• Environmental Analysis Health and Toxicology
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• 제16권2호
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• pp.67-74
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• 2001

In a previous study by Kim et al. (2000), sodium hypochlorite (NaOCl) has been demonstrated to be effective against algae that cause red tides. To secure the environmental safely of the chemical in practical use, effect of NaOCl, at concentrations required for algicidal activity, on the histology of rockfish and little neck clam was examined. When the animals were exposed to NaOCl at concentrations of 0.5 or 2ppm for 1 hr, there was no exposure-associated histological change in either animal. As the experimental exposure condition was set in consideration of the use, our results provide safety information necessary for practical application to marine fields.

• Membrane and Water Treatment
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• 제4권1호
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• pp.69-81
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• 2013

The pH-dependent inter-conversion of the three free chlorine species ($Cl_2$, HOCl, OCl-) present in the aqueous hypochlorite solution was theoretically investigated. Each species was found overwhelmingly present in a characteristic pH range. Hypochlorite treatment of the polyamide membrane was carried out over these pH ranges and various membrane responses were observed. As pH is less than 8, membrane tends to be N-chlorinated by $Cl_2$ and HOCl, and N-chlorinated membrane showed reduced water permeance and salt rejection. As pH rises to 10-12, $OCl^-$ appears to be the dominating chlorine species. Membrane hydrolysis was found to well interpret the improved water permeance and salt rejection. When the pH is between 8-10, both N-chlorination and hydrolysis contribute to the response of the membrane, and the treated membrane showed improved salt rejection but reduced water permeation. Excessive hydrolysis occurred while the membrane was treated at pH 13 for the much stronger alkalinity.

• 한국환경보건학회지
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• 제18권2호
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• pp.52-56
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• 1992

The ability of chemicals, 10% sodium hypochlorite, 28% ammonium hydroxide, 5% sodium hydroxide, 5% sodium bicarbonate, 0.1% hydrochloric acid, 5% hydrogen peroxide, and 5% acetone, to destroy aflatoxins in laboratory waste water containing 3.26 ppb of B$_{1}$ 7.64 ppb of B$_{6}$3 ppb of G$_{1}$, and 11.39 ppb of G$_{2}$ with the total of 29.11 ppb was investigated. High performance liquid chromatograph (HPLC) was used for the separation and quantitation of aflatoxins. Treatment for 2 hours by the chemicals affected the destruction of aflatoxins and the most effective chemical was 10% sodium hypochlorite (p<0.05). Sodium hypochlorite concentrations more than 1% significantly reduced aflatoxin B$_{2}$, G$_{1}$, G$_{2}$ and total aflatoxins and more than 3% reduced B$_{1}$ (p<0.05). No further significant decreases were observed above the concentration of 5% for all 4 aflatoxins. Complete destruction of aflatoxins B$_{2}$, G_{1}$, and G$_{2}$ was achieved by 5% sodium hypochlorite at 48 hours and B$_{1}$ at 72 hours.

• Restorative Dentistry and Endodontics
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• 제8권1호
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• pp.147-153
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• 1982

The purpose of this study is to observe the effect of cleansing action of irrigation solutions which are 3% hydrogen peroxide, 5% sodium hypochlorite and 15% EDTA solution on the root canal wall. After the root canal wall is enlarged with K-file in distilled water, the canal wall which is irrigated with each irrigant for 2 minutes, is compared with the. control group without using any irrigants. Each sample is dehydrated, and coated with 200-250${\AA}$ of gold, and observations are made with the use of scanning electron microscope. The results are as follows: 1. The canal walls irrigated with 3% hydrogen peroxide, 5% sodium hypochlorite and 15% EDTA solution are cleaner than the walls without using irrigants. 2. There are no significant difference of cleansing effect among 3% hydrogen peroxide, 5% sodium hypochlorite and 15% EDTA. 3. After using 3% hydrogen peroxide and 5% sodium hypochlorite solution, large debris are removed on root canal walls, but micro debris remain on the canal walls. 4. The root canal walls irrigated with 15% EDTA solution are decalcifed slightly and show clean surfaces.

• 펄프종이기술
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• 제29권3호
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• pp.51-59
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• 1997

Dissolving pulp is a low yield(30∼35%) bleached chemical pulp that has a high cellulose content (95% or higher) suitable for use in cellulose derivatives such as rayon, cellulose acetate. This research was studied for dissolving pulp preparation as the raw material of viscose rayon from commertial pulps. (TMP, CP, DIP) In the change of pulp(cellulose) characteristics after sodium hypochlorite and solvolysis treatment. the following results were obtained In the case of sodium hypochlorite pretreatment, we have obtained pulp that high purity cellulose, but degree of polymerization was inclined to decrease less than 170∼240. Comparing sodium hypochlorite pretreatment and solvolysis pretreatment, solvolysis pretreatment is superior to sodium hypochlorite process for making dissolving pulp. We think that the low degree of polymerization of cellulose because of increasing degradation of cellulose during delignification treatment.

• 한국잔디학회:학술대회논문집
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• 한국잔디학회 2004년도 제17차 한국잔디학회 정기총회 및 춘계학술발표회
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• pp.55-56
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• 2004

• 대한기계학회논문집B
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• 제41권3호
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• pp.183-189
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• 2017

상수도 소독공정에서 사용되고 있는 차아염소산나트륨은 일반적으로 유효염소 0.8 %로 생산되어 투입되고 있으며, 투입량이 많아질수록 소독부산물(Chlorate)이 증가되었고 수질기준을 초과하게 된다. 이에 따라 본 연구에서는 유효염소를 12%로 높인 차아염소산나트륨 발생장치의 전해조에 대해 소독부산물을 제어할 수 있도록 양극수 pH를 조절하였다. 실험결과 전해조 내 양극수 pH를 4.2(일반적인 차아염발생장치 운전 pH)에서 1.53으로 조절함으로서 Chlorate 농도는 95% 이상 낮아진 것으로 나타났으며, 또한 낮은 전류가 인가됨에 따라 양극의 효율도 15% 개선되는 결과를 얻었다. 이 장치의 개발로 대용량 상수도에서도 안전한 차아염소산나트륨의 적용이 가능하여 소독공정의 안전성 향상에 기여할 것으로 기대된다.

• 한국식품과학회지
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• 제29권6호
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• pp.1094-1100
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• 1997

본 연구는 옥수수 전분을 sodium hypochlorite(NaOCl)로 산화시킬 때 산화제의 농도, pH와 온도가 미치는 영향에 대하여 조사하였다. 전분의 산화 반응은 NaOCl 농도, pH와 온도의 영향을 받았다. 산화반응은 산화제가 3.0% active Cl/g starch 이하의 농도에서는 1차 반응, 3.75% active Cl/g starch이상의 농도에서는 2차 반응으로 나타났다. 1차 반응에서 산화제의 농도가 2.25% active Cl/g starch 까지는 반응속도 상수가 증가하였고, 그 이후의 농도에서는 일정한 값을 보였다. 산화에 따른 전분내 카르복실기 함량은 반응 초기에 급격히 증가하다가 반응이 진행되면서 증가정도가 완만해졌으며, NaOCl 농도가 증가함에 따라 카르복실기의 생성량도 증가하였다. 동일한 NaOCl 농도(1.5% active Cl/g starch)에서 전분의 산화는 pH 7에서 가장 빠르게 진행되었다 온도에 따른 전분의 산화속도를 1차식으로 해석한 결과, 온도가 증가됨에 따라 속도 상수(k)값이 증가되어 반응속도가 빨라지는 것을 알 수 있었다. 한편 Arrhenius 식으로부터 산화 반응의 활성화 에너지를 계산하였을 때 1차반응의 활성화 에너지는 약 13.45 kcal/mol이었다.

• 멤브레인
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• 제25권5호
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• pp.447-455
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• 2015

본 연구에서는 Polysulfone (PSf), Polyetherimide (PEI)를 각각 비율을 달리하여 아민화하였고, Polyether ether ketone (PEEK)을 설폰화하였다. 합성한 두 이온교환고분자를 더블캐스팅방법으로 SPEEK (sulfonated PEEK)/APSf (aminated PSf) 및 SPEEK/APEI (aminated PEI) 바이폴라막을 제조하였다. 각각의 막 표면을 불소화하고, 아민화 비율에 따라 차아염소산나트륨발생량을 비교하였다. 아민화 비율이 증가할수록 차아염소산나트륨 발생 농도 또한 증가하였다. SPEEK/APSf 3 : 1 막의 경우 불소화 전의 차아염소산나트륨 농도와 총 운전시간은 61.0 ppm, 220 min이고, 불소화한 막의 경우 58.6 ppm, 570 min이다. 또한 SPEEK/APEI 3 : 1 막에서 역시 불소화 전후의 차아염소산나트륨 농도는 각각 60.1 ppm, 58.3 ppm이고, 총 운전시간은 150 min에서 440 min으로 내구성이 크게 향상되었다. 따라서 표면 불소화가 막의 내구성에 중요한 역할을 한다고 사료된다.

• 대한화학회지
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• 제31권5호
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• pp.476-478
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• 1987