• Title/Summary/Keyword: Disinfection Process

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Disinfaction effect of bacteria with ozone generation by BDD electrode (붕소가 도핑된 다이아몬드 전극을 이용한 오존발생과 발생된 오존에 의한 미생물 살균 효과)

  • Yoo, Ji-Young;In, Jin-Kyoung;Einaga, Y.;Fujishima, A.;Park, Soo-Gil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.607-610
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    • 2003
  • Ozonic use of sterilization and heat treatment of raw material to extend the conservation period of food recently is increased by hard vegetable or microorganism sterilization purpose of fruit. If ozone can create as is easy comparatively because do air or oxygen by raw material and schedule period passes, there is advantage that do not leave the second contaminant because being gotten restored by oxygen. Also, because the effect is big to decolorization beside disinfection effect about microorganism, deodorization, disjointing of venomousness hazardous substance, food save, Indoor air purge, good hand processing, hydrospace agricultural chemicals processing etc. the use extent is wide. This research ran parallel a sterilization experiment of E.coli colitis germs by ozone that manufacture ozonizer that use doped diamond maund electrode (BDD) by boron and searched special quality electrochemistry enemy of the ozonizer and is created. After cultivate E.coli colitis germs during 37C 1 day is LB ship, after do ozonation, was sterilized more than 90% by ozone as result that examine disinfection effect by substance microscope and could confirm excellency of diamond electrode.

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Evaluation of Filter-Adsorber(F/A) Process for Removal of Disinfection By-products(DBPs) (소독부산물 제어를 위한 실공정 F/A 운영에 관한 고찰)

  • Kim, Seong-Su;Lee, Kyung-Hyuk;Lim, Jae-Lim;Chae, Seon-Ha;Kang, Byeong-Soo;Moon, Pil-Joong;Ahn, Hyo-Won
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.10
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    • pp.1035-1042
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    • 2005
  • Granular Activated Carbon(GAC) is widely used in drinking water treatment. At S and B Water Treatment Plant, GAC is used in place of granular media in conventional rapid filters(GAC Filter-Adsorber) for removal of Disinfection By-products(DBPs). The primary focus of this study is on the performance of existing filter-adsorber, and their operation. It was found that F/A process removed turbidity as effective as sand system. The ratio of Hydrophobic DOM (HPO) and hydrophilic DOM (HPI) fraction in the raw water at S and B WTP was similar. Filter Adsorber presented earlier DOC breakthrough and steady state condition which was contributed by biodegradation during operation period. The removal efficiency of DBPs were used to evaluate the filter performance. The DBPs concentration of F/A treated water was below treatment goal level (THM < $80\;{\mu}g/L$, HAA < $60{\mu}g/L$). The removal efficiency of THM decreased rapidly during operation period. However, HAA were removed steadily regardless of the influent concentration of HAA. These results indicate that the removal of THM depend upon the adsorption mechanism while the removal of HAA depend upon biodegradation as well as adsorption. The decrease of adsorption capacity and characteristic value of GAC may be attributed to the effect of high organic loading, residual free chlorine, coagulants, manganese oxidants and frequently backwashing. This study has confirmed that Filter adsorber process can be considered as effective alternatives for the removal of DBPs, especially HAA.

Study on the Characteristics of Dielectric Barrier Discharging System and Usability as a Disinfectant (2계면 플라즈마 방전시스템(DBD System)의 특징 및 소독제로서 방전수의 사용가능성에 대한 연구)

  • Ryu, Seungmin;Park, Heekyung;Lee, Bongju
    • Journal of Korean Society of Water and Wastewater
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    • v.18 no.4
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    • pp.529-536
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    • 2004
  • Innovated technique to inactivate microorganisms has been developed. This technique uses plasma discharge in 2-phase (Air-Water). Dielectric Barrier (two phase) Discharging system is able to produce new oxidants for microorganisms. Products from discharging are $HNO_2$, $NO_2{^-}$, $HNO_3$, $NO_3{^-}$ and ozone but many other radicals can be generated as well. DBD water has low concentration of ozone (about 0.5mg/L), $NO_2{^-}$, $NO_3{^-}$ (about 10mg-N/L, 20mg-N/L respectively) and lots of $H^+$. These products play an important role in oxidation. Oxidation power by KI titration methods is approximately equivalent to $50mg-O_3/L$. Surprisingly stored DBD water could oxidize KI and maintain stable pH (about pH3) even after several days. Stored DBD water for 5 days has also more than 4log disinfection power to E. coli. However, DBD water cannot be used for drinking water directly due to it's toxicity. Additional process to neutralize pH and decrease toxicity must be applied.

Analysis of Haloacetonitriles in Drinking Water Using Headspace-SPME Technique with GC-MS (Handspace Solid Phase Microextraction 방법에 의한 HANs 분석에 관한 연구)

  • Cho, Deok-Hee
    • Journal of Korean Society of Water and Wastewater
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    • v.18 no.5
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    • pp.628-637
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    • 2004
  • In many drinking water treatment plants, chlorination process is one of the main techniques used for the disinfection of water. This disinfecting treatment leads to the formation of disinfection by-products (DBPs) such as haloacetonitriles (HANs), trihalomethanes (THMs), haloacetic acids (HAAs). In this study, headspace-solid phase microextraction (HS- SPME) technique was applied for the analysis of HANs in drinking water. The effects of experimental parameters such as selection of SPME fiber, the addition of salts, magnetic stirring, extraction temperature, extraction time and desorption time on the analysis were investigated. Analytical parameters such as linearity, repeatability and detection limits were also evaluated. The $50/30{\mu}m$-divinylbenzene/carboxen/polydimethylsiloxane fiber, extraction time of 30 minutes, extraction temperature of $20^{\circ}C$ and desorption time of 1 minute at $260^{\circ}C$ were the optimal experimental conditions for the analysis of HANs. The correlation coefficients ($r^2$) for HANs was 0.9979~0.9991, respectively. The relative standard deviations (%RSD) for HANs was 2.3~7.6%, respectively. Detection limits (LDs) for HANs was $0.01{\sim}0.5{\mu}g/L$, respectively.

Study on performance improved design of pressure-type ozone contactor in multistorey water treatment plant by CFD (CFD에 의한 수직형 정수처리 실증시설 내 압력식 오존접촉조 성능개선에 관한 연구)

  • Choi, Jong-Woong;Kim, Seong-Su;Kim, Jeong-Hyun;Kim, Kwanyeop
    • Journal of Korean Society of Water and Wastewater
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    • v.28 no.4
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    • pp.431-440
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    • 2014
  • The ozonation process has been widely used for drinking water disinfection around the world. Recently, the pressurized ozone contactor, in which the side stream typed ozone injection method is installed, has been applied to water treatment system. In this study, numerical calculations were conducted to compare prototype and screw-type ozone contactors based on hydraulic effectiveness in more details. The prototype ozone contactor was already installed and operated in domestic water treatment plant, and the screw-type is the suggested one for improving ozone contact efficiency installing the screw plate to the prototype. Screw turn numbers of screw plate were changed as 3, 5, 7 and 9, respectively for numerical simulation. The CT(concentration of disinfectant in mg/L times time in minutes) value was considered as one of the options for evaluating disinfection ability. From the results, it could be concluded that the performance of the screw-type is higher than that of the protype contactor by controlling the variable T as the tracer time. Also, Morill index of the screw-type(turn numbers = 5 ) appeared to be lower than the other.

Adequacy of Reprocessing Gastrointestinal Endoscopes in Korea Hospitals (국내 병원 소화기내시경 재처리과정의 적절성)

  • Kim, YoungOk;Jeong, Jae Sim
    • Journal of Korean Biological Nursing Science
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    • v.18 no.4
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    • pp.288-295
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    • 2016
  • Background: This study was conducted in order to survey the current state of cleaning, disinfection, rinsing, drying, and storage of gastrointestinal endoscopes. Methods: Eighty hospitals were selected through convenient sampling. Self-reported questionnaire was distributed from September 14 to October 10 in 2015. Results: The response rate was 67.5% (54/80). In 88.9% of the hospitals, reprocessing was performed in a cleaning space separated from the laboratory and 88.9% used an enzymatic cleaner. Disinfectants used were ortho-phthalaldehyde in 63.0%, and paracetic acid in 33.3%. Eighty seven percent of the hospitals used test strips in order to test the effective concentration of disinfectant and in 61.1%, drying was done through passing air and over 70% alcohol. Microbial culture for the quality control of gastrointestinal endoscopes was performed in 77.8%. In the comparison of the adequacy of gastrointestinal endoscope reprocessing, it was observed that gastrointestinal endoscopes were reprocessed more adequately in larger and tertiary care hospitals. Conclusion: Gastrointestinal endoscopes were reprocessed in similar manners, but there were differences in the detailed process. It is still necessary to segment reprocessing into stages, to prepare standardized guidelines, and to monitor compliance with the guidelines.

A Study of Potable Water Disinfection for National Health (수돗물 살균제가 국민보건에 미치는 영향에 관한 연구)

  • Shin Soo Ok
    • Journal of Korean Public Health Nursing
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    • v.10 no.1
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    • pp.31-38
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    • 1996
  • Disinfection is a very important process in water plant on account of our surface water usage. Particularly. the rainfall of Korea is concentrated in summer time. it is almost carried away to ocean before our utilization as water resource. To overcome the unbalance of water resource, artificial dams and reservoirs are constructed. According to such storage of water to aggravate water pollution and make the increase of water cleaning chemicals. Chlorine, as a main traditional chemical for water treatment. is focused on account of THMS formation in recent days. In this paper. the data of a water plant located in Seoul is adopted as the foundation of water quality analysis and introduce the substitute chemicals to supplement the harmful formation. additionally. Conclusions are summarized as follows: 1. The water quality of water resource is the worst in summer time and the supply of cleaning chemical is inevitably increased on account of general bacteria increase. 2. Chlorine, as a main chemical for water cleaning, formed the cancer-causing organic THMS with water molecules. 3. One of substitute chemical. chlorine dioxids suppress the formation of THMS comparing with the case of chlorine only. Therefore. the continuous research of substitute chemicals should be activated. 4. As the supply of disinfected clean water concerned with the citizen sanitary, the cultivation of professionals and academic conference must be needed on the basis of nation

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Preliminary Standard Procedure for Face Lift and Correction of Nasolabial Fold using Thread-Embedding (Maeseon) of Korean Medicine (안면거상 및 팔자주름 개선을 위한 매선 시술 표준안 제안)

  • LeeL, Jae-Chul;Park, Sun-Hee;Yoon, Jeong-Ho;Kim, Jung-Won;Lim, Chang-Gyu
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.26 no.4
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    • pp.43-50
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    • 2013
  • Objectives : This study aims to suggest preliminary standard procedure for face lift and correction of nasolabial folds using thread-embedding (Maeseon) of Korean medicine(KM). Methods : Three KM practitioners of facial correction and rejuvenation who have over hundred case of practice participated in establishment of standard procedure. Standard procedure contains preprocessing, main procedure for correction, and solution of side effects. Results : Standard procedure is comprised of twelve processes with preprocessing and postprocessing. Preprocessing has position, disinfection, and anesthesia. Main process consists of overall structure correction, face lifting, nasolabial folds correction, and mesh making on cheek. Postprocess covers disinfection, edema prevention. Conclusions : To our knowledge, this is the first work to suggest standard procedure of facial rejuvenation using Maeseon. It would contribute to standardized practice in clinical fields and future study of revealing Maeseon's effectiveness.

Combined Non-Thermal Microbial Inactivation Techniques to Enhance the Effectiveness of Starter Cultures for Kimchi Fermentation

  • Su-Ji Kim;Sanghyun Ha;Yun-Mi Dang;Ji Yoon Chang;So Yeong Mun;Ji-Hyoung Ha
    • Journal of Microbiology and Biotechnology
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    • v.34 no.3
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    • pp.622-633
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    • 2024
  • For quality standardization, the application of functional lactic acid bacteria (LAB) as starter cultures for food fermentation is a well-known method in the fermented food industry. This study assessed the effect of adding a non-thermally microbial inactivated starter culture to kimchi, a traditional Korean food, in standardizing its quality. In this study, pretreatment based on sterilization processes, namely, slightly acidic electrolyzed water (SAEW) disinfection and ultraviolet C light-emitting diode (UVC-LED) of raw and subsidiary kimchi materials were used to reduce the initial microorganisms in them, thereby increasing the efficiency and value of the kimchi LAB starter during fermentation. Pretreatment sterilization effectively suppressed microorganisms that threatened the sanitary value and quality of kimchi. In addition, pretreatment based on sterilization effectively reduced the number of initial microbial colonies in kimchi, creating an environment in which kimchi LAB starters could settle or dominate, compared to non-sterilized kimchi. These differences in the initial microbial composition following the sterilization process and the addition of kimchi LAB starters led to differences in the metabolites that positively affect the taste and flavor of kimchi. The combined processing technology used in our study, that is, pre-sterilization and LAB addition, may be a powerful approach for kimchi quality standardization.

AGAR-ALGINATE COMBINED IMPRESSION TECHNIQUE AND DIMENSIONAL CHANGE RESULTING FROM IDOPHOR DISINFECTION (아기-알지네이트 연합 인상체의 보관방법 및 idophor 침적소독에 의한 체적 변화에 관한 연구)

  • Oh Nam-Sik;Seo Joung-Min;Kim Sun-Hee;Youn Young-Ah;Shim Joon-Sung
    • The Journal of Korean Academy of Prosthodontics
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    • v.42 no.1
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    • pp.21-29
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    • 2004
  • Statement of problem : Because dental impression can be a cross-infection source, disinfection, such as immersion disinfection is nessecary. However, the disinfection process may change the volume of the impression cast. Purpose : The purpose of this study is to find out the effects on dimensional change of different storage times and methods, of agar-alginate impression when immersed in a 5% idophor disinfectant. Material and Methods : An agar-alginate impression was made from a mandible model and then was disinfected and stored according the experimental conditions and a stone model was produced. Measurements were taken between reference points on the original mandible model and they were compared to measurements taken between reference points on the stone model. The study was divided into 4 groups. In group 1, the impression was stored in a 100% humidor for 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 12 hours and 24 hours and stone models were made at each time. In group 2, the impression was immersed in 5% idophor disinfectant and then stored in a 100% humidor for the same length of times as group 1, and stone models were made at each time. In group 3, the impression was stored in extend-A-pourR, a special storage solution for 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 12 hours, 24 hours 3 days, and 7 days and stone models were made at each time. In group 4, the impression was immersed in 5% idophor disinfectant and then stored in stored in extend-A-pourR, a special storage solution for the same length of times as group 3, and stone models were made at each time. 5 impressions and stone models were made at each time to make a total of 180. The Student-t test (P < .05) was used to do a statistical analysis of the measurements of the mandible model and stone models. The repeated-measure 2-way analysis of variance (P < .05) was used to do a statistical analysis of the difference in the 4 groups. Results : The percent liner dimensional change was from $0.25{\pm}0.03%$ (group 1, 30 minutes) to $0.34{\pm}0.06%$ (group 4, 7 days). No significant change was noticed between the 4 groups. Conclusion : According to the above study, in both methods, least dimensional change was recorded when the storage times were short and in both methods, immersion in 5% idophor disinfectant did not effect dimensional change in the agar-alginate impression.