• 상하수도학회지
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• 제11권1호
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• pp.53-63
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• 1997

The corrosion problems in water distribution system are reduced by decreasing the agressivity of drinking water which is evaluated by marble test and saturation indices(LSI or CCPP etc.). Marble test is a reliable method to determine the actual saturation condition of treated water. This study was done to determined the aggressivity of tap water and the effectiveness of $Ca(OH)_2$ and NaOH dosage for corrosion control. The drinking water in Seoul were evaluated by marble test and Langelier Index(LSI) and Calcium Carbonate Precipitation Potential(CCPP). The results indicated that the drinking water in Seoul were undersaturated as Calcium Carbonate($CaCO_3$). The LSI and CCPP of the water treated with $Ca(OH)_2$ were higher than that of water treated with NaOH. Therefore, to increase the Alkalinity and Calcium Hardness for corrosion control in water distribution system, $Ca(OH)_2$ is more effective than NaOH.

• 펄프종이기술
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• 제33권2호
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• pp.32-40
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• 2001

It is desirable to reduce the amounts of fresh water and reuse the recycled water in papermaking process. In an attempt to improve the efficiency of recycling water refining treatment and to enhance the productivity of OCC recycling mill, up flow anaerobic sludge blanket(UASB) reactor was developed and introduced to Korea recently. In order to maximize the operating efficiency and minimize the adverse side effects it is imperative to estimate and evaluate the total effects of new system, UASB on the whole OCC recycling process. This study was carried out with a view to investigate the effects of the high temperature and alkalinity of process water on the quality ad productivity of testliner of OCC recycling mill which is equipped with UASB reactor and almost closed. Another object of this study was searching for the best available use of UASB treated process water. The results were as follows; Reuse of UASB treated water characterized with high temp and alkalinity was useful to improve the strength and drainage properties of recycled OCC owing to its good points of promoting OCC disintegration and reducing the calcium hardness of process water. However, it might not be avoidable to induce the increase of dissolved solids in process water in accordance with direct introducing of UASB treated water into the former stage of OCC stock preparation. So it would be advisable to adopt the UASB treated water in the stage of clean, screened OCC stock.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2001년도 춘계심포지움 및 학술발표회
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• pp.142-142
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• 2001

A national survey for enteric virus contamination in treated water and its source water was performed from March to November 1999. The water samples were subjected to virus filtration at the major water plants producing over 10$^5$ tons treated water per day. Twenty surveyed sites encompass most of heavily populated residential area except for Seoul and Pusan. (omitted)

• Journal of the Korean Wood Science and Technology
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• 제33권3호통권131호
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• pp.53-63
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• 2005

본 연구는 바다목장사업 소재로서 방부처리 목재의 사용 가능성에 대한 기초자료를 얻고자 실시하였다. CCA, CCFZ, ACQ 처리재 내 포함된 유해 중금속의 해수에 대한 용탈 안전성을 평가하기 위해 각각 2% 및 3% 방부제 수용액으로 처리한 목재를 증류수, 자연해수 및 인공적으로 염도를 조절한 인공해수에 41일간 폭로하여 기간 별 각 성분의 용탈량을 측정하였다. 바닷물에서 CCA 처리재의 구리 및 크롬의 용탈은 거의 일어나지 않았으며, 다소 많은 비소의 용탈이 있었으나 증류수에서의 용탈에 비해 적은 양을 나타내었다. CCFZ는 증류수에서 크롬과 아연의 용탈량이 매우 높았으나 바닷물에서는 훨씬 적은 용탈량을 나타내었다. 방부제 흡수량 및 인공해수의 염분 농도에 따른 용탈량에는 큰 차이가 없었다. ACQ 처리재는 CCA 및 CCFZ 처리재에 비해 많은 구리 용탈을 나타내었으며 용탈 매체에 따른 차이는 나타나지 않았다.

• 환경위생공학
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• 제11권1호
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• pp.71-76
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• 1996

Bio-film module system was applied to the treated leachate water that priorly had been treated with biological nitrification process. The experiments were performed in the laboratory and treated leachate water treatment facility. Experimental results obtained from laboratory conditions and nitrogen removal efficiencies were averaged 90% for 1 hr.

• Environmental Engineering Research
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• 제12권1호
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• pp.21-29
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• 2007

For this study, we polymerized polyacrylamide base flocculants (PAA) and tested their properties and settling efficiency as a treatment for potable water. The most common chemicals for potable water treatment in Korea are alum or PAC. However, due to various reasons (such as rainy season or algae), inorganic flocculants cannot be solely depended on to solve all the problems caused by the poor quality of inflow water. When PAA coupled with coagulants in a potable water purification process is used, the turbidity removal efficiency increases by a factor of three on a single chemical system using PAC (Raw water: 5.21 NTU; Treated PAA+PAC: 0.34 NTU; and, Treated PAC: 1.04 NTU). It is possible to offset the toxic effect of residual monomers in treated water using PAA, because the concentrations of residual acrylamide are less than 400 mg/L in the polymer itself and less than $0.04\;{\mu}g/L$ in the treated water base at a dosage of 0.1 mg/L. Therefore, PAAs may be a workable, and dependable, potable water treatment process for the high pollutant level of resource water.

• 한국환경과학회지
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• 제13권7호
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• pp.627-635
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• 2004

Evaluated were household THMs exposure associated with the use of municipal tap water treated with chlorine and with ozone-chlorine. The current study measured the THMs concentrations in the tap water and indoor and outdoor air in the two types of household, along with an estimation of THMs exposure from water ingestion, showering, and the inhalation of indoor air. Chloroform was the most abundant THMs in all three media, yet no bromoform was detected in any sample. Contrary to previous findings, the fall water THMs concentrations exhibited no significant difference between the chlorine and ozone-chlorine treated water. However, the spring median chloroform concentration in the tap water treated with chlorine (17.6 ppb) was 1.3 times higher than that in the tap water treated with ozone-chlorine (13.4 ppb). It is suggested that the effects of the water parameters should be considered when evaluating the advantage of ozone-chlorine disinfection for THMs formation over chlorine disinfection. The indoor air THMs concentration trend was also consistent with the water concentration trend, yet the outdoor air THMs concentrations did not differ significantly between the two types of household. The indoor to outdoor air concentration ratios were comparable with previous studies. The THMs exposure estimates from water ingestion, showering, and the inhalation of indoor air suggested that, for the residents living in the surveyed households, their exposure to THMs in the home was mostly associated with their household water use, rather than the indoor air. The THMs exposure estimates from tap water ingestion were similar to those from showering.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 논문집 센서 박막재료연구회 및 광주 전남지부
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• pp.82-85
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• 2008

Polyimide is widely used as a high-temperature insulating material. Space charge distributions in polyimide (PI) films strongly depend upon electric field, temperature, water content and so on. We observed space charge distributions in PI films with various water contents. When a dc field was applied to as-received PI films or water-treated PI films, positive and negative homo space charges were observed near the respective electrodes at 333 K. In dried PI films, the homo space charges were much reduced, and positive and negative hetero space charges in the bulk were clearly observed. The space charge amounts in water-treated PI films were smaller than in as-received ones, while the current density in water-treated PI film was larger than that in as-received one by two or more orders of magnitude. These suggest not only that the charge injection from the electrode is enhanced by absorbed water but also that absorbed water makes carriers mobile. The decay of space charge was also faster in water-treated PI than in as-received or dried one. This also supports the enhancement of apparent mobilities of carriers in PI by absorbed water.

• 펄프종이기술
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• 제47권4호
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• pp.102-108
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• 2015

Agricultural cultivation papers treated with water repellent were investigated in order to analyse mechanical properties and durability. The water repellency was optimal when papers are treated with Wb and Sa water repellents. Also, WCPs with 5% water repellent were more effective than those of 3 and 10%. In addition, water repellency of WCPs with Wb and Sa water repellents were kept constant in correlation with aging time. Finally, WCP with Wb water repellent possesses efficiency in terms of mechanical properties and durability.

• 한국가구학회지
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• 제19권3호
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• pp.172-179
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• 2008

The objective of this study was to investigate the influence of the water repellents' treatment on the water absorptivity and the dimensional stability of Korean red pine wood(Pinus densiflora). The alkylketene dimer(AKD), fluororesin emulsion(Wood-seal, WS), and paraffin wax emulsions(PW25, PW40, and PW1200) were used as water repellents. PW40 and WS were proved as excellent water repellents for pine wood, because the samples treated with these agents showed high contact angles and large reduction in water absorptivities. Also, the dimensional stability(antiswelling efficiency) of pine wood was considerably improved by water repellents treatments, such as PW40 and WS at the pressure of 2MPa. The water repellent treated woods with WS, PW40, and PW1200 at the pressure of 2MPa were relatively stable to the wet-dry cyclic leaching test.