• Journal of the Korean Ceramic Society
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• v.24 no.1
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• pp.77-85
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• 1987

Hardened cement paste is mainly affected by corrosion of sulphate and chlorine ions in sea water. In this investigation, many specimens were made with the cement clinker minerals such as C3S, C3A, C4AF and their mixture according to cement composition added various blending materials. After the specimens were immersed in 4% MgSO4 and MgCl2 solutions, the product of reaction, the microstructure of specimen and Ca+2 ion leached in the solution were studied. The formation of Ca(OH)2 in the specimen of C3S is reduced relatively by adding pozzolanic admixtures. The chlorine ion is easily diffuse into the C3S specimen and produced CaCl2 compound, and it makes the specimen porous by leaching out itself into the solution. The specimen of C3A, C4AF are broken down by expanding reaction of ettringite and gypsum compound produced in the MgSO4 solution. At a later period, the ettringite is transformed into gypsum and 5MgO.2Al2O3·15H2O. The C3A in the MgCl2 solution combines chlorine ion to form Friedel's salt and prevents the diffusion reaction of chlorine ion into the specimen. Granulated slag shows inferior effect on the resistance of the specimen in MgSO4 solution by forming ettringite and gypsum, but good result in MgCl2 solution. Pozzolanic materials, on the whole, offer noticable effect on the resistance of the specimen in both solutions.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.492-499
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• 2017

Combined treatment with gaseous and aqueous chlorine dioxide ($ClO_2$) was performed to improve the microbiological safety and quality of paprika. A single treatment of 50 ppmv $ClO_2$ gas for 30 min decreased the populations of Escherichia coli O157:H7 and Salmonella Typhimurium by 2.33 and 2.91 log CFU/g, respectively. In addition, a single treatment of aqueous $ClO_2$ (50 ppm) for 5 min decreased these populations by 1.86 and 1.37, respectively. The most dramatic effects were achieved by combined treatment of 50 ppm aqueous and gaseous $ClO_2$ for 30 min, which decreased populations of E. coli O157:H7 and S. Typhimurium by 4.11 and 3.61 log CFU/g, respectively. With regard to the qualities of paprika, no adverse effects were elicited by the combined treatment. Thus, combined treatment with aqueous and gaseous $ClO_2$ is a suitable approach that can be used to improve the microbial safety and quality of paprika.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.3
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• pp.383-393
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• 2020

The corrosion behavior of Hastelloy C-276 was investigated to identify its applicability for carbon-anode-based oxide reduction (OR), in which Cl₂ and O₂ are simultaneously evolved at the anode. Under a 30 mL·min^-1 Cl₂ + 170 mL·min^-1 Ar flow, the corrosion rate was less than 1 g·m^-2·h^-1 up to 500℃, whereas the rate increased exponentially from 500 to 700℃. The effects of the Cl₂-O₂ composition on the corrosion rate at flow rates of 30 mL·min^-1 Cl₂, 20 mL·min^-1 Cl₂ + 10 mL·min^-1 O₂, and 10 mL·min^-1 Cl₂ + 20 mL·min^-1 O₂ with a constant 170 mL·min^-1 Ar flow rate at 600℃ was analyzed. Based on the data from an 8 h reaction, the fastest corrosion rate was observed for the 20 mL·min^-1 Cl₂ + 10 mL·min^-1 O₂ case, followed by 30 mL·min^-1 Cl₂ and 10 mL·min^-1 Cl₂ + 20 mL·min^-1 O₂. The effects of the chlorine flow rate on the corrosion rate were negligible within the 5-30 mL·min^-1 range. A surface morphology analysis revealed the formation of vertical scratches in specimens that reacted under the Cl₂-O₂ mixed gas condition.

• Journal of Applied Biological Chemistry
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• v.51 no.3
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• pp.117-122
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• 2008

Inactivation of Agrobacterium tumefaciens was evaluated on the inoculated fresh Radix Ginseng by electron beam irradiation or aqueous chlorine dioxide ($ClO_2$) treatment. Two groups of fresh ginsengs were prepared and inoculated with A. tumefaciens. One group was then irradiated at 0, 2, and 4 kGy using an electron beam accelerator, and the other group was treated with 0, 50, and 100 ppm of aqueous $ClO_2$. Microbiological data indicated that populations of A. tumefaciens significantly decreased with increasing irradiation dose or aqueous $ClO_2$ concentration. In particular, A. tumefaciens was eliminated by irradiation at 4 kGy, and 100 ppm $ClO_2$ treatment reduced the populations of A. tumefaciens by 1.44 log CFU/g. These results suggest that electron beam irradiation or aqueous $ClO_2$ treatment can be useful in improving the microbial safety of fresh ginsengs during storage.

• Resources Recycling
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• v.29 no.6
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• pp.48-56
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• 2020

In this study, raw mix was mixed with CaCl2 for analyzing characteristics of clinker added chlorine and chlorine was added by 2,000ppm at high concentration condition. The raw mix added chlorine was burned at 1250℃~1350℃ and maintained during 10minutes at each maximum temperature. Clinker target modulus was LSF 92, SM 2.5 and IM 1.6 in this study. The burnability of clinker added chlorine was identified by free-CaO content. Free-CaO content decreased as chlorine content increased and free-CaO content of 1350℃-2000ppm clinker decreased by 1.5%. Optical microscope and XRD Analyses were used for identify mineral properties of clinker added chlorine. The mineral of clinker could not be observed at 1250℃ and the size of alite grew larger as chlorine content increased at 1350℃. It showed a good crystallizability as chlorine content increased. As chlorine content of clinker increased, clinker showed a good burnability and mineral property.

• Preventive Nutrition and Food Science
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• v.10 no.2
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• pp.122-129
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• 2005

Chlorine dioxide $(ClO_2)$ treatment was evaluated for microbial growth inhibition and its effects on the quality of vacuum-packaged chicken breasts. Chicken breast samples were treated with 3, 50, and 100 ppm of $ClO_2$ solution, respectively. After $ClO_2$ treatment, chicken breast samples were individually vacuum-packaged and stored at $4^{\circ}C$, a typical storage temperature for meat and meat product, for 7 days. The vacuum-packaged chicken breasts treated with $ClO_2$ had significantly lower total bacteria, yeast and mold, total coliform, and Salmonella spp. were significantly reduced by $ClO_2$ treatment. $D_{10}-values$ of total bacteria count, yeast and mold, total coliform, and Salmonella spp. in vacuum-packaged chicken breasts was 93, 83, 85, and 50 ppm, respectively. The pH of vacuum-packaged chicken breasts decreased with increasing $ClO_2$ concentration. Thiobarbituric acid reacted substance (TBARS) values of vacuum-packaged chicken breasts increased during storage, regardless of $ClO_2$ concentration. $ClO_2$ treatment caused negligible changes in Hunter L, a, and b values in the vacuum-packaged chicken breasts. Sensory evaluation of the vacuum-packaged chicken breasts showed that there were no significant changes among the samples treated with various $ClO_2$ concentration. These results indicate that $ClO_2$ treatment could be useful in improving the microbial safety and quality of meat products.

• 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.

• Resources Recycling
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• v.6 no.1
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• pp.35-39
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• 1997

This study was carried out to find the existing forms of chlorlnc in EM dust and to understand the valaliliratian behavior and the removal of chlorine from EAF dust with lemperalure and heating almosphere The chemical compositions of dust A are 27.3%Fe. 21.8%3Zn, 3 15%Pb, 3 51%C1 and that of dust B BE 33.92%Fe, 15.94%Zn, 2.73% Pb, 3.98%Cl. The XRD analysis and water leaching test shows that chlorlne in EM dust exist mainly as NaCI, KCI, Pb (0H)Cl. Above 99% of chlorine was volatilized when dust was hentcd in alr atmosphere at 1100$^{\circ}$C h r 1 hour and that was 96% when heated in reduction atmosnherc at 1100$^{\circ}$C for 1 hour.

• JSTS:Journal of Semiconductor Technology and Science
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• v.1 no.4
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• pp.197-201
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• 2001

The influence of argon, oxygen, and nitrogen admixtures on the dissociation of $Cl_2$ molecules in a glow discharge low-temperature plasma under the constant pressure conditions was investigated. For $Cl_2/Ar$ and $Cl_2/O_2$mixtures, the concentration of chlorine atoms was observed to be a practically constant at argon or oxygen concentrations up to 50%. This invariability is a most pro bably explained by relative increase in rate of $Cl_2$ direct electron impact dissociation due to the changes in electrophysical parameters of plasma such as EEDF, electron drift rate and mean energy. For all the considered mixtures, the contribution of stepwise dissociation involving active species from gas additives (metastable atoms and molecules, vibrationally excited molecules) was found to be negligible.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.344-349
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• 2001

The removal of chlorine from aqueous solutions on dried Chlorella vulgaris(DCV) and green tea powder(GTP) were investigated as a function of contact time, pH and initial chlorine concentration. Removal by DCV and GTP reached equilibrium after 3hrs and 0.5hr, respectively. Optimum removal pH values of DCV and GTP were determined as above 10. Both Langmuir and Freundlich adsorption models were suitable for describing the short-term removal of chlorine by DCV and GTP. According to Langmuir adsorption isotherms the maximum removal capacity of DCV (2.75mg $Cl_2/mg$) was nearly two times greater than those of GTP (1.53mg $Cl_2/mg$) and activated carbon (1.47mg $Cl_2/mg$). These results suggested that Chlorella vulgaris biomass might potentially be used as an alternative to traditional water treatment materials for removal of residual chlorine in drinking water or process waste-water.