• 수도
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• s.44
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• pp.6-12
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• 1988

This study was performed to measure the elimination effects of chlorine dioxide on phenol compounds, trihalomethanes (THMs) and algae in drinking water supply. The raw and chlorinated water were treated with 0.5ppm of chlorine dioxide. The phenols contained 0.052mg/1, 0.019mg/1 of raw and treatedwater was absolutely destroyed. The THMs was reduced to 50-60% of the concentration and the algae was inhibited to about 50% of the growth.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.30 no.3
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• pp.1-6
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• 1998

Elementally Chlorine Free (ECF) bleaching will be superior than Totally Chlorine free (TCF) bleaching, not only because they have no significant difference in effluent toxicity, but also those pulps bleached by ECF have higher brightness, strength, yield, etc., over those by TCF. With this belief, this paper focused on the chemistry of chlorine dioxide decomposition and ionization, both in water solution and in pulp slurry. Special attention was paid to chlorate ion because there have been controversies as how it is formed and what its behavior to the end pH of pulp bleaching is. As a result, during ionization of chlorine dioxide with water, both chlorate and chlorite were found to increase with increasing pH, but during ionization with pulp, chlorite was found to increase with end pH while chlorate decreased with increasing end pH. In the case of ionization with water, the disproportion equation $2CIO_2 + OH^{-} \lightarrow H_2O + CIO_3^{-} + CIO_2^{-}$ was thought to become the main reaction with the increasing pH, while in the case of ionization with pulp, the reaction $HCIO + CIO_2^{-}\lightarow H^{+} + Cl^{-} + CIO_3^{-}$ was the main reaction contributing to the formation of chlorate. Based on this above opinion, the contrary results of chlorine dioxide ionization from different researchers were discussed and explained.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.4
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• pp.282-285
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• 2004

Kinetics of H-spillover over $Pt/MoO_3$ was greatly affected by the amount of residual chlorine differing by calcination temperature. Multifacetted techniques for characterization were dedicated to elucidate the faster reduction of chlorine in the isothermal reduction (ITR) at $50^circ{C}$ after calcination. Reduction of residual chlorine over Platinum resulted in opening the more channel of hydrogen pathway into more $MoO_3$ particles and controlling the kinetics of hydrogen uptake.

• Korean journal of applied entomology
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• v.56 no.2
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• pp.147-152
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• 2017

Heart contraction is essential for insect hemolymph circulation, in which various physiological changes need control of the heart contraction. Thus, interruption of heartbeats intimidate insect survival. Chlorine dioxide induces release of reactive oxygen species (ROS), which has been regarded as the main insecticidal agent. This study analyzed the effect of chlorine dioxide on heartbeats of the Indianmeal moth, Plodia interpunctella. The larvae have the dorsal vessel on the medial dorsal region in a form of an extending tube from the first thorax to 10th abdominal segment. Dorsal vessel contraction was noticeable between 3rd and 10th abdominal segments, where five heart chambers were observed. Average heartbeat rate was 118.6 beats per min at $25^{\circ}C$. However, the heartbeats varied with ambient temperature. Injection of chlorine dioxide to hemocoel suppressed the heartbeats in a dose-dependent manner. The suppressive effect of chlorine dioxide also increased with exposure time to gas form of the chemical at 100 ppm. However, vitamin E (an antioxidant against ROS) treatment significantly rescued the larvae treated with chlorine dioxide in the heart contraction activity. These results suggest that chlorine dioxide negatively influences on the heart contraction of P. interpunctella via its production of ROS.

• Food Science and Preservation
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• v.15 no.2
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• pp.236-242
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• 2008

We investigated the optimum concentration of a $NaClO_2$ solution and the amount of gaseous $Cl_2$ for production of high yield and purity of aqueous $ClO_2$ by use of a gaseous chlorine-chlorite $ClO_2$ generator. This system produced lower concentrations of chlorine dioxide and is applicable for direct-use in food processing as a cleaner and sanitizer. The concentration of $NaClO_2$ solution and the amount of gaseous $Cl_2$ was varied from 0.01-0.1% and 100-1,000 g/hr, respectively. The concentrations of chlorite, chlorate, FAC (free available chlorine), and chlorine dioxide that were produced increased with increasing concentration of $NaClO_2$ solution and with the amount of gaseous $Cl_2$. The optimum concentration of $NaClO_2$ solution and amount of gaseous $Cl_2$ were 0.1% and 900 g/hr respectively. $ClO_2$ and FAC produced at these concentrations were 882.0 ppm and 8.0 ppm, with no detection of chlorite and chlorate. The yield and purity of $ClO_2$ were 97.0% and 96.0% respectively. Immersion-cleaning experiments showed that this protocol decreased the level of CFU/g by $10^3$- to $10^4$-fold, with a similar effect on fruit.

• Biomedical Science Letters
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• v.25 no.4
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• pp.431-435
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• 2019

Chlorine dioxide is an effective chemical to inhibit the growth of bacteria and viruses or to disinfect infected areas. In this study, the effects of chlorine dioxide on several bacteria in hospitals were analyzed. Alloiococcus otitis, Kocuria rosea, Leuconostoc mesenteroides spp. and Staphylococcus lentus as gram-positive bacteria and Acinetobacter lwoffii, Aeromonas salmonicida, Brucella melitensis, Oligella ureolytica as gram-negative bacteria were done for the inhibitory analysis. The growth and morphology of the bacteria were analyzed by placing a plastic stick which was called "FarmeTok (medistick/Puristic)" provided by Purgofarm, co, Ltd. to release ClO₂ (13 ppmv/hr) next to the plate where the bacteria were incubated for 24 hours. Less than 10 bacterial colonies were evaluated as having 99% inhibitory effect. The initial bacterial culture concentration of 0.5 McFaland turbidity was good for analyzing the chlorine dioxide inhibitory effect. All bacteria could be easily counted post 24 hr co-incubation with ClO₂, but A. otitis and A. lwoffii without ClO₂ gas were not countable due to very dispersed colony types which were not affected for result analysis. As shown in this study, the FarmeTok plastic stick, which discharges chlorine dioxide at 13 ppmv / hour, was evaluated to be sufficient to suppress the above bacteria in the hospital. Bacteria existing in the clinic such as this hospital will be used as a data to inhibit the growth of bacteria by using ClO₂, and molecular biology analysis using the gene of bacteria will be possible in the future rather than inhibiting the growth of bacteria itself.

• Ecology and Resilient Infrastructure
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• v.5 no.3
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• pp.111-117
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• 2018

Disinfection of ballast water using chlorine dioxide was investigated under various initial microorganism contents, dose concentrations and pH values. Kinetics of microorganism inactivation and byproduct generation of chlorine dioxide treatment were compared with the chlorine treatment. Results of treatments with chlorine dioxide concentrations of 0 to $10mg\;Cl_2/L$ showed that The optimum concentration of chlorine dioxide required for disinfection of ballast water was 1 mg/L. The difference among the second order reaction constants for bacterial disinfection at pH 7.2 to 9.2 for chlorine dioxide was less than 5% for both bacteria. This result implied that the bactericidal effects of chlorine dioxide was independent of the pH in the examined range. On the other hand, the inactivation kinetics of chlorine for E. coli and Enterococcus decreased by 17% and 25%, respectively, when pH increased from 7.2 to 9.2. The bactericidal power of chlorine dioxide was superior to sodium hypochlorite above pH 8.2, the average pH value of sea water. Furthermore, treatments of chlorine dioxide generated less harmful byproducts than chlorine and had a long-term disinfection effect on bacteria and phytoplankton from the results of experiment for 30 days. Chlorine dioxide would be a promising alternative disinfectant for ballast water.

• Korean Chemical Engineering Research
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• v.53 no.5
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• pp.531-539
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• 2015

Chlor-alkali industry is one of the largest electrochemical processes which annually producing 70 million tons of sodium hydroxide and chlorine from sodium chloride solution. $DSA^{(R)}$ (Dimensionally Stable Anodes) electrodes such as $RuO_2$ and $IrO_2$, which is popular in chlor-alkali process, have been investigated to improve the chlorine generation efficiency. Although DSA electrode has been developed with various researches, understanding of the chlorine evolution mechanism is essential to the development of highly efficient DSA electrode. In this review paper, chlorine generation mechanisms are summarized and that of key factors are identified to systematically understand the chlorine generation mechanism. Rate determining step, effect of pH, reaction intermediate, and electrode crystal structure were intensively overviewed as key factors of the chlorine mechanism.

• Food Quality and Culture
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• v.3 no.1
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• pp.34-39
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• 2009

This study assessed the efficacy of aqueous chlorine dioxide ($ClO_2$) and commercial chlorine sanitizer in terms of its ability to eliminate Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli O157:H7 on radish sprouts (Raphanus sativus L.). Radish sprouts were inoculated with a cocktail containing one each of three strains of three different foodborne pathogens, then treated with distilled water (control) or chemical sanitizers (100 ppm commercial chlorine, and 50, 100, 200 ppm $C1O_2$) for 1, 5, and 10 min at room temperature ($22{\pm}2^{\circ}C$). Populations of S. Typhimurium, E. coli O157:H7 and L. monocytogenes were counted at 4.64, 6.05, and 4.29 log CFU/g, respectively, after inoculation. Treatment with water did not significantly reduce the levels of any of the three foodborne pathogens. The levels of all three pathogens were reduced by treatment with chemical sanitizers; however, the observed levels of reduction of E. coli O157:H7 and L. monocytogenes were not significant as compared with the controls. The levels of the three pathogens were reduced most profoundly when treated for 10 min with 200 ppm of $C1O_2$, and the reduction levels of S. Typhimurium, E. coli O157:H7, and L. monocytogenes were 1.17, 1.63, and 0.96 log CFU/g, respectively. When chemically injured cells were investigated using SPRAB for E. coli O157 :H7 and by selective overlay methods for S. Typhimurium and L. monocytogenes, respectively, it was noted that commercial chlorine sanitizer generated more numbers of injured pathogens than did $C1O_2$. These data indicate that $C1O_2$ treatment may prove useful in reducing the numbers of pathogenic bacteria in radish sprouts.

• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.127-131
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• 1992

The effects of chlorine treatment on the rheological properties (farinogram, extensogram, amylogram) of soft white wheat flour were studied by treating flour with different amounts (1, 2 and 4 ounces per 100 pounds of flour) of liquidized chlorine gas. Departure time, water absorption and dough stability increased while mechanical tolerance index decreased as the level of chlorine increased. It was appeared that extensibility and resistance at chlorine level of 1 to 2 oz was appropriate for baking properties of flour compared to those of untreated wheat flour. The temperature at maximum viscosity increased gradually with increasing levels of chlorine. It was noted that maximum viscosity was greatly increased at 4 oz compared to those of lower levels of chlorine treatment.