• Title/Summary/Keyword: chlorine dioxide

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Chlorte Reduction in $ClO_2$Prebleaching by the Addition of HClO Scavengers

  • Yoon, Byung-Ho;Lee, Myoung-Ku;Wang, Li-Jun
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2000.11a
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    • pp.15-21
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    • 2000
  • In chlorine dioxide delignification and bleaching the formation of chlorate is undesirable because it does not react with lignin and is harmful to the environment. Chlorate is mainly formed from the in-situ generated hypochlorus acid which is also the main reason for AOX formation. In previous literature scavengers of hypochlorous acid such as sulfamic aicd, DMSO, and hydrogen peroxide have been added to bleaching stages to reduce AOX formation but less attention has been paid to chlorate reduction. This paper thus focuses on the reduction of chlorate content caused by the following additives, sulfamic acid, DMSO, hydrogen peroxide, and oxalic acid. The results show that only sulfamic acid and DMSO reduce chlorate formation under our chlorine dioxide prebleaching conditions. Results by UV spectroscopy and pH adjustment show that scavengers react with hypochlorous acid much faster than with chlorine. Hydrogen peroxide and oxalic acid react with HClO/$Cl_2$much slower than DMSO and sulfamic acid do. The reason for the ineffectiveness of hydrogen peroxide and oxalic acid is ascribed to their slow reaction rates with HClO compared to that of chlorate formation. The fact that only 30-35% of the chlorate can be reduced by sulfamic acid and DMSO when charged in same mole ratio to chlorine dioxide, suggested that the reaction rate of DMSO and sulfamic acid with hypochlorous aicd are of the same magnitude as that of chlorate formation.

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Enhanced Control Efficacy of a Fumigant, Chlorine Dioxide, by a Mixture Treatment with Carbon Dioxide (이산화탄소 혼합 처리를 통한 이산화염소 훈증 처리 효과 제고 기술)

  • Kim, Chulyoung;Kwon, Hyeok;Kim, Wook;Kim, Yonggyun
    • Korean journal of applied entomology
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    • v.56 no.3
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    • pp.253-259
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    • 2017
  • Fumigation using chlorine dioxide ($ClO_2$) has been regarded as a potential control technique against stored grain insect pests. The control efficacy can be enhanced with increase of opening rates of spiracles by facilitating the toxic gas delivery to internal body. To test this hypothesis, this study used the Indianmeal moth, Plodia interpunctella, which was known to be susceptible to $ClO_2$, and analyzed the opening rate of spiracles. A total of 9 pairs of spiracles were observed in P. interpunctella larvae, in which one pair was located on the prothorax and eight pairs were on the abdomen. Within the body, the spiracles were connected to longitudinal and transverse tracheal trunks. The open spiracles were determined by the dye-infiltration method. Based on this method, the opening rate of spiracles increased up to about 60% with increase of ambient temperatures. Furthermore, exposure to carbon dioxide stimulated the opening rate of spiracles up to about 95%. In contrast, exposure to $ClO_2$ prevented the spiracle opening and resulted in only 25% of spiracles in an opening state. The addition of carbon dioxide to $ClO_2$ treatment rescued the opening rate of spiracles as much as the carbon dioxide single treatment. Based on this modulatory activity of carbon dioxide against spiracles, the combined treatment of $ClO_2$ with carbon dioxide resulted in significant increase of its toxicity against P. interpunctella compared to a single $ClO_2$ treatment.

Interaction of Oxygen and Chlorine Dioxide in Pulp Bleaching (II) - Studies on the Degradation of Carbohydrates - (펄프 표백시 산소와 이산화염소의 상호작용 (제2보) - 탄수화물의 분해에 관한 연구 -)

  • 윤병호;김세종;최경화;김영훈
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.1
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    • pp.37-42
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    • 2004
  • ECF and TCF bleaching methods are favored in bleaching plants over the world due to the increasing environment constraints. However, interaction of main stages(D and O stage) in ECF bleaching have not been understood completely yet. The degradation of holocellulose as a carbohydrate model compound was investigated by SEC(size exclusive chromatography) to estimate the change of its molecular weight distribution after O and D stage combination treatment. The molecular weight distribution of holocellulose was observed in two divisions(higher and lower molecular portions). It was also shown that DO sequence was more effective than OD, and DOD or ODO was more effective than DO. D stage had a little effect on the degradation of holocellulose, while the degradation of holocellulose increased as the time of the first O stage increased.

Effect of Aqueous Chlorine Dioxide Treatment on the Microbial Growth and Quality of Chicken Legs during Storage

  • Hong, Yun-Hee;Ku, Gyeong-Ju;Kim, Min-Ki;Song, Kyung-Bin
    • Preventive Nutrition and Food Science
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    • v.13 no.1
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    • pp.45-50
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    • 2008
  • The effect of aqueous chlorine dioxide ($ClO_2$) treatment on microbial growth and quality of chicken leg during storage was examined. Chicken leg samples were treated with 0, 50, and 100 ppm of $ClO_2$ solution and stored at $4^{\circ}C$. Aqueous $ClO_2$ treatment significantly decreased the populations of total aerobic bacteria, yeast and mold, and coliforms in chicken leg. One hundred ppm $ClO_2$ treatment reduced the initial populations of total aerobic bacteria, yeast and mold, and coliforms by 0.93, 1.15, and 0.94 log CFU/g, respectively. The pH and volatile basic nitrogen values in the chicken leg decreased with increasing aqueous $ClO_2$ concentration, while concentrations thiobarbituric acid reactive substances (TBARS) increased during storage regardless of aqueous $ClO_2$ concentration. Sensory evaluation results revealed that the quality of the chicken leg treated with aqueous $ClO_2$ during storage was better than that of the control. These results indicate that aqueous $ClO_2$ treatment can be useful for improving the microbial safety of chicken leg during storage.

Biocidal Effects of Chlorine Dioxide on Isolated and Identified Pathogens from Nosocomial Environment - Biochemical and Technical Covergence (병원내 환경으로부터 분리 및 확인된 병원균에 대한 이산화염소의 살균 효과 - 생화학 및 기술 융합)

  • Song, Kyoung-Ju;Jung, Suk-Yul
    • Journal of Digital Convergence
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    • v.15 no.6
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    • pp.339-344
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    • 2017
  • In this study, microorganisms were isolated from nosocomial environment and are identified by biochemical analysis as the part of biochemical and technical convergence. Microorganisms were collected at intense care unit of general hospital located in Pyeongtak (2014.11.28. - 2014. 11. 30). Using a VITEK2 equipment of biochemical approaches, eleven microorganisms e.g., Micrococcus luteus (or M. lylae), Granulicatella adiacens (M. luteus or M. lylae), Staphylococcus caprae, Sphingomonas paucimobilis, Kocuria kristinae, G elegans, Aerococcus viridans (or Staphylococcus arlettae), Methylobacterium spp., Dermacoccus nishinomiyaensis (or Kytococcus sedentarius), Kocuria kristinae (or M. luteus, M. lylae), Pseudomonas oryzihabitans were identified. And then identified bacteria plates were applied with a plastic stick, so called with "FarmeTok (medistick/Puristic) to produce ClO2. ClO2-releasing plastic stick showed the very strong inhibition of bacterial growth with about 99.9%. There were no bacterial colonies on the ClO2-incubated plate. Taken together, it is suggested that chlorine dioxide should be very strong inhibitor to microorganisms of nosocomial infections.