• 상하수도학회지
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• 제21권5호
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• pp.631-639
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• 2007

This study investigated the construction and operation status of sewer pipes and water-purifier tanks near densely populated areas like large apartment complexes, in order to find out cause for offensive orders. The study results revealed that the main cause arose from the water-purifier tank and public sewer pipes near ordinary residential areas. First, in case of independent water-purifier tanks, the air is forced into the rotten part of large tanks nearby which should be operated in an anaerobic state, so that the tank changes into an aerobic state, or dirty water, which is returned during the sludge return process, falls on the top of the rotten tank, preventing scum from forming within the tank. Such problems cause incompletely purified water in the purifier tank to be discharged, which in turn results in filthy water. Second, in case of public sewer pipes, deteriorated or aging pipes, or the mixture of rain water and dirty water by mixing up combined and separated sewers system can cause foul odors in residential areas. Therefore, offensive odors in residential areas can be radically reduced through the appropriate construction and management of facilities including water-purifier tanks. As well, if more separate sewers are installed as part of an improvement project for public sewer pipes, complaints about foul smell can be minimized.

• 에너지공학
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• 제26권1호
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• pp.68-75
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• 2017

Global warming affects water supply and water resources throughout the world. In many countries, climate change affects significantly on the fresh water resources. Vietnam is exposed mainly, to landslides and floods triggered by tropical storms and monsoon rains, although storm surge, whirlwind, river bank and coastal line erosion, hail rain. In addition to the prevalent drought, there are many major water challenges, including water availability, stress, scarcity and accessibility, because of poor resource management. Fast growth of urbanization, industrialization and population growth, agricultural activities and climate change cause heavy pressure on water quality. Both domestic and industrial wastewater, as well as storm water shares the same drainage. The common facilities for wastewater treatment are not available. Therefore, wastewater is treated only superficially and then discharged directly into rivers and lakes causing serious pollution of surface water environment. In this paper, we reported the severe water crisis and massive green algal blooms formation in Vietnam rivers and lakes. This is the biggest evidence of climate change variations in Vietnam.

• World Technopolis Review
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• 제3권2호
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• pp.89-96
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• 2014

Center for Research of Science and Technology ("PUSPIPTEK") has 460 hectares land area, still maintained as a green area with more than 30% green space. There are 47 centers for research and testing technology, technology-based industries, and as well as public supporting facilities in PUSPIPTEK area. Based on the concepts developed to make this area as an ecological region, PUSPIPTEK can be seen as a model of eco-innovation. The purpose of this research is to develop a model of water, energy and waste management with eco-innovation concept. As a new approach in addressing environmental degradation and maintaining the sustainability of ecosystem, studies related to eco-innovation policy that combines the management of water, energy and waste in the region has not been done. In order to achieve the objectives of the research, a series of techniques for collecting data on PUSPIPTEK existing conditions will be carried out, which includes utilities data (water, electricity, sewage) and master plan of this area. The savings over the implementation of the concept of eco-innovation in water, energy, and waste management were calculated and analyzed using quatitative methods. The amount of cost savings and feasibility were then calculated. Eco innovation in water management among other innovations include the provision of alternative sources of water, overflow of rain water and water environments utilization, and use of gravity to replace the pumping function. Eco-innovation in energy management innovations include the use of LED and solar cell for air conditioning. Eco-innovation in waste management includes methods of composting for organic waste management. The research results: (1) The savings that can be achieved with the implementation of eco innovation in the water management is Rp. 3,032,640 daily, or Rp.1,106,913,600 annually; (2) The savings derived from the implementation of eco innovation through replacement of central AC to AC LiBr Solar Powered will be saved Rp.1,933,992,990 annually and the use of LED lights in the Public street lighting PUSPIPTEK saved Rp.163,454,433 annually; (3) Application of eco innovation in waste management will be able to raise awareness of the environment by sorting organic, inorganic and plastic waste. Composting and plastic waste obtained from the sale revenue of Rp. 44,016,000 per year; (4) Overall, implementation of the eco-innovation system in PUSPIPTEK area can saves Rp. 3,248,377,023 per year, compared to the existing system; and (5)The savings are obtained with implementation of eco-innovation is considered as income. Analysis of the feasibility of the implementation of eco-innovation in water, energy, and waste management in PUSPIPTEK give NPV at a 15% discount factor in Rp. 3,895,228,761; 23.20% of IRR and 4.48 years of PBP. Thus the model of eco-innovation in the area PUSPIPTEK is feasible to implement.

• KIEAE Journal
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• 제12권5호
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• pp.3-10
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• 2012

In this study, the influence of decentralized rainwater management over the changes in evapotranspiration was analyzed. The analysis method was obtained by establishing the decentralized rainwater management plan according to different scenarios, and subsequently examined evapotranspiration in the plan. Scenario 1 refers to the analysis of the existing situation, in which was 100% of a parking lot is asphalt pavement. In Scenario 2, the pavement of the parking surface in the parking lot is replaced with lawn blocks. In Scenario 3, some asphalt pavement was removed to establish a flower-bed type infiltration system to allow rainwater to permeate. In Scenario 4, infiltration and storage of rain water would be achieved by transforming the parking surface into lawn blocks, keeping the asphalt for the parking road while establishing a vegetation strip. The amount of evapotranspiration of the target site was analyzed with a water budget analysis program (CAT) using the 2001 meteorological data for each scenario According to the analysis values of S2 and S3, it was found that evapotranspiration is critically affected by the amount of area replaced with pervious area in the total target site. An energy equivalent to 680kWh is required for 1 ton of water to evaporate. Hence, it can be seen that the active inducement of evapotranspiration in urban area makes a positive contribution not only to heat island mitigation, but also to the small-scale water circulation process in a city.

• 한국환경보건학회지
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• 제31권6호
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• pp.467-474
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• 2005

The runoff characteristics of combined sewer overflow(CSO) in the urban area of Jeonju were investigated and analyzed by using the SWMM (Storm Water Management Model) and GIS. From August to November 2004, investigations on two rainfall events were performed and flowrate, pH, BOD, COD, SS, T-N and T-P were measured. these data were used for model calibration. Using GIS technique, watershed characteristics of study area were calculated. that is, divide into sub_basin, total width, slope, make soil map etc. On the basis of the measured data and the simulation results by SWMM, it could be known that the $80-90\%$ of pollution load are discharged in early-stage storm runoff. SMC(site mean Concentration) for combined sewer system area were BOD 28.1, COD 31.5, SS 186 ppm etc. this is shown that during the rain fall, high concentration of waste was loaded to receiving water. Unit loads of combined sewer system area were BOD 306, COD 410, SS 789, T-N 79, T-P 6.8 kg/ha/yr.

• 한국습지학회지
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• 제4권2호
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• pp.57-66
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• 2002

The local storm occurred Nakdong river basin from August 4 to 11 of the year 2002, resulting in a record 500-600mm rainfall. The heavy rain continued for more than 10 days and especially between 3 to 4 am of August 9, 50mm per hour local storm occurred in Hanrim-myun area, Kimhae. 8 days after the storm, the water level of Nakdong river rose rapidly and the river flowed backward the branches. T he draining of the protected low wetland was unable and the water level of the inner bank area rose suddenly, causing the inundation in several areas. Baeksan bank of Nam river, Gahyun(Samhak) bank of Hwang river, and Kwangam bank of Shinban river, where the draining facilities were under construction or constructed recently, were failed by the piping around the draining culvert. This study analyze the cause of the damage in Nakdong river banks and suggests the countermeasures for future improvement. The damaged spot of the river bank was surveyed, and the rainfall and the fluctuation in the water levels were reviewed. Finally for the flood inundation prevention at the inner bank area, new floodplain management plan as the protect of low wetland established.

• 환경위생공학
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• 제22권4호
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• pp.87-104
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• 2007

The objective of this study is to estimate the load of pollutants caused from the forest area among non-point pollutants within the Juam lake. The surveyed forest area was classified into broad-leaved, conifer, mixed and herbage area by forest tree type. Water quality and flux were investigated under rainfall and non-rainfall, respectively. Then, pollutant loading was evaluated by using the values of unit pollutant loading factor of each point and area of forest zone. Water quality analysis results of runoff by forest tree types were as follows. - Annual BOD, $COD_{Mn}\;and\;COD_{Cr}$ concentration of runoff in conifer area was high, and particle and biological recalcitrant compounds were flowed highly. - SS, T-N and T-P concentration was high in runoff from broad-leaved area, and biological degradable compounds was flowed. - Water quality of water from valley was maintained good under non-rainfall and could be utilized as fresh drinking water. Through water quality standard investigation, a countermeasure establishment was necessary to secure a good quality of drinking water - BOD, $COD_{Mn},\;and\;COD_{Cr}$ concentration of Bo-sung river was higher 1.5 times than other 2 streams, and because of high T-N, and T-P concentration in Songgwang stream, the management for this was necessary.

• 한국환경과학회지
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• 제21권9호
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• pp.1115-1129
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• 2012

The objective of this study was to analyze long-term annual and seasonal trends of water chemistry on landuse patterns and seasonal precipitation using 72 sampling sites within Namhan River watershed during 2001-2010. Water quality, based on multi-parameters of water temperature(WT), dissolved oxygen(DO), biochemical oxygen demand(BOD), chemical oxygen demand(COD), suspended solids(SS), total nitrogen(TN), total phosphorus(TP), and electric conductivity(EC) varied largely depending on monsoon rain and landuse patterns such as forest, cropland, and residence. Concentrations of BOD and COD as an indicator for organic matter pollution, increased during summer monsoon season at the cropland and residential streams. Values of TN and TP were higher in residential streams than in the forest and cropland streams. In the meantime, DO values had weak relations to the landuse patterns of forest and cropland cover. Water quality was worst in cropland and residential streams, and also most degradated in 4th order streams. Overall, our results suggest that efficient water quality management is required in the cropland and residential landuse streams.

• 디지털융복합연구
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• 제10권6호
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• pp.289-296
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• 2012

우리나라는 지형적, 기후적 특성으로 인해 매년 여름 산사태의 가능성이 크며, 최근 난개발로 인해 이의 발생과 피해가 더욱 커지고 있다. 천안지역은 상대적으로 안전한 지역으로 인식되어 왔으나 산사태의 위험요인이 증가하고 있어 체계적 분석이 필요하다. 본 논문에서는 천안 성거산 주변을 중심으로 등고선 지도를 이용하여 지형의 특징을 추출하고, 이를 이용하여 호우 시 수로와 유역의 면적을 계산하였다. 분석결과 성거산 주변 지역은 수로의 길이와 호우 유입량 관점에서 산사태에 비교적 안정적인 것으로 분석되었으나 일부 국소지역은 계속적 관찰이 필요하다. 한편 등고선 지도는 다른 수치지도 보다 비용 면에서 경제적이므로 1차적 산사태 위험도 분석에 적합하다.

• 상하수도학회지
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• 제35권1호
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• pp.53-61
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• 2021

The quantified analysis of damages to wastewater treatment plants by natural disasters is essential to maintain the stability of wastewater treatment systems. However, studies on the quantified analysis of natural disaster effects on wastewater treatment systems are very rare. In this study, a total disaster index (DI) was developed to quantify the various damages to wastewater treatment systems from natural disasters using two statistical methods (i.e., AHP: analytic hierarchy process and PCA: principal component analysis). Typhoons, heavy rain, and earthquakes are considered as three major natural disasters for the development of the DI. A total of 15 input variables from public open-source data (e.g., statistical yearbook of wastewater treatment system, meteorological data and financial status in local governments) were used for the development of a DI for 199 wastewater treatment plants in Korea. The total DI was calculated from the weighted sum of the disaster indices of the three natural disasters (i.e., TI for typhoon, RI for heavy rain, and EI for earthquake). The three disaster indices of each natural disaster were determined from four components, such as possibility of occurrence and expected damages. The relative weights of the four components to calculate the disaster indices (TI, RI and EI) for each of the three natural disasters were also determined from AHP. PCA was used to determine the relative weights of the input variables to calculate the four components. The relative weights of TI, RI and EI to calculate total DI were determined as 0.547, 0.306, and 0.147 respectively.