• 한국물환경학회지
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• 제28권5호
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• pp.676-685
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• 2012

As impermeable layer continues to increase with the urbanization process, direct input of nonpoint source pollutants into water bodies via stormwater has caused serious effects on the aquatic ecosystem. Potential applications of rain gardens are increasing not only as best management practices (BMP) for reducing the level of nonpoint source pollutants but also as an ecological engineering alternative for low impact development (LID). In this study, remediation performance of various planting types, such as a mixed planting system with shrubs and herbaceous plants, was assessed quantitatively to effectively manage stormwater and increase landscape applicability. The mixed planting system with Rhododendron lateritium and Zoysia japonica showed the highest removal performance of $76.9{\pm}7.6%$ and $58.4{\pm}5.0%$ for total nitrogen and $89.9{\pm}7.9%$ and $82.4{\pm}5.2%$ for total phosphorus at rainfall intensities of 2.5 mm/h and 5.0 mm/h, respectively. The mixed planting system also showed the highest removal performance for heavy metals. The results suggest that a rain garden with the mixed planting system has high potential applicability as a natural reduction system for nonpoint source pollutants in order to manage stormwater with low concentrations of pollutants and will increase water recycling in urban areas.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.938-941
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• 2004

Sound generation and radiation from the duct-rotor system are calculated numerically. The wake geometries of a two-bladed rotor are calculated by using a time-marching fiee-wake method without a non-physical model of the far wake. Acoustic free field due to a rotating rotor is obtained by Lowson's equation. Using Kirchhoff source, rotating sources are modeled as stationary ones and can be inserted in the thin body boundary element method. The Kirchhoff source is validated through calculation of acoustic pressure due to a rotating point force. The thin body boundary element method (thin body BEM) is validated through calculation of acoustic radiation of ducted dipole. Using Kirchhoff source and thin body BEM, acoustic radiation of a ducted rotating source is calculated. Acoustic shielding is observed by inserting a duct and shows different phenomena at each major frequency. Acoustic radiation of a real duct-rotor system is also calculated using this method and the ducted acoustic field is significantly different from rotor only.

• 한국식품과학회지
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• 제27권4호
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• pp.483-486
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• 1995

가공적성이 우수한 알코올처리 각시가자미껍질 젤라틴을 식품산업소재로 이용하기 위한 기초자료를 얻을 목적으로 젤라틴농도, pH, 정치온도 및 시간과 같은 겔화조건에 대한 알코올처리 젤라틴의 물리적 특성 및 색조의 변화를 알코올 무처리 젤라틴과 비교하여 검토하였다. 알코올처리 및 무처리 젤라틴이 모두 농도가 증가할수록 겔강도, 졸화온도 및 겔화온도 및 점도 등과 같은 물리적 특성은 증가하였다. 젤라틴 졸의 pH가 에탄올처리한 젤라틴의 경우 6.0일 때, 무처리한 젤라틴의 경우 5.0일 때 겔강도, 졸화온도 및 겔화온도가 가장 높았으나, $pH\;5.0{\sim}8.0$의 범위에서는 거의 차이가 없었고, pH 5.0 이하 및 pH 9.0 이상에서는 급격히 감소하였다. 젤라틴 졸을 겔화시키기 위하여 정치시키는 경우 온도는 낮을수록, 시간은 길수록 겔강도 및 졸화온도는 높았다. 겔화조건을 동일하게 하였을 때 에탄올처리한 젤라틴이 무처리한 젤라틴보다 물리적 특성이 우수하였다.

• 생태와환경
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• 제40권2호
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• pp.264-272
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• 2007

본 연구는 한강 상수원 수변지역의 실제 적용에 앞서 Bench scale의 실험을 통해 식생여과대의 단점을 보완하고 보다 효율적인 비점오염물질 저감을 위해 대조군, 모래+자갈, 여재, 자갈의 토양여과대를 조성하여 토양의 침투능력을 향상시키고 효율을 비교하고자 하였다. 실험 결과 토양여과대에서 단면 및 하부로의 침투를 증가시킨 결과 대조군과 비교하였을 때 토양여과대의 평균 표면 유출부하량과 비교하여 $8.2{\sim}40.1%$까지 감소한 것으로 나타나 토양여과대 조성을 통한 표면 유출부하량의 감소 효과가 비교적 양호하게 나타난 것으로 판단된다. 오염물질의 유입부하에 따른 총유출부하량을 통해 각각의 토양여과대에 대한 저감 효과를 비교해 본 결과, 전체적인 제거율은 SS $84.5{\sim}92.5%$, BOD $67.9{\sim}80.6%$, T-N $43.4{\sim}76.6%$), T-P $40.6{\sim}87.4%$, Cu $28.3{\sim}48.1%$, Fe $92.1{\sim}97.7%$, Pb $81.4{\sim}97.3%$인 것으로 조사되었고, 각각의 토양여과대에 대한 오염물질 저감효과를 비교해 본 결과, 여재, 모래+자갈, 자갈의 순으로 저감효과가 뛰어난 것으로 나타났다. 본 연구를 통해 기존의 식생여과대에 비해 토양층을 변화시켜 토양의 침투능을 향상시킨 토양여과대가 비점오염물질 저감에 보다 효과적이며, 하천에 가해지는 오염부하량을 감소시킬 수 있을 것으로 판단되기 때문에 차후 현장 적용 시 보다 실효성 있는 비점오염 저감대책이 될 수 있을 것으로 판단된다.

• 한국농공학회지
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• 제45권2호
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• pp.116-125
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• 2003

Predictions of stream water quality require both estimation of pollutant loading from different sources and simulation of water quality processes in the stream. Nonpoint source pollution models are often employed for estimating pollutant loading in rural watersheds. In this study, a conjunctive application of SWAT model and WASP model was made and evaluated for its applicability based on the simulation results. Runoff and nutrient loading obtained from the SWAT model were used for generating input data for WASP model. The results showed that the simulated runoff was in good agreement with the observed data and indicated reasonable applicability. Loading for the water quality parameters predicted by WASP model also showed a reasonable agreement with the observed data. It is expected that stream water quality could be predicted by the coupled application of the two models, SWAT and WASP, in rural watersheds.

• 한국물환경학회지
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• 제27권6호
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• pp.841-847
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• 2011

In this study, a method to determine the design capacities of nonpoint source (NPS) pollutant treatment facilities in urban areas was suggested. A facility capacity to treat 80 percent of total SS discharge was estimated by 2-year rainfall - runoff - build-up and wash-off simulation at Goonja drainage district in Seoul. For wash-off simulation, four wash-off models (EMC, RC, EXP, and Joo model) were used. As the results, 80 percent of total SS discharge could be treated with only 7.7~31.4% facility capacity of peak flow. The suggested method and results will provide a guideline to determine design capacities of NPS pollutant treatment facility in urban areas.

• 산업기술연구
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• 제25권B호
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• pp.37-46
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• 2005

From 2000 to 2004, the research was carried out at Naerin-cheon and Inbook-cheon, the upper streams of Soyang Lake, to study the relationship between precipitation and eutrophication-causing water pollutants, BOD, T-N and T-P. During the five years, the amount of flowing water was measured, and the water quantity was examined under different precipitation levels. From the observation, outflow patterns of the water pollutants and changes in the water quality factors at the time of rainfall were clarified. In addition, estimation of the unit load was made for each stream; for Naerin-cheon at the time of rainfall, we estimated BOD to be $1,112kg/km^2/year$, T-N to be $2,077kg/km^2/year$, and T-P to be $223kg/km^2/year$; for Inbook-cheon at the time of rainfall, we estimated BOD to be $1,229kg/km^2/year$, T-N to be $1,565kg/km^2/year$, and T-P to be $255kg/km^2/year$. For the time of no rainfall different estimation was made; for Naerin-cheon, we estimated BOD to be $2,403g/km^2/day$, T-N to be $5,004g/km^2/day$, and T-P to be $53g/km^2/day$; and for Inbook-cheon, we estimated BOD to be $1,550g/km^2/day$, T-N to be $2,283g/km^2/day$, and T-P to be $42g/km^2/day$.

• 한국환경복원기술학회지
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• 제16권2호
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• pp.41-52
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• 2013

Anyang Stream Restoration Movement was started from 2001 for the construction of ecological city. The facilities for reuse of treated sewerage have been used since 2003 for improvement of water quality, maintenance of water quantity, river ecological restoration, and hydrophilic space. Thus, the Anyang city has been gradually transformed to eco-friendly city after the construction of Anyang stream and Hakui stream as natural rivers. In this study, biological and chemical methods as well as ecological indicators for Anyang mainstream and major tributaries were monitored for four years in between 2008 and 2012. The water quality and the diversity of species in most of the streams were found to be good except Anyang main stream. It appears that the influence of seasonal drying stream is almost disappeared except Sammak stream. Thus, the values for BOD (Biochemical Oxygen Demand) and BIP (Biological Index of Pollution) for Anyang main stream were found to be 5.27~3.42mg/l and 4.51~5.50, respectively. This is considered to be caused by the reused water quality of treated wastewater being exceeded the design criteria or by the non-point source of contaminants around the stream. However, entire section of tributaries shows I, II grade as a good water quality.

• 한국농공학회논문집
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• 제54권6호
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• pp.53-63
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• 2012

The objectives of this study were to develop a linked watershed-waterbody modeling system and to assess the impacts of indirect wastewater reuse on irrigation water quality. The Osan stream watershed within Gyeonggi-do of South Korea was selected for this study. The linked modeling system was composed of the SWAT (Soil and water assessment tool) and QUALKO2 models. The SWAT model was calibrated and validated using the stream discharge and water quality data from 2010 to 2011. Runoff and non-point source pollutants from each subbasin and stream discharge from 1980 to 2009 were simulated by the SWAT model and applied to the QUALKO2 model. The QUALKO2 model was calibrated and validated under the conditions of low water and normal discharges, respectively. Finally, The 10-day irrigation water quality from April to September was simulated. The statistical measures of coefficient of determination ($R^2$), reliability index (RI), and efficiency index (EI) were used to evaluate the system performance. The $R^2$, RI and EI values ranged from 0.5 to 1.0, 1.03 to 1.92, and -35.03 to 0.95, respectively. The 10-day irrigation water quality showed the concentrations of BOD and coliform exceeded the water quality guidelines for wastewater reuse. The linked modeling system can be a useful tool to estimate non-point source pollutant loads in watershed and to control the water quality of effluent from a wastewater treatment plant and irrigation water in the downstream waterbody.

• 한국물환경학회지
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• 제25권5호
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• pp.682-688
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• 2009

A plane field and a sloped field located at low-land plane and alpine areas, respectively, were monitored with respect to runoff, water quality and fertilizer uses from March to December, 2008. Runoff volume and Non-Point Source (NPS) loads were estimated and analyzed with respect to fertilizer uses. Total TN and TP loads from the sloped field were higher than those from plane field because of larger chemical uses in the alpine field than in the plane field. Organic matter load from plane field was higher than that from sloped field because more organic compost was applied to plane field than to sloped field. Event Mean Concentration (EMC) of measured water quality indices were relatively higher in both fields. Organic matter load per 1 mm rainfall were higher in plane field and TN and TP loads per 1 mm rainfall were higher in sloped field than those in respective comparing field. It was concluded that the type and application method of fertilizer could play an important role in the estimation of NPS pollution loads and the development of Best Management Practices (BMPs). However, it was recommended that long-term monitoring is necessary to better describe the relationship between fertilizer uses and water quality from agricultural fields because numerous natural and management factors other than fertilizer also affect runoff quality.