• 제목/요약/키워드: Chemical Decontamination

검색결과 123건 처리시간 0.116초

살균처리가 인삼엽록차의 화학성분에 미치는 영향 (Effects of Decontamination Treatments on Chemical Components of Panax Ginseng-Leaf Tea)

  • 권중호;변명우;최강주;권대원;조한옥
    • 한국식품과학회지
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    • 제24권1호
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    • pp.65-69
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    • 1992
  • 수출용으로 제조되고 있는 인삼엽록차에 대하여 위생적 품질개선을 목적으로 처리된 ethylene oxide(EO) 훈증제와 적정선량의 감마선 조사가 시료의 몇 가지 화학성분에 미치는 영향을 검토하였다. 인삼엽록차에 함유된 사포닌과 지방산은 상업적 조건의 EO 처리나 적정선량의 감마선 조사(5kGy 범위)에 의해 변화되지 않았다. 그러나 유리당과 아미노산에서 glucose, lysine 및 histidine은 EO 처리시 유의적으로 감소되어(p<0.05) 살균방법 중 EO gas는 감마선조사에 비해 엽록차 성분에 미치는 영향이 큰 것으로 화인되었다.

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Electrosorption of U(IV) by Electochemically Modified Activated Carbon Fibers

  • Jung, Chong-Hun;Oh, Won-Zin;Lee, Yu-Ri;Park, Soo-Jin
    • Carbon letters
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    • 제6권1호
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    • pp.25-30
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    • 2005
  • The electrosorption of U(VI) from waste water was carried out by using an activated carbon fiber (ACF) felt electrode in a continuous electrosorption cell. In order to enhance the electrosorption capacity at a lower potential, the ACF was electrochemically modified in an acidic and a basic solution. Pore structure and functional groups of the electrochemically modified ACF were examined, and the effects of the modification conditions were studied for the adsorption of U(VI). Specific surface area of all the ACFs was decreased by this modification. The amount of the acidic functional groups decreased with a basic modification, while the amount increased a lot with an acidic modification. The electrosorption capacity of U(VI) decreased on the acid modified electrode due to the shielding effect of the acidic functional groups. The base modified electrode enhanced the capacity due to a reduction of the acidic functional groups. The electrosorption amount of U(VI) on the base modified electrode at .0.3 V corresponds to that of the as-received ACF electrode at .0.9 V. Such a good adsorption capacity was due to a reduction of the shielding effect and an increase of the hydroxyl ions in the electric double layer on the ACF surface by the application of negative potential.

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전기적 흡 . 탕착에 의한 제염폐액의 정화처리기술 (The Purification of Decontamination Liquid Waste by Electrosorption)

  • 정종헌;문제권;김규남;이성호;이상문
    • 자원리싸이클링
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    • 제8권3호
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    • pp.18-25
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    • 1999
  • 화학제염이나 전지화학제염을 통해 발생된 방사성 폐액을 정화처리할 수 있는 새로운 방법으로, 다공성 활성탄소섬유(ACF)상에서 폐액중 코발트이온의 전기적 흡·탈착에 대한 연구를 수행하였다. 회전원판 전극을 사용하여 순환전압전류법으로 전기이중층 충전만이 발생하는 전위 영역을 조사하였다. ACF 전극을 사용한 회분식 전기흡착 실험결과, 음의 전위 가용은 저위 미가용 시의 흡착에 비해 코발트이온의 흡착을 증가시켰다. 또한 흡착된 코발트 이온은 역전된 가용전위에 의해 용액으로 용출되었으며 이와 동시에 탄소체 전극이 재생되어, 전기흡착 공정의 가역성을 확인 할 수 있었다.

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Evaluation of decontamination factor of radioactive methyl iodide on activated carbons at high humid conditions

  • Choi, Byung-Seon;Kim, Seon-Byeong;Moon, Jeikwon;Seo, Bum-Kyung
    • Nuclear Engineering and Technology
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    • 제53권5호
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    • pp.1519-1523
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    • 2021
  • Radioactive iodine (131I) released from nuclear power plants has been a critical environmental concern for workers. The effective trapping of radioactive iodine isotopes from the off-gas stream generated from nuclear facilities is an important issue in radioactive waste treatment systems evaluation. Numerous studies on retaining methyl iodide (CH3I131) by impregnated activated carbons under the high content of moisture have been extensively studied so far. But there have been no good results on how to remove methyl iodide at high humid conditions up to now. A new challenge is to introduce other promising impregnating chemical agents that are able to uptake enough radioactive methyl iodide under high humid conditions. In order to develop a good removal efficiency to control radioiodine gas generated from a high humid process, activated carbons (ACs) impregnated with triethylene diamine (TEDA) and qinuclidine (QUID) were prepared. In addition, the removal efficiencies of the activated carbons (ACs) under humid conditions up to 95% RH were evaluated by applying the standard method specified in ASTM-D3808. Quinuclidine impregnated activated carbon showed a much higher decontamination factor above 1,000, which is enough to meet the regulation index for the iodine filters in nuclear power plants (NPPs).