• 멤브레인
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• 제18권3호
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• pp.191-197
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• 2008

본 연구에서는 고도정수처리를 위하여 모듈 내부와 세라믹 정밀여과막 외부 사이의 공간에 입상 활성탄(GAC)을 충전한 혼성 모듈을 이용하였으며, 정수 원수 중의 자연산 유기물(NOM)과 미세 무기 입자를 대체하기 위해, 휴믹산(humic acid)과 카올린(kaolin) 모사용액을 사용하였다. GAC의 충전율(packing fraction)에 따른 처리효율의 변화를 알아보고자. GAC의 충전율을 $0{\sim}24.05%$로 변화 시켰다. 그 결과, 3시간 운전하는 동안 막오염에 의한 저항($R_f$) 및 투과선속(J)의 변화 곡선은 GAC의 충전율에 관계없이 거의 중첩되었다. 그리고 탁도의 처리효율은 모든 조건에서 99.46% 이상으로 높았으며, $UV_{254}$ 흡광도로 측정한 NOM의 처리효율은 최대 충전율 24.05%에서 제거율은 99.43%로 가장 높게 나타났다. 한편, 충전율 24.05%에서 13시간 동안 운전한 결과, J는 막오염의 증가에 따라 운전 초기 1시간 이내에 급격히 감소하였으며 3시간 운전 후부터는 거의 일정한 투과선속을 나타냈다. 그리고 탁도 및 NOM의 처리효율은 각각 99.52%와 96.63%로 안정적인 높은 처리효율을 보였다.

• 한국조리학회지
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• 제11권2호
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• pp.91-109
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• 2005

The purpose of this study was to investigate the changes of vitamin C and lactic acid bacteria count in Dongchimi used different kinds of water (distilled water, purified water, Cho Jung Carbonated Natural water). Dongchimi used different kinds of water was fermented at $10^{\circ}C$ for 46 days. The changes of pH on Dongchimi used different kinds of water decreased in all samples during fermentation period, and then showed a slow decrease after 12 days of fermentation. The total acidity of Dongchimi used Cho Jung Carbonated Natural water arrived slowly at best tasting condition(0.3~0.4 point) compared with other conditions. The changes of salt content were ranked high one by one , Cho Jung Carbonated Natural water>purified water>distilled water during fermentation period. At early stage of fermentation, the changes of turbidity of Dongchimi used Cho Jung Carbonated Natural water showed highly as compared with other test conditions for 12 days of fermentation. Vitamin C content was measured high in Dongchimi used Cho Jung Carbonated Natural water during the fermentation period. Because calcium content was high in carbonated natural water, carbonated natural water had the highest calcium content during the fermentation period. The changes of lactic acid bacteria count showed the highest price at all experimental groups in 15 days of fermentation, but those of Dongchimi used Cho Jung Carbonated Natural water showed the highest price in 19 days of fermentation.

• 한국수자원학회논문집
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• 제46권9호
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• pp.957-967
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• 2013

집중호우에 의한 고탁도 침수는 식물 성장에 영향을 줄 수 있는 요소 중 하나이다. 따라서 본 연구에서는 버드나무속 식물인 갯버들, 버드나무, 왕버들을 이용하여 고탁도 침수 발생 시 식물 키 및 엽수를 파악하여 성장정도를 정량적으로 분석하였다. 식물 키에 대한 분석 결과 비침수 상태인 대조군에서는 30일 후 갯버들, 버드나무, 왕버들이 각각 33.4%, 24.3%, 23.9% 증가하였지만 고탁도의 침수가 시작되면 대부분 성장이 멈추었다. 엽수의 경우 대조군에서는 30일 후 갯버들, 버드나무, 왕버들이 각각 144.5%, 77.3%, 40.3% 증가하였지만 고탁도 침수가 30일 지속되면 버드나무를 제외한 식물의 엽수는 0개로 관찰되었다. 식물 성장에 대한 실험 결과 전반적으로 버드나무속 식물은 고탁도 침수가 지속되면 빠른 시간 내 성장이 멈추는 것으로 나타났다. 이 결과는 향후 침수가 빈번히 발생하는 임하호 및 상류하천 사면의 친환경적인 수목조성을 위한 기초자료가 될 것으로 판단한다.

• 한국식품저장유통학회지
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• 제7권3호
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• pp.249-255
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• 2000

응고제의 종류에 따른 천연물 첨가 두부의 제조특성을 알아보았다. 수율과 물성, 관능검사결과 등을 고려한 결과 $MgCl_2$는 0.2%, $CaCl_2$ 0.4%, $CaSO_4$는 2.0%가 최적농도로 선택되었다. 또한 천연물 첨가농도는 당근 4%, 오이 10%, 시금치 1.0%, 녹차말차 0.05%를 최적농도로 선정하였다. GDL을 응고제로 사용한 천연물 첨가두부의 색도도 응고제의 종류에 따라서도 차이를 보이지 않았으며 두부의 물성에도 크게 영향을 미치지 않았다. 당근, 오이, 시금치 첨가두부에서 색소의 함량은 $MgCl_2$, $CaCl_2$를 응고제로 사용한 두부에서 함량이 높았으나 녹차 첨가두부의 polyphenol 함량은 $CaSO_4$, GDL를 응고제로 사용한 두부가 높은 값을 보였다.

• 상하수도학회지
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• 제17권4호
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• pp.487-494
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• 2003

In this research, water qualities of river water and bank-filtrate were compared for six months including winter season. The location studied was Galjon area, the downstream of the Nakdong river. The well for bank-filtrate was installed 40 m apart from riverside. Main analytic results of bank-filtrate and river water were summarized as followings; the average concentrations in bank-filtrate were turbidity 0.8NTU, TN 0.4mg/l, $BOD_5$, 0.1mg/l, $KMnO_4$ consumption 1.6mg/l, heterotrophic bacteria 350cfu/ml, Fe 0.5mg/l, Mn 0.99mg/l while the average concentrations in river water were turbidity 6.1NTU, TN 3.9mg/l, $BOD_5$, 3.6mg/l, $KMnO_4$ consumption 11mg/l, heterotrophic bacteria 1,640cfu/ml, Fe 0.28mg/l, Mn 0.04mg/l. Water quality of bank-filtrate was mostly shown a good results than it of river water excepting Fe and Mn. In even basic constituents such as water temperature and pH, bank-filtrate was very settled while river water was extraordinary changable and high. In case of nitrogen, especially, total nitrogen of river water was 3.9mg/l while it of bank-filtrate was 0.4mg/l and its reduction was very high. The reason is that $NH^+_4-N$ among total nitrogen in the river water is nitrified and then denitrified in soil layer when it is pumped up as bank-filtrate. But Fe and Mn caused by the characteristics of soil was very high in bank-filtrate while Mn in river water was particularly very low and settled. As the distance between riverside and well was longer, concentration of Fe and Mn may be went up while its bacteria may be reduced.

• 한국식품조리과학회지
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• 제32권4호
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• pp.426-432
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• 2016

Purpose: The consumption of noodles has increased domestically. However, noodles with high carbohydrate content can cause an increase in blood glucose compared with other foods. Therefore, in this study, Naengmyeon with high resistant starch was prepared for decreasing blood glucose by the addition of 0.5% citric acid (CN), 1% guar gum (GN) or 0.5% citric acid and 1% guar gum (CGN), and then it was incubated in a refrigerator for 3 days, and stored in a freezer for 1 month. Methods: The quality characteristics of these Naengmyeon noodles was evaluated based on total starch, resistant starch, water absorption, cooking loss, turbidity, in vitro starch hydrolysis, and in vivo glucose response. Results: There was no significant difference in the total starch, cooking loss, and turbidity. The resistant starch of GN (1.70%) and CGN (1.84%) was significantly increased when compared with that in Naengmyeon with no additives (N) and CN. In terms of water absorption, CN (86.01%) was the lowest in samples, followed by GN (92.17%), N (94.20%), and CGN (99.16%). CGN with high resistant starch was the lowest in in vitro starch hydrolysis in samples. However, it had no effect on the in vivo glucose response. In vitro starch hydrolysis exhibited a significant positive correlation (r=0.533; p<0.01) with in vivo glucose response. Conclusion: Therefore, future studies are needed to establish the standard for resistant starch contents in processed carbohydrate foods for delaying the increase in blood glucose. If this standard is established, it might help to develop processed foods for diabetic patients.

• 한국물환경학회지
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• 제23권2호
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• pp.228-235
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• 2007

For efficient turbid water withdrawal in the Imha reservoir, a selective withdrawal facility was recently installed and operated during summer season of year 2006. In this research, CE-QUAL-W2 model was utilized to assess the efficiency of the selective withdrawal facility, in comparison with the original surface withdrawal, on turbid water management. Model calibration was carried out using data observed at four automatic monitoring stations in the reservoir. It was found that the model appropriately simulated, with the RMSE less than 5.2 NTU, the observed vertical and horizontal distributions of water temperature and turbidity as well as the location of maximum turbid water at each monitoring station. The analysis results showed that selective withdrawal is more effective in removing high turbid water than surface withdrawal as selective withdrawal contributed to reducing $35Mm^3$ of high turbidity water (> 100 NTU) in the reservoir by increasing outflows of high turbid water. Therefore, effective management of turbid water in the reservoir can be achieved by changing locations of intake depending on turbid water distribution conditions. The results of this study will provide some basic information for establishing better operation strategies to cope with turbid water problems.

• 전기전자학회논문지
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• 제26권2호
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• pp.219-225
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• 2022

우리나라의 섬유산업 중 염색가공 분야는 에너지 다소비 업종으로, 노동 집약적 특성에 따라 원단위 생산성이 낮고, 대부분 중소·영세기업 특징이 있다. 염색 원단의 불량률이 높아지면 재염색으로 인한 생산단가 상승과 초과 에너지 투입으로 비용이 증가하기 때문에, 불량률을 최소를 통한 생산량 향상이 초점이었다. 또한 고온고압의 환경에서 이루어지는 염색공정은 사고 위험으로 염색기 원단 투입구를 실시간으로 개방할 수 없기 때문에 실시간으로 원단의 염색상태 확인이 어려웠다. 최근에는 염액을 실시간으로 모니터링하는 연구가 활발히 진행중이다. 본 논문에서는 탁도, pH, 전도도 센서를 이용하여 염액의 흡진율을 계측할 수 있는 복합센서 흡진율 모델 및 구성시스템을 제안하였으며, 실험방법소개와 실험결과 분석을 실시하였다.

• 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.

• 상하수도학회지
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• 제18권5호
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• pp.608-618
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• 2004

Since polyelectrolytes have been used as conditioners, conventionally only a single polyelectrolyte has been added for sludge conditioning. However, the amount of polyelectrolyte needed for optimal conditioning of sludge is very critical. Overdosing reduces the sludge dewaterbility. In this experimental study, sludge conditioning with single or dual polyelectrolyte was conducted to avoid problems associated with overdosing. Single polyelectrolyte conditioning was conducted by one of cationic, nonionic, and anionic polyelectrolytes. The dual polyelectrolyte conditioning was performed by adding one polyelectrolyte and another one in sequence. The dewaterbility of sludges were measured by SRF(specific resistance to filtration), TTF(time to filter), CST(capillary suction time) respectively. Additionally, parameters such as turbidity, zeta potential, viscosity of conditioned sludges or supematant were measured to evaluate the changed characteristics of sludge by addition of polyelectrolytes. From the experiment results, it was concluded that single polyelectrolyte conditioning had a high probability of overdosing, whereas dual polyelectrolyte conditioning resulted in a better dewaterbility and less chance of overdosing. But, it was also found that dosing sequence in dual conditioning was very important according to the characteristics of sludge. Parameters such as viscosity, turbidity, zeta potential were found to be useful as a means of evaluating sludge dewaterbility.