• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.409-412
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• 2001

The high purity manganese oxides were made from the dust, generated in AOD process that produces a medium-low carbon ferromanganese and collected in the bag filter. Manganese oxide content in the dust was about 90%, and its phase was confirmed as Mn₃O₄. In the extraction of manganese, because of remaining amorphous MnO₂, the dust was reduced to MnO by roasting with charcoal. The pulp density of the reduced dust can control pH of the solution more than 4 and then Fe ion is precipitated to a ferric hydroxide. Because a ferric hydroxide co precipitates with Si ion etc, Fe, Si ion was removed f개m the solution. Heating made water to be volatized and nitrates was left in reactor Then nitrates were a liquid state and stirring was possible. Among the nitrates in reactor, only the manganese nitrate which have the lowest pyrolysis temperature pyrolyzed into β-MnO₂powder and NO₂(g) at the temperature less than 200℃. When the pyrolysis of manganese nitrate has been completed about 90%, injection of water stopped the pyrolysis. Nitrates of impurity dissolved and the spherical high purity β-MnO₂powders were obtained by filtering and washing. Mn₂O₃or Mn₃O₄ powder could be manufactured from β-MnO₂powder by controlling the heating temperature. Lastly, a manufactured manganese oxide particle has 99.97% purity.

• 분석과학
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• 제13권2호
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• pp.158-165
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• 2000

배연탈황설비에서 생성된 석고 슬러리 및 석고의 순도와 불순물의 정량분석은 시운전중인 탈황설비의 성능시험시 최적의 탈황공정을 모색하는 데 유용한 자료를 제공할 뿐만 아니라 생성된 석고는 시멘트나 석고 보드 등으로 사용될 수 있으므로 품질관리의 측면에서도 매우 중요하다. 석고의 순도는 결합수분, 삼산황 및 칼슘이온의 농도를 측정한 다음 환산식에 의해서 gypsum($CaSO_4{\cdot}2H_2O$)의 형태로 변환할 수 있다. 성능시험시 시료의 수가 상당히 많으므로, 좀 더 간편하면서도 정확한 분석방법의 확립을 위해 여러가지 비교실험을 실시한 결과, 열분석을 통하여 결합수분을 측정하는 방법이 1시간 이내에 분석이 완료된다는 장점 외에 재현성 또한 아주 우수하였다. 그 외 실리카를 포함한 각종 석고의 불순물의 분석은 산으로 처리하는 방법과 융제를 사용한 용융법을 비교한 결과, 용융법이 훨씬 간편하고 정확한 결과를 나타내었다. 한편 소량의 탄산 마그네슘과 탄산 칼슘의 정량을 위해 사용되는 이산화탄소 측정장치의 트랩부분을 수정하여 이산화탄소 흡수제의 역류를 막도록 하였다. 열분석을 통한 결함수분 측정, 융제를 사용한 용융법 및 이산화탄소의 정량법으로 확립된 분석 방법을 통해 석고 슬러리 및 석고의 분석은 보다 짧은 시간내에 간편하면서도 정확하게 실시될 수 있음을 확인하였다.

• 한국물환경학회지
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• 제22권3호
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• pp.437-443
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• 2006

The Water usage is relationship which is close with the administrative cost from industrial facility. It is not easy to reduce a water usage. This research is the optimization of the waste water quantity which process waste water integration of the standard thermal power plant in system operate time. The turbine rotates by force of the steam and it produces an electricity. Demineralization Water is manufacture purity manufacturing equipment and it is supplied in power plant channel. We knew a possibility of reducing from pure control process. When it is reduced the Back Washing time, Rinsing time of the gravity filter and the activated carbon filter. Also, It is possible even from regeneration phase in Condensate Polishing Demineralization System. In addition, There is also the water which the drain of the sampling water for watching the condition of power plant process will be able to use. Integrates these processes it will be able to reduce an annual 30,000 ton degree. The research is want to use the fundamental data for the water curtailment of the power plant.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2008년도 학술발표회 논문집
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• pp.2122-2126
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• 2008

With the degradation of water quality and, at the same time increased water usage, the sources of high quality, for examples, river/stream, municipal reservoir, wells, artisan and surface water, are diminishing. Therefore, the importance of water quality has been emphasized over the years through publications and various literature sources. Even though considerable research has resulted in significant strides for providing interpretive information and mitigation strategies for improvement of waters, the quality of which is still questionable. This study aims to propose a completely independent self-contained system for purifying waters, solar-powered ozone generator. It is a semi-permanent and cost effective environmental solution. Functions of ozone treatment are: 1) to maintain oxidative flexibility, 2) remove harmful chemicals, wastes, and other substances, and 3) prevent epizootic microbial outbreaks. Recent advances in technology have allowed the development of the practical, self-contained and independent solar powered device. Solar electrical producing panels that charge batteries are the key to using these systems anywhere electrical power is not available. This paper invites the readers to examine the problem and consider the viable, proven solution the solar powered ozone purifying system. This paper also introduces basic concept and background of solar powered ozone generators and examine its feasibility for improving water quality in rivers and streams.

• 한국환경보건학회지
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• 제35권5호
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• pp.365-375
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• 2009

Agriculture reservoirs need a systematic approach that can control water purity and water improvement. The area under study, Bunam Lake exceeds the agricultural water standard level due to contamination from the upper stream. When the Taean Enterprise City was planned, the water quality improvement plan was applied to minimize the environmental change. However, in order to continuously maintain the water quality in the Bunam Lake, it was essential to apply the Total Pollution Load Management System (TPLMs). In order to achieve the targeted water quality in the Bunam Lake, standard flow rates and targeted water quality levels were applied to obtain the loading capacity which is as follows : BOD 1,891.2 kg/d, T-N 1,945.7 kg/d, T-P 131.7 kg/d. Also, the regional development load was calculated as, BOD 1,083.6 kg/d, T-N 942.2 kg/d, T-P 61.8 kg/d, which is required to be deceased :- by BOD 378.4 kg/d, T-N 198.9 kg/d, T-P 31.6 kg/d in order to safely achieve the targeted water quality in the Bunam Lake.

• 상하수도학회지
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• 제11권2호
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• pp.105-111
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• 1997

Chlorine dioxide is being used to control THMs formation or taste & odor in water treatment plant. Recently, some operators or academic circles doubted the effectiveness of stabilized chlorine dioxide which is presumed as a liquid form of chlorine dioxide. In this study, we investigated components which consist of stabilized chlorine dioxide in terms of chlorine dioxide and chlorite. Two analytical methods used in this study are UV method and Iodometric method. Iodometric method is recommended by Korean EPA to check the purity of stabilized chlorine dioxide. The samples of stabilized chlorine dioxide from four water treatments were investigated and compared with that produced from chlorine dioxide generator on-site. This study demonstrated that the component of stabilized chlorine dioxide was overwhelmingly chlorite (${ClO_2}^-$) not chlorine dioxide ($ClO_2$) by UV method. It was also proved that Iodometric method (2nd method) recommended by Korean EPA could not differentiate between $ClO_2$ and ${ClO_2}^-$. Iodometric method (2nd method) recommended by Korean EPA should be revised accordingly to measure chlorine dioxide properly.

• 한국산학기술학회논문지
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• 제12권1호
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• pp.545-551
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• 2011

최근 고품질의 수돗물에 대한 소비자의 요구가 상승함에 따라 상수도 배급수관의 내부 부식에 의한 수질악화 및 부식제어 연구에 대한 관심이 높아지고 있다. 이에 따라 노후 관 교체 사업을 대신하여 수질 관리를 위한 부식 제어 수단을 강구하지 않고서는 근본적인 문제 해결이 이루어질 수 없는 실정이다. 본 연구에서는 수질안정화 약품 주입에 의한 상수도관 내부 부식제어 효율을 평가하기 위해 Pilot Plant 실험을 실시하였으며, 부식성제어 효율은 물의 부식성을 나타내는 LSI(Langelier Saturation Index)값에 의해 평가되었다. 실험결과, Pilot Plant에 의해 제조된 반응수는 수질안정화 약품인 액상소석회($Ca(OH)_2$, liquid lime)의 주입으로 부식성이 개선되어 철 용출이 억제되는 효과가 확인되었다. 강관과 동관을 절단하여 제작한 시편의 부식도 측정을 통해 각각 35.4, 44.5%의 부식제어 효과가 있음을 확인하였고 수질안정화 약품이 주입된 Sample관이 더 두터운 부식 생성물 층을 갖고 있는 것으로 밝혀졌으며, 결과적으로 수질안정화 약품을 투입한 배관이 부식 방지 측면에서 안정한 수질을 갖고 있음을 알 수 있었다.

• 상하수도학회지
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• 제26권2호
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• pp.201-208
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• 2012

Wangsong Reservoir needs a systematic approach that can control water purity and water quality improvement. This study was carried out to assess the seasonal variation of water quality and the effect of pollutant being loaded from watershed in a sallow eutrophic reservoir(Wangsong Reservoir) from March to November, 2011. Wangsong Reservoir, located in Uiwang City, has the capacity of 2 million $m^{3}$ in irrigation water supply with the drainage of 4.2 $km^{2}$. Average concentrations of BOD, COD, T-N, T-P, and Chloropyll-a in Wangsong Reservoir were 5.8 mg/L, 9.7 mg/L, 4.299 mg/L, 0.106 mg/L and 73.1 mg/$m^{3}$, respectively. In the inflow streams and treated sewage of Wangsong Reservoir, the T-N concentrations of 4.114 - 14.619 mg/L were higher than those in the Reservoir and the other pollutants were lower. As a result of investigation, Wangsong Reservoir exceeded the agricultural water standard level due to algal growth and accumulation from the upper streams and sewage. In order to achieve the targeted water quality in Wangsong Reservoir, it is required to be decreased in pollutants of internal and inflow streams.

• 환경영향평가
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• 제14권2호
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• pp.55-62
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• 2005

This study applied the Neural Network and Fuzzy theory to show water-purity control and preventive measure in water quality forecasting of the future river. This study picked out NAJU and HAMPYUNG as the subject of investigation and used monthly the water quality and the outflow data of KWANGJU2, NAJU, YOUNGSANNPO and HAMPYUNG from 1995 to 1999 to forecast BOD, COD, T-N, T-P water density. The datum from 1995 to 1999 are used for study and that of 2000 are used for verification. To develop model of water quality forecasting, firstly, this research formed Neural Network model and divided Neural Network model into two case - the case of considering lag and not considering. And this study selected optimal Neural Network model through changing the number of hidden layer based on input layer(n) from n to 3n. Through forecasting result, the case without considering lag showed more precise simulated result. Accordingly, this study intended to compare, analyse that Fuzzy model using the method without considering lag with Neural Network model. As a result, this study found that the model without considering lag in Neural Network Network shows the most excellent outcome. Thus this study examined a forecasting accuracy, analyzed result and verified propriety through appling the method of water quality forecasting using Neural Network and Fuzzy Algorithms to the actual case.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 제33회 추계학술대회논문집
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• pp.309-312
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• 2009

성공적인 발사나 시험 운용을 위해서는 여러 가지 위험 요소들을 사전에 제거하여야 한다. 오염된 추진제 사용은 발사 혹은 시험을 실패하게 하는 원인들 중 하나이다. 특히 액체산소를 산화제로 사용하는 발사체 및 공급시스템의 경우 기계적 불순물, 유지분, 수분 등의 오염원들로 청정상태를 유지하지 못할 경우 예기치 못한 화재나 폭발의 위험도가 높아지게 된다. 본 논문에서는 이러한 오염원들을 제거하고 시스템을 청결하고 안전한 상태로 유지하기 위한 방법을 제시하고 그 적용결과 및 교훈을 정리해 보았다.