• 수도
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• 제24권4호통권85호
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• pp.79-87
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• 1997

In an effort to prevent the formation of DBPs from disinfection and the microbial regrowth in distribution systems, the ozonation followed by biological filtration process in drinking water treatment train has been recently developed as an alternative process to reduce effectively water-born organic matter as precursor. There are, however, insufficient for the consistent information and data about the relation between ozone dosage based on organic surrogate parameter, TOC or DOC and effect of ozonation on BDOC formation. This study is to review critically for the effect of ozonation on biodegradability on the basis of published technical papers including the output from author's research laboratory. It truned out that : 1. ozonation in the presence of organic matter has a tendancy to increase in BDOC content, 2. the rate of BDOC formation was maximum below 1mg $O_3/mg$ DOC of ozone dose, but about maximum content of BDOC was obtainable at the range from 1.5mg $O_3/mg$ DOC to 2mg $O_3/mg$ DOC, 3. from above 1mg $O_3/mg$ DOC, the rate of BDOC formation became slow down, 4. from above 2mg $O_3/mg$ DOC, BDOC formation was quantitatively negligible, In conclusion, it needs further systematic study and research concerned to biodegradability and treatability by ozonation in terms of organic characteristics and experimental conditions because it was hard to find out the consistent experimental data comparable each other that were performed by numbers of research authors.

• 대한환경공학회지
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• 제39권7호
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• pp.412-417
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• 2017

촉매오존화 공정에 의한 메틸오렌지 제거특성과 그에 미치는 운전변수의 영향에 관한 회분식 실험과 동력학적 연구를 수행하였다. 활성탄은 오존의 자가분해를 촉진시켜 $OH{\cdot}$를 발생시키므로 메틸오렌지 분해속도를 증가시키는 것으로 나타났다. 활성탄의 투입량이 증가함에 따라 메틸오렌지 분해반응의 속도상수가 증가하는 것으로 나타났다. 가스상 오존농도 증가는 수용액으로의 물질전달을 증가시켜 메틸오렌지 분해반응의 속도를 증가시키는 것으로 나타났다. 메틸오렌지 제거반응은 실험된 5~12 범위에서, TOC 제거는 7 이상의 pH에서 큰 영향을 미치지 않는 것으로 나타났다. 이러한 결과는 촉매오존화공정이 효과적인 염료처리 기술로서 고려될 수 있음을 보여준다.

• Environmental Engineering Research
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• 제11권2호
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• pp.84-90
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• 2006

UV-catalytic oxidation technique was applied for the treatment of bio-refractory character of the leachate, which is generally present in the form of adsorbable organic halogens (AOX). Destruction of AOX was likely to be governed by pH adjustment, quantitative measurement of oxidants, and the selection of oxidation model type. Peroxide induced degradation ($UV/H_2O_2$) facilitated the chemical oxidation of organic halides in acidic medium, however, the system showed least AOX removal efficiency than the other two systems. Increased dosage of hydrogen peroxide (from 0.5 time to 1.0 time concentration) even did not contribute to a significant increase in the removal rate of AOX. In ozone induced degradation system ($UV/O_3$), alkaline medium (pH 10) favored the removal of AOX and the removal rate was found 11% higher than the rate at pH 3. Since efficiency of the $UV/O_3$ increases with the increase of pH, therefore, more OH-radicals were available for the destruction of organic halides. UV-light with the combination of both ozone and hydrogen peroxide ($UV/H_2O_2$ 0.5 time/$O_3$ 25 mg/min) showed the highest removal rate of AOX and the removal efficiency was found 26% higher than the removal efficiency of $UV/O_3$. The system $UV/H2O_2/O_3$ got the economic preference over the other two systems since lower dose of hydrogen peroxide and relatively shorter reaction time were found enough to get the highest AOX removal rate.

• 대한수의학회지
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• 제43권3호
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• pp.493-500
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• 2003

This study was performed to determine the optimal dose of ozone for wound healing. Twenty Korean black goats were allocated to 4 groups. The skin wound with $1{\times}1cm$ was induced over the hoof. For 5 minutes per day, 0.1 ppm (Group I), 1 ppm (Group II) and 6 ppm (Group III) ozone gas was applied. In control group, 5 ml of normal saline was applied daily on the wound. Wound square was determined using color image analyzer at day 0, 4 and 14. Soft tissue depth of wound was determined using radiograph. Before the application of ozone gas, $1{\times}1cm$ of skin tissue was resected and observed for histopathologic findings. To determine the healing effect, $2{\times}1cm$ of wound tissue was resected and observed for histopathologic findings at day 14. In mean squares of wound, all experimental groups revealed more reduced mean squares than control group at day 4, and especially Group II (p<0.05) and Group III (p<0.05) revealed significant reduction. At day 14, Group I and Group II (p<0.05) revealed more reduced mean squares than control group, but Group III revealed less reduced mean squares than control group. In soft tissue depth of wound, all experimental groups and control group revealed swelling at day 4, compared with day 0. At day 14, all experimental groups and control group revealed reduction, compared with day 4, and especially Group II (p<0.05) revealed significant reduction. In histopathological findings, inflammation findings in epidermis and dermis, hemorrhagic finding in epidermis were revealed in control group. In Group I, inflammation finding was reduced, compared with control group. Formation of scab and many reepithelialization of epidermis were revealed. In Group II, inflammation findings in epidermis and dermis which were observed in control group were not found, normal skin tissue was revealed. In Group III, inflammation findings in epidermis and dermis were revealed, reepithelialization of epidermis was not founded. Slow healing process was observed, compared with Group I and II. It was concluded that Group II has excellent promotion effect of wound healing.

• 대한환경공학회지
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• 제29권5호
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• pp.533-539
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• 2007

본 연구에서는 염소, 오존, UV에 의한 크립토스포리디움의 불활성화정도를 평가하기 위해 HCT-8세포를 사용하는 세포배양법과 최적확수기법을 결합하였다. 이 방법은 크립토스포리디움 감염성을 평가하는데 있어 "gold standard"라고 여겨지는 동물감염성 실험 만큼이나 민감하였고 소독제에 의한 크립토스포리디움의 불활성화를 측정할 수 있는 유용한 방법이었다. 실험실규모의 연구결과, $5^{\circ}C$, pH 7.0 조건에서 크립토스포리움을 약 1 log 불활성화시키기위한 염소와 오존 CT값은 각각 $1,250mg{\cdot}min/L,\;16mg{\cdot}min/L$ 이었다. 이는 오존을 사용하여 소독하였을 때 조차도 낮은 온도에서는 크립토스포리디움을 불활성화시키기 어렵다는 것을 보여주는 것이다. 염소와 오존과는 달리 UV는 온도에 상관없이 크립토스포리디움을 불활성화시키기에 매우 효과적이어서 UV가 2 $mJ/cm^2$ 조사되었을 때 크립토스포리디움이 3 log 이상 불활성화되었다.

• Environmental Analysis Health and Toxicology
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• 제24권3호
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• pp.213-218
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• 2009

1-bromopropane (1-BP) has been used in numerous purposes such as an intermediate in the synthesis of pharmaceuticals, a solvent for fats, waxes, or resins and a substitute for chlorofluorocarbons that destroy the ozone layer. However, the studies related to the modulation of activities of hepatic cytochrome P450s (CYPs) are not reported yet. This study was the first study to investigate the potential effect for the activities of hepatic CYPs by the treatment of 1-BP in vivo. When 1-BP was treated to male ICR mice by dose-dependently at the dose levels of 200, 500 and 1,000 mg/kg of body weight once, the activity of CYP2E1 was selectively increased for 24 h. The inductive potency for the activity of CYP2E1 by 1-BP was equal to induction by acetone a well-known selective CYP2E1 inducer. The present results indicated that 1-BP would affect the metabolism of 1-BP itself and/or other xenobiotics.

• 산업기술연구
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• 제17권
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• pp.297-303
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• 1997

This study investigates the characteristics of humic acid before and after ozonation. The results were comapred in such terms as CODCr, CODMn, TOC(total organic carbon) and molecular size distribution. As a result of ozonation (with the dose of 3mgO3/mgHumic Acid), UV NIS absorbance, CODCr, CODMn and TOC were decreased with similar tendency. The mole fraction of high molecular size was rapidly decreased and the fraction ratio of low molecular size was increased through ozone treatment. This fact can be correlated with the change in the difference and the ratio of CODCr and CODMn (the value of CODCr-CODMn and CODMn/CODCr). From this result, it can be inferred that the molecular size and the degree of chemical oxidative degradation of humic acid after ozonation were changed.

• 환경위생공학
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• 제13권3호
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• pp.30-36
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• 1998

A study on the color removal by irradiation of ${\gamma}-ray$ was carried out to reclaim the secondary effluent for the purpose of industrial water. Coagulation, ozone and ion exchange methods were compared. It could know that irradiation method was the most effective in color removal. The color was removed by 87.5% at 0.5 Mrad and it was increase with dose. High removal efficiency could be obtained in low pH and low concentration of $CO3^{-2}$. This process can be applied to the treatment of secondary effluent and is considered to be one of the most useful tertiary treatment.

• 한국축산식품학회지
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• 제44권1호
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• pp.19-38
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• 2024

Meat contains high-value protein compounds that might degrade as a result of oxidation and microbial contamination. Additionally, various pathogenic and spoilage microorganisms can grow in meat. Moreover, contamination with pathogenic microorganisms above the infectious dose has caused foodborne illness outbreaks. To decrease the microbial population, traditional meat preservation methods such as thermal treatment and chemical disinfectants are used, but it may have limitations for the maintenance of meat quality or the consumers acceptance. Thus, non-thermal technologies (e.g., high-pressure processing, pulsed electric field, non-thermal plasma, pulsed light, supercritical carbon dioxide technology, ozone, irradiation, ultraviolet light, and ultrasound) have emerged to improve the shelf life and meat safety. Non-thermal technologies are becoming increasingly important because of their advantages in maintaining low temperature, meat nutrition, and short processing time. Especially, pulsed light and pulsed electric field treatment induce few sensory and physiological changes in high fat and protein meat products, making them suitable for the application. Many research results showed that these non-thermal technologies may keep meat fresh and maintain heat-sensitive elements in meat products.

• Toxicological Research
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• 제19권3호
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• pp.227-234
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• 2003

2-Bromopropane (2-BP), a halogenated propane analogue, is a substitute for chlorofluorocarbones (CFCs) which have a great potential to destroy the ozone layer and to warm the earth's environment. The present study was undertaken to evaluate the potential adverse effects of 2-BP on pregnant dams and embryo-fetal development after maternal exposure during the gestational days (GD) 6 through 17 in ICR mice. The test chemical was administered subcutaneously to pregnant mice at dose levels of 0, 313, 625 or 1,250 mg/kg/day. All dams were subjected to caesarean section on GD 18 and their fetuses were examined for external, visceral and skeletal abnormalities. In the 1,250 mg/kg group, maternal toxicity included an increase in the incidence of abnormal clinical signs and a decrease in the maternal body weight, body weight gain, and corrected body weight. Developmental toxicity included a decrease in the fetal body weight, a reduction in the placental weight, an increase in the fetal skeletal variation and ossification delay. There were no adverse effects on either pregnant dams or embryo-fetal development in the 313 and 625 mg/kg groups. These results suggest that a 12-day subcutaneous dose of 2-BP is embryotoxic at a maternally toxic dose (i.e., 1,250 mg/kg/day) in ICR mice. In the present experimental condition, the no-observed-adverse-effect level of 2-BP is considered to be 625 mg/kg/day for dams and embryo-fetuses, respectively.