• 한국농공학회논문집
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• 제47권5호
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• pp.87-97
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• 2005

The field scale experiment was performed to examine the effect of physical design parameters on the constructed wetland performance and recommend the feasible design of constructed wetland in Korean polder areas. Four sets (each set of 0.85 ha) of wetland (0.8 ha) and pond (0.08 ha) systems were used. Two different wetland systems, a wetland-pond system and a pond-wetland system, were studied to examine the effect of wetland and pond configuration. And two different length-to-width ratios were used, 2: 1 and 0.8: 1, to examine the effect of aspect ratio. A pond-wetland system was more preferable than a wetland-pond system, and also requires a smaller area than a wetland-pond system or a wetland system to reduce T-P. There was no difference in effluent concentration between the 2:1 system and the 0.8:1 system. Although the linear velocity of the 2:1 aspect was higher than the 0.8:1 aspect, resuspension was not a factor in this study due to a very low linear velocity. From this study and other literature review, it was found that design method of paddy rice field could be applied and expanded to the design of constructed wetland in Korea. Further investigation for the detailed design parameters of constructed wetland needs be continued for design method of paddy rice to be applied in full scale.

• 한국농공학회논문집
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• 제60권6호
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• pp.65-71
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• 2018

The Long-Term Hydrologic Impact Assessment (L-THIA) model is a quick and straightforward analysis tool to estimate direct runoff and nonpoint source pollution. L-THIA was originally implemented as a spreadsheet application. GIS-based versions of L-THIA have been developed in ArcView 3 and upgraded to ArcGIS 9. However, a major upgrade was required for L-THIA to operate in the current version of ArcGIS and to provide more options in runoff and NPS estimation. An updated L-THIA interfaced with ArcGIS 10.0 and 10.1 has been developed in the study as an ArcGIS Desktop Tool. The model provides a user-friendly interface, easy access to the model parameters, and an automated watershed delineation process. The model allows use of precipitation data from multiple gauge locations for the watershed when a watershed is large enough to have more than one precipitation gauge station. The model estimated annual direct runoff well for our study area compared to separated direct runoff in the calibration and validation periods of ten and nine years. The ArcL-THIA, with a user-friendly interface and enhanced functions, is expected to be a decision support model requiring less effort for GIS processes or to be a useful educational hydrology model.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2007년도 춘계학술발표논문집
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• pp.116-118
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• 2007

비강우시와 강우시 학장천의 수질은 BOD, COD, T-N, T-P, SS에 대해 각각 $11.0{\sim}31.3mg/L$, $15.6{\sim}31.4mg/L$, $5.762{\sim}15.937mg/L$, $0.918{\sim}1.291mg/L$, $18.1{\sim}31.41mg/L$와 $27.2{\sim}65.11mg/L$, $32.1{\sim}73.2rng/L$, $13.409{\sim}18.051mg/L$, $1.263{\sim}2.282mg/L$, $66.0{\sim}417.9mg/L$로 나타나 학장천은 전형적인 생활하수의 특성을 지녔으며, 강우시 발생되는 초기월류수에 다량의 비점오염물질이 포함됨을 알 수 있었다. 강우시 발생된 월류수의 유량을 측정한 결과 학장천의 유출계수는 $0.61{\sim}0.83$의 범위였고, 초기세척효과는 SS>T-N>COD>BOD>T-P>1 의 순서로 그 정도가 크게 나타났다. 학장천 초기월류수의 유량가중평균농도를 산정한 결과 대부분의 항목에서 청천시의 수질농도보다 높게 나타나 강우에 의한 월류수의 비점오염물질의 유출이 심각함을 알 수 있다.

• 한국농공학회지
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• 제37권E호
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• pp.63-71
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• 1995

Three types of land use were investigated to describe the effect of land use on both surface and ground water quality. Typical land uses of a grazing pasture, Sudan grass field and paddy in Kangwon province were selected and flumes and monitoring wells were installed. Land managements were carefully monitored, water samples were collected periodically and analyzed with respect to nitrate, TP and TKN at a laboratory of Kangwon Provincial Institute of Health and Environment from August, 1993 to May, 1994. Runoff from the pasture was formed mostly with seeping subsurface flow in the lower areas of the pasture. A few overland flows were observed during heavy storms, and when it occurred, runoff increased sharply. For the Sudan grass field, runoff was formed with overland flow. Nitrate concentration in runoff from both land uses seemed not affected by runoff and ranged from 0.241 to 4.137mg'/1. TP and TKN concentrations from the pasture were affected by overland flow. When overland flow occurred, TP and TKN concentrations abruptly increased to 5.726 and 12.841mg/1, respectively, from less than 1.0mg/l. However, these concentrations from the Sudan grass field were quite stable ranging from 0.191 to 0.674mg/l for TP and 0A70 and 1.650mg/l for TKN. Nitrate concentration was significantly affected by land use(Sudan grass field) and the concentration increase reached about 2mg/l per lOOm ground water flow. Nitrate concentration from a well located in the middle of rice fields also was significantly higher than that measured from a well located relatively undisturbed mountain toe area. TP and TKN concentrations in shallow ground water affected by the depth of the monitoring wells. The deeper the monitoring wells, the less TP and TKN concentrations were measured.

• 한국농공학회논문집
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• 제54권2호
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• pp.27-35
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• 2012

Various Best Management Practices (BMPs) have been suggested to reduce Nonpoint source pollutant loads from agricultural fields. However, very little research regarding water quality improvement with sediment trap has been performed in Korea. Thus, effects of sediment trap were investigated in this study. Three sediment traps were installed at the edge of six plots and flow and water quality of inflow and outflow were monitored and analyzed. It was found that approximately 64.1 % of flow reduction was observed. In addition, pollutant concentration of outflow was reduced by 39.0 % for $BOD_5$. For SS, $COD_{Mn}$, DOC, T-N, T-P, approximately 62.1 %, 43.4 %, 43.5 %, 40.0 %, and 41.2 % reduction were observed, respectively. Over 80 % and 90 % of pollutant loads were reduced from sediment trap #2 and #3 because of less outflow from plots covered with rice straw/straw mat. In case of intensive rainfall events occurred from July 26~29, 2011, over 60 % of pollutant and 88.9 % of sediment reduction were observed from sediment trap #3. As shown in this study, small sediment traps could play important roles in reducing pollutant loads from agricultural fields. If proper management practices, such as rice straw/straw mat, are used to protect surface from rainfall impacts and rill formation, much pollutant reduction could be expected.

• 환경위생공학
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• 제21권4호
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• pp.39-48
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• 2006

In Juam basin, the ratio of non-point pollution source among pollutant loading of basin was significantly high, since the utilization level of land was high. In addition, the most pollutants were not treated and flowed out. In this study, the correlation between non-point source pollutants from the forest area and increasing algae was investigated. 1. Chl-a concentration flowed out to runoff from forest area and stream water was low as $0.1{\sim}20.3{\mu}g/{\ell}$ and $0.1{\sim}9.3{\mu}g/{\ell}$, respectively, and chl-a concentration ($0.1{\sim}28.5{\mu}g/{\ell}$) of branch stream was higher $5{\sim}7$ times than that of runoff from forest area. 2. In correlation between runoff from forest area and Juam lake water, annual chl-a concentration of area front Juam dam was higher twice than forest area. 3. In runoff from forest area within Juam basin, flagellate, green, diatom and blue algae occupied $33.0{\sim}41.7%$, $22.2{\sim}30.8%$, $17.3{\sim}22.5%$ and $13.7{\sim}17.6%$, respectively. 4. In runoff from forest area, both green and diatom algae were maintained constantly irrespectively of season, and flagellate algae dominated since August. 5. In characteristics by forest tree types, four types algae were inhabited in mixed forest, and flagellate algae were higher in conifer and broadleaf forest than in other area. And green algae in herbaceous forest were higher than other area.

• 상하수도학회지
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• 제23권5호
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• pp.557-564
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• 2009

A combined sewer system can quickly drain both storm water and sewage, improve the living environment and resolve flood measures. A combined sewer system is much superior to separate sewer system in reduction of the non-point source pollutant load. However, during rainfall. it is impossible in time, space and economic terms to cope with the entire volume of storm water. A sewage system that exceeds the capacity of the sewer facilities drain into the river mixed with storm-water. In addition, high concentration of CSOs by first-flush increase pollution load and reduce treatment efficiency in sewage treatment plant. The aim of this study was to develope a processing unit for the removal of high CSOs concentrations in relation to water quality during rainfall events in a combined sewer. The most suitable operational design for processing facilities under various conditions was also determined. With a designed discharge of 19.89 m/min, the removal efficiency was good, without excessive overflow, but it was less effective in relation to underflow, and decreased with decreasing particle size and specific gravity. It was necessary to lessen radius of vortex separator for increasing inlet velocity in optimum range for efficient performance, and removal efficiency was considered to high because of rotation increases through enlargement of comparing height of vortex separator in diameter. By distribution of influent particle size, the actual turbulent flow and experimental results was a little different from the theoretical removal efficiency due to turbulent effect in device.

• 한국환경복원기술학회지
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• 제15권6호
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• pp.69-77
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• 2012

This study observes the purchased lands in riparian areas of Suncheon City region and proposes a reasonable management method. For the study, the site surveying and analysis on the neglected purchased lands is executed, then, based on the site analysis result, the appropriate management method for each neglected purchased land is established. Each management method is approached from the ecological restoration perspective. According to site surveying and analysis of the neglected purchased lands, most of the sites were bare and agricultural lands. The reason for this is thought to be as when purchasing a land, the areas with higher nonpoint source pollution are bought preferentially. As for the dominant species coverage, 26% ($364,000m^2$) of the total neglected purchased land area in Sucheon City was covered with the dominated species, and for the exotic species coverage, 17% ($232,000m^2$) of the total neglected purchased land area in Sucheon City was covered with the exotic species. The survey site constituted of five different invasive species such as Japanese Hop (Humulus japonicus), Daisy Fleabane (Erigeron annuus), and Evening Primrose (Oenothera odorata). As for the natural succession on site, about 47% of the area showed poor natural succession process. The reason for this outcome is understood as having a lack of appropriate management for purchased lands. Based on the site surveying and analysis, especially the current management state of the and its location, the research site was categorized into preservation, restoration, and improvement sites. During the establishment of the ecological riparian belt, the comprehensive management for preservation, restoration, and improvement of the purchased lands should be executed.

• 한국물환경학회지
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• 제30권3호
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• pp.340-350
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• 2014

Recently, TMDL has been implemented to estimate the amount of pollutant loads and to establish proper mitigation strategy to decrease the pollutant loads by the Ministry of Environment. To estimate the amount of pollutant loads with reasonable accuracy, securing landcover map with periodically updating is essential. However, in reality, due to the technical and financial difficulties, the landcover map has not been updated annually. Hence, this study mainly aims to suggest an effective GIS-based updating method in order to promote utilization of landcover map in the estimation of pollutant loads. Bupyeong-gu at the City of Incheon with the total area of $31.98km^2$ was chosen for this study and spatial data including digital topographic maps, ortho aerial photo, and satellite images were collected and utilized. A total of 7,235 feature entities were newly produced through the updating process of five steps and it was revealed that the classification of landcover with the total area of $3.34km^2$ was to be changed. The validity and feasibility of the suggested method were proved with the accuracy of 97.9% from the field verification. Further study needs to be made for devising more automated method to update landcover map to facilitate TMDL for individual local governments.

• 상하수도학회지
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• 제24권4호
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• pp.443-451
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• 2010

This study was conducted to confirm the CSOs characteristics, and to estimate treatment efficiency of CSO treatment process. Flowrate was average $53,500m^3$/d, maximum $58,100m^3$/d during dry season, but after rain-fall, the flowrate was increased more than twice that of the dry season. And, water pollution concentrations, such as $COD_{Cr}$, SS, $BOD_5$, TN and TP of after rain-fall, were also increased. Thus, for more efficient treatment of pollutants during rainy season, The vortex separator and continuous fiber filter devices were used. From the results on particle range, removal efficiency of particle was 99.7% at the particle size range of $40{\sim}100{\mu}m$ but decreased as 55-80% at the below $40{\mu}m$. The removal efficiencies of $COD_{Cr}$, SS, TN and TP were approx. 70, 60, 70 and 50, respectively during the dry season and approx. 50, 50, 8 and 18% during the rainy season. Also, when compared with the primary sediment basin, $COD_{Cr}$, SS, TN and TP removal efficiencies were high. especially, at the case of TN and TP, TN was more removed than TP because of higher conversion factor value. But we needed more study for the injection of a coagulants to get more stable treatment efficiency for soluble pollutants. Consequently, This process can be used for CSOs treatment as well as replace the primary sedimentation basin during the dry season.