• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.461-466
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• 2010

In this study the feasibility of simultaneous electricity generation and treatment of swine farm wastewater using microbial fuel cells (MFCs) was examined. Two single-chamber MFCs containing an anode filled with different ratio of graphite felt and stainless-steel cross strip was used in all tests. The proportion of stainless-steel cross strip to graphite felt in the anode of control microbial fuel cell (CMFC) was higher than that of swine microbial fuel cell (SMFC) to reduce construction costs. SMFCs produced a stable current of 18 mA by swine wastewater with chemical oxygen demand (COD) of $3.167{\pm}80\;mg/L$ after enriched. The maximum power density and current density of SMFCs were $680\;mW/m^3$ and $3,770\;mA/m^3$, respectively. In the CMFC, power density and current density was lower than that of SMFC. CODs decreased by the SMFC and CMFC from $3.167{\pm}80$ to $865{\pm}21$ and $930{\pm}14\;mg/L$, achieving 72.7% and 70.6% COD removal, respectively. The suspended solid (SS) of both fuel cells was also reduced over 99% ($4,533{\pm}67$ to $24.0{\pm}6.0\;mg/L$). The concentration of nutritive salts, ${NH_4}^+$, ${NO_3}^-$, and ${PO_4}^{3-}$, dropped by 65.4%, 57.5%, and 73.7% by the SMFC, respectively. These results were similar with those of CMFC. These results show that the microbial fuel cells using electrode with mix stainless-steel cross strip and graphite felt can treat the swine wastewater simultaneously with an electricity generation from swine wastewater.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.746-752
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• 2005

In this study, the effect of reaction parameters including reaction temperature, time, and pressure on sludge degradation and conversion to intermediates such as organic acids were investigated at low critical wet air oxidation(LC-WAO) conditions. Degradation pathways and a modified kinetic model in LC-WAO were proposed and the kinetics model predictions were compared with experimental data under various conditions. Results in the batch experiments showed that reaction temperature directly affected the thermal hydrolysis reaction rather than oxidation reaction. The efficiencies of sludge degradation and organic acid formation increased with the increase of the reaction temperature and time. The removal of SS at $180^{\circ}C$, $200^{\circ}C$, $220^{\circ}C$ and $240^{\circ}C$ of reaction temperatures and 10 min of reaction time were 52.6%, 68.3%, 72.6%, and 74.4%, respectively, indicating that most organic suspended solids were liquified at early stage of reaction. At $180^{\circ}C$, $200^{\circ}C$, $220^{\circ}C$ and $240^{\circ}C$ of reaction temperatures and 40 min of reaction time, the amounts of organic acids formed from 1 g of sludge were 93.5 mg/g SS, 116.4 mg/g SS, 113.6 mg/g SS, and 123.8 mg/g SS, respectively, and the amounts of acetic acid from 1 g of sludge were 24.5 mg/g SS, 65.5 mg/g SS, 88.1 mg/g SS, and 121.5 mg/g SS, respectively. This suggested that the formation of sludge to organic acids as well as the conversion of organic acids to acetic acid increased with reaction temperature. Based on the experimental results, a modified kinetic model was suggested for the liquefaction reaction of sludge and the formation of organic acids. The kinetic model predicted an increase in kinetic parameters $k_1$ (liquefaction of organic compounds), $k_2$ (formation of organic acids to intermediate), $k_3$ (final degradation of intermediate), and $k_4$ (final degradation of organic acids) with reaction temperature. This indicated that the liquefaction of organic solid materials and the formation of organic acids increase according to reaction temperature. The calculated activation energy for reaction kinetic constants were 20.7 kJ/mol, 12.3 kJ/mol, 28.4 kJ/mol, and 54.4 kJ/mol, respectively, leading to a conclusion that not thermal hydrolysis but oxidation reaction is the rate-limiting step.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.5
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• pp.549-557
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• 2006

The characteristics of supercritical water oxidation have been studied to decompose the waste anionic exchange resins which were produced from a power plant. The waste resins from a power plant were mixture of anionic and cationic exchange resins. The waste anionic exchange resins had been separated from the waste resins using a solid-liquid fluidized bed. It was confirmed that the cationic exchange resins were not included in the separated anionic exchange resins by the elemental and thermogravimetric analysis. A slurry of anionic exchange resins which could be fed continuously to a supercritical water oxidation apparatus by a high pressure pump was prepared using a wet ball mill. Although the COD of liquid effluent had been reduced more than 99.9% at 25.0 MPa and $500^{\circ}C$ within 2 min, the total nitrogen content was reduced only 41%. The addition of nitric acid to the slurry could reduce the total nitrogen content in treated water. The central composite design as a statistical desist of experiments had been applied to optimize the conditions of decomposing anionic resin slurry by means of the COD and total nitrogen contents in treated waters as the key process output variables. The COD values of treated waters had been reduced sufficiently to $99.9{\sim}100%$ af the reaction conditions of $500{\sim}540^{\circ}C$, 25.0 MPa within 2 min. The effects of temperature and nitric acid concentration on COD were not significant. However, the effect of nitric acid concentration on the total nitrogen was found to be significant. The regression equation for the total nitrogen had been obtained with nitric acid concentration and the coefficient of determination($r^2$) was 95.8%.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.3
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• pp.171-178
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• 2013

In this study, the sludge that occurs in the initial operation of coagulation system developed for the treatment of CSOs were returned to the flocculation reactor. The purposes of this study were to analyze the Characteristics of flocs that are generated through the recycling sludge and settling characteristics of sludge, and to evaluate the possibility that high concentrations of particulate matter in the initial inflow of CSOs could be used as an weighted coagulant additive. As a result, the concentration of treated CSOs pollutants at the beginning of the CSOs influent with a large amount of particulate matter over 20 ${\mu}m$ was low, after gradually increasing the concentrations of them. The flocs generated from the sludge return were similar in size compared to flocs generated through injection of micro sands, and settling velocity in case of return sludge injection was decreased from 55.1 cm/min to 21.5 cm/min. SVI value of the sludge accumulated at the bottom of the sedimentation tank was 72, and settled sludge volume decreased rapidly due to the consolidation of sludge to the time it takes to 10 minutes. these mean that sludge used for recycling has good settling characteristic. A condition of returned sludge which is 0.1% return of 0.3% extraction was formed in the balance of settlement and extraction. In this case, This condition was to be adequate to maintain the proper concentration such as 100~200 mg/L of TS and 50~100 mg/L of VS in the flocculation reactor. The usage of the return sludge containing particulate matters of CSOs as an weighted coagulant additive was able to secure a stable treated water quality despite the change of influent water quality dynamically. Furthermore, it can be expected to reduce the alum dosage along with the sludge production.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.2
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• pp.83-99
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• 2005

To evaluate environmental charateristics of the South Sea and East China Sea on summer, water and sediment quality were measured in June 2001-2003. Surface layer was affceted by Warm water originated from the high temperature and salinity-Tsushima Warm Current, on the other hand, Yellow Sea Cold Water was spread to the bottom layer in the south-western part of the Jeju island, and salinity at stations near the Yangtze River was decreased below 29psu because of a enormous freshwater discharges. Thermocline-depth was formed at about 10m, and chlorophyll maximum layer was existed in and below the thermocline. COD(Chemical Oxygen Demand), TN(Total Nitrogen), and TP(Total Phosphorus) concentrations showed seawater quality grade II in surface layer of the most area, but concentrations of such as COD, Chl. a, TSS(Total Suspended Solid), and nutrients were greatly increased in the effect area of Yangtze River discharges. Correlations between dissolved inorganic nitrogen, Chl. a and salinity were negative patterns strongly, in contrast, those of inorganic phosphorus, COD and Chl. a were positive, which indicates that phytoplankton biomass and phosphorus are considered as important factors of organic matter distribution and algal growth, respectively. in the study area. The distribution of ignition loss, COD, and $H_2S$ of surface sediment were in the ranges of 2.61-8.81%, $0.64-11.86mgO_2/g-dry$, and ND-0.25 mgS/g-dry, respectively, with relatively high concentration in the eastern part of the study area. Therefore, to effective and sustainable use and management of this area, continuous monitoring and countermeasures about major input sources to the water and sediment, and prediction according to the environmental variation, are necessary.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1708-1714
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• 2015

Fermented red ginseng concentrate is known as a healthy food source, whereas it has off-flavor such as bitterness and sour flavor based on fermentation. ${\beta}$- and ${\gamma}$-cyclodextrin (CD) were used to encapsulate the off-flavor of fermented red ginseng concentrate by using response surface methodology design on ${\beta}$- and ${\gamma}-CD$ combination. The reducing effects were analyzed by sensory evaluation for bitter and sour tastes, ginsenoside Rb1, and total acidity. The optimized mixing ratio of ${\beta}$- and ${\gamma}-CD$ for reducing bitterness was the least expected value of 2.07 at ${\beta}-CD$ 3.74% versus the soluble solid content of fermented red ginseng concentrate and the ${\gamma}-CD$ 20.63% mixture. The encapsulation effects of ginsenoside Rb1 were the most expected value of 96.75% at ${\beta}-CD$ 3.47% and ${\gamma}-CD$ 19.89% mixture. The encapsulation effects of sour taste were the least expected value of 5.63 at ${\beta}-CD$ 9.34% and ${\gamma}-CD$ 9.96% mixture. The encapsulation effects of lactic acid were the most expected value of 67.73% at ${\beta}-CD$ 16.0% and ${\gamma}-CD$ 13.18% mixture. Based on encapsulation and each optimized combination, the most effective entrapping ${\beta}$-and ${\gamma}-CD$ combination ratio was ${\beta}-CD$ 10% and ${\gamma}-CD$ 13%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.866-873
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• 2007

To analyze and differentiate volatile compounds of 13 extra virgin olive oils from market, solid-phase micro extraction (SPME) GC-MS and electronic nose (EN) equipped with metal oxide sensors were applied. The volatiles identified in extra virgin olive oils include hexanal, 4-hexen-1-ol, (Z)-3-hexen-1-ol, acetic acid, and 2,4-dimethyl-heptane, etc. Response from EN was analysed by the principal component analysis. Proportion of the first Principal component was 99.70%, suggesting that each aroma pattern of the 13 extra virgin olive oils could be discriminated by EN. Fatty acid compositions were oleic (61.1${\sim}$77.9 mole%), palmitic (11.7${\sim}$16.5 mole%), linoleic (4.7${\sim}$9.7 mole%), stearic (2.5${\sim}$2.9 mole%), Palmitoleic (0.8${\sim}$2.4 mole%), and linolenic acid (0.7${\sim}$1.2 mole%). In color study, extra virgin olive oil showed $L^{\ast}$ value of 81.7${\sim}$92.9, $a^{\ast}$ value of -28.3${\sim}$13.5 and $b^{\ast}$ value of 52.2${\sim}$139.0. Total phenol and ${\alpha}-tocopherol$ contents were 6.2${\sim}$24.9 mg/100 g and 5.5${\sim}$12.8 mg/100 g, respectively. In Rancimat test, the induction period of 13 extra virgin olive oils showed 31.76${\sim}$54.04 hr while their POV ranged from 13.5 to 22.9 meq/kg oil.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.859-865
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• 2007

The chemical components and antioxidative activity of Korean gold kiwifruit were investigated. The values of pH, soluble solid and total acidity were 4.43${\pm}$0.16, 17.01${\pm}$0.04$^{\circ}Brix$, and 0.082${\pm}$0.02%, respectively. Hunter L, a, and b values were 49.80${\pm}$0.24, -6.79${\pm}$0.02, and 19.72${\pm}$0.18 value, respectively. Proximate compositions were as follows; moisture 78.62${\pm}$2.26%, crude protein 1.34${\pm}$0.25%, crude lipid 0.70${\pm}$0.06%, crude fiber 1.99${\pm}$0.13%, crude ash 0.99${\pm}$0.26%, and carbohydrate 16.36${\pm}$1.23%, respectively. Mineral elements were K 265.86${\pm}$5.00, P 71.82${\pm}$29.18, and Ca 23.84${\pm}$2.10 mg%, respectively. Free sugar compositions were sucrose (1.04${\pm}$0.18%), glucose (2.17${\pm}$0.21%) and fructose (1.86${\pm}$0.11%). Amino acid contents of Korean gold kiwifruit was very rich in glutamic acid 86.51 ${\pm}$5.58 mg/100 g and deficient in tyrosine 15.00${\pm}$4.91 mg/100 g. Organic acid compositions were quinic acid (6.65${\pm}$0.21 mg/g), malic acid (1.62${\pm}$0.13 mg/g) and citric acid (4.82${\pm}$0.21 mg/g). Contents of ascorbic acid and total phenols were 0.27${\pm}$0.06 mg/g and 0.047${\pm}$0.002 mg/g, respectively. The DPPH radical scavenging activity and reducing power of the water extract from Korean gold kiwifruit was 86.87% and 1.96 at a concentration of 25 mg/mL. The water extract showed considerable antioxidative activity against linoleic acid autoxidation in a dose-dependent manner.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.3
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• pp.426-434
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• 2011

In order to increase the use of rice, ginseng Garaedduks and Topokki were made and the physicochemical and sensory properties were investigated. Topokki and Garaedduks were added with 0, 1, 3 and 5% ginseng powder and stored at $20^{\circ}C$ for 48 hours. The moisture contents were not different to the increasing amount of ginseng powder and increasing storage time for 48 hours. The moisture content of Garaedduks for control and 5% added ginseng powder were 48.08% and 49.62%, respectively. The L value in color of uncooked ginseng Garaedduk decreased according to the added amount of ginseng powder, and the b value in color increased significantly according to the added amount of ginseng powder and during 48 hours storage at $20^{\circ}C$. Textural analysis, measured using a texture analyzer, of Garaedduk revealed that hardness, cohesiveness, chewiness decreased significantly and adhesiveness increased according to the added amount of ginseng powder. In sensory evaluation, 5% ginseng Garaedduk (uncooked, cooked) scored higher in overall acceptability than those of the other samples. In cooking properties, water absorption and solid contents increased according to the added amount of ginseng powder. Therefore, Garaedduk containing 5% ginseng powder was the most preferable. These results implied that the degree of retrogradation of ginseng Garaedduk might be low due to its high dietary fiber content.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.3
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• pp.343-349
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• 2011

The chemical composition and antioxidative activity of kiwifruit varieties in Jeju, such as Jecy Gold (Actinidia chinensis var. 'Jecy Gold'), Halla Gold (A. chinensis var. 'Halla Gold'), Jecy Sweet (A. deliciosa var. 'Jecy Sweet') and Hwabuk 94 (A. deliciosa var. 'Hwabuk 94') were investigated. The crude protein, crude lipid, and pH showed no differences among variety and maturity whereas the moisture contents showed differences among the variety and maturity. Jecy Sweet in mature stage showed the highest values in soluble solid, crude protein, crude lipid, and crude ash. The changes in chemical components of kiwifruit by maturity stage were as follows: during ripening, the glucose and the fructose contents increased considerably with the decrease of sucrose content. Potassium, phosphorus, sodium, and magnesium were estimated as the major minerals in kiwifruit and Jecy Sweet contained the highest amounts of potassium and magnesium. At maturity stage, ascorbic, malic and lactic acid were increased with the decrease of citric acid content. The polyphenol contents were 26.81~56.10 ${\mu}g/g$ and 8.64~26.45 ${\mu}g/g$, respectively, in immature and mature fruits. During ripening, the polyphenol content was decreased. The DPPH radical scavenging activity of methanol extracts were 84.47~89.37% and 43.94~76.96% at 500 ppm, respectively, in immature and mature fruits. The immature varieties of kiwifruit have a high DPPH radical scavenging activity. Therefore the chemical composition and physiological activity of kiwifruit was affected by variety and maturity.