• Title/Summary/Keyword: CSOs

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Impacts Assessments of River Linked with Runoff Characteristics of Non-Point Source by CSOs in Urban Area (도시지역 월류수에 의한 비점오염원의 유출 특성과 연계한 하천 영향 평가)

  • Kim, You-Seong;Ko, Hyuk-Bae;Ahn, Sang-Dae;Kim, Won-Il;Ahn, Won-Sik
    • Proceedings of the Korea Water Resources Association Conference
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    • 2008.05a
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    • pp.92-96
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    • 2008
  • 최근에 이상기후로 인한 집중호우는 단시간의 높은 강우 강도의 발생을 증가시켜 재해 유발의 측면에서 뿐만 아니라 유역 내 비점오염원이 합류식 관거의 월류수인 CSOs(Combined Sewer Overflows)의 형태로 강우와 함께 유입되어 수질 및 환경을 오염시키는 문제점이 발생한다. 이에 따라 월류수의 유출특성에 대한 정량적인 분석을 통하여 유량 및 수질 등의 오염부하량에 대한 적절한 저감 방안이 요구되고 있는 실정이다. 이에 본 연구에서는 비점오염원의 농도가 상대적으로 높은 도시유역에 강우로 인한 월류수의 유출 특성 변화를 분석함과 동시에 월류수가 하천에 방류되었을 때의 하천에 미치는 영향 분석을 통하여 하천의 효율적인 수질 관리 방안을 제시하고자 한다. 경기도 구리시를 대상유역으로 선정하였으며, 도시 강우-유출 모델인 SWMM을 사용하여 유역의 유출량 및 월류수의 수질 모의를 수행하였으며, 유역의 최종 방류구에 비점오염 저감을 위해 설치된 저류지를 통해 하천으로 배출되는 유출수와의 연계는 미국 환경청에서 개발된 WASP 모델을 적용하여 왕숙천 본류에 대한 월류수 변화가 하천에 미치는 영향을 분석하였다. 저류지 설치 전 후의 하천에 월류수가 미치는 영향을 BOD 농도를 중심으로 비교 분석하였다. 분석 결과 저류지 설치 후 BOD 농도의 저감율은 설치 전 보다 최소 1.9%, 최대 81.2%의 저감 효과가 있는 것으로 분석되었다. 향후 신뢰도 높은 수질모의를 위해서는 월류수 발생시 월류수와 하천의 지속적인 모니터링을 통해 현장 여건을 반영할 수 있는 입력변수의 도출이 매우 중요한 것으로 나타났다.

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Characteristics and Combined Sewer Overflows (합류식 하수관거의 유출 특성 분석 조사)

  • An, Ki-Sun;Jang, Sung-Ryong;Kwon, Young-Ho
    • Journal of Environmental Science International
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    • v.19 no.6
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    • pp.747-753
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    • 2010
  • It follows in quality and sewage exclusion method of the investigation objective sector and the Combined Sewer Overflows which is suitable in regional characteristics and the confluence area against the rainfall initially a flow and the medulla and measurement - it analyzes the initial rainfall outflow possibility control plan which is suitable in the domestic actual condition and it proposes the monitor ring plan for the long-term flow and pollution load data accumulation. From the research which it sees the Infiltration water/Influent water and CSOs investigation it passes by the phase of hazard chain and Namwon right time 4 it does not hold reverse under selecting, Measurement it used the hazard automatic flow joint seal Sigma 910 machine and in case 15 minute interval of the I/I, it measured a flow at case 5, 15 minute standing of the CSOs. The water quality investigation for the water leakage investigation of the I/I and the sewage from the point which is identical with flow measurement during on-the-spot inspection duration against 6 items which include the BOD sampling and an analysis, when the rainfall analysis for CSOs fundamental investigation analyzed against 18 items which include the BOD sampling. Consequently, for the optimum interpretation invasion water / inflow water of the this investigation area day average the lowest flow - water quality assessment veterinarian optimum interpretation hazard average per day - lowest flow - it averages a medulla evaluation law department one lowest flow evaluation technique and it selects, it presentation collectively from here it gets, position result with base flow analysis of invasion water / inflow water.

Research on Non-Union Representation for Contingent Worker's Representation Mechanism : Focusing on CSO's Representation Mechanism in Civil Society (비정규 노동자 이해대표 기제로서 비노조 이해대표에 관한 연구 : 시민사회진영 내 CSO를 통한 이해대변 기제를 중심으로)

  • Sohn, Jeong-soon
    • Korean Journal of Labor Studies
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    • v.24 no.2
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    • pp.61-94
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    • 2018
  • While the unionization of contingent workers is at a standstill, the newly emerging peripheral workers' representation mechanism is CSO(Civil Society Organization). Unlike trade union's representation based on coercive collective bargaining and agreements CSO represents the interests of marginal workers through counseling, advocacy, public relations, and education. In the case of Korea, since the 2000s, labor CSOs, called "contingent centers", have started to spread. As a result of the survey, contingent centers which are contracted out by local governments show the possibility that the representation activities are restricted, because most of their resources are covered from the local government. This is because CSOs have limitations due to a dilemma in the process of representing funders and the represented. Nevertheless, the contingent workers' CSO in Korea shows the possibility of supplementing and supporting the role of trade unions' representation. In this regard, through the solidarity of trade unions and CSOs, it will be possible to expand the representation of unorganized and contingent workers in Korean society.

Set up Reduction Goals of Combined Sewer Overflow Pollutant Load Using Long-Term Rainfall-Runoff Model Simulation (장기간 강우-유출 모의를 통한 합류식하수관로시스템의 월류부하량 저감목표 설정 연구)

  • Lee, Gunyoung;Na, Yongun;Ryu, Jaena;Oh, Jeill
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.11
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    • pp.785-794
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    • 2013
  • Combined sewer overflows during rainfall events contain sewer sediments and surface pollutants. This can cause significant chemical, physical and biological problems to receiving watershed. However, there are no method that can commonly apply to decide criteria for controlling the pollutant load. In this study, it sets up the reduction goals of combined sewer overflow through long-term simulation using the rainfall-runoff model. From a review of domestic and foreign management standard of combined sewer overflow for this, it makes decision that 60% (phase 1), 85% (phase 2) of total pollutant load and frequency per year for reduction goals is more proper. Also, the result of analyzing long-term simulation (minimum 10 years) applied to research basin indicates that reduction goals of BOD pollutant load are 1,123 kg (phase 1) and 2,374 kg (phase 2), and overflow volumes for research objective achievement are $11,685m^3$ (phase 1) and $24,701m^3$ (phase 2).

Energy Scenarios and the Politics of Expertise in Korea (한국의 에너지 시나리오와 전문성의 정치)

  • Han, Jae-Kak;Lee, Young Hee
    • Journal of Science and Technology Studies
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    • v.12 no.1
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    • pp.107-144
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    • 2012
  • Recently concerns on the energy future are rising in Korea after nuclear disaster of Fukushima in Japan last year. However, even after Fukushima disaster Korean government keeps on insisting nuclear oriented energy policy. Contrary to it, some of civil society's organizations(CSOs) including environment groups and progressive political parties are making strong voices for phase-out nuclear. As a way of phase-out nuclear activity researcher groups based on CSOs have presented several alternative energy scenarios against the official government scenario so that contest between the two senarios seems not to be avoided. This article aims to analyse the politics of expertise around energy scenarios in Korea by highlighting differences between two scenarios of government and CSOs in terms of epistemological and methodological base, value orientation, institutional foundation, and the socio-political contexts of scenarios. Our research shows that government's energy scenario is based on scientific-positivist epistemology, firm belief in value neutrality and forecasting method, and is built by neo-classical economists at government-sponsored research institutes in accordance with the 'Business As Usual' approach. In contrast, alternative scenarios of CSOs can be said to be based on epistemological constructivism, value oriented attitudes and backcasting method, and be built by collaboration of researchers and activists with different academic and social backgrounds after Fukushima nuclear disaster.

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Spent-GAC Regeneration Using Variable Frequency Sono-Fenton Oxidation (가변 주파수 Sono-Fenton 산화를 이용한 Spent-GAC 재생기술)

  • Joo, Soobin;Lee, Sangmin;Kim, Hyungjun;Shim, Intae;Kim, Heejin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.4
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    • pp.449-458
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    • 2023
  • As an adsorption technology for dissolved organic matter, the adsorption capacity of granular activated carbon, GAC, can be applied, but activated carbon whose adsorption capacity is significantly reduced by use is inevitably replaced or regenerated. However, due to the economics of replacement cost, thermal regeneration method is used commercially, but high energy cost and loss of activated carbon occur under high temperature conditions above 800℃. In this study, the Sono-Fenton method, a multi-oxidation technology that combines Fenton oxidation and ultrasonic oxidation, was applied to improve the regeneration efficiency of spent GAC used to treat dissolved organic matter in combined sewer overflows (CSOs), and the regeneration efficiency of spent GAC by oxidant and ultrasonic frequency was investigated. In the applied Sono-Fenton treatment, the highest regeneration efficiency of 68.5% was obtained under the regeneration conditions of Fe2+ 10 mmol/L, H2O2 concentration 1,000 mmol/L, ultrasonic treatment time of 120 min, and ultrasonic frequency of 40 kHz. And similar efficiency was also obtained at 750 kHz, while ultrasonic waves of other frequencies had poor regeneration efficiency, and the magnitude of frequency and GAC regeneration efficiency did not show a linear relationship. In the case of continuous operation of the GAC adsorption tower with CSOs prepared by diluting raw sewage, about 700 hours of operation without regeneration was possible, and as a result of applying one Sono-Fenton treatment, 40-70% CODcr removal efficiency was obtained during a total of 1,000 hours of GAC adsorption operation.

Addition of Coagulants for Phosphorus Removal from Combined Sewer Overflows (CSOs) (합류식 하수관거 월류수의 인제거를 위한 응집제 투여)

  • Son, Sang-Mi;Jutidamrongphan, Warangkana;Park, Ki-Young
    • Journal of Korean Society of Water and Wastewater
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    • v.26 no.2
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    • pp.295-302
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    • 2012
  • The coagulation of combined sewer overflows ($CSO_{s}$) was investigated by jar-testing with several commercial coagulants. $CSO_{s}$ sample showed different characteristics of coagulation from secondary wastewater with three common coagulants, aluminum sulfate, ferric chloride and polyaluminum chloride (PACl). Jar-tests showed that relatively wide range of optimal SS and T-P removal yielded with alum and ferric chloride compared with cationic polymers, though efficient SS and T-P removal can be achieved with all three coagulants. The decrease of pH was caused by the increase in dosage of aluminum sulfate, ferric chloride and PACl as coagulants. The pH was changed from 7.0 to 4.7 with the dosages of ferric chloride 25 mL/L. Aluminum sulfate revealed pH of 5.0 and PACl was highest pH of 5.4 after dosing of coagulants. The optimal pH to treat $CSO_{s}$ with aluminum sulfate were 6-6.5; with PACl 6-7, and with ferric chloride higher than 7.