• 한국환경과학회지
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• 제23권9호
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• pp.1655-1662
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• 2014

A comprehensive fractionation technique was applied to a set of water samples obtained along drinking water treatment process with ozonation and biological activated carbon (BAC) process to obtain detailed profiles of dissolved organic matter (DOM) and to evaluate the haloacetic acid (HAA) formation potentials of these DOM fractions. The results indicated that coagulation-sedimentation-sand filtration treatment showed limited ability to remove hydrophilic fraction (28%), while removal of hydrophobic and transphilic fraction were 57% and 40%, respectively. And ozonation and BAC treatment showed limited ability to remove hydrophobic fractions (6%), while removal of hydrophilic and transphilic fractions were 25% and 18%. The haloacetic acid formation potential (HAAFP)/dissolved organic carbon (DOC) of hydrophilic fraction was the highest along the treatment train and HAAFP/DOC of hydrophilic fraction was higher than hydrophobic and transphilic fraction as 23%~30%, because of better removal for hydrophobic fraction both in concentration and reactivity.

• Environmental Engineering Research
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• 제12권5호
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• pp.224-230
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• 2007

The objectives of this study were to evaluate the change of molecular weight (MW) profiles in natural organic matter (NOM) through various treatment processes (coagulation, granular activated carbon (GAC), and ozonation) using high performance size exclusion chromatography based on ultraviolet absorbance and dissolved organic detection (HPSEC-UVA-DOC). In addition, relationships between MW profiles and disinfection by-production (DBP) formation were evaluated. Each treatment process results in significant different effects on NOM profiles. Coagulation is effective to remove high molecular weight NOM, while GAC is effective to remove low molecular weight NOM. Ozonation removes only a small portion of NOM, while it induces a significant reduction of UV absorbance due to breakdown of the aromatic groups. All treated waters are chlorinated, and chlorination DBPs such as trihalomethanes (THMs) and haloacetic acids (HAAs) are measured under formation potential conditions. Both THM and HAA formation potentials were significantly reduced through the coagulation process. GAC was more effective to reduce THM formation compared to HAA formation reduction, while ozonation showed significant HAA reduction compared to THM reduction.

• 상하수도학회지
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• 제26권2호
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• pp.219-228
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• 2012

Problems due to the taste and odor in drinking water are common in treatment facilities around the world. Taste and odor are perceived by the public as the primary indicators of the safely and acceptability of drinking water, and are mainly caused by the presence of two semi-volatile compounds-2-methylisoborneol(2-MIB) and geosmin. Conventional treatment processes in water treatment plants, such as coagulation, sedimentation and chlorination have been found to be ineffective for the removal of 2-MIB and geosmin. Pulse UV system is a new UV irradiation system that is a non-mercury lamp-based alternative to currently used continuous wave systems for water disinfection. This study shows pulse UV system to be effective in treatment of these two compounds. Geosmin removal efficiency of UV process alone achieved approximately 70% at 10sec contact time. 2-MIB removal efficiency of UV only process achieved approximately 60% at 10sec contact time. The addition of $H_{2}O_{2}$ 7mg/L increased geosmin and 2-MIB removal efficiency upto approximately 94% and 91%, respectively.

• 상하수도학회지
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• 제20권1호
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• pp.27-34
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• 2006

This study was conducted to evaluate the performance of a membrane bioreactor filled with high concentration of powdered activated carbon (HCPAC-MBR) to reduce DBPs at the drinking water treatment. The pilot system was installed after the rapid sand filtration process whose plant was the conventional treatment process. The removal efficiencies of DBPs were measured during pilot operation period of 2 years. HAA and THM removal rates could be maintained around 80~90% without any troubles and then tremendous reduction of HAA and THM reactivity were observed more than 52%. The average removal rate of HAA formation potential (FP) and THM formation potential (FP) were 70.5% and 67.6% respectively. It is clear that the PAC membrane bioreactor is highly applicable for advanced water treatment to control DBPs.

• 상하수도학회지
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• 제19권1호
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• pp.78-91
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• 2005

Performance limiting factors (PLFs) derived from 161 drinking water treatment plants (DWTPs), assessed by International Technical Diagnosis & Assistance Center, were analyzed and evaluated in more detail in this study. In order to conduct study, 161 DWTPs were divided into five categories depending on their capacity, and into twelve groups according to processes and facilities. From the results of analysis, PLFs and their distribution ratio derived from each category were significantly different. Filtration was the most important performance limiting process in all DWTPs of five categories, and the PLFs in filtration were backwashing velocity, media configuration, bed depth, and formation of mud-ball. The PLFs in coagulation-flocculation process were found out to be coagulant dosage, mixing speed, mechanical problems, and others in the order of frequency of occurrence. Also, insufficient disinfection ability that is resulted from insufficient hydraulic detention time and improper chlorine dose and injection point, is the most significant among PLFs in a clear well. In the case of sedimentation, inappropriate baffle structure and excessive upward velocity were PLFs. In addition, the results showed that high turbid water and low alkalinity in a rainy season, ferric and manganese ions, and ammonia nitrogen have been contributed significantly on the performance of DWTPs.

• Journal of Korean Biological Nursing Science
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• 제11권1호
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• pp.92-98
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• 2009

Purpose: This study was aimed to investigate the colony counts by different disinfecting processes and duration of the operation for humidifiers in an intensive care unit (ICU) in Busan. Method: The four steps of disinfecting process were taken with four different humidifiers according to the use of disinfectant (1:100 $Deconex^{(R)}$ 50FF/nothing) and refilling water (tap water/distilled water). First, the colony counts using water sample from wick was conducted at 0 hr, 24 hr, and 48 hr respectively after turning on the humidifiers. Next, the colony counts using waterdrop from the outlet was done at 0 hr, 24 hr, 48 hr, and 72 hr respectively after turning on the humidifiers. Result: No colony was counted after disinfecting with 1:100 $Deconex^{(R)}$ 50FF until 72 hr after turning on the humidifiers. However, without disinfecting with $Deconex^{(R)}$ 50FF, the colony count was increased in the humidifiers from 24 hr after turning on the humidifiers. The result was the same regardless of the refilling water. Conclusion: According to the results, the study found that disinfection of humidifiers in the ICUs with 1:100 $Deconex^{(R)}$ 50FF every 72 hr is effective to remove general bacteria.

• 분석과학
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• 제33권1호
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• pp.42-48
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• 2020

Bromate is a disinfection by-product generated mainly from the oxidation of bromide during the ozonation and disinfection process in order to remove pathogenic microorganism of drinking water, and classified as a possible human carcinogen by International Agency for Research of Cancer (IARC) and World Health Organization (WHO). For the purpose of determining the trace level concentration of bromate, several sensitive techniques are applied mostly based on suppressed conductivity detection and UV/Visible detection after postcolumn reaction (PCR). In this study, the suppressed conductivity detection method and the PCR-UV/Visible detection method through the triiodide reaction were compared to analyze the trace bromate in water samples and estimated for the availability of these analytical methods. In addtion, the state-of-the-art techniques was applied for the determination of trace level bromate in various water matrices, i.e., soft drinking water, hard drinking water, mineral water, swimming pool water, and raw water. In comparison of two analytical methods, it was found that the conductivity detection had the suitable advantage to simultaneously analyze bromate and inorganic anions, however, the bromate might not be precisely quantified due to the matrix effect especially by chloride ion. On the other hand, the trace bromate was analyzed effectively by the method of PCR-UV/Visible detection through triiodide reaction to satisfactorily minimize the matrix interference of chloride ion in various water samples, showing the good linearity and reproducibility. Furthermore, the method detection limit (MDL) and recovery were 0.161 ㎍/L and 101.0-108.1 %, respectively, with a better availability compared to conductivity detection.

• Ecology and Resilient Infrastructure
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• 제3권3호
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• pp.182-188
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• 2016

본 연구는 도시 홍수문제의 구조적 해결방안을 도출하기 위하여 내구성-비용지수 (robustness cost index, RCI)를 수질오염 문제 사례에 재해석 및 적용하였다. 처리기준 산정방식이 다른 하수 처리수 내 내생호르몬 오염과 취수원 원생동물 번성을 대표 사례로 선정하여 기존시설과 대안시설 (구조적 대안)의 내구성 지수 (RI) 값이 1 이상인 경우를 내구성을 확보한 대안으로 판정하고 내구성 지수와 비용지수 (CI)를 결합한 RCI 값을 산정하였다. 하수 처리수 내 내생호르몬 오염은 인체로부터 기인하는 $17{\beta}$-estradiol 을 대상 오염물질로 하여 현재 하수처리시설과 대안시설 (고도처리공정 증축)을 비교하였고, 고도처리공정을 증축한 사례에서 RI뿐만 아니라 RCI 값이 큰 결과가 나타났다. 취수원 원생동물 번성의 경우 크립토스포리디움을 처리하기 위한 소독방안으로 자외선 소독과 오존 소독을 대상으로 RCI를 산정하였고 오존 소독시설이 RCI값이 더 높은 것을 확인하였다. 처리기준이 다른 수질오염사례의 RCI 산정과정과 도출한 값을 바탕으로 재해 발생 시 피해 복구와 피해 방지를 위한 구조적 대안 수립과정의 방향을 제시하고 그 구축전략을 제안하였다.

• 대한환경공학회지
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• 제38권9호
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• pp.513-520
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• 2016

수중에 용존된 가스뿐 아니라 소독부산물과 같은 휘발성 화합물은 탈기에 의해 효과적으로 제거할 수 있는 것으로 알려져 있다. 탈기공정에 사용되는 미세 기포는 수백~수천 ${\mu}m$이지만 부상 공정의 기포는 수 ${\mu}m$ 정도로 작다. 이에 따라 부상공정에서의 마이크로 기포는 수중의 휘발성 화합물이 대기로 방출될 수 있는 매우 넓은 기-액 비표면적을 제공한다. 또는 마이크로 기포는 상승 속도가 느려서 휘발성 화합물이 방출될 수 있는 긴 체류시간을 갖게 된다. 본 연구에서 일련의 탈기와 부상 실험을 실시한 결과, THMs의 제거율에서 상당히 큰 차이가 있었다. THMs의 물질전달계수 $K_La$ 역시 큰 차이를 보였다. 따라서 부상공정에서 THMs과 같은 휘발성 화합물을 제거하기 위해서는 일반적으로 입자제거를 위하여 적용되는 통상적인 운전범위보다 더 높은 기포체적농도가 필요함을 알 수 있다.

• 한국기록관리학회지
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• 제15권2호
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• pp.165-179
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• 2015

역사적 학술적으로 중요한 가치를 가지고 있는 고문서와 기록물들은 현재는 물론 후세에도 주요한 정보자원의 보고로서 대대로 후손에게 물려주어야 할 값진 문화유산이다. 그런 이유로 각종 고문서 등 기록물을 효율적으로 관리하기 위한 보존시설의 표준화와 서고 수장고의 보존환경에 대한 연구가 세계적으로 꾸준히 진행되고 있다. 하지만 기록물의 종이, 접착제, 전분, 섬유 등의 화합물들은 곰팡이나 세균, 해충 등의 영양원으로 생물학적인 피해가 발생할 수밖에 없다. 이러한 생물학적 피해는 기록물 표면과 내부까지 번식하여 변 퇴색을 촉진하거나 갉아 먹어 복구마저 불가능한 경우도 발생하게 된다. 특히 중동의 오만과 말레이시아는 고온다습한 기후로 인해 기록물이 생물학적 피해를 입기 쉬우며, 한번 피해를 입은 기록물들은 전이속도가 빠르고 광범위하여 소독작업은 일반화 된 실정이다. 하지만 그 동안 소독에 사용해온 MB(메틸브로마이드)와 ETO(에틸렌옥사이드)는 살충효과는 뛰어나나 살균효과는 미미하고, 오존층파괴문제와 1급 발암물질의 유독성문제 그리고 가죽이나 고무재질에 대한 재질약화 초래 등의 복합적인 문제로 친환경 소독방식의 필요성이 대두되었다. 주)바이오미스트 테크놀로지는 1990년대 말부터 몬트리올협정에 따른 기존소독제의 사용금지 및 약제의 유독성으로 인한 작업자의 피해를 예방하기 위하여 질소와 식물추출성분 등을 이용하는 친환경 기록물 소독장비 개발에 성공한 이후 지속적인 성능개선을 통하여 장비의 질적 수준을 제고하였다. 본 실험에 사용한 장비는 대기압 이하로 소독 공간(챔버)을 유지하면서 자체 발생된 질소를 이용하여 챔버를 저 산소 환경으로 만든 후 천연 소독 약제를 챔버 내부에서 급속 기화시켜 소독하는 친환경 훈증소독 방식으로 기록물의 생물학적 피해를 근원적으로 예방하여 보존성 향상에 기여하고, 친환경 및 인체에 안전한 소독장비로서 향후 기록물의 생물학적 피해를 예방하는데 큰 기여를 할 것으로 판단된다.