• 한국물환경학회지
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• 제20권2호
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• pp.170-175
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• 2004

The purpose of this study was to monitor bacteria present in raw water and to investigate the effect of ozone, UV and combined ozone/UV processes for inactivating bacteria. Both polymerase chain reaction (PCR)-fragment length polymorphic analysis (PRA) and PCR-sequence analysis (PSA) were applied for the simultaneous analysis of numerous bacteria species present in each tested water, such as drinking water (DRW), drinking water source (DRWS) and sewage effluent water (SEW). According to the result, the number of detected bacteria species was zero in DRW, 58 in DRWS and 13 in SEW. After treatment of the each process, the ozone/UV process was the most successful for inactivating almost all bacteria. However, it was found that Flavobacterium sp., Pseudomonas sp. and Beta proteobacterium sp. had strong resistant to all tested processes, requiring further detailed study.

• 한국식품저장유통학회지
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• 제17권3호
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• pp.425-429
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• 2010

햄버거 패티에 L. monocytogenes cocktail을 인위적으로 접종한 후 UV-C 조사 처리에 따른 저장 중 미생물 수 변화를 조사하였다. 햄버거 패티에 접종된 L. monocytogenes의 초기 균수가 6-7 log CFU/mL가 되게 하였고, 사용된 UV-C 조사선량은 1, 5, 10 kJ/$m^2$이었으며 조사된 시료는 $4{\pm}1^{\circ}C$에서 7일 동안 저장하였다. UV-C 조사는 L. monocytogenes 수에 있어서 조사선량이 증가할수록 유의적으로(p<0.05) 감소하는 것을 나타냈다. 특히, 10 kJ/$m^2$ 처리구는 대조구와 비교하여 L. monocytogenes 수를 2.03 log CFU/g까지 감소시켰다. 햄버거 패티의 UV-C 처리에 의한 품질 변화 척도로써 측정한 TBARS 값은 저장 중 UV-C 처리 여부와 관계없이 증가하였다. 따라서 본 연구결과, UV-C 조사 처리는 햄버거 패티의 저장 중 품질 변화에 큰 영향을 주지 않으면서 미생물학적 안전성 확보에 효과적인 것으로 판단된다.

• 한국양식학회지
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• 제12권3호
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• pp.167-173
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• 1999

Blocking the 1st mitotic cleavage was performed in mud loach (Misgurmus mizolepis) using UV-irradiated cyprinid loach (M. anguillicaudatus) sperm and ternal shocks Optimum UV range for inactivation of cyprinid loach sperm and thermal shocks. Optimum UV range for inactivation of cyprinid loach sperm was between 3,150 to 4,050 ergs/m$m^2$. Heat shock treatment ($41^{\circ}C$ for 3mins) with various treatment initiation times ranged from 22 to 50 min post insemination resulted wide range of success for induced gynogenesis. Best result was obtained when haploid egges were shocked at 28 min after insemination (corresponding to metaphase division of the 1st cleavage); 26% of total eggs inseminated were viable diploid gynogens. The hatching success and early survival of the both meiotic and mitotic gynogenetic groups were significantly lower than those of control crosses (P<0.05). Maternal origin of induced gynogenetic mud loach was verified by multi-locus DNA fingerprinting.

• 한국환경보건학회지
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• 제39권3호
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• pp.289-299
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• 2013

Objectives: For the field application of the dielectric barrier discharge plasma reactor, scale-up of the plasma reactor is needed. This study investigated the possibility of inactivation of microorganisms in sewage using pilot multi-plasma reactor. We also considered the possibility of degradation of total organic carbon (TOC) and nonbiodegradable matter ($UV_{254}$) in sewage. Methods: The pilot plasma reactor consists of plasma reactor with three plasma modules (discharge electrode and quartz dielectric tube), liquid-gas mixer, high voltage transformers, gas supply equipment and a liquid circulation system. In order to determine the operating conditions of the pilot plasma reactor, we performed experiments on the operation parameters such as gas and liquid flow rate and electric discharge voltage. Results: The experimental results showed that optimum operation conditions for the pilot plasma reactor in batch experiments were 1 L/min air flow rate), 4 L/min liquid circulation rate, and 13 kV electric discharge voltage, respectively. The main operation factor of the pilot plasma process was the high voltage. In continuous operation of the air plasma process, residual microorganisms, $UV_{254}$ absorbance and TOC removal rate at optimal condition of 13 kV were $10^{2.24}$ CFU/mL, 56.5% and 8.6%, respectively, while in oxygen plasma process at 10 kV, residual microorganisms, $UV_{254}$ absorbance and TOC removal rate at optimal conditions were $10^{1.0}$ CFU/mL, 73.3% and 24.4%, respectively. Electric power was increased exponentially with the increase in high voltage ($R^2$ = 0.9964). Electric power = $0.0492{\times}\exp^{(0.6027{\times}lectric\;discharge\;voltage)}$ Conclusions: Inactivation of microorganisms in sewage effluent using the pilot plasma process was done. The performance of oxygen plasma process was superior to air plasma process. The power consumption of oxygen plasma process was less than that of air plasma process. However, it was considered that the final evaluation of air and oxygen plasma must be evaluated by considering low power consumption, high process performance, operating costs and facility expenses of an oxygen generator.

• 한국물환경학회지
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• 제25권5호
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• pp.667-673
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• 2009

This study has carried out to evaluate the performance of single (electrolysis, UV and ultrasonic process) and complex process (Electrolysis+UV, UV+Ultrasonic and Electrolysis+Ultrasonic) for the purpose of disinfection of Escherichia coli in water. The order of disinfection performance for E. coli in single process lie in: Electrolysis ${\fallingdotseq}$ UV >> ultrasonic process. OH radical was not produced in single disinfection process. Among the three kinds of complex process, disinfection performance of the Electrolysis+UV was higher than that of the other process (UV+Ultrasonic and Electrolysis+Ultrasonic). It demonstrated a synergetic effect between the UV and electrolysis. When the use of $Na_2SO_4$ as electrolyte instead of NaCl, current increase or more reaction time was needed for the complete disinfection. The disinfection performance of pre-electrolysis (20 W, 30sec) and post-UV (10 W, 30 sec) was higher than that of the simultaneous electrolysis+UV process at same electric power (30 W, 30 second).

• 대한환경공학회지
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• 제32권7호
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• pp.722-729
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• 2010

하수 재이용에 대한 관심이 급부상하고 있는 가운데, 재이용수의 미량물질 등에 의한 화학적 리스크와 더불어 미생물학적 안전성에 대한 고려가 요구되고 있다. 본 연구에서는 벤치스케일의 연속식 실험장치를 이용, 미량물질 중 최근 주목을 받고 있는 의약품류를 대상으로, UV처리공정의 의약품류 제거효과 및 미생물학적 안전성의 달성 가능성을 고찰하였다. 시험수로 이용한 하수 2차 처리수중에서는 항생물질, 해열진통제 등 38종의 의약품류가 수 ng/L에서 수백 ng/L의 범위로 검출되었으며, 이를 대상으로 하여 UV 및 UV/$H_2O_2$ 처리실험을 행한 결과, UV 단독처리에 의한 의약품류의 효과적인 제거에는 상당량의 UV조사량이 필요할 것으로 예상되었다. 반면, UV/$H_2O_2$ 공정의 경우 $H_2O_2$의 첨가농도를 약 1 mg/L에서 6mg/L까지 증가시킴에 따라 각 의약품류의 제거율은 점점 증가하는 것으로 나타났다. 한편, $923\;mJ/cm^2$의 UV 조사량과 6.2 mg/L의 $H_2O_2$를 병용한 UV/$H_2O_2$ 처리는 Naproxen(>89%)외 모든 의약품류의 농도를 90% 이상까지 감소시킬 수 있었다. 또한 이 운전조건은 현행 하수처리장 유출수중의 대장균군에 대한 규제농도($3,000/cm^3$)를 기준으로 하였을 때, 4~5 log의 불활성화를 달성할 수 있을 것으로 예상되어, 하수 재이용에 요구되는 California Title 22의 criteria를 만족시킬 수 있을 것으로 판단되었다.

• 한국유체기계학회 논문집
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• 제17권6호
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• pp.44-51
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• 2014

The disinfection method using UV has emerged as photodissociation in water disinfection. In order to predict performance for UV disinfection, CFD analysis was performed due to saving cost. Most CFD studies of UV reactor have used particle tracking method. However it demands additional analysis time, computing resource and phase besides working fluid. In this paper, pathogenic microorganisms' route is assumed to streamline of fluid to save computing time. the computational results are in good agreement with experimental results. The results of streamline method are compared with the particle tracking method. In conclusion, the effectiveness of streamline method for UV disinfection are confirmed.

• KSBB Journal
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• 제25권1호
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• pp.33-40
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• 2010

Conventional disinfectants and disinfection method are expensive, hazardous and often require long periods of exposure. Recently, there is growing interest in complex disinfection process as a disinfection technique in medical instruments such as endoscope, hand piece bur to improve the disinfection efficiency and conveniency. The aim of this study was to evaluate the performance of a new complex process for the purpose of disinfection of Escherichia coli in water. Three single process (electrolysis, UV and ultrasonic process) was combined dual and triple disinfection process. The order of disinfection performance for E. coli in dual process lie in: Electrolysis + UV > Electrolysis + Ultrasonic > UV + Ultrasonic process. Disinfection efficiency of E. coli and degradation of N, N-Dimethyl-4-nitrosoaniline (RNO, indicating material of OH radical formation) of dual process was higher than that of the triple process (Electrolysis + UV + Ultrasonic process). In electrolysis + UV process, disinfection tendency was well agreed with RNO degradation tendency.

• 상하수도학회지
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• 제35권6호
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• pp.489-496
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• 2021

Water disinfection using UV-LED(Light emitting diode) has many advantages, such as smaller footprint and power consumption as well as relatively longer lifespan than those of conventional mercury-UV lamps. Moreover, UV-LED disinfection is considered an environmentally benign process due to its mercury-free nature. In this study, disinfection using an LED module emitting 275nm UV was carried out. 384 UV-LEDs were put into a cylinder tube with a capacity of 1.7 liters. The UV intensity of the UV-LED module was controlled from 1.7 to 8.4 mW/cm². The disinfection efficiency for the model microorganism solutions(E. coli ) was monitored. As the UV intensity(I) and contact time(t) varied, inactivation of the microorganisms from 2 to 4-log-removals(i.e., 99 to 99.99% of disinfection efficiency) was achieved. Disinfection using UV-LED was followed to 1^st order reaction and the reaction rate constant, k was determined. In addition, the relationship between UV intensity(I) and contact time(t) in order to obtain 99.99% of disinfection efficiency was modeled: I^1.2·t= 460, which indicates that the product of UV intensity and contact time requiring 4-log-removals is always constant.

• 산업식품공학
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• 제22권4호
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• pp.386-391
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• 2018

양산형 UV-P 처리는 장비를 20분 이상 작동하였을 때 후춧가루의 토착 중온 호기성 세균을 유의적으로 저해시켰다. UV-P 처리는 토착 미생물 저해에 있어 상승효과를 보여주었으나 후춧가루의 색을 어둡게 하였다. UV-P 처리의 후춧가루 미생물 저해 효과와 색 변화에 대한 영향은 처리되는 후춧가루를 오염시키는 미생물과 후춧가루 종류에 영향을 받음을 알 수 있었다. 또한 본 연구 결과는 UV-P 장비 내 플라즈마 충적 시간과 후춧가루의 $a_w$ 상승이 UV-P 처리된 후춧가루의 미생물 저해 효과 향상과 색 유지에 효과적이지 않음을 알 수 있었다. 본 연구는 UV-C와 플라즈마 처리를 병합한 양산형 UV-P 처리가 후춧가루의 토착 미생물을 저해시키는 기술로서의 가능성을 보여주었다. 그러나 앞으로 추가적인 연구를 통해 UV-P 처리부의 온도상승 및 후춧가루의 색도 변화를 최소화할 수 있는 방법이 제시되어야 할 것이다.