technology
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• v.24 no.1
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• pp.47-53
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• 2007

The acenaphthene(ACE) or acenaphthylene(ACEL) is one of the most frequently found compound in polycyclic aromatic hydrocarbon (PAH)-contaminated soil. In this study, we make 10mg/L ACE or ACEL in ethanol which is the model washing solvent for contaminated soil. This was followed by Fenton treatment in which 0.2 or 0.3mL of 30% $H_2O_2$ and 0.2 ml of 0.5 M $Fe^{2+}$ were added. The results showed more than 88 or 99% of ACE or ACEL removal efficiency, respectively. Additionally, we employed GC-MS to identify the main oxidation product generated by the optimized Fenton oxidation [i.e., ACE or ACEL degraded in to 21, 34 % 1,8-naphthalic anhydride(NAPAN), repectively]. It is expected that biodegradability of NAPAN is enhanced because NAPAN has three oxygens compared with ACE and ACEL. Therefore the results suggest that the hybrid treatment system (i.e., ethanol washing -Fenton oxidation treatment) can be effectively applied to remove ACE or ACEL from soil..

• Journal of the Korean Vacuum Society
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• v.19 no.5
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• pp.326-330
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• 2010

The surface oxidation of magnesium was performed by burning and PEO treatment method. The scanning electron microscopy (SEM), EDS, and I-V characteristics have been applied to the study of the oxidation status. The sample formed by buring method shows weaker corrosion-resistant property than that by PEO method, but this shows more conducting property.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.946-949
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• 2000

Amorphous MnO$_2$$.$ nH$_2$O in 1M KOH aqueous electrolyte proves to be an excellent electrode for a faradic electrochemical capacitor cycled between -0.5 and +1.0 versus Ag/AgCl. In order to observe morphology and crystalline structure of MnO$_2$powder, we analyzed it by XRD and SEM. The effect of oxidation treatment on MnO$_2$electrode was observed by different oxidation voltages. A maximum capacitance of 364F/g was obtained by 1.1V oxidation treatment. This capacitance was attributed solely to a surface redox mechanism