• Title/Summary/Keyword: formation of hydrogen peroxide

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Evaluation of Advanced Oxidation Process(AOP) as a Pretreatment Process of Biological Activated Carbon in Drinking Water Treatment (정수처리에서 생물활성탄의 전처리로서 고급산화처리법의 평가)

  • Kim Woo-Hang
    • Journal of Environmental Science International
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    • v.8 no.6
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    • pp.725-730
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    • 1999
  • The advanced oxidation process (AOP) using ozone combined with hydrogen peroxide and ultraviolet treatment were evaluated for biodegradable dissolved organic carbon (EDOC) formation and dissolved organic carbon (DOC) removal. Oxidation treatment were conducted alone or combination with ozone, hydrogen peroxide and ultraviolet processes. Ozone dosage of ozone process was varied from $0.5mg/l{\ell}\cdot}min$ to $5mg/{\ell}{\cdot}min$. Ozone/hydrogen peroxide process was done using $20mg/{\ell}{\cdot}min$ of hydrogen peroxide concentration. Ozone/ultraviolet process was irradiated with $12mW/cm^2$ of density and 254nm. Ozone dosage was varied from $0.5mg/{\ell}{\cdot}min$ to $5mg/{\ell}{\cdot}min$ at the ozone/hydrogen peroxide and ozone/ultraviolet processes too. Contact time of all the process was 20 minutes. Oxidation treatment were performed on microfiltration effluent samples. BDOC formation was reached to an optimum at ozone dosage of $1.5mg/{\ell}{\cdot}min$ in the ozone/hydrogen peroxide process and $1mg/{\ell}{\cdot}min$ in ozone/ultraviolet process, after which BDOC formation was decreased at higher ozone dosages. But BDOC formation was increased with ozone dosages increasing in ozone process. The efficiency of DOC removal was higher AOPs than ozone process. Ozone/ultraviolet proces was the highest for DOC removal efficiency in each process. THMFP. removal efficiency by ozone/ultraviolet process was higher than that by each of ozone process and ozone/hydrogen peroxide process.

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Subtilisin QK, a Fibrinolytic Enzyme, Inhibits the Exogenous Nitrite and Hydrogen Peroxide Induced Protein Nitration, inVitro and inVivo

  • Ko, Ju-Ho;Yan, Junpeng;Zhu, Lei;Qi, Yipeng
    • BMB Reports
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    • v.38 no.5
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    • pp.577-583
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    • 2005
  • Subtilisin QK, which is newly identified as a fibrinolytic enzyme from Bacillus subtilis QK02, has the ability of preventing nitrotyrosine formation in bovine serum albumin induced by nitrite, hydrogen peroxide and hemoglobin in vitro verified by ELISA, Western-blot and spectrophotometer assay. Subtilisin QK also attenuates the fluorescence emission spectra of bovine serum albumin in the course of oxidation caused by nitrite, hydrogen peroxide and hemoglobin. Furthermore, subtilisin QK could suppress the transformation of oxy-hemoglobin to met-hemoglobin caused by sodium nitrite, but not the heat-treated subtilisn QK. Compared with some other fibrinolytic enzymes and inactivated subtilisin QK treated by phenylmethylsulfonylfluoride, the ability of inhibiting met-hemoglobin formation of subtilisin QK reveals that the anti-oxidative ability of subtilisin QK is not concerned with its fibrinolytic function. Additionally, nitrotyrosine formation in proteins from brain, heart, liver, kidney, and muscle of mice that is intramuscular injected the mixture of nitrite, hydrogen peroxide and hemoglobin is attenuated by subtilisin QK. Subtilisin QK can also protect Human umbilical vein endothelial cell (ECV-304) from the damage caused by nitrite and hydrogen peroxide.

Effects of $\beta$-Mercaptoethanol and Hydrogen Peroxide on Enzymatic Conversion of Human Proinsulin to Insulin

  • Son, Young-Jin;Kim, Chang-Kyu;Choi, Byoung-Taek;Park, Yong-Cheol;Seo, Jin-Ho
    • Journal of Microbiology and Biotechnology
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    • v.18 no.5
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    • pp.983-989
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    • 2008
  • Human insulin is a hormone well-known to regulate the blood glucose level. Recombinant preproinsulin, a precursor of authentic insulin, is typically produced in E. coli as an inactive inclusion body, the solubilization of which needs the addition of reducing agents such as $\beta$-mercaptoethanol. To make authentic insulin, recombinant preproinsulin is modified enzymatically by trypsin and carboxypeptidase B. The effects of $\beta$-mercaptoethanol on the formation of human insulin derivatives were investigated in the enzymatic modification by using commercially available human proinsulin as a substrate. Addition of 1 mM $\beta$-mercaptoethanol induced the formation of various insulin derivatives. Among them, the second major one, impurity 3, was found to be identical to the insulin B chain fragment from $Phe_1$ to $Glu_{21}$. Minimization of the formation of insulin derivatives and concomitant improvement of the production yield of human insulin were achieved by the addition of hydrogen peroxide. Hydrogen peroxide bound with $\beta$-mercaptoethanol and thereby reduced the negative effects of $\beta$-mercaptoethanol considerably. Elimination of the impurity 3 and other derivatives by the addition of over 10 mM hydrogen peroxide in the presence of $\beta$-mercaptoethanolled to a 1.3-fold increase in the recovery efficiency of insulin, compared with those for the case without hydrogen peroxide. The positive effects of hydrogen peroxide were also confirmed with recombinant human preproinsulin expressed in recombinant E. coli as an inclusion body.

Pulp Bleaching Effect and Ionization Rate of Chlorine Dioxide by Additive and Various pH Conditions (II) (pH와 첨가제에 의한 이산화염소의 분해율 및 펄프 표백효과(2)-첨가제가 chlorate 생성량의 감소와 펄프 표백 효과에 미치는 영향)

  • 윤병호;왕립군
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.4
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    • pp.49-57
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    • 1999
  • In CLO2 delignification and bleaching process, formation of chlorate corresponds to a loss of 20-36% of the original CKO2 charge. Because chlorate is inactive and harmful to environmental, it will be of benefit to find methods that can reduce the formation of chlorate during chlorine dioxide bleaching. Chlorate is mainly formed by the reaction HCIO +ClO2 $\longrightarrow$H+ + Cl_ +ClO3-2 On the other hand, AOX in chlorine dioxide bleacing is formed also due to the in-situ produced hypochlorous acid. THus both AOX and chlorate could be reduced by addition of hypochlorous acid. Some paper son the reduction of AOX by additives appeared , but systematic data on chlorate reduction as well as pulp and effluent properties are not available. THus this paper of focused on the effects on the reduction of chlorate and chlorine dioxide bleachability. The additives, fulfamic a챵, AMSO, hydrogen peroxide, oxalic acid were found to eliminate chlorine selectively in chlorine and chlorine dioxide mixture.However, when they were added to bleaching process, sulfamic acid and DMSO showed significant reduction of chlorate formation but hydrogen peroxide and oxalic aicd did not, and significant amount ofhydrogen peroxide was found resided in the bleaching effluent , In addition, sulfamic acid and DMSO decreased the bleaching end ph values while hydrogen peroxide and oxalic acid did not, which also indicated that hydrogen peroxide and oxalic acid were ineffective. The difference might be ascribed to the competitives of hypochlorous acid with lignin, chlorite (CKO2) and additives. Sulfamic acid and DMSO showed better pulpbrightness development but less alkaline extraction efficiency than hydrogen peroxide , oxalic acid and control, which means that insitu hypochlorous acid contributes to the formation of new chromophore structures that can be easily eliminated by alkaline extraction. DMSO decreased the delignification ability of chlorine dioxide due to the elimination of hypochlorous acid, but sfulfamic acid did to because the chlroinated sulfamic acid had stable bleachability. In addition, sulfamic acid, and SMSO shwed decreased color and COD of bleaching effluents, hydrogen peroxide decreased effluent color but not COD content, and oxalic acid had no statistically significant effects. No significant decreases of pulp viocosity were found except for hydrogen peroxide. Based on our results , we suggest that the effectiveness of hydrogen peroxide on the reduction of AOX in literature might be explained by other mechanisms not due to the elimination of hypochlorous acid , but to the direct decomposition of AOX by hydrogen peroxide.

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Effect of DNA Repair Inhibitors and Iron on the Chromosome Aberration Induced by Bleomycin and Hydrogen Peroxide in CHO Cells (DNA 회복합성저해제 및 철이 Bleomycin과 과산화수소에 의해 유발된 CHO 세포의 염색체 이상빈도에 미치는 영향)

  • 정해원;유은경
    • Journal of Environmental Health Sciences
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    • v.19 no.4
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    • pp.59-66
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    • 1993
  • The cellular toxicity and antitumor effects of bleomycin are thought to be occurred by formation of O$_2$-Fe$^{2+}$-bleomycin complexes that degrade DNA and release O$_2^-$ and $^{\cdot}$OH radicals. Hydroxyl radicals derived from hydrogen peroxide seem most likely to be involved in the various stages of carcinogenesis, and transition metals such as iron play a central role in activation of bleomycin and in formation of hydroxyl radicals. This study was performed to investigate whether treatment with ferrous sulfate increase chromosome aberration induced by bleomycin and hydrogen peroxide, and whether there is different repair mechanism for DNA damage induced by those chemicals. Treatment with 3AB, Ara C, during G$_1$ and post-treatment with caffeine, and Hu during G$_2$ increased the frequency of chromosome aberration induced by bleomycin but post-treatment with caffeine only did function that way when hydrogen peroxide was treated. When 6.6X 10$^{-7}$ M of bleomycin or 5.0X10$^{-5}$M of hydrogen peroxide were treated simultaneously with iron, the frequency of chromosome aberration was reduced, if compared with the results by bleomycin or hydrogen per oxide alone.

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Suppressive Effect of Galangin on the Formation of 8-OH2'dG and DNA Single Strand Breaks by Hydrogen Peroxide ($H_2O_2$ 유도 8-OH2'dG 생성 및 DNA Single Strand Break에 미치는 Galangin의 억제효과)

  • Kim, Soo-Hee;Heo, Moon-Young
    • YAKHAK HOEJI
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    • v.54 no.1
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    • pp.32-38
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    • 2010
  • The aim of this study was to evaluate the effect of galangin towards hydrogen peroxide-induced DNA damage. The calf thymus DNA and Chinese Hamster Lung (CHL) cells were used to measure 8-hydroxy-2'-deoxyguanosine(8-OH2'dG) as an indicator of DNA oxidative damage using high performance liquid chromatography with electrochemical detection. Hydrogen peroxide in the presence of Fe(II) ion induced the formation of 8-OH2'dG in both calf thymus DNA and CHL cells. The DNA damage effects were enhanced by increasing the concentration of Fe(II) ion and inhibited by galangin. In the single cell gel electrophoresis (Comet assay), galangin and dl-a-tocopherol showed an inhibitory effect in CHL on hydrogen peroxide induced DNA single strand breaks. Galangin showed more potent activity than dl-$\alpha$-tocopherol under our experimental conditions. These results indicate that galangin can modify the action mechanisms of the oxidative DNA damage and may act as chemopreventive agents against oxidative stress.

Oxidation of Pyridazinyl Sulfides: Synthesis of New Pyridazinyl Sulfoxides and Pyridazinyl Sulfones with Aqueous Hydrogen Peroxide (Pyridazinyl Sulfides의 산화반응: 과산화수소를 이용한 새로운 Pyridazinyl Sulfoxides 및 Pyridazinyl Sulfones의 합성)

  • Park, Eun-Hee;Park, Myung-Sook
    • YAKHAK HOEJI
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    • v.56 no.6
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    • pp.390-394
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    • 2012
  • A series of new pyridazinyl sulfoxides 3a~e and pyridazinyl sulfones 4a were synthesized for development of candidates to retain anticancer activity. The utility of sulfoxides and sulfones in both laboratory and industrial practice was quickly recognized, and these species have been extensively utilized, including as pharmaceutical intermediates and anticancer agents. Alkylthiopyridazines 2a~e were prepared from the 3,6-dichloropyridazine using allylthiolation with alkyl mercaptan. Sulfides could be oxidized to sulfoxides or sulfones using 1~3 equivalents of hydrogen peroxide as an oxidant. The oxidation of sulfoxides to sulfones was also accomplished with aqueous hydrogen peroxide. Formation of 3a~e and 4a was undertaken with stirring using 35% hydrogen peroxide at room temperature in acetic acid for 18~72 h. Synthetic compounds were identified using NMR spectrum.

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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Formation of Mixed Oxidants and Inactivation of E. coil by the Electrochemical Process using a Grid Shape Pt/Ti Electrode (Pt/Ti 격자형 평판 전극을 이용한 혼합 산화제 생성 및 E. coli 불활성화)

  • Jung, Yeon Jung;Oh, Byung Soo;Park, Sang Yeon;Baek, ko Woon;Kang, Joon-Wun
    • Journal of Korean Society on Water Environment
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    • v.22 no.5
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    • pp.851-855
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    • 2006
  • The aim of this study was to investigate characteristics of formation of mixed oxidants and some aspects of the performance of electrochemical process as an alternative disinfection strategy for water purification. The study of electrochemical process has shown free chlorine to be produced, but smaller amounts of stronger oxidants, such as ozone, hydrogen peroxide and OH radicals, were also generated. The formation of ozone and hydrogen peroxide increased with increasing electric conductivity, but was limited at conductivities greater than 0.6 mS/cm. Also, formation of OH radical was enhanced as electric conductivity was increased to 0.9 mS/cm and The stead-state concentrations of OH radical were calculated at $1.1{\sim}6.4{\times}10^{-14}M$. Using E. coti, inactivation kinetic studies were performed. With the exception of free chlorine, the role of mixed oxidants, especially OH radical, was investigated for enhancement of the inactivation rate.

Rates and Mechanism of Decomposition of Hydrogen Peroxide by Copper(Ⅱ)-Amines Complexes (구리(Ⅱ)-아민류착물에 의한 과산화수소의 분해반응속도와 메카니즘)

  • Sun-Deuk Kim;Yun-Yeol Shin;Jeong-Eun Park;Chang-Su Kim
    • Journal of the Korean Chemical Society
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    • v.37 no.2
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    • pp.199-205
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    • 1993
  • The decomposition of hydrogen peroxide by copper-amines complexes was studied in the pH range of 7.3∼11.3 by measuring the rate of the decreasing concentration of $H_2O_2$. Decomposition rate of hydrogen peroxide increased with increasing pH, and then decreased with increasing pH successively. The mechanism for this type of reaction involves the formation of peroxo complexes in the rate-determining step preceding deprotonation of hydrogen peroxide and copper-amines complexes.

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