• Journal of Environmental Science International
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• v.21 no.3
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• pp.289-296
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• 2012

The purpose of this study was to identify the irrigation intervals and the amount of suitable growing substrate needed to achieve the desired shallow-extensive green roof system during a dry summer in Korea. In terms of treatment, three types (SL, $P_6P_2L_2$, $P_4P_4L_2$) with varying soil mixture ratios and two types (15 cm, 25 cm) with varying soil depths were created. The results have been analyzed after measuring growth and soil water contents. The difference of growth by treatment was significant in terms of green coverage, height, leaf width and photosynthesis. In measurement of chlorophyll content, no difference was detected when measured against soil depth. According to the growth measurement of Zoysia japonica with respect to differing soil mixture ratios in the 15 cm-deep treatment, a statistical difference was detected at the 0.05 significance level in photosynthesis. In case of green coverage, height, chlorophyll content and leaf width, no statistical significance was observed. In case of the 25 cm-deep treatment, a statistical significance was observed in height and photosynthesis. In terms of green coverage, chlorophyll content and leaf width, no statistical significance was detected. In comparisons of soil moisture tension and soil water contents, the irrigation interval and amount were 8 days and 14.9 L in the SL (15 cm) treatment, respectively. The irrigation interval showed for 10 days a 1.3-fold increase, and the irrigation amount was 27.4 L 1.8-fold more than SL (25 cm), respectively. For $P_6P_2L_2$ (15 cm) treatment, the irrigation interval and amount were 12 days and 20.7 L, respectively. However, an irrigation interval under $P_6P_2L_2$ (25 cm) was for 15 days 1.3 times longer than $P_6P_2L_2$ (15 cm), and an irrigation amount of 40 L was 1.9 times more than that under $P_6P_2L_2$ (15 cm). In $P_4P_4L_2$ (15 cm) treatment, it was indicated that the irrigation interval was 15 days, and the irrigation amount was 19.2 L. It was not needed to irrigate for 16 days under $P_4P_4L_2$ (25 cm) treatment during the dry summer and the longest no-rain periods. The irrigation interval and amount under $P_4P_4L_2$ were 1.8-fold and 1.3-fold, respectively, more than SL treatment as affected by soil mixture ratio. Comparatively $P_4P_4L_2$ had more 1.3-fold and 0.9-fold in irrigation interval and amount more than $P_6P_2L_2$. Therefore, it can be noted that different soil depth and soil mixture ratios had a significant effect on the irrigation interval and amount.

• Korean Journal of Environmental Agriculture
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• v.6 no.1
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• pp.38-43
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• 1987

This study was carried out to investigate the effect of ozone gas on paddy rice at the different nutrition levels. Jinjubyeo variety of rice plant was exposed to 0.3 ppm ozone gas for 3 hours. It was cultivated at three different application levels, optimum, -50%, and +50% of optimum of nitrogen, phosphorus, and potassium, respectively. After ozone gas fumigation, percentage of damaged leaf, malondialdehyde contents, activity of peroxidase, and nutrient contents of rice plant were observed. The results obtained are as follows. 1) Percentage of damaged leaf was increased at the both additional 50% application of nitrogen and 50% reduction of potassium. 2) Malondialdehyde contents of leaves were increased with the ozone gas exposure. 3) Percentage of damaged leaf was increased at the lower level of $K_2O/N$ ratio in leaves. 4) Nitrogen, phosphorus, and potassium contents in rice leaves were decreased with the ozone gas exposure. 5) The peroxidase bands on gel in electrophoresis were changed by the ozone gas exposure.

• Korean Journal of Environmental Agriculture
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• v.6 no.2
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• pp.31-38
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• 1987

The present study was carried out to determine the effect of the physical, chemical and mineralogical properties of paddy soil on the adsorption and desorption of $Sr^{90}$ from absorbed soils. The results obtained were as follows: 1. Most of the adsorbed $Sr^{90}$ was exchangeable and water soluble. $Sr^{90}$ extracted by ammonium acetate was very high compared to the water soluble fractions, and the ammount decreased with the increase of calcium application, but increased proportionally with the increase of $Sr^{90}$ treatment. 2. The distribution of $Sr^{90}$ in paddy soil depend on the soil type. Average-distribution rates of water soluble, exchangeable and non-exchangeable fractions of $Sr^{90}$ in the soils were 28.6%, 59.3% and 12.1% respectively. 3. The non-exchangeable from of $Sr^{90}$ was high in the soils of high illite and low vermiculite content. 4. The desorption of $Sr^{90}$ from adsorbed soils decreased with the increase of pH and ex-cations of the soils, but increased with the amount of organic matter and clay content in the soil.

• Environmental Mutagens and Carcinogens
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• v.26 no.4
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• pp.125-132
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• 2006

Previous studies showed that epigallocatechin gallate(EGCG) have substantial effects of suppressing the N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)-initiated cell transformation process on the bases of foci formation frequency and loss of anchorage dependency. In this study we tried to clarify the molecular mechanism of suppressing the cell transformation process. Mouse cell line balb/c 3T3 A31-1-1 was exposed 2 days to MNNG followed by 15 days 12-O-tetradecanoylphorbol-13-acetate(TPA) treatment for our transformation process. EGCG was added after the time point of 24 hours exposure to TPA and incubated for 19 days. 2029 genes were selected in our transformation process that showed fold change value of 1.5 or more in the microarray gene expression analysis covering the mouse full genome. These genes were found to be involved mainly in the cell cycle pathway, focal adhesion, adherens junction, TGE-$\beta$ signaling, apoptosis, lysine degradation, insulin signaling, ECM-receptor interaction. Among the genes, we focused on the 631 genes(FC>0.5) reciprocally affected by EGCG treatment. Our study suggest that EGCG down-regulate the gene expressions of up stream signaling factors such as nemo like kinase with MAPK activity and PI3-Kinase, Ras GTPase and down stream factors such as cyclin D1, D2, H, T2, cdk6.

• 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.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.1
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• pp.9-14
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• 2009

In this research, a polyester manufacturing company (i.e. K Co.) in Gumi, South Korea was investigated regarding the release of high concentrations of 1,4-dioxane(about 600 mg/L) and whether treatment prior to release should occur to meet with the level of the regulation standard (e.g., 5 mg/L in 2011). The pilot-scale (reactor volume, 10 $m^3$) treatment system using Photo-Fenton Oxidation was able to remove approximately 90% of 1,4-dioxane under the conditions that concentrations of 2,800 ppm $H_2O_2$ and 1,400 ppm $FeSO_4$ were maintained along with 10 UV-C lamps (240 ${\mu}W/cm^2$) illuminated during aeration. However, the effluent concentration of 1,4-dioxane was still high at about 60 mg/L. Thus, further investigation is needed to see whether the bench scale (reactor volume, 8.9 L) of activated sludge could facilitate the decomposition of 1,4-dioxane. As a result, 1,4-dioxane in the effluent has been decreased as low as about 2~3 mg/L. Consequently, Photo-Fenton Oxidation coupled with activated sludge process can make it possible to efficiently decompose 1,4-dioxane to keep up with that of the regulation standard.

• Korean Journal of Environmental Agriculture
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• v.7 no.1
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• pp.21-25
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• 1988

A pot experiment was conducted to find out the effect of arsenic(As) added to soil on the number of roots, root diameter, root length and root tissue of the rice plant. The results obtained were as follows: Higher As levels in soil remarkably reduced not only the number of roots, root length and root diameter, but also the diameter of the central cylinder, the route of the water and inor ganic nutrients of the roots. When arsenic was treated in soil, abnormal cells in the cortex of rice root were developed and considerably increased with higher As levels in the soil. These were only observed in the middle and upper parts of root segments except root tips and they looked like rice roots without epidermis in shape. Therefore, the occurrence of the abnormal cells in the root was attributed to high arsenic accumulation in the root. Its mechanism is not clear. However, it is assumed that the abnormal cells had occurred to compensate for lower amount of water and inorganic nutrient absorption by the injured rice root or self-defense against the penetration of arsenic within the rice root.

• Korean Journal of Environmental Biology
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• v.27 no.1
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• pp.114-123
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• 2009

The species composition and biomass of coralline algae around three (Uljin, Wolseong and Gori) nuclear power plants on the east coast of Korea were investigated seasonally from February 1997 to October 2006. As a result, 13 species of coralline algae were found during the past ten years. Among them, Corallina pilulifera, C. officinalis, Amphiroa zonata and Pneophyllum zostericolum were common species that occurred more than 50% in frequency during the study period. Species number of coralline algae were between 10$\sim$12 species at the breakwaters near the outfalls of power plants and 8$\sim$12 species at the control area, and differences in species composition were not observed among study sites. Seasonal fluctuations of mean biomass were 0$\sim$2,530 g dry wt m$^{-2}$ and dominant species in biomass was Corallina pilulifera at all the study sites. The breakwaters of power plants generally had a greater coralline algal biomass than the control area. Biomass proportions of coralline algae at the breakwaters of power plants were also higher than those at the control area. At the Uljin sites, particularly, biomass of coralline algae showed greatest in summer and biomass proportion showed highest during the summer season. Differences in the spatio-temporal patterns of coralline algae around three nuclear power plants on the east coast of Korea were presumably due to the regional temperature variations.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.288-294
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• 2013

Recently, sustainable production of biofuel using algal biomass is being pursued because of its enormous potential. First and foremost, securing superior strains to develop an efficient production system for algal biodiesel through screening or genetic improvement of microalgae is necessary. The genus of Botryococcus is regarded as one of the superior microalgae for biodiesel production due to its ability to accumulate high amounts of lipids and hydrocarbons. However, its low growth rate is a bottleneck for large-scale production and commercialization. The purpose of this study is to obtain indigenous Botryococcus strains which possess high lipid content and biomass productivity. The Botryococcus sp. was isolated from the Seobu Reservoir in Jeju Island and identified as Botryococcus sudeticus J2 by comparative analysis of 18s rRNA gene and ITS regions. The biomass productivity and lipid content of B. sudeticus J2 were 0.116 g $L^{-1}day^{-1}$ and 40.1% of dry wt., respectively. This was higher than the value of B. braunii UTEX 572, which is widely regarded as a superior strain among Botryococcus species. The relatively high growth rate of B. sudeticus J2 was achieved under a light intensity of 240 ${\mu}mol$ photons $m^{-2}s^{-1}$ with ambient air spargingwhen compared to 120 ${\mu}mol$ photons $m^{-2}s^{-1}$ with 2% $CO_2$ supply. In summary, it is likely that the isolated B. sudeticus J2 can be used for the mass cultivation and biodiesel production.

• Journal of Animal Environmental Science
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• v.16 no.3
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• pp.215-226
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• 2010

The pig slurry leachate was dark brown-colored solution that leaches out of woodchip trickling filter. The purpose of this research was to investigate the effect of pig slurry leachate and byproduct on growth characteristics of leaf lettuce in hydroponics culture. The effects of addition of fish meal, bone meal and crab shell for the growth of leaf lettuce were investigated. Leaf lettuce were grown in each of six combination treatment solutions; slurry leachate, slurry leachate + fish meal, slurry leachate+bone meal, slurry leachate + crab shell and chemical hydroponic solution for lettuce based on EC content. The chemical nutrient solution was the solution of National Horticulture Research Station for the growth of lettuce. The all of nutrient solution was adjusted 1.5 mS/cm in EC in hydroponics culture. 1. The pH level of leachate of trickling filter was increased and EC decreased gradually during treatment. Pig slurry leachate was low in suspended solids (SS), phosphorus (P), but rich in potassium (K). 2. The plot of slurry leachate (SL) was lowest in the growth characteristics of lettuce. The leaf length and width of lettuce treated with mixture plot of slurry leachate and fish meal (SL + FM) was higher compared with plot in slurry leachate. The chlorophyll reading was reduced in plot treated with slurry leachate, but that in plot of SL+FM was similar compared with control plot. 3. The fresh weight of lettuce showed lowest in the plot treated with slurry leachate. The addition of fish meal increased the yield of comparing plot of slurry leachate, but plots of bone meal and crab shell addition were not significantly difference. The fresh weight of leaf lettuce in plot of SL+FM was 87% as 400.0g compared with control. In conclusion, the mixture solution of pig slurry leachate and fish meal could be used as a nutrition solution of organic lettuce hydroponics.