• 한국습지학회지
• /
• 제18권4호
• /
• pp.363-377
• /
• 2016

본 연구는 낙동강수계 오염도가 높은 금호강 및 남강 중권역의 지천들 가운데 수질측정망과 일정한 거리에 있고 오염도가 높은 지천들을 선정하여 각 지점의 오염부하량, 오염특성, 중점관리지천별 세부 유입되는 지천의 오염현황 및 중점 지류가 낙동강 본류에 미치는 영향 등을 살펴보았다. 그 결과, 금호강 및 남강의 대부분의 수질항목별 오염도는 유사하였으나, TN, Chl-a 및 SS는 금호강이 남강에 비해 약 20~120% 이상 높은 오염도를 보였다. 오염발생부하율(kg/day) 및 발생밀도($kg/day/km^2$)는 유량과 하천유하면적에 따라 하천 오염도 순위가 달랐으며, 이러한 영향은 남강에서 더 크게 차이가 발생하였다. 금호강 및 남강의 상세오염조사는 하천의 유로길이, 합류되는 소하천의 개수와 형태에 따라 상세지점을 2개에서 최대 9개까지 나누어 조사하였으며, 그 결과 달서천과 의령천의 오염도가 높게 나타났다. 이외에도, 달서천과 의령천의 본류오염 기여율이 약 10% 내외로 높게 나타났으며, 이는 주변공단, 생활거주지역 형태 및 크기, 농경지 경작 유 무 및 축사 존재 유 무에 따라 오염도 및 상 하류 오염형태가 다르기 때문으로 판단된다

• 한국물환경학회지
• /
• 제34권5호
• /
• pp.494-502
• /
• 2018

The purpose of this study was to understand distribution characteristics of organic matters through concentration of $BOD_5$, $COD_{Mn}$ and TOC in 31 streams in Han River region, and to establish the relationship among organic matter concentration, and discharge load and flow rate. Concentration of $BOD_5$ and TOC in 22 streams were above IV grade except 9, and the average 80.9 % of total organic matter (by TOC) accounted for dissolved organic type. Correlation among organic matter parameters were higher ($r^2$ > 0.78) and the relationship between TOC and $COD_{Mn}$ concentration was higher than $BOD_5$. Ratio of biodegradable organic matter/total organic matter in the 31 streams was estimated at 41.4 % with $BOD_5$ oxidation rate, and 78.0 % with $BOD_5/COD_{Mn}$ concentration ratio. Ratio of $NBOD/BOD_5$ concentration in four sites with $BOD_5/COD_{Mn}$ concentration ratio exceeding 1 ranged from 54.5 % ~ 79.3 %. Among 979 flow rate data measured at 31 streams, 87 % of measured data was below 0.1 cms and increased water pollution under low flow conditions. Correlation between $BOD_5$ concentration and $BOD_5$ discharge load in the watershed was low, and it was revealed that several streams have more $BOD_5$ delivery load than $BOD_5$ discharge load. Results suggest that many biodegradable forms of organic matter are being introduced into the stream from pollutant sources in the watershed.

• 한국자동차공학회논문집
• /
• 제13권5호
• /
• pp.188-194
• /
• 2005

The direct injection diesel engine is one of the most efficient thermal engines. For this reason DI diesel engines are widely used for heavy-duty applications. But the world is faced with very serious problems related to the air pollution due to the exhaust emissions of diesel engine. So, that is air pollution related to exhaust gas resulted from explosive combustion should be improved. Exhaust Gas Recirculation(EGR) is a proven method to reduce NOx emissions. In this study, the experiments were performed at various engine loads while the EGR rates were set from $0\%$ to $30\%.$ The emissions trade-off and combustion of diesel engine are investigated. The brake specific fuel consumption rate is very slightly fluctuated with EGR in the range of experimental conditions. The ignition delay increased with increasing EGR rate. The maximum value of premixed combustion for the rate of heat release is increased with increasing EGR rate. NOx emissions are decreased with increasing EGR rate at high load and high speed. It was found that the exhaust emissions with the EGR system resulted in a very large reduction in oxides of nitrogen at the expense of higher smoke emissions.

• 한국농공학회논문집
• /
• 제52권4호
• /
• pp.19-26
• /
• 2010

To provide the basic information for the water quality management of the Sumjin River Basin, delivery ratios for flow duration were studied. Using the day-interval data set of discharge and water quality observed from the Chooryeong-cheon watershed, the flow-duration and discharge-load relation curves for the watershed were established, then the load-duration curve was constructed. Delivery ratios for flow duration were also developed. Delivery ratios showed wide variation according to flow conditions. In general, delivery ratio of high flow condition showed higher value reflecting nonpoint source pollution contribution from the forest dominating watershed. To resolve this problem, a regression model explaining the relation between flow rate and delivery ratio was suggested. The delivery ratios for different flow regime could be used for pollutant load estimation and TMDL (Total maximum daily load) development.

• 한국습지학회지
• /
• 제26권1호
• /
• pp.1-9
• /
• 2024

이 연구에서는 서낙동강을 구성하는 소유역 중 대지면적 비율이 크고 인구밀도가 높은 해반천 유역의 유출 및 수질을 모의하기 위한 HSPF(Hydrological Simulation Program-FORTRAN)모형을 개발하였다. 유역에서 발생하는 비점오염 부하량을 관리하기 위한 세 가지 시나리오가 개발되어 모형에 적용되었고, 오염부하량의 감소와 부하지속곡선에 대비한 수질 기준 초과율이 분석되었다. 시나리오는 비점오염의 발생을 줄이기 위한 도로 청소, 다양한 저영향 개발 기법을 고려한 유출 저감 조치, 그리고 강으로 들어가는 비점오염원을 완화하기 위한 유입 저감 조치로 구성되었다. 첫 번째 시나리오에서는 김해시의 도로 청소 차량 수와 같은 실제 조건이 고려되었으며, 두 번째와 세 번째 시나리오에서는 적용 가능한 토지 이용별 면적의 50%에 저영향 개발 기법을 적용하는 것으로 적용되었다. 모든 세 가지 조치를 적용한 결과, BOD 오염 물질 부하가 58.28%, T-N은 58.49%, T-P는 51.56% 감소할 수 있는 것으로 도출되었다. 또한, 5년간 누적된 수질 측정의 60번째 백분위수를 목표 수질로 설정하고 구축된 유량지속곡선에 의한 초과율분석 결과, 결과적으로, BOD의 경우 조치 적용 전 41.57%의 초과율이 조치 후 16.32%로 감소하여, 초과율이 25.25% 감소하였다. T-N의 경우 조치 전 40.31%에서 조치 후 22.84%로, T-P의 경우 62.43%에서 27.22%로 감소하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
• /
• pp.149-151
• /
• 2005

A new approach considering CO2 air pollution constraints in the long-term generation mix is proposed under uncertain circumstances. A characteristic feature of the presented approach in this paper is what effects give the air pollution constraints in long term best generation mix. Best generation mix problem is formulated by linear programming with fuel and construction cost minimization with load growth, reliability (reserve margin rate) and air pollutionconstraints. The proposed method accommodates the operation of pumped-storage generator. It was assumed in this study that the construction planning of the hydro power plants is given separately from the other generation plans. The effectiveness of the proposed approach is demonstrated by applying to the best generation mix problem of KEPCO-system, which contains nuclear, coal, LNG, oil and pumped-storage hydro plant multi-years.

• 한국농공학회논문집
• /
• 제55권5호
• /
• pp.1-7
• /
• 2013

The objective of this research was to experimentally test the effect of tillage methods on the reduction of runoff, non-point source (NPS) pollution load, sediment and discharge under a rainfall simulation. We used the runoff plots of $5m{\times}30m$ ($L{\times}W$) in size. Experimental treatments were conventional tillage (CT), CT-rice straw bundle (CT-RSB) and two no-till (NT) plots; slope of 3 % or 8 % ; and rainfall intensity of 30 mm/hr. The rainfall simulation was conducted to three times. The time to initial runoff from NT plots was less than that from CT plots regardless of the slope and it was delayed about 65~90 % compared to that of CT plot. And sediment discharge of 8 % slope reduced to 55 % compared to CT plot. But the sediment discharge was not occurred at 3 % slope. The NT and CT-RSB methods have a great possibility of reducing runoff and NPS pollution loads. Runoff rate of NT plots was significantly lower than those of CT plot. The average NPS pollution loads of the NT plots and CT-RSB plot reduced about 55~80 % and 2.1~40 % compared to those of the CT plots, respectively. It was also shown that runoff and NPS pollution loads reduction by NT method could be very significant and contribute to improve the water quality of streams in agricultural regions. It was concluded that the use of NT method on agricultural fields could reduce soil erosion and muddy runoff significantly and help improve the water quality and aquatic ecosystem.

• 환경영향평가
• /
• 제29권6호
• /
• pp.414-429
• /
• 2020

하천의 관리를 위하여 수질오염총량 및 물환경기본계획을 수립하여 목표수질을 설정하고 있으며 금호강의 경우 T-P는 목표수질을 달성하고 있으나 BOD, COD, TOC의 경우 지난 5년간 물환경기본계획 목표수질을 초과하였다. 이에 금호강을 대상으로 BOD, COD, TOC를 이용하여 유달부하량 및 유달부하밀도, 오염기여율을 분석하고 수질오염총량관리에서 사용하고 있는 1차원 수질모델인 QUAL-MEV를 활용하여 목표수질 만족을 위한 필요유량을 모의하였다. 유달부하량을 분석한 결과 금호C 지점에서 BOD, COD, TOC 모두 9,832.2 kg/day, 20,656.6 kg/day, 15,545.1 kg/day로 가장 높게 나타났으며, 유달부하밀도는 강우기 및 비강우기에 달서천에서 9.47 kg/day/㎢, 37.55 kg/day/㎢, 30.20 kg/day/㎢과 17.19 kg/day/㎢, 47.59 kg/day/㎢, 39.14 kg/day/㎢로 가장 높게 나타났다. 오염기여율은 강우기에 팔거천이 약 25%, 비강우기에 달서천이 모든 항목에서 약 50%로 가장 높게 나타났다. 또한 금호강본류 및 지류 유기물질간의 상관관계 분석을 수행한 결과 비강우기, 강우기 모두 COD-TOC가 0.8 이상으로 BOD-COD, BOD-TOC보다 상관관계가 높게 나타났다. 그리고 금호C 지점에서 수질오염총량 및 물환경기본계획 목표수질을 만족하기 위한 유량을 조사한 결과 2019년 4월(3.46 ㎥/sec)을 기준으로 약 14배, 22배의 추가유량이 필요한 것으로 분석되었다.

• 한국물환경학회지
• /
• 제23권6호
• /
• pp.850-862
• /
• 2007

This study was carried out to survey the actual conditions of wastewater treatment facilities to obtain basic data for the management of wastewater from industrial complexes in Chungcheongnam-do province. Wastewater production flow per site area by watersheds was $49.2m^3/km^2/d$ for Sapgyoho, $8.1m^3/km^2/d$ for Anseongcheon, $5.7m^3/km^2/d$ for Seohae, and $2.9m^3/km^2/d$ for Geumgang. Sapgyoho showed 75% of the total production flow, which was the highest value, Geumgang showed 4% of total flow, which was the lowest value. Average total extra rate as production flow/capacity flow in the wastewater treatment facilities for industrial complex is 49%. Considering by watersheds, the extra rates of Seohae, Geumgang, Anseongcheon, and Sapgyoho, are 73%, 65%, 62%, and 33% respectively. This means that the design of capacity flow in wastewater treatment facilities was too large. Effluent concentration of wastewater treatment facilities did not exceed discharge limit mostly. The removal efficiency rate for water quality item was 90% in BOD, 70% in COD, 80% in SS, 30 to 80% in TN, and 20 to 90% in TP, so the organic removal was good, but the nutrient removal was low and interval of variation was high. The removal efficiency rate of the agricultural was industrial complexes is lower than the national and local complexes. The construction cost of the wastewater treatment facilities in Chungcheongnam-do was $1,756Won\;per\;m^3$, treatment cost was $189Won\;per\;m^3$, and they were about two times and 1.2 times higher than the nation-wide cost, respectively. The treatment cost consists of 39% for man power, 21% for chemical, 16% for power, 11% for sludge treatment, and 13% for others.

• 도시과학
• /
• 제10권1호
• /
• pp.39-48
• /
• 2021

In this study, to evaluate the characteristics of the pollution in the major inflow tributaries and major environmental facilities in the watershed of Ara waterway, An inflow flow rate measurement and water quality analysis were conducted during dry and rainy seasons. In addition, the flow rate measurement, water quality analysis, and pollutant load at each monitoring point were compared and evaluated. Influx of BOD5, T-P and T-N into the tributaries of the ARA waterway watershed, excluding the Gulpo river watershed, during dry season were only 0.007%, 0.005% and 0.004% respectively of the incoming loads in the entire ARA waterway basin. In addition, it was confirmed that the discharge pollutant loads during rainfall event was about 440 times more for BOD5, about 545 times on T-P, and about 23 times on T-N in comparison to the pollutant loads during the dry days. When the Gulhyeon rubber dam was deflated, the discharged pollutant load during a rainfall was higher than the estimated load at the G7 monitoring point because the deposited pollutants from the upstream riverbed flowed down. Therefore, during a rainy season, it is necessary to manage the influx of high-load water pollutants from the overflow and deflation of the Gulhyun rubber dam as well as to find a strategy to reduce the pollutant loads in the Gulpo river watershed.