• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.6
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• pp.145-159
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• 2010

A Sustainable Structured wetland Biotop (SSB) system was planned, designed, and finally constructed, and maintained in the An-teo Reservoir ecological park, which is the habitat of the endangered Gold-spotted Pond Frog. The system purifies polluted water of An-teo Reservoir which flows from up to bottom within the system. Water was sampled once a month at the inlet and at the outlet from December, 2009 to August, 2010. BOD5, SS, T-N and T-P were analyzed. Average influent and effluent BOD5 concentration was 2.9 and 1.0 mg/L, respectively, and BOD5 removal was 67%. SS concentration of influent and effluent averaged 18.1 mg/L and 2.5 mg/L, respectively, and SS abatement amounted to 86%. Average influent and effluent T-N concentration was 0.426 mg/L and 0.147 mg/L, respectively, and T-N retention was 66%. T-P concentration of influent and effluent averaged 0.071 mg/L and 0.022 mg/L, respectively, and T-P removal amounted to 68%. Plant and frog species of the system were monitored during the period. Amphibia and reptiles provided 7 species and 4 families including the Endangered Gold-Spotted Pond Frog (Rana chosenica ) which also lives in the system. Twenty-six plant species were naturally introduced into the system, however, they didn't make up a significant portion of the plant populations compared with the planted species. The endangered plants, Bladderwort (Utricularia vulgaris var. japonica ) and Euryale ferox were observed in An-teo Reservoir as well as in the system.

• Journal of Korean Society on Water Environment
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• v.26 no.2
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• pp.215-224
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• 2010

This study was carried out to estimate effects of sediment reduction with net type sediment settling pond at highland agricultural areas. Flow and sediment monitoring system with rainfall gauge were installed at the study area for real-time monitoring and analysis. It was found that amount and intensity of rainfall events strongly affect sediment yield from the study area. With net type sediment settling pond, it was expected that approximately 61% of sediment could be removed. The correlation between heavy metals and SS were analyzed in this study. $R^2$ values were 0.644, 0.876, 0.945, and 0.928 for Fe, Mn, Al, and Si, respectively. This results indicate that heavy metals also could be removed with net type sediment settling pond. As shown in this study, the sediment settling pond will be an efficient sediment reduction facility at highland agricultural areas. For maximum reduction efficiencies of sediment and other pollutants at agricultural fields, simplified sediment settling pond should be designed and implemented.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.2
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• pp.304-313
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• 1987

The behaviors of layers developed in a solar pond were studied by experimental and analytical methods. An experimental solar pond heated from below was constructed and operated at the net heat fluxes of 110 and 160W/m$^{2}$ and at the initial salt concentration gradients of 18.2, 27.3 and 36.4%/m. The thicknesses, growth rates, temperature and salt concentration in the top and the bottom mixed layers, the diffusive layer and the upper and the lower interfacial boundary layers were measured. The shadowgraph technique was used in order to observe all layer formation and an electroconductivity-temperature probe consisting of four electrodes was fabricated and used in measuring the salt concentration. Based on the experimental results, a model for the solar pond was developed and the governing equation and the assumptions were established. The governing equations were solved by the numerical method. The calculated results obtained from the analysis were compared with the experimental results.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.1
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• pp.52-59
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• 1999

Paddy rice is semi-tropical crop and requires warmirrigation water. If mean water temperature at the water source during the growing period is below 18$^{\circ}C$, sime kinds of water warming mechanism should be taken. In this study irrigation water temperature is measured and preventive measures to cold water damage on paddy rice are suggested. Field observations were performed at 100ha field area downtream of the Unmoon reservoir during the growing season of 1997. Land use, canal system, water temperature at irrigation canals. reservoir, and paddy fields were observed. In addition, growth and yield of the rice at selected plots were observed. Accordingly to the record, cold water damage occurred in this area due to the cold irrigation water supply in 1996. It did not occur because of the effective irrigation water management practice in 1997. However, several preventive measures such as pontoon intake system, using existing weir and construting a new warming pond, are suggested to prevent cold water damage in the future. If a new warming pond is construted to raise irrigation water temperature by 2 $^{\circ}C$, a pond area of 2.94 ha is required.

• Korean Journal of Environmental Agriculture
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• v.18 no.2
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• pp.191-195
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• 1999

An integrated wastewater treatment pond system is developed for treatment and recycling of excreta from dairy cattle. It is composed of three ponds in series. A pit with a capacity of $10m^3$, 2-day hydraulic residence time, and overflow velocity of $1.5m^3m^{-2}day^{-1}$ is located internally in primary pond. It is designed for efficient sludge sedimentation and effective methane fermentation. It receives $5m^3/day$ of diluted cattle excreta by the water used for clearing stalls. A submerged gays collector for the recovery of methane is installed on the top of the pit. The average BOD_5 concentration of influent is 398.7mg/l. That of the effluent from primary pond is 49.2mg/l. About 88% of BOD_5 are removed in primary pond. It is assumed that about 60% of the influent BOD_5 is removed in the pit and that almost all of the carbon of the removed BOD_5 in the pit is converted to methane and carbon dioxide. Methane fermentation of the pit is well established at $16^{\circ}C$. This phenomena results from temperature stability, complete anaerobic condition, and neutral pH of the pit. Gas from the collector is almost 90% methane, less than 9% nitrogen, and less than 1% carbon dioxide. Thus a purified methane is produced, which can be used as energy source.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.323-329
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• 2005

In this paper, performance of a hybrid sequential aerobic-anaerobic natural system was investigated. Continuous aerobic and anoxic conditions were created by alternatively placing waste stabilization pond (WSP) and wale. hyacinth pond (WHP). Two pilot-scale treatment lines were built and operated; The first consists of WSP integrated with WHP and the second of WSP connected with Dark Pond(DP), namely control system ponds which were used to examine the effects of water hyacinth on nitrification and de-nitrification. The overall performance in nitrogen was 86% reduction in WSP-WHP and 36% in WSP-control pond system. Nitrogen was mostly removed by nitrification and de-nitrification which simultaneously occurred in the same water hyacinth ponds. For the de-nitrification, benthic layer was found out to be adequate support as a carbon source. In addition, WSP-WHP system was very effective in reducing phosphorus. Overall P removal efficiency in WSP-WHP is 81%, while it is only 16% in WSP-control. difference in phosphorus reduction between those two systems is thought to be caused by the plants and probably their roots producing extra-cellular materials, but these aspects need to be further studied.

• Journal of environmental and Sanitary engineering
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• v.14 no.3
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• pp.123-129
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• 1999

The utilization methods of algae biomass have been studied constantly in whole world. These are $\circled1$the wastewater treatment if waste stabilization pond and oxidation ditch etc. and $\circled2$the biosorption of heavy metals and recovery of strategic' precious metals and $\circled3$the single-celled protein production and the production of chemicals like coloring agent and $\circled4$the production of electric energy through methane gasification. The culture system also has been developed constantly in relation with such utilization method developments. In the result of experimental operation under continuous and cyclic irradiation of light, using high rate algae biomass culture pond(HRABCP), which had been made so as to be an association system with the various items which had been managed to have high efficiency for algae culture, the algae production of the 12 hours-irradiance pond was 41.48 Chlorophyll-a ${\mu}g/L$ only in spite of having the more chance of $CO_2$ synthesis to algae cell than the 24 hours-irradiance pond. This means that the energy supply required for dark-reaction of photosynthesis is very important like this. The difference of algae production between continuous and cyclc irradiation explains that the dark-reaction of photosynthesis acts on algae production as the biggest primary factor. The continuous irradiance on HRABCP made the good algae-production($1403.97{\;}{\mu}g$ Chlorophyll-a/mg) and the good oxygen-production(5.8 mg $O_2/L$) and the good solid-liquid seperation. especially, DO concentration through the oxygen-production was enough to fishes' survival.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.1
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• pp.24-32
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• 2004

A mathematical model is used to investigate nitrogen dynamics in the intensive aquaculture ponds in the western coast of Korea. Parameters associated with water quality, sediments and growing of shrimp (Fenneropenaeus chinensis) are measured to calibrate the model for feeding ponds A and B and storage ponds. The model describes the fate of nitrogen including loadings of ammonia from feeds, phytoplankton assimilation, nitrification, sedimentation, volatilization and discharge. The model obtains good agreements with the measured values of TAN $(NH_4,\;NH_3),\;NO(NO_2,\;NO_3)$ and Chl (chlorophyll a). Impacts of water exchange on TAN and Chl are investigated, showing that the range of 0.01-0.2 (/day) cannot effectively reduce TAN but reduces Chl. Nitrogen in the ponds A is removed by sedimentation $66\%,$ volatilization $8\%,$ discharge of particulate and dissolved $8\%.$ The pond B shows $56\%\;and\;26\%$ of sedimentation and volatilization, respectively, to yield $10\%.$ decrease and 8c/o increase compared to those in the pond A. While the pond A has larger area (1.02:0.66 ha) and same stocking density (0.025 md./L) at the beginning of culture, the pond B obtains higher stocking density (0.0065:0.0091 md./L), longer feeding period (103:121 day) and resultant higher shrimp production (1.15:2.13 t/ha/cycle) at harvest. This is possibly due to the hydraulic characteristics driven by paddlewheels. At low ratio of the low speed area and the pond area, the rate of sedimentation is high, while the rate of gas exchange is low. Thus, the measurement and model analysis suggest that water quality and shrimp production are positively correlated with the hydraulic characteristics in the shrimp ponds.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.651-651
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• 2015

The Because reduction facilities of existing non-point pollution source weren't balanced with each element technologies, most of case were what damaged scene nature of river, neutralized pollution sources and reduction effect. Therefore it's necessary to find a solution by integrating the operation system. Based on the comparative analysis that we have ran, we examined the capacity at individual operation's water purification and linked the treatment to detention pond, wetland and revetment.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.6
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• pp.316-326
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• 2017

Commercial buildings and institutions are predominantly cooled, thereby dissipating excess heat to a vertical ground heat exchanger (VGHE), than heat extracted over an annual cycle. Surface waters, such as lakes and ponds, provide a cost-effective means of reducing the VGHE length, and in balancing the thermal loads to the ground. This paper presents the measurement and analysis of the cooling performance of ground-coupled heat pump (GCHP) system, using surface water heat exchanger (SWHE) submerged in an artificial pond. In order to measure the performance of the system, we installed monitoring equipment, including sensors, for assessing the temperature and power consumption, after which the operation parameters were determined. The results from the thermal performance test for the SWHE indicate that the temperatures at the outlet of the SWHE and within the pond were affected by outdoor air temperature. In addition, the results reveal similar variation trends on temperatures; however, the peak temperatures of the SWHE were somewhat greater than those of outdoor air, due to the thermal capacity of the pond. Analyzing the cooling performance over the measurement period, the average coefficient of performance (COP) of heat pump was found to be 5.71, while that for the entire system was 2.99.