• 한국축산시설환경학회지
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• 제18권sup호
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• pp.13-20
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• 2012

연구는 양돈분뇨의 액비화 처리과정 중 농지환원 직전단계인 액비 후숙처리 단계에 있어서 $SCOD_{Mn}$ 농도 및 산도(pH)의 조정이 후숙액비의 이화학적성상에 미치는 영향을 알아보고 적절한 후숙 액비화 공정을 구축하기 위하여 수행하였으며, 실험결과를 요약하면 다음과 같다. 1. $SCOD_{Mn}$ 감소율은 알칼리발효 처리구에서 평균 29.9%, 인산중성화 처리구에서는 평균 36.9%로 인산 중성화 처리구가 비교적 높은 감소율을 보였다. 2. 30일간 처리 후 $SCOD_{Mn}$의 농도가 가장 낮은 처리구는 유입농도가 가장 낮았던 인산 중성화 처리구 T-6이다. 후숙 액비의 목표수준을 $SCOD_{Mn}$ 3,000 ppm 이하로 가정할 경우 후숙 발효조의 초기 투입농도는 5,500 ppm 이하로 조정하는 것이 적합하다고 사료된다. 3. 질소의 잔존율은 알칼리발효 처리구에서 평균 29.3%, 인산중성화 처리구에서 평균 38.9%로 인산중성화 처리구가 비교적 질소의 손실이 적은 한편, T-P의 경우 인산중성화 처리구에서 높은 농도(평균 1,473 ppm)로 유지되었다. 4. 본 연구를 통해 액비 후숙처리 시 '저인산-저질소'의 형태는 "알칼리발효 처리구", '고인산-고질소'의 형태는 "인산중성화 처리구"의 조건이 유리할 것으로 기대된다.

• 대한지하수환경학회지
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• 제2권1호
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• pp.38-47
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• 1995

이 연구에서는 삼척탄전 내에 위치하는 폐탄광인 동해탄광을 대상으로 산성 광산폐수의 중화 처리를 위한 각종 기초자료를 제시하고자 하였다. 산성 광산폐수의 측정시기에 따른 변화양상을 관찰한 결과 갈 수기에는 각종 잠재적 유독성 원소들의 함량이 증가하며, pH가 하락하여 수질이 악화되는 경향을 보였다. 공업용 소석회는 처리효율 및 경제성을 고려할 경우 산성 광산폐수의 처리를 위한 최적의 중화제로 판단되며, 평형 모델링 결과 중화처리과정에서 Fe는 FeOOH의 형태로, Al은 Al(OH)$_3$, 의 형태로 침전되는 것으로 추정된다. GIS를 이용하여 동해탄광일대 산성 광산폐수 처리시설의 위치를 제시하였으며 수문학적 자료를 이용하여 최대강우량 및 첨두유량을 계산하였다.

• 한국습지학회지
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• 제23권1호
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• pp.54-59
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• 2021

폐수처리장에서 발생하는 바이오가스 중의 황화수소를 처리하기 위하여 습식스크러빙 장치가 적용되었다. 유입 H2S의 농도가 5,000mg/L이상에서 DIWS 장치에 물만을 사용할 경우 25%의 제거율을 나타내어 후속으로 소각처리 공정이 도입되어야만 98% 이상의 제거율을 나타냈다. 유입 H2S의 농도가 5,000mg/L일 때 CH4과 CO2는 각각 8.7%와 28.6% 감소하여 배출되었다. DIWS 장치에 중화약품으로 Na2CO3와 NaOH를 사용하였을 때 pH가 11.2~11.5를 유지하면서 H2S는 97.2% 제거되었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 가을 학술논문 발표대회
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• pp.188-189
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• 2020

In the field of architecture, concrete and steel bars are the most common and popular combinations. The relationship between the two in a structure is a complementary good that increases in utility when consuming both materials at the same time. However, the combination of the two, which has been perceived as semi-permanent, often faces repairs or reconstruction without its lifespan reaching decades. There are a number of deterioration factors at work for the reason for this phenomenon. Among them, the neutralization of concrete in particular refers to the process in which calcium hydroxide inside concrete reacts with carbon dioxide and loses alkalinity, which creates a corrosive environment for rebars inside concrete, causing serious damage to concrete. In this study, we intend to use a multi-physical analysis program using finite element analysis method to analyze the degree of carbonation according to the internal temperature and concentration of carbon dioxide in concrete, thereby contributing to the prediction of long-term neutralization of concrete and the research related to measures for neutralization of concrete.

• Journal of Biosystems Engineering
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• 제25권3호
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• pp.187-194
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• 2000

One of effective utilization technique of rice husk is known to carbonize it for using as the culture materials. A series of study on the production of carbonized rice husk by a cyclone combustor shows that the carbonized rice husk produced have a strong alkalinity. Therefore, carbonized rice husk produced by a cyclone combustor is required to neutralize with proper normality. This work is the third part of a series on the production of carbonized rice husk by a cyclone combustor. In this work, the development of neutralization process was carried out in the range of experimental conditions recommended in the previous study. Those include the preheat temperature of combustion chamber of T1b=1273∼1373K, equivalence ratio =1.68∼2.17, auxiliary gas flow rates Qg=5.15∼6.43$\ell$/min. The injection technique of dilute acid was employed for neutralization. At the lower position of the outside of combustor, a dilute nitric acid selected as neutralization liquid was injected to the carbonized rice husk exhausted from the combustion chamber. The normalities of dilute nitric acid were varied to 0.01, 0.03 and 0.05N, respectively. The injection flow rates of the solution were changes from 1.7∼4$\ell$/min. The required carbonized and neutralized rice husk could be obtained at the dilute nitric acid with normality of 0.3N and flow rate of dilute nitric acid of 2∼3.5$\ell$/min. However, the carbonized and neutralized rice husks of about 10∼20% were destroyed by spray with high injection pressure.

• 신재생에너지
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• 제19권4호
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• pp.2-10
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• 2023

The current mandatory domestic biodiesel blending ratio is 3.5%, which is planned to be gradually increased to achieve carbon neutrality by 2050. The aim of this study was to improve domestic self-sufficiency in biodiesel raw oil by conducting a technical review on the possibility of utilizing waste oils, such as soup oil, chicken oil, and leather oil, as biodiesel feedstocks. These waste oils have an acid value that is too high to be converted directly into biodiesel. Therefore, a pretreatment to reduce the acid value is necessary. The neutralization process was examined as a potential technology for reducing the acid value. The oil recovery rate of the soup oil after neutralization was significantly low at 37.6 wt%. The oil recovery rates of leather oil and chicken oil were 66.49 wt% and 79.08 wt%, respectively. Based on biodiesel conversion experiment using waste oil with a reduced acid value, the conversions were analyzed as 89 wt%, 91.1 wt%, and 90.5 wt% for soup oil, leather oil, and chicken oil, respectively. Thus, it is technically possible to use soup oil, leather oil, and chicken oil as raw materials for producing biodiesel.

• 한국환경과학회지
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• 제7권1호
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• pp.81-88
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• 1998

This study was conducted to assess the characteristics of plgment wastewater and the removal rates of appropriate treatment by physical, chemical and biological Process, and the possibility of reuse for effluent. Based on the results, the wastewater qualities of pigment were pH 5.1$\pm$3.4, temperature 43.0$\pm$ 15.$0^{\circ}C$, BOD 1,431.4$\pm$589.6mg/l, COD 2,282.8$\pm$466.5mg/l, turbidity 1,340$\pm$820NTU, color 243.0$\pm$147.0unit, Pb 36.5$\pm$9.5mg/l and $Cr^+6$ 10.3$\pm$ 1.3mg/l, respectively. The removal rates of adsorption by activated carbon and filter process were BOD 40.6% , COD 57.0% , turbidity 89.6%, color 87.2%, Pb 86.0% and $Cr^+6$ 10.6%, respectively. And the removal rates of reduction, neutralization, coagulation and aP floatation process were BOD 18.2%, COD 24.3%, turbidity 74.3%, color 56.7%, Pb 68.6% and $Cr^+6$ 97.8%, respectively. The removal rates of activated sludge process were BOD 95.9%, COD 86.0%, turbidity 27.8%, color 25. 2%. Pb 26.9% and $Cr^+6$ 50.0% , respectively. The total removal rates of treatment by physical, chemical and biological process were BOD 98.0% , COD 95.4%, turbidity 98.1%, color 95.8%, Pb 97.0% and $Cr^+6$ 99.0%, respectively. According to the test results for possibility of reuse with coagulation-adsorption by activated carbon process of effluent, COD was higher than that of raw water and others were similar to that of raw water thus, it Is considered to be reused.

• 한국안전학회지
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• 제13권3호
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• pp.67-73
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• 1998

The technology for neutralizing static electricity by soft X-ray radiation has been newly developed. This technology involves ionization of gas molecules in the vicinity of a charged substrate to generate ions and electrons to reduce electrostatic potential. The ULSI device substrate and liquid crystal display substrate tend to get charged instantly to a high potential level when they are handled in the manufacturing process. Soft X-ray radiation is adequate in air or $O_2$ gas at atmospheric pressure. This newly developed neutralization method is effective to be superior to the conventional technique, i.e., an ionizer by using corona discharge ,in every aspect. The new method features excellent neutralization capability and is able to completely reduce electrostatic potential to 0 V within a short time. Moreover, this is a very clean antistatic technology free from particle generation ,ozone generation, and electromagnetic noise, which are problems in using the corona discharge ionizer.

• Bulletin of the Korean Chemical Society
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• 제6권6호
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• pp.329-333
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• 1985

A procedure for the preparation of peptizable pseudoboehmite has been described in detail based upon a process of neutralization of an aqueous aluminum sulfate or chloride solution with aqueous ammonia. In order to obtain peptizable pseudoboehmite products, carefully controlled conditions were required in the whole processes of neutralization, aging, washing, and drying. The optimum conditions experimentally found are the following. The aluminum salt solution is neutralized with aqueous ammonia until the final pH of the solution reaches 10.0 to 10.8 or 9.0 to 9.3 for the sulfate of chloride, respectively. The alumina gel formed is subjected to aging at $80^{\circ}C for about 3 hours and washed with water more than 5 times to reduce the residual sulfate or chloride ion in the final products to less than 4%. The pseudoboehmite gel thus obtained should be dried oven at 80 to $100^{\circ}C for a few to several hours depending on the selected temperatures.

• Transactions on Electrical and Electronic Materials
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• 제14권1호
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• pp.36-38
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• 2013

Eight sample panels using an indium tin oxide(ITO)-coated glass substrate were fabricated, with barrier ribs formed of 55 ${\mu}m$ height and 10 ${\mu}m$ width. The upper and lower substrates were designed with the same panel condition, so a cell gap of 110 ${\mu}m$ was obtained. The charged particles in a cell consisted of $TiO_2$ (for white color) or carbon black (black color), negative or positive charge control agents, and a polymer. The average diameter of the two types of particles was commonly 10 ${\mu}m$, and their q/m value was -4.5 ${\mu}C/g$ and +4.5 ${\mu}C/g$, respectively. The electrically opposite particles mixed by an agitator were loaded into their cells by a simple particle-loading method. The discharging process proceeded at a humidity of 80% and a temperature of $30^{\circ}C$. Reflectivity was measured depending on discharging time, and a hysteresis curve by bias voltage obtained for comparison between the neutralized and non-neutralized panel, in which the superior optical property of the neutralized panel was ascertained.