• Title/Summary/Keyword: Intercepting capacity

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Study on the determination of optimum size of storage tank and intercepting capacity for CSOs reduction in urban area (도시지역 CSOs 저감을 위한 저류조 및 이송관로의 최적 용량결정에 관한 연구)

  • Lee, Kwan Yong;Choi, Won Suk;Lee, Yong Jae;Koo, Won Suk;Song, Chang Soo
    • Journal of Korean Society of Water and Wastewater
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    • v.26 no.6
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    • pp.735-745
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    • 2012
  • Storage method is one of major measures for reduction of CSOs pollutant loads and several projects have been done nationwide. But systematic analysis of intercepting capacity has not been studied to determine optimum size of storage facility. In this research, not only storage volume but also intercepting capacity which means flow capacity from intercepting facility to CSOs storage facility was studied and optimum sizing method for storage facility was proposed. The result shows that pollutants reduction efficiency can be increased significantly by increasing intercepting capacity and it might reduce storage volume and total construction costs. Intercepting capacity for the study area was evaluated and it was shown as equivalent to 83 % probability rainfall intensity.

Determination of Interception Flow by Pollution Load Budget Analysis in Combined Sewer Watershed (II) - Establishment of Intercepting Capacity and Reduction Goal of Overflow Pollution Load - (오염부하 물질수지 분석을 통한 합류식 하수관거 적정 차집용량 결정(II) - 차집용량과 월류오염부하 삭감목표 설정 -)

  • Lee, Doojin;Shin, EungBai
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.5
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    • pp.557-564
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    • 2005
  • The objective of this study is to evaluate a criteria of intercepting capacity and a reduction goal of overflow pollution load in combined sewer system. In the current criteria of intercepting capacity in the domestic sewage facility standard, it is known that three times of peak sewage (Q) in dry period or runoff flow by 2mm/hr is not appropriate since the intercepted flow is estimated by runoff and show different result even in the same watershed. Though a reduction goal of overflow pollution load can be determined from 1) same level of storm-water runoff pollution load in separated storm sewer, 2) less than 5% sewage load in dry weather period, by the domestic sewage facility standard, the simulated results from storm-water model show large differences between two criteria. While it is predicted that sewage pollution load standard three time larger than separated storm sewer standard in high population density and urbanized area, it is shown that separate storm sewer standard larger than sewage pollution load standard in middle population density and developing area. Accordingly, it is proposed that more reasonable intercepting flow and reduction goal of overflows pollution load should be established to minimize discharging pollution load in combined sewer systems. For the purpose, a resonable standard has to be amended by pollution load balance considering the characteristics of a watershed for generation, collection, treatment, and discharging flow.

Determination of Interception Flow by Pollution Load Budget Analysis in Combined Sewer Watershed - Analysis of Pollution Load Budget in Watershed - (오염부하 물질수지 분석을 통한 합류식 하수관거 적정 차집용량 결정(I) -오염부하 물질수지 분석-)

  • Lee, Doojin;Kim, Juwhan;Woo, Hyungmin;Ahn, Hyowon
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.5
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    • pp.547-556
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    • 2005
  • The objective of this study is to obtain adequate intercepting flow during wet weather conditions in combined sewer system. Two study sites are selected under considering different population density, one is developed area with heavy urbanization. Another is recently developing area. In the analysis of field investigation, SS was most significant in initial flushing effects compared with other factors and showed the result with the order of COD, TP, TN. As compared with event mean concentration(EMC) of runoff, BOD, TN and TP showed high concentrations in wide area with relatively large population density. It is by the reason that much pollution load was discharged to receiving water from urbanized area during wet period. According to results of storm-water modeling, 53% of total COD and 52% of total SS pollution load were discharged to receiving water by overflow than intercepting capacity in middle population density site. Also, in the urbanized area, pollution load was discharged to receiving water by 49% of total COD and 77% of total SS. These results can be applied to setup for pollution load flow(budget) generation, collection, treatment and discharging in order to obtain adequate intercepting flow.

Effects of Combined Sewer Overflows According to Drainage Basin Types (유역형상에 따른 합류식 하수도의 월류부하량 추정)

  • Lee, Cheol-Kyu;Hyun, In-Hwan;Jeong, Jeong-Youl;Shim, Jae-Hyun
    • Journal of the Korean Society of Hazard Mitigation
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    • v.4 no.4 s.15
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    • pp.21-26
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    • 2004
  • It is muck important to determine the intercepting capacities as measures for reducing the load of contamination influenced by CSOs during wet weather period. Intercepting and treating the whole rainfalls can be best measured for reducing the contamination load, but it is not desirable in view of scale and preservation of the wastewater treatment facilities. This study analyzed the quantity and quality of the water in the combined sewer by method of changing the type and size of drainage basin and intercepting capacities in rainfalls, estimate the influence the other CSOs at the change of planned intercepted quantity, and compared the degree of contamination load between the combined system and separate system by examining the influence of the other CSOs at the change of planned intercepted quantity.

Standard-Rainfall and Capacity of Intercepting Sewer to Control CSOs (CSOs 제어를 위한 기준강우 및 차집 용량 산정)

  • Lee, Jung-Ho;Joo, Jin-Gul;Kim, Joong-Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.1
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    • pp.129-135
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    • 2008
  • The combined sewer overflows(COSs) which enters to river are involved with water pollution of rivers. Therefore, the standard capacity should be decided in proper standard considering water pollution density and characteristic of outflow. But in domestic, the standard capacity is not considered the characteristics of rainfall-outflows and is applied uniformly in all areas. The standard is triple of a maximum amount of sewage per one hour ; 3Q. The outflow of 3Q enters to sewage treatment plant and the overflows enter to river. In this study, a standard rainfall is estimated to determine the capacity of intercepting sewer by statistical analysis of rainfall data and it is considered about the regional characteristic of the rainfall-outflow. The standard rainfall is analyzed through the data of Seoul. In the result the standard rainfall was 6.76mm of 4hr duration. The rainfall-outflows and CSOs are analyzed using SWMM(Storm Water Management Model).

The Effect of Pervious Pavement on Reducing the Surface Runoff (투수성 포장재의 우수 표면유출 저감 효과)

  • Lee, Chun-Seok;Ryu, Nam-Hyung;Han, Seung-Ho
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.11 no.6
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    • pp.26-37
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    • 2008
  • The purpose of the study was to evaluate the effect of pervious pavements on reducing the surface runoff caused by rainfall. The surface runoff from twelve steel experimental beds with different pavement had been recorded every minute from May to September 2008, by the measuring system of tipping buckets(0.1mm/count) and data aquisition systems(National Instrument's Labview and DAQ boards & Autonics PR12-4). The dimension of the experimental bed was $1.5m(W){\times}2.0m(L){\times}0.6m(D)$ and eleven different kinds of vegetational(grass, grass+cubic stone, grass+hole brick), modular(brick, cubic stone, small cubic stone, wood block, interlocking block, clay brick, granular clay brick) and granular(naked soil, gravel) paving materials and concrete were applied for the comparison. Six rain events with depth over 30mm were selected and compared. The maximum depth of the rainfall selected was 137.5mm for 28 hours, and the minimum 30mm for 5 hours. The maximum rainfall per hour was 23mm/hr and the minimum 11.4mm/hr. The major findings were as follows; 1. All pervious pavement applied reduced over 75% of the surface runoff compared with concrete pavement. The grassy and porous pavements were relatively efficient in reducing surface runoff. 2. The grass was the more efficient as intercepting average 69.5mm of initial surface runoff, and maximum 77.8mm at the condition of 13.5mm/hr rainfall. The next was gravel intercepting maximum 65.5mm at the condition of 13.5mm/hr and the 40.9mm at 19.1mm/hr, average 55.7mm. 3. The modular pavements common in urban area were not good in intercepting the runoff except the 'clay granular brick' compared with others. The 'clay granular brick' showed relatively efficient intercepting average 14.1mm, which was the bigger amount than the 'grass+hole brick'. 4. The 'naked soil' were more effective than the 'concrete', 'brick', and 'interlocking block' in reducing the surface runoff, but less efficient than other materials. The capacity of the 'naked soil' to intercept the initial rainfall was similar to the 'brick'. As summary, the more grassy and porous pavement shows more effective in reducing surface runoffs.

The Effect of the Pea Carb (Pinnotheres pholadis) on the Reproductive Capacity of the Blue Mussel (Mytilus edulis galloprovincialis) (섶 속살이게, Pinnotheres pholadis의 기생이 진주담치의 번식력에 미치는 영향)

  • YOO Myong Suk;KAJIHARA Takeshi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.18 no.6
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    • pp.581-585
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    • 1985
  • This study was carried out with blue mussels at Otsuchi Bay in Japan from August 1981 to May 1982, in order to investigate the effect of the parasitic pea crab (Pinnotheres pholadis) on the reproductive capacity of host blue mussels (Mytilus edulis galloprovincialis). The results show that pea crabs delay gonad development of host mussels about one month and lower their fatness rate by intercepting nutrients. The parasitization with pea crabs is thought not to prevent spawning activity itself, but to reduce the number of germ cell resulting in the reduced space of gonads.

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Effect of infiltration/inflow by rainfall for sewerage facilities in the area with partially separate sewer system (불완전 분류식 하수처리구역의 강우에 의한 하수도시설의 침입수/유입수 영향 분석)

  • Shin, Jungsub;Han, Sangwon;Yook, Junsu;Lee, Chungu;Kang, Seonhong
    • Journal of Korean Society of Water and Wastewater
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    • v.33 no.3
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    • pp.177-190
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    • 2019
  • The purpose of this study was to analyze the effects of sewerage facilities through I/I analysis by rainfall by selecting areas where storm overflow diverging chamber is remained due to the non-maintenance drainage equipment when the sewerage system was reconstructed as a separate sewer system. Research has shown that wet weather flow(WWF) increased from 106.2% to 154.8% compared to dry weather flow(DWF) in intercepting sewers, and that the WWF increased from 122.4% to 257.6% in comparison to DWF in storm overflow diverging chamber. As a result, owing to storm overflow diverging chamber of partially separate sewer system with untreated tributary of sewage treatment plant, rainfall-derived infiltration/inflow(RDII) has been analyzed 2.7 times higher than the areas without storm overflow diverging chamber. Meanwhile, infiltration quantity of this study area was relatively higher than that of other study areas. Therefore, it is necessary to reduce infiltration quantity through sewer pipe maintenance nearby river. Drainage equipment maintenance should be performed not to operate storm overflow diverging chamber in order to handle the appropriate sewage treatment plant capacity for rainfall because it is also expected that RDII due to rain will occur after maintenance. In conclusion, it is necessary to recognize aRDII(allowance of rainfall-derived infiltration/inflow) and to be reflected it on sewage treatment plant capacity because aRDII can occur even after maintenance to the complete separate sewer system.

Phil-Environmental Tide Land Reclamation and Korean Agriculture (친환경간척농지개발과 우리농업)

  • Heo Yu Man
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2001.09a
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    • pp.59-71
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    • 2001
  • In Korea, It was natural and inevitable to reclaim tidal land for farming due to over-population in small territory. Looking back upon the history of tidal land reclamation in Korea, We can find the first case of it in 13th century KangHwaDo(Island), and also find several records of small scale reclamations of western sea-coast from Korea dynasty to Chosun dynasty. A lot of wide fertile agricultural areas on western sea-coast have been developed through tidal land reclamation for about 1000-year after Korea dynasty. and on these areas, we have produced rice which we live on. An average areas of farming land per capital in korea is only 0.04ha, which is one sixth of global average. For water resources, similarly, capacity of water resources alloted to one person is $11{\%}$ of global average. So, without supplementary water development, we will have suffered from a severe deficiency of water Therefore we must prepare for these predictable short water and food problems. and tidal land reclamation may be suitable alternative to settle these problems. However, tidal land reclamation is a work of closing estuary, intercepting sea water inflow, developing a freshened estuary lake and farming lands etc. therefore it apparently causes a change of ecosystem, water quality and littoral environment. Nowadays, widely recognized the importance of environmental preservation, it is desirable or requested to make phil-environmental and sustainable development minimizing the environmental influence due to tidal land reclamation project. In this paper, the role of tidal land reclamation project in the development process of Korean agriculture was reviewed and the direction of afterwards tidal land reclamation project was suggested.

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Methodology for Intercepting the Ransomware Attacks Using File I/O Intervals (파일 I/O Interval을 이용한 랜섬웨어 공격 차단 방법론)

  • Youn, Jung-moo;Jo, Je-geong;Ryu, Jae-cheol
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.26 no.3
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    • pp.645-653
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    • 2016
  • Ransomware was first created in 1999, but its existence become widely known in Korean by 2015. As information and communication technology have developed, the storage capacity of computer has enlarged, it accordingly is getting more important to effectively manage these information, rather than the information itself. In such situation, the ransomware break into other people's computer and encrypt an files without a user's permission. So, it adversely affect the user. In this paper, we monitor an access of a specific process to the file. And on the basis of this monitoring information, we detect whether the abnormal approach happened. Through the detection result, we block the permission about access to the file for a specific process. Using this method, we propose a blocking technique for the ransomeware's abnormal approach and encryption to the files.