• Food Science and Preservation
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• v.15 no.5
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• pp.769-773
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• 2008

Aqueous chlorine dioxide ($ClO_2$) treatment of Samgae chicken was evaluated in terms of microbial safety and quality during refrigerated storage. Samgae chicken samples were treated with 0, 50, or 100 ppm of $ClO_2$ solution, and stored at $4^{\circ}C$ for 10 days. $ClO_2$ treatment significantly decreased the populations of total aerobic bacteria. One-hundred ppm $ClO_2$ treatment reduced the initial populations of total aerobic bacteria by 0.73 log CFU/g. The pH and volatile basic nitrogen values of Samgae chicken increased during storage, with no significant between-treatment difference. Sensory evaluation results showed that the quality of chicken treated with $ClO_2$ prior to refrigerated storage was better than that of the control. These results suggest that $ClO_2$ treatment could be useful in improving the microbial safety and quality of Samgae chicken.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.12a
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• pp.103-114
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• 2005

Chlorine disinfection has been used in drinking water supply to disinfect the water-borne microbial disease which may cause to serious human disease. As Chlorination is still the least costly, relatively easy to use, chlorination is the primary means to disinfect portable water supplies and control bacterial growth in the distribution system. However, chlorine also reacts with natural organic matter (NOM), which presents in nearly all water sources, and then produces disinfection by-product (DBps), which may have adverse health effects. Although the existent DBPs have been reported in drinking water supplies, it is not feasible to predict the levels of the various DBPs due to the complex chemistry reaction involved. The objectives of this study were to investigate seasonal variation of DBPs formation and difference of DBPs concentration in the plant to tap water. The average concentration of THMs was 20.04 ${\mu}g/{\ell}$, HAAs 8-15 ${\mu}g/{\ell}$, HANs 2-4.5 ${\mu}g/{\ell}$ respectively. Distant variation of DBPs formation is that THMs concentration increase by 17% at 2 km point from the plant and by 28% at 7 km and HAAs, HANs also increase each by 16%, 32%, at 2 km from the plant and 35%, 56%, at 7 km. DBPs increase in water supply pipe continually. The seasonal occurrence of DBPs is that in May and August DBPs concentration is very high then in March, in May DBPs concentration is highest. The temperature is main factor of DBPs formation, precursor also. Precursor which was accumulated for winter flowed into the raw water by flooding in spring and summer and produced DBPs. Therefore for the supply of secure drinking water, it is required to protect precursor of flowing into raw water and to add to BCAA and DBAA to drinking water standards.

• Journal of the Korean Society of Tobacco Science
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• v.35 no.1
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• pp.1-6
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• 2013

Near InfraRed Spectroscopy(NIRS) is a quick and accurate analytical method to measure multiple components in tobacco manufacturing process. This study was carried out to develop calibration equation of near infrared spectroscopy for the prediction of the amount of chemical components and hot water solubles(HWS) of reconstituted tobacco leaf. Calibration samples of reconstituted tobacco leaf were collected from every lot produced during one year. The calibration equation was formulated as modified partial least square regression method (MPLS) by analyzing laboratory actual values and mathematically pre-treated spectra. The accuracy of the acquired equation was confirmed with the standard error of prediction(SEP) of chemical components in reconstituted tobacco leaf samples, indicated as coefficient of determination($R^2$) and prediction error of sample unacquainted, followed by the verification of model equation of laboratory actual values and these predicted results. As a result of monitoring, the standard error of prediction(SEP) were 0.25 % for total sugar, 0.03 % for nicotine, 0.03 % for chlorine, 0.16 % for nitrate, and 0.38 % for hot water solubles. The coefficient of determination($R^2$) were 0.98 for total sugar, 0.97 for nicotine, 0.96 for chlorine, 0.98 for nitrate and 0.92 for hot water solubles. Therefore, the NIRS calibration equation can be applicable and reliable for determination of chemical components of reconstituted tobacco leaf, and NIRS analytical method could be used as a rapid and accurate quality control method.

• Korean journal of food and cookery science
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• v.20 no.6 s.84
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• pp.589-597
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• 2004

This study was conducted to investigate the effects of various kinds of electrolyzed and chlorinated waters on the sensory and microbiological qualities of fresh-cut lettuce and to determine the most suitable electrolyzed water for the vegetable dishes, without heat treatment, at institutional foodservices. The sensory evaluation resulted in higher scores on the 1st-day of storage for the EW-1 (diaphragm type 1) and EW-3 (non-diaphragm type) compared to that for EW-2 (diaphragm type 2), with regard to their appearance, discoloration, texture, taste and overall acceptability characteristics. However, over time, EW-3 ranked highest, with a score of 8.00 (very like), on the 4th-day of storage, which maintained the highest level up to the 7th-day of storage, at which time the score was 7.00 (fairly like). The CW (chlorinated Water) had a significantly lower score, due to the smell of chlorine, although there was no concern with relation to chlorine residue from the electrolyzed waters. Microbial examinations of the total plate count revealed that immersing lettuce into EW-3 brought about l/3,000 to 1/30,000 reductions in the microbial counts of the TW treatment or untreated samples for up to seven days of storage. The CW treatment gave a 1/10 reduction in the microbial counts compared with the TW (tap water) treatment. The coliform bacterial counts also showed similar trends to those of the total plate count values. With regards to the psychotropic bacterial count, EW-3 was able to result in as much as a 1/30,000 reduction in the initial counts. As vegetable dishes, such as salad, can not be heat-sterilized, the utilization of EW-3 for the preparation of vegetable dishes without heat treatment will be an excellent choice to improve the critical control point in production state as a new effective means for sanitizing management.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.733-738
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• 2017

In this study, we selected chlorine, a typical toxic material used in many workplaces, as the leakage material, and through the analysis of alternative scenarios based on the meteorological conditions in the summer frequently encountered in accidents, we suggest ways to improve the (method of analysis/accident scenario modeling). The analysis of 296 chemical accidents from January 2014 to December 2016 found that the highest rate of occurrence was in summer, accounting for 35.81% of the total. According to the risk assessment, the influence range and number of inhabitants in the influence area were 712.4 m and 20,090 under the annual mean weather conditions and 796.2 m and 27,143 people under the summer mean weather conditions, respectively. This result implies that, under certain conditions, the range of impacts in the current alternative scenario is incomplete. Therefore, risk assessment systems need to be improved in order to take into consideration the characteristics of each chemical substance.

• Environmental Engineering Research
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• v.11 no.1
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• pp.45-53
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• 2006

Conventional coagulation is still the main treatment process for algae removal in water treatment. The coagulation efficiency can be significantly improved by the preoxidation of algae-containing water. Jar test was conducted to determine the optimal condition for the removal of diatoms, especially Cyclotella sp. by preoxidation and the subsequent coagulation. The effects of various concentration of PAC (Polyaluminum chloride) on coagulation with and without preoxidation using chlorine or potassium permanganate at different pHs (7.7 and 9.0) were evaluated. At pH 7.7, preoxidation with 2ppm $Cl_2$ followed by coagulation with 7.5 ppm PAC coagulant could reduce Cyclotella sp. concentration by 86%. At pH 9.0, preoxidation with 1 mg $KMnO_4/L$ followed by coagulation with 12.5 ppm PAC coagulant reduced Cyclotella sp. concentration by 85%. Non-linear regression was applied to determine the optimal condition. At pH 7.7 and 9.0, R was over 0.9, respectively. The pH of algal blooming water is over 9.0. Algae (diatom; Cyelotella sp.) can be controlled in the following ways: preoxidation with 1 mg $KMnO_4/L$ followed by coagulation with 12.5 ppm PAC coagulant can remove 80% algae from water. If water pH is adjusted to 7.7, it was expected that less amount of coagulant (7.5 or 10 mg PAC /L) after preoxidation ($Cl_2$ 2 ppm or $KMnO_4$ 0.33, 1 ppm) would be needed to achieve similar level of algae removal. The oxidation with 0.33ppm $KMnO_4$ followed by coagulation with 7.5 ppm PAC coagulant was preferable due to cost-effectiveness of treatment condition and color problem after treatment.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.12
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• pp.685-688
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• 2017

Using ALOHA and PHAST Program, it was modeled assuming the leakage accident scenarios of chlorine which is designated as accident preparation chemical in chemical control act. End-point distances corresponding to ERPG-2 concentrations were calculated while varying annual mean temperature, wind speed, humidity, and atmospheric stability. The calculated endpoint distance values were compared and the correlation with each meteorological factor was analyzed. And we also investigated strengths and weaknesses of ALOHA and PHAST. The results show that ALOHA has little or no correlation with annual average temperature, humidity and it has a large correlation with wind speed and atmospheric stability. In the case of PHAST, the end-point distances were correlated with all the meteorological factors such as average annual temperature, wind speed, humidity, and atmospheric stability, Among them, the effect of atmospheric stability were the largest.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.219-225
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• 2017

An aqueous chlorine dioxide ($ClO_2$) treatment combined with highly activated calcium oxide (CaO) and mild heat was tested for inactivating naturally existing bacteria and Escherichia coli O157:H7 inoculated on fresh-cut kale. Kale samples were treated with different concentrations of $ClO_2$ (10, 30, and 50 ppm), CaO (0.01%, 0.05%, 0.1%, and 0.2%), and mild heat ($25^{\circ}C$, $45^{\circ}C$, $55^{\circ}C$, and $65^{\circ}C$) as well with combinations of 30 or 50 ppm $ClO_2$ and 0.2% CaO at $55^{\circ}C$ for 3 min. An increasing concentration of $ClO_2$ and CaO significantly reduced the microbial population compared with the control. In addition, mild heating at $55^{\circ}C$ elicited greater microbial reduction than the other temperatures. A combined treatment of 50 ppm $ClO_2$ and 0.2% CaO at $55^{\circ}C$ reduced the population of naturally existing bacteria on kale by 3.10 log colony forming units (CFU)/g, and the counts of E. coli O157:H7 were below the detection limit (1 log CFU/g). In addition, no significant differences in the Hunter color values were evident in any treatment during storage. Therefore, a combined treatment of $ClO_2$ and active CaO at $55^{\circ}C$ can be an effective sanitizing method to improve the microbiological safety of fresh-cut kale without affecting its quality.

• Journal of Environmental Science International
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• v.11 no.3
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• pp.241-246
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• 2002

One of the Musty and earthy smell compounds in raw water is generally attributed to 2-methylisoborneol (2-MIB). It is well known that activated carbon and oxidants such as $O_3$, Cl $O_2$, are effective ways to control 2-MIB. In isotherm equilibrium experiments, 2-MIB in distilled water was much more adsorbed to the activated carbon(A/C) than raw water containing dissolved organic carbon (DOC). The Freundlich constants(k) of distilled water and raw water were 3.36 and 0.049, and 1/n values were 0.80 and 0.42, respectively. The 2-MIB residual rate were Y = $e^{-0}$.55x/~ $e^{-0}$.54x/ with Ozone( $O_3$) dose by 5 minutes contact time at the 241 and 353 ng/L initial concentrations. The 2-MIB residual rate were Y = $e^{-0}$.32x/~ $e^{-0}$.35x/ with Chlorine dioxide(Cl $O_2$) dose by 15 minutes contact time at the 89 and 249 ng/L initial concentrations. 2-MIB was decreased from 1911 ng/L to 569ng/L by post-ozonation(70%removal efficiency) and removal efficiencies of 2-MIB by the following 4 kinds Granular Activated Carbon(GAC) process such as coal base, coconut base, wood base and zeolite＋carbon base were 95.8, 89.5, 88.4, and 93.7% respectively.ely.

• Journal of Applied Biological Chemistry
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• v.57 no.2
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• pp.161-164
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• 2014

To establish the pre-freezing treatment and to secure microbial safety of blueberry, Korean raspberry, and mulberry, the effects of chemical sanitizers on the populations of microorganisms in the berries were examined. Among the treatments, the combined treatment of 50 ppm aqueous chlorine dioxide and 0.1% fumaric acid reduced most the populations of total aerobic bacteria in the blueberry, Korean raspberry, and mulberry by 2.56, 2.26, and 2.56 log CFU/g, respectively, compared to the control. The populations of yeast and mold in the blueberry, Korean raspberry, and mulberry by the combined treatment were also reduced by 2.24, 2.08, and 1.49 log CFU/g, respectively. These results suggest that the combined treatment can be useful for reducing the microbial contamination and maintaining the quality of frozen berries.