• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.105-114
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• 2007

The most advanced oxidation processes (AOPs) are based on reactivity of strong and non-selective oxidants such as hydroxyl radical (${\cdot}OH$). Decomposition of typical DNAPL chlorinated compounds (TCE, PCE) using various advanced oxidation processes ($UV/Fe^{3+}$-chelating agent/$H_2O_2$ process, $UV/H_2O_2$ process) was approached to develop appropriate methods treating chlorinated compound (TCE, PCE) for further field application. $UV/H_2O_2$ oxidation system was most efficient for degrading TCE and PCE at neutral pH and the system could remove 99.92% of TCE after 150 min reaction time at pH 6($[H_2O_2]$ = 147 mM, UVdose = 17.4 kwh/L) and degrade 99.99% of PCE within 120 min ($[H_2O_2]$ = 29.4 mM, UVdose = 52.2 kwh/L). Whereas, $UV/Fe^{3+}$-chelating agent/$H_2O_2$ system removed TCE and PCE ca. > 90% (UVdose = 34.8 kwh/L, $[Fe^{3+}]$ = 0.1 mM, [Oxalate] = 0.6 mM, $[H_2O_2]$ = 147 mM) and 98% after 6hrs (UVdose = 17.4 kwh/L, $[Fe^{3+}]$ = 0.1 mM, [Oxalate] = 0.6 mM, $[H_2O_2]$ = 29.4 mM), respectively. We improved the reproduction system with addition of UV light to modified Fenton reaction by increasing reduction rate of $Fe^{3+}$ to $Fe^{2+}$. We expect that the system save the treatment time and improve the removal efficiencies. Moreover, we expect the activity of low molecular organic compounds such as acetate or oxalate be effective for maintaining pH condition as neutral. This oxidation system could be an economical, environmental friendly, and practical treatment process since the organic compounds and iron minerals exist in nature soil conditions.

• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.69-75
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• 2006

Improper disposal of petroleum and spills from underground storage tanks have created large areas with highly toxic contamination of the soil and groundwater. Methyl tert-butyl ether (MTBE) is widely used as a fuel additive because of its advantageous properties of increasing the octane value and reducing carbon monoxide and hydrocarbon exhausts. However, MTBE is categorized as a possible human carcinogen. This research investigated the Modified Photo-Fenton system which is based on the Modified Fenton reaction and UV light irradiation. The Modified Fenton reaction is effective for MTBE degradation near a neutral pH, using the ferric ion complex composed of a ferric ion and environmentally friendly organic chelating agents. This research was intended to treat high concentrations of MTBE; thus, 1,000 mg/L MTBE was chosen. The objectives of this research are to find the optimal reaction conditions and to elucidate the kinetic and mechanism of MTBE degradation by the Modified Photo-Fenton reaction. Based on the results of experiments, citrate was chosen among eight chelating agents as the candidate for the Modified Photo-Fenton reaction because it has a relatively higher final pH and MTBE removal efficiency than the others, and it has a relatively low toxicity and is rapidly biodegradable. MTBE degradation was found to follow pseudo-first-order kinetics. Under the optimum conditions, [$Fe^{3+}$] : [Citrate] = 1 mM: 4 mM, 3% $H_2O_2$, 17.4 kWh/L UV dose, and initial pH 6.0, the 1000 ppm MTBE was degraded by 86.75% within 6 hours and 99.99% within 16 hours. The final pH value was 6.02. The degradation mechanism of MTBE by the Modified Photo-Fenton Reaction included two diverse pathways and tert-butyl formate (TBF) was identified to be the major degradation intermediate. Attributed to the high solubility, stability, and reactivity of the ferric-citrate complexes in the near neutral condition, this Modified Photo-Fenton reaction is a promising treatment process for high concentrations of MTBE under or near a neutral pH.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1113-1118
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• 2010

The antioxidative activities and growth inhibitory effects of fermented soymilk (FS) by Bacillus subtilis KC-3 (KCCM 42923) in AGS human gastric adenocarcinoma cells were studied during fermentation at pH 5.5, 5.25 and 5.0. The pH of B. subtilis KC-3 from Cheonggukjang, decreased from 6.8 to 5.0 during the fermentation. The acidity decreased, but amino and ammonia type nitrogen contents increased significantly as pH decreased. FS at pH 5.0 (FS 5.0) exhibited the highest DPPH free radical scavenging activities among other samples. The hydroxy radical scavenging activity of FS 5.0 was found to be approximately 2.5 times higher than that of the non-fermented soymilk (NFS). The SOD-like activity of FS 5.0 was 32.1% at 1.0 mg/mL and 50.6% at 2.0 mg/mL compared to the NFS of 9.1% and 17.3%, respectively. FS, especially FS 5.0, showed increased anticancer effect in AGS human gastric adenocarcinoma cells. These results suggest that soymilk fermented by B. subtilis KC-3 has increased antioxidative activities and anticancer effects during fermentation (pH 6.0 to pH 5.0).

• Journal of environmental and Sanitary engineering
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• v.14 no.3
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• pp.54-62
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• 1999

2,4-Dichlorophenol was known pollutants caused by the endocrine disruptor into the refractory substances of environment and this is difficult to be degradable by conventional methods. Therefore, a considerable interest has been devoted to developing new process where 2,4-Dichlorophenol can easily decomposed. In this study, the series of ultrasonic irradiation for removal of 2,4-Dichlorophenol has been selected as a model reaction in the batch reactor system in order to obtain the basic data investigate the influence of various experimental parameters such as concentration, pH, reaction temperature, acoustic intensity. The products obtained form the ultrasonic irradiation were analysed by GC/MS and HPLC. The formation of $H_2O_2$, a well-known the strong oxidant was found proportionally to increase with irradiation time. The intermediates of ultrasonic irradiation of 2,4-Dichlorophenol were identified as HCl, catechol, hydroquinone, o,p-benzoquinone, muconic acid, and maleic acid. The final products of this was $CO_2$ and $H_2O$. As the decomposition of 2,4-Dichlorophenol proceeds by the ultrasonic irradiation, the pH of 2,4-Dichlorophenol containing aqueous solution increases slowly, The decomposition of 2,4-Dichlorophenol was found to be occured fast in the basic medium. In general, the rate of reaction is proportional to the reaction temperature obeying the Arrhenius' law. However, in the ultrasonic irradiation, this suggests as the reaction temperature increase the decomposition rate of the reactant decreases. This result meant that the increase of reaction temperature due to the increase of vapor pressure of water accelerated the decrease of acoustic intensity which was can be proportional to the decomposition rae of these compounds. It was found that more than 80% of phenol solution was removed within hours in all reaction conditions. The reaction order in the degradation of the 2,4-Dichlorophenol compounds was verified as the Pseude-first order. From the fore-mentioned results, it can be concluded that the refractory organic compounds caused by endocrine disruptor as 2,4-dichlorophenol could be removed by the ultrasonic irradiation with radicals, such as $H{\;}{\cdot}{\;}and{\;}OH{\;}{\cdot}$ radical causing the high increase of pressure and temperature. Finally, it apeared that the technology using ultrasonic irradiation can be applied to the treatment of refractory substances caused by endocrine disruptor which are difficult to be decomposed by the conventional methods.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.889-894
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• 1998

This study was designed as a part of efforts to investigate the biochemical pollutant markers for diagnosis of marine pollutions by changes in oxygen radicals and their scavenger enzymes of the flounder (Paralichthys olivaceus) in the South Sea of Korea. Protein contents in brain and muscle of cultured flounder in the South Sea were remarkably lower ($19\~42\%$ and $25\~41\%$, respectively) than those of wild flounder in Pohang of the East Sea as a control group. Lipid Peroxide (LPO) levels in serum of cultured in the South Sea were considerably higher ($5\~33\%$) Elan those of wild flounder in Pohang. Hydroxyl radical formations in serum of cultured flounders in the South Sea were lower ($4\~25\%$) than those of wild flounders in Pohang. Superoxide dismutase (SOD) activities in serum of cultured flounders in South Sea were also significantly lower ($7\~31\%$) than those of wild flounders in Pohang. It is believed that significant decrease of protein contents in brain and muscle, and remarkable increases of LPO in serum of cultured flounders may be used as a biochemical pollutant markers for diagnosis of marine pollutions. These results suggest that near-coastal water as well as neritic water of the South Sea might be affected by pollutant input as well as the Yellow Sea of Korea.

• Food Science and Preservation
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• v.24 no.8
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• pp.1138-1148
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• 2017

In this study, contetnts of phenolic acid and isoflavone, and biological activities of soy sauce were compared the soy sauce added bitter melon powder (BMPs). After the fermentation, pHs were decreased from 5.83 (0% BMP), 5.47 (5% BMP), and 5.32 (10% BMP) to 5.28, 5.36, and 5.16 at 90 days, whereas the acidities of soy sauce were increased from 0.06%, 0.07%, and 0.09% to 0.30%, 0.28%, and 0.36% at 90 days, respectively. In addition, the salinities of soy sauce were decreased, while viable cell numbers including Bacillus and yeast were increased. The contents of total phenolic, isoflavone-aglycone, and phenolic acid and antioxidant and ${\alpha}$-glucosidase inhibition activities were significantly increased for 90 days, while the isoflavone-glycoside contents were decreased. In Particular, soy sauce with 10% BMP at 90 days showed the highest contents of glutamic acid (GA, 9,876.09 mg/100 mL) and ${\gamma}$-aminobutyric acid (GABA, 325.02 mg/100 mL) contents than among other samples. Additionally, the radical scavenging activities (DPPH, ABTS, ${\cdot}OH$, and FRAP) and ${\alpha}$-glucosidase inhibition activities of soy sauce with 10% BMP at 90 days were shown to be high 96.07%, 97.27%, 59.47%, 1.98%, and 79.96%, respectively.

• Journal of Food Hygiene and Safety
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• v.20 no.1
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• pp.53-57
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• 2005

This study was performed to observe the components, antioxidative, antimutagenic and cytotoxic effects of the mineral water using AOAC method, DPPH free radical donating method, Ames test and SRB assay. Mineral water contained eleven kinds of minerals among the total seventeen components and sodium and potassium ion were main components. Mineral water showed electron donating activities ($175.9{\mu}g$). The inhibition rate of mineral water ($200{\mu}g/plate$) in the Sallmonella typhimurium TA98 strain showed $54\%$ against the mutagenesis induced by Trp-P-1. In addition, same concentration of mineral water the Sallmonella typhimurium TA100 strain showed highest $67\%,\;65.8\%\;and\;63\%$ inhibition against $B({\alpha})P$, 4NQO and Trp-P-1, respectively. The cytotoxic effects of mineral water against the cell lines with Human lung carcinoma (A549), Human breast adenocarcinoma (MCF-7), Human stomach adenocarcinoma (AGS) and Human cervical adenocarcinoma (Hela) were inhibited with the increase of the mineral water. The treatment of $50{\mu}g/well$ of mineral water showed cytotoxicities of $66\%,\;47.6\%,\;37.7\%\;and\;45.6\%$ against A549, MCF-7, AGS and Hela.

• Applied Chemistry for Engineering
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• v.20 no.1
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• pp.87-93
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• 2009

Pd/activated carbon (Pd/AC) and Pd/alumina (Pd/AO) catalysts were prepared by the impregnation of palladium into activated carbon and alumina. The catalytic characteristics according to the kinds of support materials were compared. The decomposition efficiencies of ozone according to kinds of support materials are about the same when these were compared by adding 10 g of catalysts into the water saturated with ozone. The decomposition efficiencies and the oxidation characteristics (TOC, $COD_{Cr}$) of dichloroacetic acid were compared with the ozone only process and the catalytic ozonations using Pd/activated carbon and Pd/alumina catalysts. The decomposition efficiencies of dichloroacetic acid by catalytic ozonations were better than the one by ozone only process, but there was slight difference of the one between Pd/activated carbon and Pd/alumina catalyst. The decomposition efficiency of dichloroacetic acid was increased with increasing ozone dose at a constant concentration of dichloroacetic acid, but the one was little increased with increasing ozone dose at more than 1.0 L/min of ozone dose. It was seemed that the bicarbonate and the chloric ion formed throughout the decomposition of dichloroacetic acid acted as the scavenger of hydroxyl radical.

• Journal of Soil and Groundwater Environment
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• v.15 no.2
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• pp.10-17
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• 2010

Advanced oxidation processes (AOPs) have advantages to reduce the processing time and mineralize contaminants dissolved in groundwater. Recently, remediation techniques for organic contamination in groundwater have been studied, and technology using $UV/H_2O_2$ is generally accepted as one of the most powerful and reliable alternative for the remediation of groundwater contamination. In this study, $UV/H_2O_2$ technology, which generates hydroxyl radical ($\cdot$ OH) as known for strong non-selective oxidant, was used to degrade chlorinated solvents (TCE and PCE), and it was expanded to apply continuous stirred tank reactor (CSTR) system (i.e. combinations of three CSTR). The tested parameters for CSTR system were retention time and groundwater/$H_2O_2$ injection volume ratio. To find optimum parameters for CSTR system, various retention time (6 min ~ 90 min) and groundwater/$H_2O_2$ injection volume ratio (5/1 ~ 119/1) were tested. Other conditions for CSTR were adapted from the batch test results, which concentration of $H_2O_2$ and UV dose were 29.4 mM (0.1%) and 4.3 kWh/L, respectively. Based on the experimental results, the optimum parameters for CSTR system were 20 min for retention time and 119/1 for groundwater/$H_2O_2$ injection volume ratio. Applying these optimum conditions, chlorinated solvents (TCE and PCE) were removed at 99.9% and 99.6%. Moreover, the effluent concentrations of TCE and PCE are 0.036 mg/L and 0.087 mg/L, respectively, which are satisfied the regulatory level (TCE 0.3 mg/L, PCE 0.1 mg/L). Consequently, the CSTR system using $UV/H_2O_2$ technology can achieve high removal efficiency in the event of treatment of groundwater contaminated by chlorinated solvents (TCE and PCE).

• Radiation Oncology Journal
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• v.22 no.3
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• pp.184-191
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• 2004

Purpose: In order to improve the proper use of radiotherapy and breast-conserving treatment (BCT) in the management of breast cancer, current status of breast cancer treatment in Korea was surveyed nationwide and the use of BCT were evaluated. Materials and Methods: Patients characteristics and treatment pattern of 1048 breast cancer patients from 27 institutions diagnosed between January, 1998 and June, 1998 were analyzed. The incidence of receiving BCT was analyzed according to the stage, age, geography, type of hospital, and the availability of radiotherapy facility. Results: Radical mastectomy was peformed in 64.8$\%$ of total patients and 26$\%$ of patients received breast- conserving surgery (BCS). The proportions of patients receiving BCT were 47.5$\%$ in stage 0, 54.4$\%$ in stage I, and 20.3$\%$ in stage II, Some of the patients (6.6$\%$ of stage I, 10.1$\%$ of stage II and 66.7$\%$ of stage III) not received radiotherapy after BCS. Only 45$\%$ of stage III patients received post-operative radiotherapy after radical mastectomy. The proportion of patients receiving BCT was different according to the geography and availability of radiotherapy facilities. Conclusion: Radiotherapy was not fully used in the management of breast cancer, even in the patients received breast-conserving surgery. The proportion of the patients who received BCT was lower than the report of western countries. To improve the application of proper management of breast cancer, every efforts such as a training of physicians, public education, and improving accessibility of radiotherapy facilities should be done. The factors predicting receipt of BCT were accessibility of radiotherapy facility and geography. Also, periodic survey like current research is warranted.