• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.123-127
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• 2003

This experiment was performed to investigate the characteristics of sonolytic reaction as the basic data for development of the ultrasonic AOP(Advanced Oxidation Process) process from which the refractory organic compounds in aqueous solution which are not readily removed by the existing conventional wastewater treatment processes can be destructed and removed. Trichloroethylene (TCE), benzene, and 2,4-dichlorophenol(DCP) were used as the samples, and their destruction efficiency were measured in terms of experimental parameters of the initial solution concentration, initial solution pH, reaction temperature, acoustic frequencies and intensities. Results showed that the destruction efficiencies of all of the sample materials were above 80% within 120 minutes of sonolytic reaction in all reaction condition. The reaction order of these three compounds was verified as Pseudo first order. From the fore-mentioned results, it can be concluded that the refractory organic compounds could be removed by the ultrasonic irradiation with radicals, such as H$.$and OH$.$causing the high increase of pressure and temperature. Finally, it appears that the new AOP technology using ultrasonic irradiation can be applied to the treatment of refractory substances which are difficult to be decomposed by the conventional methods.

• Journal of the Korean Home Economics Association
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• v.4 no.1
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• pp.589-594
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• 1963

Ascorbic acid has a strong power to reduce other materials, so by using this reducing power we can analise many materials quantitatively. Dihydro-ascorbic acid is quantitatively changed into ascorbic acid under a certain condition, if reduced by hydrogen-sulfide. Dihydro-ascorbic acid also has physiolosical effect, but less effect than ascorbic acid. The effect of dihydro-ascorbic acid is regarded as a half of that of ascorbic acid. Among the analytical methods applying this theory the method using 2.6 dichlorophenol indophenol what called the method of Indophenol is used most widely; so does Hydrazine-method. But comparing these two methods the former shows a little higher rate in analytical value. Vegetable are vital sources for vitamin C. According to the report of the commitee of FAO Korean branch the amount of daily per head average intake of vitamin C is about 70mg in raw materials. Since vitamin C is easily affected by heating or oxidation in Cooking the loss is not a little. Consequntly it is regarded that the actual amount of intake will be much less than basic amount. It is therefore very important to find out that how much percent of the loss there will be in case of cooking, in order to dicide the actual amount of in take as proper nutrition for a person. Therefore this paper intended to give some help in setting a standard amount of V.C intake, by measuring the change of the V.C amount using the general cooking method and by measuring amount of V.C contained in the part of vegetable, used in Korea abundantly.

• The Korean Journal of Mycology
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• v.19 no.1
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• pp.32-40
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• 1991

Mitochondria in Pleurotus ostreatus were isolated and purified by the stepped sucrose density gradient centrifugation, to investigate the effects of the light on the enzymatic activity of the mitochondrial ATP synthase. This enzyme, which was illuminated by the light ranging from 400 nm to 700 nm, showed that the specific activity was stimulated at 490 nm for 15 sec. Effects of organic compounds on the mitochondrial ATP synthase were also investigated at the optimum conditions; The activities of this enzyme were increased to 168 percent by the addition of 2,6-dichlo­rophenol indophenol(DCPIP), 224 percent by phenazine methosulfate(PMS), but inhibited 91 per­cent by oligomycin, 14 percent by 2-heptyl-4-hydroxyquinoline-N-oxide(HQNO) and 75 percent by 2,4-dinitrophenol (DNP), respectively. Effects of metal ions of the mitochondrial ATP synthase were investigated at the optimum conditions. The activities of the enzyme were inhibited 35 percent by $Ca^{2+}$, 14 percent by $Co^{2+}$ and 73 percent by $Mn^{2+}$. For effects of anions, the activities of this enzyme were inhibited 80 percent by $CN^{-}$, 52 percent by $SO_{4}\;^{2-}$, 28 percent by each of $CO_{3}\;^{2-}$­and $NO_{3}\;^{-}$, respectively.

• Journal of Plant Biology
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• v.25 no.3
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• pp.135-151
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• 1982

This investigation was carried out to clarify the changes of pigments and soluble protein, and photosystem II activity in the leaves of barley (${SO}_2$-sensitive) and corn (${SO}_2$-resistant) seedlings induced by the ${SO}_2$ fumigation (10, 50ppm). The pH changes of the leaf extract, the content of sulfite and sulfate, the activities of catalase, peroxidase, and polyphenoloxidase were compared in the leaves of barley and corn seedlings induced by ${SO}_2$ fumigation. The results are summarized as follows: An appreciable effect of pH change of leaf extract by ${SO}_2$ fumigation was observed in barley leaves (pH 6.10 to 5.18), but only a small change occurred in corn leaves (pH 5.66 to 5.50). The same pattern of pH changes was recorded when the solution of 0.2N HCl was added to leaf extract, providing lower buffering capacity of the barley leaves than corn leaves. After 2 hours of exposure to 10 ppm ${SO}_2$, the contents of ${SO}^{2-}_3$ and ${SO}^{2-}_4$ were increased in barley leaves, while only ${SO}^{2-}_4$ increased in corn leaves. After fumigation with 10ppm ${SO}_2$ for 2 hours, barley leaves showed significant decreases in activities of catalase, to 17% peroxidase, to 58%, and polyphenoloxidase, to 88%. Corn leaves showed increases in activities of peroxidase, to 136%, and polyphenoloxidase, to 128%. Absorption spectra of pigments obtained from ${SO}_2$-fumigated leaves were gradually decreased with the fumigation time increases, but the decrease was more significant in barley leaves. Fumigation with 50ppm ${SO}_2$ for 2 hours induced the greatest decomposition in carotenoid, followed by chlorophyll a and then chlorophyll b in barley leaves. The ratio of chlorophyll a/b was decreased from 4.1 to 3.6 in barley leaves, but in corn leaves it was maintained almost a constant level(4.9-4.8). The rate of decomposition of chlorophyll and carotenoid in corn leaves was very slow than those in the barley leaves. Fumigation with 50 ppm ${SO}_2$ for 2 hous, decreased the protein content of barley leaves to 59%, and that of corn leaves to 89%, and the extent of decrease in protein content was greater than that of pigments in barley and corn leaves. The rate of DCIP9dichlorophenol indophenol) photoreduction in ${SO}_2$-fumigated leaves was decreased to 18 and 67% in barley and corn leaves, respectively. However, DCIP photoreduction was considerably recovered about 32 and 92% with the addition of DPC(diphenylcarbazide) as an exogenous electron donor in barley and corn leaves, respectively.

• Microbiology and Biotechnology Letters
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• v.29 no.2
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• pp.115-121
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• 2001

Biological Treatment of Wastewater Containing Chlorinated Phenols by a Mixed Culture. Lee, Wan-Seok1, Sang-Wook Jung, Chan-Sun Park, Byung-Dae Yoon, Jang-Eok Kim\ and Hee-Mock Oh*. Environmental Bioresources Laboratory, Korea Research Institute of Biosicence and Biotechnology, Taejon, Korea, 1 Department of Agricultural Chemistry, Kyungpool< National University, Taegu, Korea - The biodegradation of chlorinated phenols in an artificial wastewater was investigated using a mixed culture. The mixed culture was composed of 8 microorganisms isolated from the soil contaminated with various chlorinated phenols. Pseudomonas sp. BM as a main constituent of a mixed culture was Gram-negative, catalase- and oxidase-positive, and rod-shaped, and did not grow at 41°C. It degraded 99% of initial 500 mg!1 of pentachlorophenol (PCP) in the minimal salts medium as a sole source of carbon and energy within 3 days. The degradation efficiency of Pseu.domon.as sp. BM was not affected by the other organic carbon and nitrogen compounds. Pseudomonas sp. BM was able to grow in a broad range of pH 5 - 8, and degrade 2,000 mg/1 PCP. In the experiment with an artificial wastewater containing chlorinated phenols, the degradation efficiency of the mixed culture was the range of 73% (2,4-dichlorophenol) -96% (2-chlorophenol) during an incubation of 7 days. In a continuous culture experiment, the degradation efficiency of mixed culture plus activated sludge was about 2 times higher than that of the control containing only activated sludge. These results indicate that it is possible to apply the mixed culture to other wastewaters containing chlorinated phenols. Key words: Biodegradation, chlorinated phenols, pentachlorophenol, Pseudomonas sp. BM

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.1006-1015
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• 2005

We investigated the effect of hydroxyl radicals on the photolysis of triclosan (TCS), which is a potent broad-spectrum antimicrobial agent. TCS degradation during the initial reaction time of 5 min followed a pseudo-first order kinetic model ai all light intensities at a wavelength of 365 nm and at the low light intensities at a wavelength of 254 nm. The photodegradation rate significantly increased with decreasing wavelength and increasing the UV intensities. The activity of hydroxyl radicals was suppressed when methanol was used as the solvent instead of water. An increase in the photon effect was observed when the UV intensity was higher than $5.77{\times}10^{-5}$ einstein $L^{-1}min^{-1}$ at 254 nm, and lower than $1.56{\times}10^{-4}$ einstein $L^{-1}min^{-1}$ at 365 nm. The quantum yield efficiency for the photolysis of TCS was higher at 365 nm than at 254 nm among the above mentioned UV intensities. Dibenzodichloro-p-dioxin (DCDD) and dibenzo-p-dioxin were detected as intermediates at both UV intensities of $1.37{\times}10^{-4}$ and $1.56{\times}10^{-4}$ einstein $L^{-1}min^{-1}$ at 365 nm. Dichlorophenol and phenol were also detected in all cases. Based on our findings, we presented a possible mechanism of TCS photolysis.