UV-TiO_2 광촉매 반응기를 이용한 미생물의 살균효과

김시욱,이정섭,정혜광,박열,윤성명,유진철,이범규,이인화,박진열 조선대학교 환경연구소 1998 環境硏究 Vol.14 No.1

UV-TiO_2 반응기를 이용하여 Escherichia coli와 Aspergillus oryzae var. oryzae의 살균효과를 측정하였다. 254㎚에서 최대 14 watt의 자외선 방출량을 내는 램프를 원형 Pyrex유리관 중앙에 설치하였고 TiO_2는 석영관에 박막증착(Thin Film Coating)된 형태와 슬러리 형태로 나누어 회분식으로 살균정도를 측정하였다. E. coli에 대한 살균력은 1.7×10^7 cells/㎖에 대해 5분간 자외선 조사를 하였을 경우 2.0×10^2 cells/㎖으로 감소하였고, 자외선 조사와 함께 슬러리 형태의 TiO_2를 첨가하였을 경우에는 3.4×10 cells/㎖으로, 자외선 조사와 함께 TiO_2가 석영관에 박막증착된 경우에는 7.6×10^2 cells/㎖으로 감소하였다. 한편 위와 같은 조건에 유리관 하부에서 기포를 주입수 11분 동안 자외선을 조사시킨 경우에는 1.3×10^2 cells/㎖으로, 자외선 조사와 함께 슬러리 형태의 TiO_2를 첨가하였을 경우에는 1×102 cells/㎖으로, 자외선 조사와 함께 TiO_2가 박막증착된 경우에는 7.9×10 cells/㎖을 나타내었다. 결국 UV-TiO_2 반응기에 사용되는 TiO_2가 슬러리 형태일 때 최대 살균효과를 나타내었으나 기포가 첨가되었을때는 오히려 살균에 장애를 받는 것으로 나타난 반면 석영관에 박막증착된 경우에는 기포가 첨가되는 것이 살균에 효과적인 것으로 관찰되었다. The killing effect of UV-TiO_2 photocatalytic system on the Escherichia coli DH5-α and Aspergillus oryzae var. oryzae (KCTC 6095) was studied. The UV lamp which emits maximum 14 watts at 254 ㎚ was set on the center of pyrex round glass tube. Two types of TiO_2, one of which is slurry and another which is thin film coated form, were used to determine the killing effect. When UV was irradiated to 1.7×10^5 cells/㎖ of E. coli for 11 min, the living cell number decreased to 4.0×10^0 cells/㎖. The effect of UV system together with slurried TiO_2 was less than 1 cells/㎖, whereas that of UV-coated TiO_2 system decreased to 7.1×10^3 cells/㎖. To study the effect of bubble on the killing of microorganisms, air was bubbled to the bottom of glass tube. When 1.7×10^5 cells/㎖ were exposed to UV for 11 min in combination with air bubble, the living cell number decreased to 1.3×10^2 cells/㎖. In the same condition except the addition of slurried TiO_2, the living cells were 1×10^2 cells/㎖. However, more cells could be killed by the system which consists of UV, coated TiO_2, and air bubble (7.9×10^1 cells/㎖). From these results, it was found that UV-slurried system is the most effective one, but its killing effect is not stimulated by air bubble. However, bubbling was very effective in the UV-coated TiO_2 system.

UV-TiO₂광촉매 반응기를 이용한 미생물의 살균효과

김시욱,이정섭,정해광,박열,윤성명,유진철,이범규,이인화,박진열 조선대학교 환경공해연구소 1998 環境公害硏究 Vol.14 No.-

UV-TiO_(2) 반응기를 이용하여 Escherichia coli와 Aspergillus oryzae var. oryzae의 살균효과를 측정하였다. 254 ㎚에서 최대 14 watt의 자외선 방출량을 내는 램프를 원형 Pyrex유리관 중앙에 설치하였고 TiO_(2)는 석영관에 박막증착(Thin Film Coating)된 형태와 슬러리 형태로 나누어 회분식으로 살균정도를 측정하였다. E. coli에 대한 살균력은 1.7× 10^(7) cells/㎖에 대해 5분간 자외선 조사를 하였을 경우 2.0× 10^(2) cells/㎖으로 감소하였고, 자외선 조사와 함께 슬러리 형태의 TiO_(2)를 첨가하였을 경우에는 3.4× 10 cells/㎖으로, 자외선 조사와 함께 TiO_(2)가 석영관에 박막증착된 경우에는 7.6× 10^(2) cells/㎖으로 감소하였다. 한편 위와 같은 조건에 유리관 하부에서 기포를 주입후 11분 동안 자외선을 조사시킨 경우에는 1.3× 10^(2) cells/㎖으로, 자외선 조사와 함께 슬러리 형태의 TiO_(2)를 첨가하였을 경우에는 1× 100 cells/㎖으로, 자외선 조사와 함께 TiO_(2)가 박막증착된 경우에는 7.9× 10 cells/㎖을 나타내었다. 결국 UV-TiO_(2) 반응기에 사용되는 TiO_(2)가 슬러리 형태일 때 최대 살균효과를 나타내었으나 기포가 첨가되었을때는 오히려 살균에 장애를 받는 것으로 나타난 반면 석영관에 박막증착된 경우에는 기포가 첨가되는 것이 살균에 효과적인 것으로 관찰되었다. The killing effect of UV-TiO_(2) photocatalytic system on the Escherichia coli DH5-慣 and Aspergillus oryzae var. oryzae (KCTC 6095) was studied. The UV lamp which emits maximum 14 watts at 254 nm was set on the center of pyrex round glass tube. Two types of TiO_(2), one of which is slurry and another which is thin film coated form, were used to determine the killing effect. When UV was irradiated to 1.7 * 10^(5) cells/??of E. coli for 11 min, the living cell number decreased to 4.0 * 1.0^(0) cells/?? The effect of UV system together with slurried TiO_(2) was less than 1 cells/?? whereas that of UV-coated TiO_(2) system decreased to 7.1 * 10^(3) cells/?? To study the effect of bubble on the killing of microorganisms, air was bubbled to the bottom of glass tube. When 1.7 * 10^(5) cells/??were exposed to UV for 11 min in combination with air bubble, the living cell number decreased to 1.3 x 10^(2) cells/?? In the same condition except the addition of slurried TiO_(2), the living cells were 1 * 10^(2) cells/?? However, more cells could be killed by the system which consists of UV, coated TiO_(2), and air bubble (7.9 * 10^(1) cells/??. From these results, it was found that UV-slurried system is the most effective one, but its killing effect is not stimulated by air bubble. However, bubbling was very effective in the UV-coated TiO_(2) system.

에너지 절약과 환경보전을 위한 초등교육 방안 연구

윤병욱,김시욱 조선대학교 환경공해연구소 1999 環境公害硏究 Vol.15 No.-

This study was performed to improve the methods for elementary education to save energy and preserve the environment. To obtain lots of data, domestic and foreign references and articles which are related to the education for the environmental preservation were analyzed. At the same time, the curriculum and the present situation of the elementary education were also studied. From these studies, several suggestions were proposed. First, a number of stories and animations relating to save energy and preserve the environment should be contained in the curriculum. The curriculums containing the above contents were only Natural Science, Social Studies, and Practical Course. However, the composition was very simple and was not systematic. Second, lots of references and textbooks were required to teach and study the environmental situation. The elementary schools only had several student textbooks, and the teachers also had several video tapes recorded from television. Third, several practical education should be reinforced to make a new life style for saving energy. Only a limited number of posters and television programs explaining environmental problems were given to the students, and practical motivations to make a real life pattern were not prepared so far. Fourth, the environmental education in the school should be closely related to home education. To obtain maximum effect, the home education was absolutely required because home is the best place to practice a good life style to save energy and preserve the environment.

처분장근처에서 침식에의한 Sr 화학종의 평형

조윤정,김성현,이인화,김시욱,고문주,박성규,이범규 조선대학교 환경연구소 2000 環境硏究 Vol.16 No.1

Leaching and adsorption equilibria of Sr Chemical Species from the near field of a repository has been studied in solidified cement with Fe and oxidized Fe. The absorption percent, Ads %, and distribution coefficient, K_d were calculated using equilibrium concentration to predict the extent of leaching and adsorption. In the mixed aqueous solutions the Ads % increase as Cement(C)/Water(W) ratios increase and K_d was decreased for Sr. These behaviors were discussed by adsorption and equilibrium of spiked ions. Oxides Fe promoted adsorption of spiked ions, but pure Fe had no effect. E_h values were also estimated and discussed to elucidate oxidation-reduction environment of experimental system.

전남지역에 발병되는 가금티푸스의 역학적 특성에 관한 연구

박숙희,김중곤,김시욱 조선대학교 환경연구소 2001 環境硏究 Vol.17 No.2

The anato-pathological histopathological and microbiologic examinations were conducted with the chickens in 310 poultry farms in Jeollanamdo that entrusted Jeollanamdo Livestock Research Institute to diagnose fowl diseases from September 1998 to August 2001. Microbiologic isolation/identification, biological test as well as the antibiotic susceptibility test were carried out to the 58 strains of S. gallimarum isolated from the chickens in 58 poultry farms which were diagnosed to have fowl typhoid, epidemiological characteristics such as breeding region of the farms with incidences of fowl disease: occurring month, breed, and weeks of age: and the monthly change of average temperature, etc. were examined. The results were as follows ; Fowl typhoid were diagnosed in 58(18.7%) places among the 310 poultry farms where fowl diseases occurred. The incidence rate was the most frequently occurred in May∼August. The gross lesions of the chickens in the total of 58 farms infected with fowl typhoid were lever swelling and liver necrotic foci, spleen swelling, bronze liver, proventricular haemorrhage, heart nodular lesions. In the biochemical tests, all the 58 isolated strains were positive in methyl red; were negative in urea, H2S and indole productive test ; and had non motility. In the fermentive assay, they showed positive response to glucose, maltose, mannitol, dulcitol, and cellobiose; were negative to lactose, sucrose, and adonitol; glucose were without acid; and turned out to be positive in ducitol resolving power. The incidence rates according to the Jeollanamdo area were compared, 43(71%) of fowl typhoid broke out in the Northwest area; 12(23%) in the South area; 3(6%) in the Eastern area. The rate was higher in the broilers 39(67%) than in the layer 19(33%). Fowl typhoid occurred most frequently in the 2 weeks(38.4%), 5 weeks(25.6%) of age in the broilers, and in the initial period of breeding from above 20 to 30 weeks 11(58%) of age in the layer. In the antimicrobial drugs susceptiblity test to the isolated 58 strains of fowl typhoid, the antibiotics that showed high susceptibility above 80% were six kinds - Trimethoprim/ Sulfamethoxazole(93%), Cefoxitin(88%), Gentamicin(86%), Chloramphenicol(84%), Ampicillin(83%), Neomycine(81%) -, and those with 70∼50% of susceptibility were four kinds - Kanamycin(74%), Cephalothin(71%), Norfloxacin(67%), Tetracycline(55%). The other four kinds, Colistin(38%), Streptomycin(29%), Nalidixic acid(5%), Novobiocin(0%), showed very low susceptibility of below 50%.

토양 미생물인 Streptomyces tubercidicus에서 분리한 GTPcyclohydrolase Ⅰ 저해제

한지만,김시욱,이인화,박열,정혜광,윤성명,유진철 조선대학교 약학연구소 1998 藥學硏究誌 Vol.19 No.1

GTP cyclohydrolase I (EC 3.5.4.16) catalyzes the conversion of GTP to D-erythro-7,8-dihydroneopterin triphosphates and formic acid. and thus performs the first committing step in the biosynthesis of the pteridine moiety of folk acid in microorganisms and of tetrahydrobiopterin in higher animals. GTP cyclohydrolase I isolated from Streptomyces tubercidicus was inhibited by DL-6-methyl-5,6,7,8-tetrahydropterin and xanthopterin, and was not inhibited by tetrahydrofolic acid, pterin, pterin-6-carboxylic acid, biopterin, neopterin, ribofravin. These results suggest that bacterial GTP cyclohydrolase I may be regulated by its metaboilic end product.

전남지역에 발병되는 가금티푸스의 역학적 특성에 관한 연구

박숙희,김중곤,김시욱 조선대학교 환경공해연구소 2001 環境公害硏究 Vol.17 No.2

生態指向的 環境敎育을 위한 中等學校 環境敎科書 分析

이인화,김시욱,조은주 조선대학교 환경공해연구소 1999 環境公害硏究 Vol.15 No.2

A analysis of environmental text book for secondary education has been conducted toward ecocentric education, eventually to provide a creative and open-minded teaching. Based on the result of analysis, the following problems suggested, the content of the text book has too wide scope for the intelligence of the middle school student. Furthermore, the text book is mainly focused on demonstrating the surface of the phenomena as an existing public nuisance in society, however, the present book deals with the superficial aspects of environmental problems and makes the problems considered as simple. From the analysis study of present environmental text book several suggestion has been conducted as follows : First, additional education units are needed for judgement traning toward emotional approach to law of nature and environmental phenomena. Second, it is necessary for teachers to develop various teaching methods in an environmental class.

처분장근처에서 침식에 의한 Sr 화학종의 평형

조윤정,김성현,이인화,김시욱,고문주,박성규,이범규 조선대학교 환경공해연구소 2000 環境公害硏究 Vol.16 No.1

Leaching and adsorption equilibria of Sr Chemical Species from the near field of a repository has been studied in solidified cement with Fe and oxidized Fe. The absorption percent, Ads %, and distribution coefficient, K_(d) were calculated using equilibrium concentration to predict the extent of leaching and adsorption. In the mixed aqueous solutions the Ads % increase as Cement(C)/Water(W) ratios increase and K_(d) was decreased for Sr. These behaviors were discussed by adsorption and equilibrium of spiked ions. Oxides Fe promoted the adsorption of spiked ions, but pure Fe had no effect. E_(h) values were also estimated and discussed to elucidate oxidation-reduction environment of experimental system.

에너지 절약과 환경보전을 위한 초등교육 방안 연구

윤병욱,김시욱 조선대학교 환경연구소 1999 環境硏究 Vol.15 No.1

This study was performed to improve the methods for elementary education to save energy and preserve the environment. To obtain lots of data, domestic and foreign references and articles which are related to the education for the environmental preservation were analyzed. At the same time, the curriculum and the present situation of the elementary education were also studied. From these studies, several suggestions were proposed. First, a number of stories and animations relating to save energy and preserve the environment should be contained in the curriculum. The curriculums containing the above contents were only Natural Science, Social Studies, and Practical Course. However, the composition was very simple and was not systematic. Second, lots of references and textbooks were required to teach and study the environmental situation. The elementary schools only had several student textbooks, and the teachers also had several video tapes recorded from television. Third, several practical education should be reinforced to make a new life style for saving energy. Only a limited number of posters and television programs explaining environmental problems were given to the students, and practical motivations to make a real life pattern were not prepared so far. Fourth, the environmental education in the school should be closely related to home education. To obtain maximum effect, the home education was absolutely required because home is the best place to practice a good life style to save energy and preserve the environment.