• 상하수도학회지
• /
• 제21권2호
• /
• pp.225-233
• /
• 2007

Road runoff water is one of the non-point sources (NPSs) of pollution negatively influencing drinking water source. Numerous road runoff NPS waters have been studied for over the last decade. However, the sources of pollution can be conditional, seasonal, or accidental. Therefore, measurement of pollutant loadings in different site is necessary to estimate the effect of road runoff water. The objective of this study was to examine the quality of road runoff water from a city bridge in Seoul, Korea. This study was conducted for two years to assess annual discharge pollution loads. In this study, key water quality parameters including chemical oxygen demand ($COD_{Cr}$), biochemcial oxygen demand ($BOD_5$), total nitrogen (T-N), total phosphorus (T-P), and suspended solid (SS) were measured at 18 different events. The results showed that typically the pollutant concentrations are higher at the beginning of each event and decrease afterwards. The first 20% of the volume of the runoff from each event is transporting 46% ($COD_{Cr}$), 48% ($BOD_5$), 50% (T-N), 34% (T-P), 30% (SS), respectively. The event mean concentrations (EMCs) were $COD_{Cr}$ (199 mg/L), $BOD_5$ (41.2 mg/L), T-N (7.97 mg/L), T-P (0.42 mg/L) and SS (113 mg/L). Although the results were consistent with the previous study (Barbosa and Hvitved-Jacobsen, 1999), $COD_{Cr}$, $BOD_5$, T-N exhibit a stronger first flush effect compared to the other contaminants.

• 한국습지학회지
• /
• 제14권4호
• /
• pp.581-589
• /
• 2012

비점오염원은 유역 및 지역의 토지이용 형태별로 강우유출수의 유출특성이 다양하고, 강우시 지표면의 각종 오염물질들이 도시하천으로 유입되어 수질에 심각한 영향을 미치고 있다. 본 연구에서는 도시지역을 주택 및 공단구역으로 구분하여 강우유출수의 유출특성을 파악하고자 오염물질별 EMC를 산정하였다. 분석 결과 강우시 주택 및 공단지역의 비점오염원은 강우초기에 유출수의 농도가 급격히 증가한 후 서서히 감소하는 초기세척현상이 발생하였으며, 초기우수의 제어가 필요하였다. 향후 장기적인 강우사상 및 수질조사 자료의 축척, GIS를 이용한 토지이용형태, 지형 및 지질특성의 자료 축척 등 지속적인 연구가 필요할 것으로 판단된다.

• 한국물환경학회지
• /
• 제20권5호
• /
• pp.494-499
• /
• 2004

Growth in population and urbanization has progressively increased the loadings of pollutants from non-point sources as well as point sources. Therefore, it is necessary to manage both point and non-point sources contaminations for protecting water environment and improving water quality. This study investigated the characteristics of pollutant release over a wide range of rainfall intensities as a requisite to control road runoff that accounts for the largest portion of non-point source contamination in urban areas. Samples of runoff rainwater collected from real road surfaces were analyzed for physicochemical parameters such as pH, suspended solids, and heavy metals. A experimental model road ($30cm{\times}30cm$) was also used to evaluate wash-off properties of pollutants deposited on the surface as functions of time and rainfall intensity. Analysis of runoff samples on rain events showed that the pollutant wash-off patterns for heavy metal and suspended solids were similar. This implies that the particles in rainwater adsorb heavy metals. Experiments using the model road made of impervious asphalt demonstrate a strong first flush phenomenon. At high rainfall intensity, approximately 80% of total pollutants were released within 15 min. The pollutant wash-off rates rapidly increase from 9 mm/hr to 12 mm/hr of rainfall intensity and decrease over 12 mm/hr of rainfall intensity.

• 한국물환경학회지
• /
• 제27권1호
• /
• pp.36-43
• /
• 2011

This study is selected two points of combined sewer that occurred Fish Kill after first flush, that analyzed generation of pollutants and stream runoff generation of combined sewer overflows (CSOs) as fine weather and rainfall. In addition, this study was to analyze the relationship between CSOs and sediments, to propose measures to reduce the sediment relevant with CSOs and rainfall runoff from entering sewage treatment plants and measures for discharged directly into streams when indicate relatively good water quality after overflow. Sediments in combined sewer system was discharged about 50~80% as overflows during rainfall and we can reduce the amount of the CSOs at least 50% or more if the sewer does not exist in the sediments because of the amount of discharge about the amount of intercept has been investigated by 3~5 times. Because of velocity at sediment interval in sewer is very low, sewage velocity of about 3~5 times as much as it can increase the amount of sediment can be reduced if the separation wall is installed. Effective control of BOD overflow load is respectively 77.5%, 75.8% at first point, second point by the separation wall is installed. Drainage area greater than area in this study or many combined sewer overflows region is increased the more effective control of separation wall. Turbidity to measure changes in water quality of overflows can be used as an factor to control the intercept flows because the intercept flows(3Q) after the first flush has lowered removal efficiency and increases the operational load of sewage treatment plants. Sewage water quality after a overflow when the reasonable turbidity was measured at this point flows to excluded intercept flow(1Q) can be discharged to stream.

• 한국도로학회논문집
• /
• 제8권1호
• /
• pp.99-106
• /
• 2006

고속도로는 건조시 많은 차량의 운행으로 인하여 오염물질의 축적이 높고, 강우시 불투수율이 높아 다량의 강우유출 수가 발생하는 지역이다. 특히 고속도로에서 발생하는 중금속, 각종 독성물질 및 입자상 오염물질들은 유출시 생태계에 큰 영향을 끼치게 된다. 따라서 본 논문은 2005년 개정된 수질환경보전법 및 비점오염원 관리 지침에 의거하여 바람직한 친환경적 고속도로 건설 및 유지관리를 위한 기초자료 제공을 위하여 수행된 연구이다. 이러한 기초자료를 확보하기 위하여 국내 4개 고속도로 지역에서 강우시 모니터링이 수행되었으며, 그 결과를 본 논문에 정리하고자 한다. 건조시에 축적된 각종 오염물질들은 강우 시작과 함께 고속도로로부터 유출되게 되는데, 특히 강우 초기에 다량의 오염물질 유출이 발생하는 초기강우 현상을 모니터링을 통하여 확인하였다. 유출되는 오염물질의 95% 신뢰 범위를 살펴보면, TSS의 경우 154.7-257.1 mg/L, COD가 138.9-197.6 mg/L, oil & grease가 3.5-6.4 mg/L, TN이 6.3-9.2 mg/L 그리고 TP는 2.3-3.31 mg/L의 범위를 나타냈다. 대부분의 모니터링에서 초기강우 현상이 발생하였으며, 이러한 초기강우는 강우지속시간 30분 이내에 대부분 끝나는 것으로 분석되었다. 또한 본 논문은 방대한 모니터링 자료를 통계 분석하여 그 결과를 정리였는데, 이는 향후 고속도로 오염물질 처리 및 저감 시설 설치시 중요한 기초 자료로 활용될 수 있을 것이다.

• 한국환경과학회지
• /
• 제24권12호
• /
• pp.1617-1627
• /
• 2015

This study was carried out to investigate the characteristics of suspended solid concentration in small forest watershed, Hwacheon, Gangwondo. For five rainfall events from July 2013 to August 2013, rainfall, discharge, and suspended solid load has been measured. The results showed that the fist flush effect was observed for suspended solid in each rainfall event, sediment rating curve was obtained with $y=30.029x^{1.573}$ at rising limb and $y=12.902x^{1.8827}$ at falling limb, and EMC (event mean concentration) of suspended solid was calculated to 9.4 mg/L. EMC was compared to the values from the watershed that has various land use types and EMC from forest watershed was much lower that from the crop, paddy or low covered forest watershed.

• 동의생리병리학회지
• /
• 제28권6호
• /
• pp.643-649
• /
• 2014

This study was designed to report treatment for Behcet's disease with arthritis We treated 2 Behcet's disease patients with arthritis. A 46-year-old female patient was treated with Cheongsimyeonja-tang. Another case, 44-year-old female patient was diagnosed as Sjogren's disease at first and diagnosed as The Behcet's diseases about 1 year later, treated with Cheonglijagam-tang. The progress was evaluated with the visual analogue scale for joint pain and hot flush, and length of sleeping time. There was improvement in the symptoms of visual analogue scale for joint pain and hot flush, also length of sleeping time. Cheongsimyeonja-tang, Cheonglijagam-tang can be considered as a treatment for patient diagnosed as Behcet's disease suffering from arthritis, especially.

• ETRI Journal
• /
• 제39권6호
• /
• pp.820-831
• /
• 2017

File systems and applications try to implement their own update protocols to guarantee data consistency, which is one of the most crucial aspects of computing systems. However, we found that the storage devices are substantially under-utilized when preserving data consistency because they generate massive storage write traffic with many disk cache flush operations and force-unit-access (FUA) commands. In this paper, we present DJFS (Delta-Journaling File System) that provides both a high level of performance and data consistency for different applications. We made three technical contributions to achieve our goal. First, to remove all storage accesses with disk cache flush operations and FUA commands, DJFS uses small-sized NVRAM for a file system journal. Second, to reduce the access latency and space requirements of NVRAM, DJFS attempts to journal compress the differences in the modified blocks. Finally, to relieve explicit checkpointing overhead, DJFS aggressively reflects the checkpoint transactions to file system area in the unit of the specified region. Our evaluation on TPC-C SQLite benchmark shows that, using our novel optimization schemes, DJFS outperforms Ext4 by up to 64.2 times with only 128 MB of NVRAM.

• 한국환경과학회지
• /
• 제23권3호
• /
• pp.511-520
• /
• 2014

The MFFn(Mass first flush), EMCs(Event mean concentrations) and runoff loads were analyzed for various rainy events(monitoring data from 2011 to 2012) in transportation area(rail road in station). The pollutant EMCs by volume of stormwater runoff showed the BOD5 9.6 mg/L, COD 29.9 mg/L, SS 16.7 mg/L, T-N 3.271 mg/L, T-P 0.269 mg/L in the transportation areas(Railroad in station). The average pollutant loading by unit area of stormwater runoff showed the BOD5 $27.26kg/km^2$, COD $92.55kg/km^2$, SS $50.35kg/km^2$, T-N $10.13kg/km^2$ and T-P $10.13kg/km^2$ in the transportation areas. Estimated NCL-curve(Normalized cumulated-curve) was evaluated by comparison with observed MFFn. MFFn was estimated by varying n-value from 10% to 90% on the rainy events. The n-value increases, MFFn is closed to '1'. As time passed, the rainfall runoff was getting similar to ratio of pollutants accumulation. The result of a measure of the strength of the linear relationship between observed data and expected data under model was good.

• 한국습지학회지
• /
• 제14권1호
• /
• pp.11-20
• /
• 2012

본 연구의 목적은 더 나은 빗물관리를 위해 건물지붕에서 흘러내리는 빗물의 성상을 분석하고, 그 자료를 축적하는데 있다. 이에 빗물 유출수 성상을 분석한 결과(pH, COD, TSS, T-N, T-P, $NH_4$-N, $NO_3$-N, 장내세균, 일반미생물, 납, 카드뮴, 구리)지붕 유출수에서 흘러나오는 빗물의 성상이 직접 받은 빗물에 비해 약 2 ~ 3배 가량 더 오염되었고 (미생물 지수의 경우는 100배 이상) 초기 10분 동안 내린 오염물질량이 30분 모니터링한 빗물 오염물질량의 60% 이상 차지하고 있음을 알 수 있었다. 또한, 통계 요인분석을 통해 빗물 유출수 분석 항목들을 상대적으로 가까운 지표(변수)들로 구분 지을 수 있었다. 본 연구진은 이러한 지속적인 건물지붕빗물의 모니터링이 국내의 안전하고 경제적인 빗물 저장시설을 설치하는데 도움을 줄 거라 예상한다.