• Journal of Korean Society on Water Environment
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• v.25 no.2
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• pp.245-255
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• 2009

CN values are changed by various surface condition, which is cover type or treatment, hydrologic condition, or percent impervious area, even the same combination of land use and hydrologic soil group. In this study, CN parameters were regionalized for Nakdong River Basin by Long-Term Hydrologic Impact Assessment (L-THIA) coupled with SCE-UA, which is one of the global optimization technique. Six watersheds were selected for calibration (optimization) and periodic validation and two watersheds for spatical validation as ungauged watershed within Nakdong River Basin. Nash-Sutcliffe (NS) values were 0.66~0.86 for calibration, 0.68~0.91 for validation, and 0.60 and 0.85 for ungauged watersheds, respectively. Urban area for the selected watersheds covered high impervious area with 85% for residential area and 92% for commercial/industrial/transportation area. Hydrologic characteristics for crop area was similar to row crop with contoured treatment and poor hydrologic condition. For the forested area, hydrologic characteristics could be clearly distinguished from the leaf types of plant. Deciduous, coniferous, and mixed forest showed low, moderate, and high runoff rates by representing wood with fair and poor hydrologic condition, and wood-grass combination with fair hydrologic condition, respectively. CN parameters from this study could be strongly recommended to be used to simulate runoff for ungauged watershed.

• Korean Journal of Environment and Ecology
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• v.16 no.2
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• pp.179-187
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• 2002

Constructed wetland was built for industrial factory wastewater treatment with environmentally sound method from July to October, 2000. Ultimately this case study was carried out to conserve water quality of river and underground water and to provide wildlife habitat and rest place for people in the industrial area. The size of constructed wetland was 10m$\times$6m (upper area) with a treatment capacity of 2.5㎥ per day. It was supplied with wastewater 0.625㎥ at intervals of six hours. Vertical flow system was chosen to promote efficiency. Draining layer was built one meter in soil depth out of sand mixed with pebbles in a ratio of two to one. Perennial emergent plants, Phragmites communis, Typha orientalis, Juncus effusus, Iris pseudoacorus, 20 individuals per square meter were planted. In the aspect of reusing, eco-pond was created for increasing biological species diversity and also deck and information signboard were established for the education of environment. As the result of monitoring, it was revealed that the constructed wetland was effective in removal of BOD$_{5}$, COD, T-N, T-P and has being gradually improved as a wildlife habitat(biotope).

• Clean Technology
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• v.12 no.1
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• pp.1-9
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• 2006

Aqueous cleaning agents which are considered to be environmental-friendly and promising alternative ones among various industrial cleaning agents were evaluated in this words. In order to formulate aqueous cleaning agents, primary alcohol ethoxylates with 3, 5 and 7 moles of ethylene oxides among nonionic surfactants were selected as main surfactants. And anionic surfactants and alcohols were chosen as their cosurfactants. Builders such as NaOH, KOH, $Na_2CO_3$ and $NaHCO_3$ were also evaluated as additives for improvement of cleaning efficiency of aqueous cleaning agents. The experimental results of cleaning ability tests show that introduction of anionic surfactant TLS as cosurfactant in alcohol ethoxylate-based aqueous solution gives the best cleaning efficiency for removing mixed soil of cutting oil and grease. NaOH and $Na_2CO_3$ are also shown to play an important role for improvement of cleaning efficiency in a aqueous cleaning agent.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.6
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• pp.800-809
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• 2011

The objective of this study was to investigate the effects of different ratios of corn silage (CS): alfalfa hay (AH), and extruded soybeans (ESB) on milk yield, milk composition, blood metabolites, and fatty acids in milk fat and plasma. Ninety multiparous Holstein cows were arranged in a randomized block design experiment which lasted 14 weeks. Treatments were arranged as a $3{\times}3$ factorial with 0%, 5% or 10% ESB (dry matter basis) and three forage treatments: I) 30% CS, 10% AH and 10% Leymus chinense hay (LC); ii) 20% corn silage, 20% alfalfa hay and 10% LC; iii) 10% CS, 30% AH and 10% LC. Cows were allowed to consume a total mixed ration ad libitum. There was no change of dry matter intake when cows were fed the experimental diets. As more AH was added to the diets, milk yield, milk protein content and yield, and trans9, cis11-conjugated linoleic acids (CLA) concentrations in milk fat and plasma increased. When ESB were supplemented to the diets, milk yield, and trans9, cis11-CLA concentration in milk fat and plasma increased. When 10% ESB was added to the diet containing 30% AH the trans9, cis11-CLA content (1.46 g/100 g of total fatty acids) in milk was the highest among all treatments. These results suggests that AH could replace part of a CS diet and be a good forage source of diet for dairy cows to improve milk yield and milk composition. Meanwhile, ESB could be included in the diet with high AH to improve production performance of dairy cows.

• Journal of the Korean GEO-environmental Society
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• v.3 no.4
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• pp.67-79
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• 2002

The purpose of this study is to present criteria of selection of optimum grout materials through analyzing the limitation of permeability of each materials(MSG-N, OPC), in various ground conditions by comparing presentation of strength and permeability of MSG method and LW method(or SGR method). To do that, physical and chemical characteristics of grout materials were analyzed and compressive tests of homogel, mixed coagulation materials and hardening materials in certain mixing ratio, and of milk paste. In addition, permeability tests for each ground soil, each injection pressure, and each materials in combined stratum were performed with massive chamber. The results of tests showed that ultra fine grout materials like grout of MSG is necessary to construct effective grouting in sand and silty sand ground. Also, it is expected to become chemical grouting guide data to layout construction engineers because presented proper injection pressure by kind of object ground in case using ultra-fine grout material.

• Journal of Environmental Science International
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• v.6 no.2
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• pp.153-163
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• 1997

In order to fad the most fitted biodegradation model, biodegradation kinetics model to the initial phenol and p-cresot concentrations were investigated and had been fitted by the linear regression. Bacteria capable of degrading p-cresol were isolated from soil by enrichment culture technique. Among them, strain Ml capable of degradillg p.rcresol has also degraded phenal and was identified as the genus Micrococcus from the results from of taxonomical studies. The optimal tonditlons for the biodegradation of phenal and p-cresol by Micrococcus sp. Ml were $NH_4NO_3$ 0.05%, pH 7.0, 3$0^{\circ}C$, respectively, and medium volume 100m1/250m1 shaking flask. iwicrococcus sp. Ml was able to grow on phenal concentration up to 14mM and p-cresol concelltration up to 0.8mM. With increasing substrate concentraction, the lag period increased, but the maximum specific growth rates decreased. The yield coefficient decreased with increasing substrate concentation. The biodegradation kinetics of phenol and p-cresol were best described by Monod with growth model for every experimented concentration. In cultivation of mixed substrate, p-cresol was degraded first and phenol was second. This result implies that p-cresol and phenol was not degraded simultaneously.

• Journal of Environmental Science International
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• v.16 no.9
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• pp.1011-1018
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• 2007

This study was conducted to analysis the ecological characteristics of "Wando HolIy"$(llex{\times}wandoensis)$ which is expecting as a possible ornamental tree with its beautiful leaves, flowers and fruits, and to find special breeding material which have particular characteristics and also provide correct environmental information which are required for commercial cultivation. The hill of Galmoon-Ri, Gunoei-Myon, Jeonnam Province, Korea, were reported as a original habitat of native $llex{\times}wandoensis$. The investigation shows that soil pH of native habitat was 6.18, hardness was 2.39, humidity was 38.6%, direction of slope is SSW, and average inclination was $15^{\circ}. The vegetation around $I.{\times}wandoensis$ is occupied by trees like an Quercus variabilis, Q. serrata, Q. acuta and so on. These are mixed forest of deciduous trees. Tree height reached up to about 12m and its coverage is about 30%. Q. salicina, Camellia japonica, I. integra, Cryptomeria japonica account for sub-tree layer. Tree height is around 8m and coverage is about 20%. Shrub layer was taken by Viburnum furcatum, Callicarpa japonica, Styrax japonica, Eurya japonica, Lindera obtusiloba, Ligustrum japonicum, Smilax china, Cornus walteri etc. Tree height reaches around l.2m and coverage is around 20%. Herb layer includes Trachelospermum asiaticum var. intermedium, Cymbidium goeringii, Dryopteris bissetiana, Disporum viridescens, Disporum smilacinum, Sasa borealis var. gracilis etc. Trachelospermum asiaticum var. intermedium, which are observed in southern evergreen zone, are dominant and its coverage is around 20%. The native habitat was in spoiled condition because of artificial thin out.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.2
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• pp.53-61
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• 1999

This study was conducted to determine the optimal collecting time and methods of utilization of forest topsoil as a seed-bank source for revegetation materials of slopes. From April to November of 1998, nursery seedbeds in the greenhouse of Seoul National University were seeded with mixtures of forest topsoil and seeds. The nursery seedbeds were treated to evaluate the effect of depths of forest topsoil and seeding amounts. Seasonal experiments with $3{\times}3$ factorial design were conducted in April, June and August. More than 40 seedlings/$m^2$ were observed as the naturally-emerged species in the plot, treated with the top-layer forest soil within the depth of 10cm. However, it was found, as seeding more seeds, the number of appearance of the naturally-emerged species reduced because of the heavy competition between the seeded and the naturally-emerged. According to the results of this research, it is recommended that seeding amount should be no more than 1,000 seeds/$m^2$ to avoid the severe competition. Also it was observed that the forest topsoil collected in spring(April) is better than that collected in summer. The more species of the naturally-emerged were found in the forest topsoil collected in spring. Forest-topsoil-mixed-materials as a seed-bank source could significantly increase the plant diversity and productivity. Effective use of forest topsoil as a seed-bank source may become a valuable tool in future restoration of disturbed slopes for promoting plant community diversity and recycling of spoiled-soils from the slopes.

• Journal of Animal Environmental Science
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• v.12 no.1
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• pp.41-44
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• 2006

Broiler manure has much nutrient that can be used as the organic fertilizer to enhance the fertility of soil. However, if it is used directly without biodegradation of organic materials and destruction of weed seed and harmful bacteria, it can produce the generation of weed and disease of plant. Composting of manure is a biodegradation of organic materials into inorganic materials and humus. To proceed biodegradation of manure effectively and enhance the composting performance, optimum environmental condition for microbial growing should be maintained. Environmental variables which can influence the growing activity of microbes are moisture content, pH, porosity, C/N of the composting materials and oxygen supply quantity. Oxygen and porosity are usually supplied by aeration or mixing of materials. This study was intended to investigate the effect of mixing frequency on the composting performance. Mixing of composting materials was performed by turning the bioreactor up and down by hand without any mechanical energy. The broiler manure was captured from the greenhouse type broiler ham as the compounds of broiler manure and rice-hulls, which were used as the base materials. To compost the compounds of broiler manure and rice-hulls, dairy manure was mixed to get appropriate characteristics of composting material. Composting temperature over $55^{\circ}C$ for killing pathogen and weed seed was maintained for longer period with increase of mixing frequency.

• Journal of Korean Society on Water Environment
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• v.28 no.4
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• pp.495-504
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• 2012

In recent years, urbanization has been a hot issues in watershed management due to increased pollutant loads from impervious urban areas. The Soil and Water Assessment Tool (SWAT) model has been widely used in hydrology and water quality studies at watershed scale. However, the SWAT has limitations in simulating water flows between HRUs and hydrological effects of LID practices. The Storm Water Management Model (SWMM) has LID capabilities, but it does not simulate non-urban areas, especially agricultural areas. In this study, a SWAT-SWMM coupled model was developed to evaluate effects of LID practices on hydrology and water quality at mixed-landuse watersheds. This coupled SWAT-SWMM was evaluated by comparing calibrated flow with and without coupled SWAT-SWMM. As a result of this study, the $R^2$ and NSE values with SWAT are 0.951 and 0.937 for calibration period, and 0.882 and 0.875 for validation period, respectively. the $R^2$ and NSE values with SWAT-SWMM are 0.877 and 0.880 for validation period. Out of four LID scenarios simulated by SWAT-SWMM model, the green roof scenario was found to be most effective which reduces about 25% of rainfall-runoff flows.