• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.239-240
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• 2017

• Restorative Dentistry and Endodontics
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• v.44 no.1
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• pp.7.1-7.10
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• 2019

Apical periodontitis is a biofilm-mediated infection. The biofilm protects bacteria from host defenses and increase their resistance to intracanal disinfecting protocols. Understanding the virulence of these endodontic microbiota within biofilm is essential for the development of novel therapeutic procedures for intracanal disinfection. Both the disruption of biofilms and the killing of their bacteria are necessary to effectively treat apical periodontitis. Accordingly, a review of endodontic biofilm types, antimicrobial resistance mechanisms, and current and future therapeutic procedures for endodontic biofilm is provided.

• 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.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.1
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• pp.9-17
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• 2016

Disinfectant/oxidation process is a crucial process in water treatment for supplying safe drinking water. Chlorination is still widely used for water treatment area due to its effectiveness on microbial inactivation and economic feasibility. Recently, disinfection concern in marine environment is increasing, for example, movement of hazardous marine organism due to ballast water, marine environmental degradation due to power plant cooling water discharge, and increase of the amount of disinfectant in the offshore plant. It is needed to conduct the assessment of disinfectant behavior and the development of disinfectant prediction model in seawater. The appropriate prediction model for disinfectant behavior is not yet provided. The objective of the study is to develop chlorine decay model in seawater. Various model types were applied to develop the seawater chlorine decay model, such as first order decay model, EPA model, and two-phase model. The model simulation indicated that chlorine decay in seawater is influenced by both organic and inorganic matter in seawater. While inorganic matter has a negative correlation with the chlorine decay, organic matter has a positive correlation with the chlorine decay.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.2
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• pp.215-221
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• 2004

Effluent of wastewater treatment plant is to be disinfected to protect drinking water sources. DOF (Dissolved Ozone Flotation) was developed to meet this purpose. DOF was developed by combining DAF system with ozone. DAF system has good floating power with numerous microbubbles, and ozone has strong oxidation capability. And DOF system has good floating power and strong oxidation capability simultaneously. When DOF was applied to secondary wastewater effluent, color of 11CU in raw water which was secondary effluent was reduced to 1CU by the DOF system. Removal rate of other water quality parameters treated by DOF were also higher than that by DAF, which were proved the strength of oxidation capability of ozone. When ozone concentration of 3.3mg/l were applied in DOF system, general aerobic bacteria were reduced to 5CFU/ml from TNTC (Too many Numbers To Count). With the same ozone concentration, total coliform were not detected at all. These figures are under the numbers of drinking water regulation. These microbes were the target parameters of DOF. It was proved that DOF was very effective in disinfection of wastewater treatment plant effluent as well as in removal of color, turbidity, and T-P.

• Journal of the FoodService Safety
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• v.5 no.1
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• pp.1-4
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• 2024

This study investigated the effect of sodium hypochlorite and ethanol on reducing Staphylococcus aureus on gloves depending on material and food contaminant. S. aureus inoculated onto rubber gloves with various organic substances (pork extract, perilla leaf extract, and 0.2% peptone water) and inoculated rubber gloves were stored in a desiccator at 100% RH and 25℃ for 24 h before treatments with distilled water, ethanol, or sodium hypochlorite. Levels of S. aureus were significantly reduced on both types of rubber gloves when treated with ethanol and sodium hypochlorite. However, sodium hypochlorite treatment resulted in 3.27 log CFU/each of S. aureus in pork extract on nitrile gloves, indicating that the effectiveness of disinfection may vary depending on the glove material and the type of organic substance. The results of this study suggest that ethanol treatment is the most effective disinfection method for S. aureus on rubber gloves, regardless of the material and organic substances.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.699-701
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• 2002

The current study demonstrates the ability of the marine cyanobacterium Oscillatoria willei BDU130511 to disinfect raw sewage. Within a holding time of 3 h under laboratory conditions, the organism drastically reduced in the total bacterial and coliform counts at various pH levels, in both unbuffered and buffered sewage, thereby suggesting a potential role for cyanobacteria in wastewater treatment.

• Journal of Korean society of Dental Hygiene
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• v.14 no.5
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• pp.783-788
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• 2014

Objectives : The purpose of this study was to investigate the effect of non-thermal atmospheric pressure plasma jet(NTAPPJ) on surface properties and Streptococcus mutans disinfection of denture base resin. Methods : Self-cured denture base resin (Jet denture repair resin, Lang dental Mfg, co., USA) was used to make specimen($12mm{\times}2mm$). To observe surface change before and after plasma process, surface roughness and contact angle were measured. For sterilization experiments, the surfaces of specimens were treated with nitrogen and air NTAPPJ for 1 minute after S. mutans was inoculated on the material surfaces. Results : Before plasma process, surface roughness of denture base resin was $0.21{\mu}m{\pm}0.02{\mu}m$. After air and nitrogen NTAPPJ process, surface roughness was $0.19{\mu}m{\pm}0.03{\mu}m$ and $0.18{\mu}m{\pm}0.01{\mu}m$ respectively. There was no significant difference(p>0.05). Contact angle of control group without plasma process was $83.81^{\circ}{\pm}3.14^{\circ}$, while after plasma treatment, contact angles of air NTAPPJ and nitrogen NTAPPJ groups were $63.29^{\circ}{\pm}2.27^{\circ}$ and $46.68^{\circ}{\pm}5.82^{\circ}$ respectively. The result showed a significant decrease in contact angle after plasma process(p<0.05). Compared to the control group 6020.33(CFU/mL) without plasma process, CFU decreased significantly after air NTAPPJ 90.75(CFU/mL) and nitrogen NTAPPJ 80.25(CFU/mL) treatment(p<0.05). Conclusions : It was considered that NTAPPJ can be used for denture disinfection without changing surface properties of materials.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.296-308
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• 2010

The peroxone process overcomes many of the limitations associated with conventional and advanced water treatment systems using chlorine disinfection and ozone oxidation processes. Ozone and hydrogen peroxide generate highly reactive hydroxyl free radical which oxidize various organic compounds and has highly removal efficiency. The key issue to operate peroxone process is developing the method to achieve high process effectiveness when scavengers that inhibit generation of OH radicals or consume OH radicals are co-existing in the process. Also many studies, to minimize inorganic oxidative by-products such as bromate and to reduce disinfection by-products after chlorination behind peroxone process, are needed. And we should consider the excess residual hydrogen peroxide in the water. On-line instruments and control strategies need to be developed to ensure effective and robust operation under conditions of varying load. If problems above mentioned are solved, peroxone process will be applied diversely for water treatment.

• Research in Plant Disease
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• v.26 no.2
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• pp.72-78
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• 2020

Clover cyst nematode, Heterodera trifolii, is one of the most important plant-parasitic nematode on Kimchi-cabbage in highland in Korea. Recently, a demand of soil disinfection machine for fumigants is increasing. This study was conducted to assess the control effects of a newly developed prototype soil disinfection machine to the cyst nematode. Two fumigants, dimethyl disulfide (DMDS) and metam sodium (MNa), were treated using the machine in a field, which was infected with the cyst nematode. After 4 weeks, control effects of fumigants were assessed as eggs hatching rates inside of cysts extracted from the soil, and as a number of females reproduced in roots of Kimchi-cabbage. DMDS (39 l/10 a) suppressed over 99.0% of the eggs hatching rate and the number of females reproduced. On the other hand, MNa (29 l/10 a) controlled the egg hatching rates from minimum 78.3% to maximum 99.4%, and the number of females from 34.7% to 49.3%. The control effects of two fumigants to clover cyst nematode by treated depth were no significant differences statistically. These results showed that DMDS treatment using the soil disinfection machine was expected to have the control effects for the clover cyst nematode.