• Membrane Journal
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• v.24 no.3
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• pp.194-200
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• 2014

The purpose of this study was to evaluate the performance of newly developed Large Pore Micro-Filtration (LPMF) membrane in Lab size for the application of water treatment, and to find its problems with solutions. The out-to-inside filtration hollow fiber LPMF membrane of which average pore size was $5{\mu}m$ was used at this study and its material was the PET braid reinforced PVDF. Filtration tests were done through gravity with 30 cm water head difference or pressure below 1.5 bar, and the backwash was done instantaneously with the filtrate after pressurizing it to about 4 bar. The water flux of the LPMF membrane with 0.2 bar TMP (Trans Membrane Pressure) was 2 times higher than $0.4{\mu}m$ MF membrane with $0.05{\mu}m$ UF filtrate of the tap water and it was measured also with 20~30 cm water head difference which showed over 800 LMH at 30 cm water head difference. And Time-To-Filter (TTF) was performed by using $5{\mu}m$ filter paper to optimize coagulants and dosage which enhanced filtrate's turbidity and stabilized filtration flux. When the LPMF was operated with 30 cm gravity with very high dose of inorganic coagulants, the flux was maintained over 80 LMH with 93.5~99.5% turbidity removal. Especially, the filtration was maintained stably in the flux and about 97% of the recovery rate by instantaneous pressurized backwash with about 4 bar of the filtrate when the packing density was about 19%. But there was instability in filtration, since the TMP was continuously going up by inefficient backwash when the packing density was 43%.

• Korean Journal of Environment and Ecology
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• v.30 no.1
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• pp.71-80
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• 2016

The fauna of freshwater fish and water chemistry characteristics were investigated from June, 2014 to October, 2014 at 10 sites in Taebaeksan Provincial Park. A total of 7 species under three families were collected from the survey sites and among them one endangered species - Koreocobitis naktongensis - was identified. The endemic species of Korea were 2 species: Koreocobitis naktongensis, Iksookimia koreensis. Dominant species was Rhynchocypris oxycephalus(89%) and subdominant species was Orthrias nudus(8.9%). Water quality including conductivity, turbidity, pH and total dissolved solids(TDS) varied largely depending on the sampling locations. Values of ambient conductivity and TDS were greater in the upstream than in the downstream, and seasonal variabilities were also higher in the upstream. The pH decreased towards the downstream, and especially showed a sharp decrease in S5. This phenomenon was evident due to a dilution by the influx in the acid mine drainage(AMD) of S4. Physical habit conditions, based on qualitative habitat evaluation index(QHEI) model, indicated a "Sub-optimal" condition(mean: 157.3; range: 78 ~ 194) in the Sodo stream watersheds.

• Journal of the Korean Institute of Gas
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• v.14 no.3
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• pp.1-7
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• 2010

According to Indoor Air Quality(IAQ) management law for multi-use buildings, SEEONE CO., Ltd. made pilot and tested it to remove minute particle, odor, VOCs, etc. within the standards of IAQ. This pilot made by SEEONE CO., Ltd. is vortex scrubber washing electrolyzed water. As 30 minutes test result in multi-use building indoor place, minute particle(the smoke of a cigarette) was reduced $920{\mu}g/m^3{\rightarrow}112{\mu}g/m^3$, gaseous contaminants was reduced Formaldehyde (HCHO) 20ppm$\rightarrow$4ppm, Ammonia($NH_3$) 50ppm$\rightarrow$1ppm, Trimethylamine ($(CH_3CH_2)_3N$) 15ppm$\rightarrow$trace, Methylethylketone($CH_3COC_2H_5$) 25ppm$\rightarrow$trace, Acetic acid ($CH_3COOH$) 20ppm$\rightarrow$trace, Acetaldehyde($CH_3CHO$) 15ppm$\rightarrow$2ppm and Acetone($CH_3COCH_3$) 50ppm$\rightarrow$N.D. The pilot test result of the air filter using electroyzed water in vortex scrubber showed high removal efficiency. Because purified air maintain indoor humidity of approximately 40~60%, so users can feel pleasant. In E.coli, S.aureus sterilization test and CODcr, turbidity treatment test by electrolysis, germs was sterilized over 99.99% and CODcr and turbidity was decreased gradually. So water used for washing can be reused by electrolysis.

• Food Science and Preservation
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• v.21 no.3
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• pp.341-349
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• 2014

The antioxidative effect and quality characteristics of different drying methods (hot air drying, far-infrared radiation drying, vacuum freeze drying) from Schizandra Chinensis Baillon were investigated. The moisture contents and water activity(Aw) contents each 4.46% and 0.38 values of the vacuum freeze drying were lower than those of other samples. A significant not difference in pH values occurred in all samples (p<0.05). The highest content $^{\circ}brix$ vacuum freeze drying was $6.60^{\circ}Brix$ respectively. The turbidity values of the samples were hot air drying 8.24 T%, far infrared radiation drying 0.32 T%, vacuum freeze drying 71.85 T%. The Hunter's L, a and b values of vacuum freeze drying were higher than those of other samples. The order of the free sugar content was glucose>fructose>sucrose, and that of the total free sugar contents were vacuum freeze drying (6.33 g/100 g) > far infrared drying (5.01 g/100 g) > hot air drying (3.73 g/100g). Antioxidant acitivy (DPPH radical scavenging, ABTS radical scavenging) and total phenol, total flavonoid, and total tannin content was highest in vaccum freeze drying than other different drying methods except nitrite scavenging ability.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.3
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• pp.237-247
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• 1987

The present study deals with the physico-chemical and meteorological conditions in Porphyra-cultivation ground to determine the relationship between laver production and its environmental factors in Kwangyang Bay from January to April in 1986. As a result, major environmental factors which are thought to have a great influence upon the poor harvest during the cultivation period are as follows; 1) the excessive rainfall in the beginning of cultivation period 2) the accumulation of suspended matters on the thallus of laver 3) the decrease of current velocity and the stagnation of the water in the cultivation ground.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.378-382
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• 2006

Clarified orange juice was prepared using different clarification methods including centrifugation, enzyme treatment, ultrafiltration (UF), and combined treatment(CT). Effect of clarification methods as well as other quality parameters were investigated. Clarification was improved with increase in centrifugation speed and by lowering operating temperature. The optimum condition for centrifugation process was $5^{\circ}C$ and 10,000 rpm. UF and CT processes were very effective to produce clarified orange juice. The optimum condition of UF process was $45^{\circ}C$ and 150 kPa considering flux and turbidity CT did not significantly improve the clarification efficiency since most of the clarification was already achieved during UF process. $L^*$-values increased while $a^*$-values decreased significantly after clarification regardless of methods (p<0.05) Considering color, and recovering rate of vitamin C and soluble solids, UF process was superior than the other methods in producing clarified orange juice.

• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.317-330
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• 2009

To diminish the levels of organic matters, a novel S-CROM (continuous removal of organic matters in the stream system using freshwater bivalve), was developed and applied to the polluted stream discharging from the wastewater treatment plant, Pocheon stream, Pocheon city (Korea). Major pollutants of the stream were human population and industrial wastewaters. The study was conducted at a small dam constructed within the stream, often called 'bo', and designed with four tanks; no mussels and no sediment (negative control), no mussels and sediment (positive control), 30 mussels and sediment (D1), and 60 mussels and sediment (D2). Physicochemical and biological parameters were measured at 12 hours interval (day and night) after mussel stocking. Results indicated that Anodonta woodiana Lea (D2) clearly removed approximately 72% of chl-$\alpha$ and 57% of suspended solids on second day, however, there were no differences in removal activities between animal densities (P>0.5). Dislike a laboratory CROM system, which previously developed, there were no huge release of nutrient ($NH_3$-N and SRP), due perhaps to the higher flow rate and the lower animal density. Therefore, we may suggest that if we can determine the relevant current and the animal density considering the stream state, an S-CROM system has a strong potential to water quality improvement of eutrophic streams. Some characteristics on both CROM and S-CROM were compared.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1146-1151
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• 1998

To prevent deterioration of the jujube wine quality by using heat sterilization while commercial production, ultrafiltration and microfiltration were applied. The permeate flux and physicochemical properties of jujube wine determined by MF and UF membrane ($0.2\;{\mu}m$ pore size and 50 K dalton cut off) were investigated. The permeate flux increasing caused the increased operating pressure. The Hunter L value of jujube wine treated MF and UF was increased and that of b value was decreased. The turbidity of jujube wine treated MF and UF was largely decreased. And the values of pH, ethanol, total acid and soluble solid were decreased or were at the same level comparing with untreated jujube wine. Retention percentage of sugar and organic acid was more than 80% and was not influenced by operating pressure. Results of sensory evaluation indicated that the color of UF was superior to un-treatment and commercial ones. And the flavor and taste were not significantly different with untreated jujube wine. The quality deterioration of commercial jujube wine could be improved by MF and UF. According to the sensory evaluation, there was also not difference between MF and UF for preference test. Therefore, the quality of jujube wine could be improved by MF having better separation yield efficiency than UF.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.1
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• pp.39-47
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• 2020

In order to investigate current characteristics at the Gungpyung beach, which is a macrotidal flat, field measurements were carried out in the summer and winter at the intertidal and the subtidal zones. The distribution of residual current at intertidal flat was dominant in the northward direction in the summer and dominant in the northward and southwestern directions in the winter. The direction and speed of the residual current in the winter are highly correlated with the significant wave height, and the turbidity is also highly correlated with the significant wave height. Therefore, in the winter, high sediment rates are suspended by high waves, and sediments are transporting due to the residual current in the southwest direction. On the other hand, it is expected that the northward residual current is predominant due to the small wave in the summer, and sediment transport does not occur largely due to less suspended sediments. In addition, sediment transport in the southern direction is blocked by the dock, which is the artificial structure, and the erosion occurs in the south side of the dock. The erosion pattern in the macrotidal zone of Yellow sea is dominated by seasonal waves, and blocking of sediments by artificial structure is very important.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.159-167
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• 2000

In recent years, combined and separated sewer overflows (CSOs, SSOs) have been recognized as a significant pollution problem. To solve this problem a series of experiments were performed in a small scale Rapid Floc Settler (RFS) device to determine its ability in removing micro particles and dissolved materials from polluted waters. The RFS device is a compact physico-chemical wasterwater treatment system. Polyacrylamide (PAM) is used as a coagulant for treating stormwater in the RFS. The results of Jar test showed that PAM could be an excellent coagulant as compared with aluminum sulfate. and ferric chloride. In several experimental conditions, the influence of different variation parameters was tested to measure the efficiency of the RFS. Tests have been carried out with typical CSOs concentrations (50~1.000mg SS/L). The treatment efficiency with regard to SS and COD, which can be obtained at an overflow rate of $130m^3/m^2/day$, are 90% and 80%, respectively. Comparing other sedimentation technologies with RFS, the overflows rate of RFS is ten times faster. The distribution of particle size and number were analyzed. The RFS is suitable for the treatment of CSOs and also the removal of settleable and dissolved materials in urban stormwater runoff.