• 한국물환경학회지
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• 제23권6호
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• pp.934-944
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• 2007

Fine suspended solids (SS) induced into a reservoir after flood events play important ecological and water quality roles by presenting persistent turbidity and attenuating light. Thus the origin and physical features must be characterized to understand their transport processes and associated impacts, and for the establishment of watershed based prevention strategies. This study was aimed to characterize the physical properties of the SS sampled from Daecheong Reservoir and its upstream rivers during flood events. Extensive field and laboratory experiments were carried out to identify the turbidity-SS relationships, particle size distributions, settling velocity, and mineral compositions of the SS. Results showed that the turbidity-SS relationships are site-specific depending on the locations and flood events in the system. The turbidity measured within the reservoir was much greater than that measured in the upstream rivers for the same SS value. The effective diameters ($D_{50}$) in the rivers were in the range of $13.3{\sim}54.3{\mu}m$, while those in the reservoir were reduced to $2.5{\sim}14.0{\mu}m$ due to a fast settling of large particles in the rivers. The major minerals consisting of the SS were found to be Illite, Muscovite, Albite, and Quartz both in the rivers and reservoir. Their apparent settling velocities at various locations in the reservoir were in the range of 0.06~0.13 m/day. The research outcome provides a fundamental information for the fine suspended particles that cause persistent turbidity in the reservoir, and can be used as basic parameters for modeling study to search watershed based optimal control measures.

• 상하수도학회지
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• 제20권2호
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• pp.215-223
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• 2006

The internal corrosion of water distribution systems is the main cause for the problem of the public health threat as well as water leakage in the damaged pipeline, red water, and odor and taste of the tap water. This study was examined the effect of chemicals used for pH and alkalinity control and corrosion inhibitors for producing the optimal corrosion control method. Corrosion study at different pH and alkalinity indicated that these control using alkaline chemicals was effective in corrosion rate, Fe release reduction, but examined to be increased in turbidity and corrosion-by-products(TTHMs) problems. The turbidity was slightly increased, requiring caution in controlling corrosion with $Ca(OH)_2$. At pH 9.0, TTHMs concentration is increased two times corn pared with non-control of pH. Using the pipe which had experienced 28 years of exposure, iron release was decreased with the corrosion inhibitor. Consequently, pH, Alkalinity control method using alkaline chemicals must be complemented by corrosion inhibitor application for efficient corrosion control.

• 상하수도학회지
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• 제28권2호
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• pp.249-255
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• 2014

So many drinking water treatment plants are under various difficulties by new reinforced effluent standards. Since the target turbidity, much higher than annual average, for designing sludge thickener have to be set to confront high turbidity season, the sludge at thickener should be put up for a long time during usual days. So the soluble manganese and chloroform may be formed under the anaerobic environment in the sludge thickener when the sludge retention time is longer with low turbidity. This phenomenon results in difficulties to keep regulatory level of the discharged effluent. For an effort to overcome the problems, a sludge aeration was successfully implemented into the thickening process. As a result, the final effluent quality and sludge volume were much improved; 41 % of manganese, 62 % of chloroform and 35 % of sludge volume. Additionally, effluent quality was improved ; 61 % of Manganese on aeration with pH control and we could make sure of stability effluent quality despite a long sludge retention time. We recommended the standard of installation sludge aeration equipment to nationally supply water treatment plant under effluent water quality problem ; Manganese, Chloroform, etc.

• Journal of Advanced Marine Engineering and Technology
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• 제33권8호
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• pp.1187-1195
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• 2009

본 논문은 완전 혼화조를 이용한 폐수처리 공정의 응집특성에 대한 연구를 목적으로 한다. 완전 혼화조 시스템은 유체 저장조, 임펠러가 장착된 3단의 혼화 및 응집부, 응집보조제 및 응집제 주입부, 응집 침전조 그리고 제어부로 구성된다. 실험용 폐수는 터널 공사현장에서 폐수 슬러지를 수거하여 약 1,000NTU의 탁도를 갖도록 만들었다. 응집보조제의 주입량이 증가함에 따라 약 99% 정도까지 탁도 제거율이 증가하였으며, 응집제의 주입량이 일정한 범위 이상으로 증가하면 탁도 제거율이 감소하는 것을 알 수 있다.

• 상하수도학회지
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• 제28권3호
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• pp.277-286
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• 2014

Water discolouration and increased turbidity in the local water service distribution network occurred from hydraulic incidents such as drastic changes of flow and pressure at large consumer. Hydraulic incidents impose extra shear stresses on sediment layers in the network, leading to particle resuspension. Therefore, real time measuring instruments were installed for monitoring the variation of water flow, pressure, turbidity and particulates on a hydrant in front of the inlet point of large apartment complex. In this study, it is attempted to establish a more stable water supply plan and to reduce complaints from customers about water quality in a district metering area. To reduce red or black water, the water flow monitoring and control systems are desperately needed in the point of the larger consumers.

• 한국농공학회지
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• 제45권2호
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• pp.126-137
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• 2003

The feasibility study of UV-disinfection system was performed for disinfection of effluent from wastewater treatment plant. Three low-pressure UV lamps of 17, 25, and 41 W were examined with various flow rates. Low-pressure UV lamps of 17W were examined with various turbidity, DOM (dissolved organic matter), and SS (suspended solid). The pilot plant was a flow-through type UV-disinfection system, and the range of exposure time varied from 5 to 40 seconds, turbidity from 0 to 40 NTU, DOM from 0 to 30 mg/L, and SS from 10 to 40 mg/L. The 41W lamp demonstrated complete disinfection showing no survival ratio in all the experimental conditions, and generally 17W and 25W lamps also showed high removal ratio over 97%. For the same UV dose (UV intensity times exposure time), high intensity-short exposure conditions showed better disinfection efficiency than low intensity-long exposure conditions. While the effects of turbidity and DOM were not apparent, the effects of SS was significant on the disinfection efficiency which indicates that SS control before UV-disinfection appears to be necessary to increase removal efficiency. Considering characteristics of effluent from existing wastewater treatment plants, cost-effectiveness, stable performance, and minimum maintenance, the flow-through type UV-disinfection system with high intensity and low-pressure lamps was thought to be a competitive disinfection system for wastewater reclamation.

• 한국전자통신학회논문지
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• 제17권6호
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• pp.1237-1242
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• 2022

대기오염물질인 미세먼지의 50% 이상을 차지하고 있는 비산먼지는 건설공사가 주요 배출원(29.5%)으로 이에 대한 관리를 위하여 비산먼지 억제를 위한 시설 설치 및 조치에 관한 기준을 법으로 제시하고 있다. 그러나 소규모 건설현장은 관리 대상기준이 아니며 건설현장에서 발생하는 비산먼지를 개량적으로 측정하여 조치하는 항목이 미흡하다. 본 논문에서는 비산먼지를 더욱 쉽게 측정하고 모니터링하기 위하여 먼지의 혼탁도를 측정하는 광학기법을 사용한 방법을 설계하고 구현하였다. 먼저 광학기법을 이용한 비산먼지의 혼탁도를 측정하는 방법을 제시하고 비산먼지측정 시스템을 구현하여 건설현장에서 발생하는 실제 비산먼지의 혼탁도를 측정하였다.

• Applied Biological Chemistry
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• 제41권2호
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• pp.166-174
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• 1998

저장성이 좋지 않은 숙면(熟麵)을 식초, 젖산, 구연산, 사과산과 같은 유기산에 침지하여 총균수와 기계적 물성을 측정하고 관능검사를 하여 유기산의 효과를 알아보았다. 면가닥을 각각의 유기산 수용액에서 30초간 침유(沈遺)시켜 $pH\;4.7{\pm}0.25$로 맞추어 포장 후 $15^{\circ}C$에서 4일간 저장하는 동안 총균수와 혼탁도를 비교 측정했다. 총균수에서는 식초, 젖산, 구연산, 사과산, 대조구 순으로 총균수 억제 효과를 나타내었고 혼탁도에서는 대조구, 젖산, 사과산, 구연산, 식초 순으로 높았다. 또한 $35^{\circ}C$에서 30일간 저장하면서 Rheometer를 이용하여 물성을 측정한 결과 견고성과 부착성은 대조구보다 유기산처리구가 높게 나타났고, 응집성과 탄성은 다소 감소 추세였으나 큰 변화가 없었다. 껌성은 대조구보다 사과산과 구연산 처리구가 다소 높았다. 관능검사에 의한 종합적인 선호도 순서는 사과산>구연산, 젖산>대조구, 식초순으로 1% 수준의 유의적 차이의 결과를 얻었다.

• 한국물환경학회지
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• 제27권1호
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• pp.36-43
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• 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.

• 한국식품과학회지
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• 제34권3호
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• pp.454-458
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• 2002

과실가공품에서의 갈변을 억제하기 위하여 사과농축액에 갈변억제제 즉, PVPP (polyvinylpolypyrrolidone), bentonite, gelatin, celite 545, tannic acid, sodium sulfite를 첨가하여 여과한 후 갈변억제효과를 측정하였다. 색도의 변화는 PVPP를 첨가한 농축액에서 L값(lightness)이 8.16으로 대조구와 다른 농축액에 비해 갈변억제에 효과가 있음을 알 수 있었으며, 탁도(660 nm에서의 흡광도)는 대조구 0.05인데 비해, PVPP, gelatin celite 545, tannic acid, sodium sulfite를 함유한 사과농축액은 각각 0.003, 0.038, 0.038, 0.018, 0.022로 다소 낮은 수치를 보여 부유물 등의 제거효과가 나타났으며 특히 PVPP의 효과가 뚜렷하였다. 또한, PVPP 처리된 사과농축액 중의 PPO(polyphenoloxidase)활성과 폴리페놀화합물(catechol, catechin, chlorogenic acid, epicatechin 등) 함량에서도 현저하게 감소하여 효소적 갈변이 억제되었음을 알 수 있었다. 따라서, PVPP가 사과농축액의 색상, 탁도, PPO활성 및 폴리페놀화합물 함량 등 효소적 갈변특성을 개선시키는 우수한 갈변억제제임을 확인하였다.