• Journal of Korean Society of Environmental Engineers
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• v.32 no.9
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• pp.900-904
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• 2010

Polyvinyl chloride (PVC) hoses, polyethylene hose and silicone hose for tap water were tested with respect to migration of phenolic compounds to water. The highest concentrations (0.36~1.97 mg/L) of total phenolic compounds were observed in the test water from PVC hoses. Increasing residual Cl concentration from 0 to 0.5 mg/L or increasing water temperature from 4 to $25^{\circ}C$ increased 3~3.2 times and 100~104 times for migrated total phenolic compounds concentrations, in respectively. A major migrating phenolic compounds from PVC hoses were bisphenol-a (BPA) and it was observed that the concentration of migrating phenolic compounds in the order: DEHP > 2-chlorophenol > 2,4,6-trichlorophenol > 2,4-dichlorophenol from PVC hoses.

• Journal of Soil and Groundwater Environment
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• v.11 no.1
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• pp.23-36
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• 2006

Experimental leaching of tailings was performed as a function of times (1, 2, 4, 7, 14, 21 and 30 days) in the laboratory using reaction solutions equilibrated to three different pH set-points (pHs 1,3 and 5). The initial pHs of 5 and 3 stabilized at either 4.6-6.1 or 2.8-3.5 in 2 days and decrease gradually with time afterwards. The results of the leaching tests indicate that the significant increase in the sulfate concentrations and in acidity after 7 days of leaching results from the oxidation of sulfide minerals. There were no significant variations in the extractable Pb found in the leach solutions of pH 5 and 3 within the reaction time (1-30 days), while Zn, Cd and Cu concentrations tend to significantly increase with time. In tailings leaching at an initial pH=1, two trends were observed: i) The 'Zn-type' (Zn, Cd and Cu), with increasing concentrations between days 1 and 30, corresponding to the expected trend when continuous dissolution is the dominant process, ii) the 'Pb-type' (Pb), with decreasing concentrations over time, suggesting rapid dissolution of a Pb source followed by the precipitation of 'anglesite' in relation to the large increase in dissolved sulfates. The high sulfate concentrations were coupled with high concentrations of released Fe, Zn and Cd. Release of Zn and Cd and acidity from these leaching experiments can potentially pose adverse impact to surface and groundwater qualities in the surrounding environment. The kinetic problems could be the important factor which leads to increasing concentrations of trace metals in the runoff water.

• Applied Biological Chemistry
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• v.12
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• pp.19-24
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• 1969

As a one of the new methods for soybean protein food processings, an attempt was made to decompose steamed soybean protein to amino acids, peptides, and other water soluble forms by the use of protease produced by Aspergillus sojae, and extract them to use as additives of low protein foods or weaning-foods of children. In this paper, as a one part of this subject, the optimum condition, such as optimum pH, temperature, digestion period, raw material's mixing ratio with wheat meal, amount of water added, and effect of sodium chloride addition, to decompose and extract soybean protein were studied. They were obtained when mixing raw materials with wheat meal in the ratio of 10:4 and adding six folds of water at $40-45^{\circ}C$, pH 5-8 for 18 hrs. digestion. Although sodium chloride addition exerted an unfavorable influence upon the decomposition of the aforementioned materials, it was effective to prolongation of digestion period. Under the abovementioned optimum conditions, the maximum extractability of soybean protein as forms of amino acids, peptides, and other water soluble forms, was nearly 70 percent against protein content of raw materials.

• Journal of Ginseng Research
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• v.10 no.1
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• pp.80-93
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• 1986

The tail portion of dried 6-year old white ginseng was extracted and sugars and nitrogen compounds were also evaluated for chemical properties depending on varying conditions of extractions. The factors studied were extraction temperature in the range of 70-$100^{\circ}C$, ethanol concentration of 0-90% and the times of extractions which was taken 8 hours per each extraction in water at $80^{\circ}C$. For the effect of ethanol concentration in the extraction solvent, it was found that the amounts of free, reducing and total sugars and starch recovered in extract were almost linearly decreased along with the increase of concentration and the nonprotein nitrogen accounted over 84% of total nitrogen in extract. As ethanol concentration became increased, extractions of total nitrogen and water souluble nonprotein nitrogen were decreased especially in 90% ethanol. For the extraction temperature, all the sugar fractions with water and 70% ethanol except free sugar have tended to increase along with the temperature raised from 70 to $100^{\circ}C$ and it was found there is little changes of nitrogen compounds in the temperature range except a rapidly increase in water soulble protein at $100^{\circ}C$. For the times of extractions, showed that most of extractable compounds were extracted in 3 times of extractions with water at $80^{\circ}C$. It was shown that more than 95f) of sugars and 80% of nitrogen compounds were yielded with water extraction. Accordingly it was efficient to extract with water or 70% ethanol in 3 times in terms of !actor and energy consumption.

• Journal of Korea Water Resources Association
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• v.48 no.1
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• pp.9-21
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• 2015

This study examined pollution level of sediment in Sookchun lake, and studied dredging validity by examining phosphorous release characteristics on surface polluted soil. Total phosphorous, the principal cause of algal blooms, exceeded dredging assessment standards regarding Daechung lake (1.5 mg/g) at all points. Also at all points, total nitrogen exceeded the dredging assessment standard regarding Paldang Lake (1.1 mg/g), but fell short of the standard regarding Daechung lake (3.0 mg/g). Dredging zone was suggested in this study is Chuso water body (WS-6~WS-12) in Sookchun lake. In relation to sediment pollution levels measured at different depths, LOI tended to decrease as it became deeper. The concentrations of T-N varied depending upon the depth as well as points, but no regular pattern was observed. The depth and site did not significantly influence T-P. From the results of phosphorous release tests, it was shown that total phosphorous release flux was calculated to be $7.2{\sim}15.4mg/m^2/d$ for anaerobic condition, $0.5{\sim}2.0mg/m^2/d$ for aerobic condition and $2.0{\sim}4.1mg/m^2/d$ for facultative condition. Release flux and T-P concentration of surface sediments had positive correlation ($R^2$ 0.7871). And The corelation between release flux and DO condition in reactor had strong negative correlation ($R^2$ 0.8824).

• Korean Journal of Food Science and Technology
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• v.18 no.6
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• pp.497-502
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• 1986

Soaking of soybeans is usually considered necessary as a part of further processing. However the soaking process causes the loss of soluble solids from soybean. The temperature effect on the leaching rate of soluble solids during soaking of soybeans were determined at temperatures ranging from $10^{\circ}-50^{\circ}C$. Soaking temperature and time were found to greatly influence the content of soluble solids. Solid leaching rate constant was increased with temperature ranging from 10 - 33 mg/min. Overall mass transfer coefficient of $66.7\;mg/m^2{\cdot}h$ at $20^{\circ}C$ for Saeal variety was higher as compared with other variety (Kwanggyo, Tanyob), and activation energy was found to be 4026 cal/mole. Z-values to reach different degree of leaching showed the descending tendency with increase of solid leaching.

• KSBB Journal
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• v.18 no.2
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• pp.122-126
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• 2003

Multi-cycle chromatographic separation of Iysozyme from egg white was investigated. Multi-cycle chromatography was performed by repeated cycling(one cycle: resin equilibration, sample loading, washing, elution). Two types of cation exchange resins, Cellufine CM C-200 and Bio-rex 70, were used to determine the optimum condition for the separation of Iysozyme by multi-cycle chromatography. The resin was equilibrated in 20 mM Na-phosphate buffer(pH 7.0). Chromatograms of UV absorbance levels of every cycle were compared to confirm the eluting ability of Iysozyme in the two types of gel. Collected samples from eluting regions in every cycle were assayed by 15% SDS-PAGE.

• Korean Journal of Food Science and Technology
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• v.17 no.3
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• pp.227-231
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• 1985

The effect of ethanol concentration on saponin composition of red ginseng extract was studied during extraction at $80^{\circ}C$ for 5 times of 8 hours. The increase in ethanol concentration from 0% to 90% resulted a gradual reduction in solids yield and an increase in the recovery of total ginsenosides. All of the ginsenosides determined were also significantly increased, but ginsenoside-$Rb_1.$-$Rb_2$ and -Rd were relatively decreased a little by raising the concentration 70% to 90%. The yield ratio of protopanaxadiol/protopanaxatriol saponin were in the range of 1.69${\sim}$1.95. No significant improvement in pure saponin yield was observed between 70% and 90% ethanol. Extraction with 70% ethanol was suggested for preparation of red ginseng extract from the result of this work.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.1027-1032
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• 2012

We investigate the changes of fatty acids in blood for an evaluation of the effects of soft and enteric coated capsules containing omega 3 fatty acids. Fish oil, which contained 62.87 g/100 g of sum of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), was used as nutracueticals for omega 3 fatty acids. Lipid releasing amount in soft capsule was 70% in stomach condition. However, there was 10% of releasing amount of lipid observed in enteric coated capsule in stomach condition. In intestinal condition, 50% of lipid releasing amount in enteric coated capsule showed until 6 hr, but soft capsule until 90 min. EPA and DHA contents in soft capsule administration showed higher level than those in enteric coated capsule until 8 hr. However, the administration of enteric coated capsule showed higher level of EPA and DHA in blood after 8 hr. After 24 hr, mono-, poly-unsaturated and saturated fatty acids contents with enteric coated capsule showed higher level than those with soft capsule. The enteric coated capsule containing omega 3 fatty acids was expected to sustain omega 3 fatty acids.

• Journal of the Korean Applied Science and Technology
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• v.30 no.4
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• pp.790-796
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• 2013

The following is the study result of herbal tea roasted at different temperatures between $80{\sim}140^{\circ}C$. Depending on treatment temperature the water content decreased, some carbonization occurred and crude ash content relatively increased. Also crude protein and crude fat changed little. Benzopyrene content (0.17~0.35ppb) showed a tendency to increase with higher treating temperature. From this result, the $B({\alpha})P$ content differed depending on the treatment temperature and raw materials. In case of roasting, the actual inside temperature is around $200^{\circ}C$ but since the surface temperature of the roaster reaches around $2,000^{\circ}C$ some portion of $B({\alpha})P$ content was presumed to be produced from the area that came in contact with this surface. Solid elution rate of herbal tea showed 0.18~0.35%(w/w) and the rate of solid elution decreased with higher roasting temperature. There was no big change in $80{\sim}110^{\circ}C$ treatment section but the solid elution decreased rapidly in $110{\sim}140^{\circ}C$ section. The reason for decreasing solid elution rate at higher treatment temperature is because the compact inner tissue makes elution difficult.