• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.1
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• pp.53-64
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• 2020

A 2㎥/d combined wastewater treatment pilot plant containing the multi-stage vertical stacking type nitrification reactor was installed and operated for more than 1 year under the operating conditions of the short-circuit nitrogen process (pH 8, DO 1mg/L and Internal return rate 4Q from nitrification to denitrification reactor). For economically the combination treatment of food wastewater and the leachate from a landfill, the optimal combination ratio was operated by adjusting the food wastewater with the minimum oil content to 5-25% of the total throughput. The main treatment efficiency of the three-phase centrifugal separator which was introduced to effectively separate solids and oil from the food wastewater was about 52% of SS from 116,000mg/L to 55,700mg/L, and about 48% of normal hexane (NH) from 53,200mg to 27,800 mg/L. During the operational period, the average removal efficiency in the combined wastewater treatment process of BOD was 99.3%, CODcr 94.2%, CODmn 90%, SS 70.1%, T-N 85.8%, and T-P 99.2%. The average concentrations of BOD, CODcr, T-N, and T-P of the treated water were all satisfied with the discharge quality standard for landfill leachate ("Na" region), and SS was satisfied after applying the membrane process. On-site leachate had a relatively high nitrite nitrogen content in the combined wastewater due to intermittent aeration of the equalization tanks and different monthly discharges. Nevertheless nitrite nitrogen was accumulated, denitrification from nitrite nitrogen was observed rather than denitrification after complete nitrification. The average input of anti-forming chemical during the operation period is about 2L/d, which seems to be economical compared to the input of methanol required to treat the same wastewater.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.6
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• pp.16-24
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• 2015

This study quantified storage and annual uptake of carbon for riparian greenspaces established in watersheds of four major rivers in South Korea and explored desirable strategies to improve carbon reduction effects of riparian greenspaces. Greenspace structure and planting technique in the 40 study sites sampled were represented by single-layered planting of small trees in low density, with stem diameter at breast height of $6.9{\pm}0.2cm$ and planting density of $10.4{\pm}0.8trees/100m^2$ on average. Storage and annual uptake of carbon per unit area by planted trees averaged $8.2{\pm}0.5t/ha$ and $1.7{\pm}0.1t/ha/yr$, respectively, increasing as planting density got higher. Mean organic matter and carbon storage in soils were $1.4{\pm}0.1%$ and $26.4{\pm}1.5t/ha$, respectively. Planted trees and soils per ha stored the amount of carbon emitted from gasoline consumption of about 61 kL, and the trees per ha annually offset carbon emissions from gasoline use of about 3 kL. These carbon reduction effects are associated with tree growth over five years to fewer than 10 years after planting, and predicted to become much greater as the planted trees grow. This study simulated changes in annual carbon uptake by tree growth over future 30 years for typical planting models selected as different from the planting technique in the study sites. The simulation revealed that cumulative annual carbon uptake for a multilayered and grouped ecological planting model with both larger tree size and higher planting density was approximately 1.9 times greater 10 years after planting and 1.5 times greater 30 years after than that in the study sites. Strategies to improve carbon reduction effects of riparian greenspaces suggest multilayered and grouped planting mixed with relatively large trees, middle/high density planting of native species mixed with fast-growing trees, and securing the soil environment favorable for normal growth of planting tree species. The research findings are expected to be useful as practical guidelines to improve the role of a carbon uptake source, in addition to water quality conservation and wildlife inhabitation, in implementing riparian greenspace projects under the beginning stage.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1331-1343
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• 2000

Through the integration of USLE and GIS, the methodology to estimate the soil loss was developed, and applicated to the Sacheon river in Gangrung. Using GIS, spatial analysis such as watershed boundary determination, flow routing. slope steepness calculation was done. Spatial information from the GIS application was given for each grid. With soil and land use map, information about soil classification and land use was given for each grid too. Based upon these data, thematic maps about the factors of USLE were made. We estimated the soil loss by overlaying the thematic maps. In this manner, we can assess the degree of soil loss for each grid using GIS. Annual average soil loss of Sacheon river watershed is 1.36 ton/ha/yr. Soil loss in forest, dry field, and paddy field is 0.15 ton/ha/yr, 27.04 ton/ha/yr, 0.78 ton/ha/yr respectively. The area of dry field, which is 4% of total area, is $2.4km^2$. But total soil loss of dry field is 6561 ton/yr, and it occupies 84.9 % of total soil loss eroded in Sacheon river watershed. Comparing with the 11.2 ton/ha/yr of an average soil loss tolerance for cropland, provision for the soil loss in dry field is necessary. Run-off and water quality of Sacheon river were measured two times in flood season: from July 24, 1998 to July 28 and from September 29 to October 1. As the run-off of the river increased, SS, TN, TP concentrations and pollutant loadings increased. SS, TN, TP loads of Sacheon river discharged during the 2 heavy rains were 21%, 39%, and 19% of the total pollutant loadings generated in the Sacheon river watershed for one year. We can see that much pollutants are discharged in short period of flood season.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.249-256
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• 2009

The amount of nutrients from the effluents of rice culture - free-range ducks (RCFD) paddy fields and the effects of natural wetlands located at downstream of RCFD on water quality and aquatic plants was evaluated. This was carried out in a 61.9 ha paddy fields in Ulsan, Gyeongnam, where downstream is a 5.9 ha natural wetland, 61% of which was covered with well-developed aquatic plants. The amounts of T-N and T-P in the effluent from paddy field with RCFD were 13.7 and $2.5kg\;ha^{-1}$, respectively, which is 1.2~2.5 times higher than those observed in conventional rice culture practice. The amount of runoff from the RCFD area, calculated using the revised TANK model, was $543mm\;ha^{-1}$ with 808 kg of T-N and 130 kg of T-P during rice cultivation period. The dominant aquatic plants in the wetland includes Phragmites communis, Zizania latifolia, Persicaria thunbergii. etc. The nutrient contents of the aquatic plants which amounted to 761 kg of T-N and 103 kg of T-P were almost equivalent to 94% and 79% of the T-N and T-P in RCFD and CRC effluent. Therefore, the use and maintenance of wetlands in RCFDs area could be a good solution to management the non-point pollution from duck feces in RCFD paddy fields.

• Korean Journal of Microbiology
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• v.51 no.4
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• pp.389-397
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• 2015

Dongchun, one of the representative streams in urban area, is a downstream that is connected to Hogyechun, Bujeonchun, Jeonpochun, Danggamchun, and Gayachun as its upstream. Hogyechun has been mostly covered with concrete structures for decades, causing sewage pollution from the upstream, overflow of the downstream region and other serious pollution that gave rise to many civil complaints from the residents nearby. In this study, we analyzed 3 stations, including control station for water quality and malodor changes of Hogyechun after applying the microbial augmentation (BM-2) for a few months including the rainy season. Amounts (g/h) of DO in the middle site (Middle) and the downstream site (Borim) increased by 1.7 times compared with the upstream site (Chuhae) after augmentation for about 2 months. Amounts (g/h) of COD and $NO_3{^-}N$ decreased by 2 and 1.7 times, respectively, in the middle and downstream sites while SS increased by 7.5 and 22 times in the middle and downstream sites, respectively. Moreover, odor removal efficiencies at the middle and downstream sites were 65% and 19%, respectively, indicating the microbial activity in reduction of malodor in the polluted stream. The dominant microbial species of the sampling sites were Hydrogenophaga caeni, Sphaerotilus natans, Acidovorax radicis, Acidovorax delafieldii, and Cloacibacterium rupense. Densities of the two species Sphaerotilus natans and Acidovorax delafieldii were significantly increased in the middle site after augmentation which possessed potential odor removal and denitrification activity, respectively. Potential pathogens (e.g., Arcobacter cryaerophilus) were also removed from the middle site after the implementation.

• Journal of the Korean Society of Groundwater Environment
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• v.1 no.1
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• pp.23-32
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• 1994

To determine the apparent equilibrium constants, K$_{ad,app}$, for the adsorption reactions of trace metals on amorphous iron oxyhydroxide (AIO) in the Taebag coal mine area, time-adsorption and pH-adsorption experiments were performed for a selected bottom sediment mainly comprised of AIO from the study area. The results from the adsorption experiments indicate that most of the trace metals, except Pb, achieve equilibrium states with AIO and thus, the calculated K$_{ad,app}$ may represent the true apparent equilibrium constants. K$_{ad,app}$ and the stoichiometric coefficients of proton, x, of the adsorption reactions between the trace metals and AIO were respectively calculated from the intercepts and slopes of the regression lines of log($\Gamma$/ ［M］$_{aq}$)against pH provided by pH-adsorption experiments. The calculated K$_{ad,app}$ this study has the values of the range from 10$^{－4.5}$ to 10$^{2.75}$ , which is much different from the reported values by other investigators for simple experimental systems. K$_{ad,app}$ of this study is more or less close but not exactly pertinent to the estimated values for the other natural systems. It indicates that K$_{ad,app}$ for the adsorption reactions in the aquatic system in the study area is unique and thus should be determined befor the adsorption modelling. The calculated x of this study has the values of the range from -0.3 to 0.7, which is also much different from what most geochemists generally accept. The discrepancy in x may be due to the competition among different kinds of ionic species on the adsorption site or simulataneous occurrence of different kinds of adsorption reactions. The results from this study should help construct an appropriate adsorption model for the aquatic systems polluted by the coal mine drainage in the Taebag area. With the constructed model, one can describe the concentration variations of trace metals due to the adsorption in the system, which is an essential part of the investigation on the water quality affected by coal mine drainage in the Taebag coal field.

• Journal of Aquaculture
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• v.11 no.2
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• pp.193-201
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• 1998

This study was carried out to investigate the enviromental quality and the growth of transplanted pen shell, Atrinna pectinata japonica. Followings are the results of growth of transplanted pen shell with respect to the shell size groups from the natural habitat (Usando) in May 1995, and cultivated upto November in the transplantated area (Soomoonri). The water depth of transplantated area andnatural habitat were 3m, 20~25m, respectively. The seawater temperature of the two culturing farms were ranged of 10.9~$27.8^{\circ}C.$, 8.5~$30.0^{\circ}C.$, respectively at the lowest in November adn the highest in July. The seawater salinity of the two areas were ranged of 29.54~35.26$^0\prime\infty$, 28.75~36.31$^0\prime\infty$, respectively at the lowest in July and the highest in November. The phosphoric acid ($PO_4$-P) of the two areas were 0.09~$1.14 ^{\mu}$g-at/l, 0.23~$1.33 ^{\mu}$g-at/l, respectively at the lowest in June and the highest in September. The bottom type of the two areas was a silty mud, 85.23% (82.17~87.26%) in natural habitat and 92.12% (90.76~92.94$^0\prime\infty$) in transplanted area. In this study area, phytoplankton were composed of 19 species. Of these 19 species, Skeletonema costatum was dominant species in seawater between natural habitat and transplantatied area, and 157 cells/ml, 165 cells/ml at August respectively. Stock of phytoplankton in transplantated area were more than those of natural habitat except June and November. The growth of shell length, shell height, total weight, soft part weight and posterior adductor muscle weight of pen shell on different size groups (SL 10, 10~15, 15~20, 20cm) were excellent in shell length of 10cm group, and 99.32%, 107.66%, 871.09%, 951.26% and 1,223.76%, respectively. The survival rate of pen shell was 98.10% in the shell length of 10cm groups, 90.35~94.76% in the others groups. The growth of shell length, total weight, soft part weight and posterior adductor muscle weight of pen shell in transplantated area were more 1.3, 2.6, 2.7 and 4.5 times than those of natural habitat.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.11
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• pp.1546-1553
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• 2012

In this study, sorghum teas were prepared from Sorghum bicolor L. Moench subjected to different types of milling (no milling (0%), minimum milling (5%), and milling (20%)) and pan-firing times (1 to 10 minutes), and its quality characteristics were investigated. With regards to milling type, total polyphenolic, flavonoid, tannin contents, and antioxidant activities of ethanol extracts from both no milling sorghum and its tea were highest, followed by minimum milling and milling in decreasing order. Crude nitrogen content was highest in milling sorghum and its tea regardless of pan-firing time. With regards to pan-firing time, total polyphenolic, flavonoid, tannin contents, and antioxidant activities of sorghum teas increased with increasing pan-firing time regardless of milling type. The highest DPPH and ABTS radical scavenging activities were observed at a pan-firing time between 7 to 9 minutes. In contrast to ethanol extracts of pan-fried sorghum tea, antioxidant activities, chromaticity, and turbidity of hot water leaching liqueur of sorghum tea were highest in milling sorghum tea, followed by minimum milling and no milling sorghum tea.

• Journal of Agricultural Extension & Community Development
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• v.21 no.4
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• pp.1125-1147
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• 2014

This study was conducted to develop the health evaluation indicator of pond wetland in order to enhance the quality of eco-experience in rural area. The methods for development of evaluation indicator were consisted of 3 stages; 1st, the precedent assessment protocol was applied to 10 pond wetlands in farm villages, and eco-experience expert survey was conducted to selection the evaluation item and criteria at 2nd and 3rd stages. In the results of applying the precedent assessment protocol, we found out two problems; 1) the evaluation result of value determination and conservation value were too simple, and 2) the score by evaluation items were nearly the same, because evaluation criteria in not precisely for application in rural area. These results were reflected to expert survey. According to the 1st survey results, they suggested that 4 items should be maintained, and 3 items should be deleted, and 2 items should be modified among a total of 9 times. Therefore, it was modified into the evaluation protocol having a total of 8 items. According to the 2nd survey results, the selected evaluation items were generally proper. With regard to items for assessing the health condition of pond wetland, we selected a total of 8 items; (1) Connectivity to forest, (2) Connectivity between water body and wetland connection, (3) Number of Vegetation, (4) Surround land use, (5) Interspersion of Vegetation, (6) Crossing Structure, (7) Wetland size, and (8) Outlet structure. In addition, it was suggested that accessibility, visibility, and trash were need for utilization of pond wetland as a place for eco-experience. It is expected that the selected evaluation indicator can help to utilize the pond wetland as an eco-experience space in rural area, and maintain the pond wetland as a space for conservation of biodiversity.

• Culinary science and hospitality research
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• v.17 no.4
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• pp.307-315
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• 2011

The purpose of this study was to investigate the physicochemical properties of modified green gochujang, produced by Chengyang pepper powder and roasted soy powder. The moisture content of control gochujang (CON) made by red pepper powder was 32.64% whereas the content of sample 1 gochujang (S1) made by Chengyang pepper powder was 26.50%. Crude fat content of CON was 1.81% while the content of S1~S4 was a range of 2.64~2.80%. Furthermore, crude protein content of CON was 5.58% while the content of S4 was the highest value of 9.01 % In crude ash cases, S1~S4 groups were also increased to a range of 10.32~10.37% when compared to 9.91% of CON. Color properties of modified gochujang made by Chengyang pepper powder were significantly decreased in values of redness and yellowness, compared to that of CON. In pH test, it showed that pH 6.15 of S4 was significantly increased, compared to ph 5.26 of CON (p < 0.001). Total acidity of all sample groups has significantly decreased according to increased roasted soy powder than that of CON (p < 0.001). In textural properties, hardness of gochujang was a range of 622.33~3670.70 and S2 showed the highest value among others. Meanwhile, S4 showed the highest value in the adhesiveness, and S2 showed the highest gumminess. According to these results, modified gochujang was increased in nutritive values such as protein, fat, and various minerals, even though it was decreased in color and water contents. Therefore, modified gochujang would have beneficial effects on health, but it could be needed to find out the optimizing condition through a sensory evaluation for developing a new sauce using Chengyang.