• 한국환경과학회지
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• 제13권1호
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• pp.55-59
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• 2004

The effect of ozone on the formation and the removal of disinfection byproducts(DBPs) of chlorination process was studied to elucidate the performance of water treatment process. The samples of raw water, prechlorination process, and preozonation process were analyzed quantitatively according to the Standard Methods for the Examination of drinking water. As a result, most of total trihalomethanes(THMs) which were formed in prechlorine treatment process was not removed in the preozonation process. Most of haloacetic acids(HAAs), haloacetonitriles(HANs), and chloral hydrate(CH) was removed in sedimentation and biological activated carbon(BAC) filtration processes. However, DBPs were increased more or less by postchlorine step. In particular, the formation of THMs and HAAs depends on ozone more than chlorine, but, the formation of HANs and CH depends on chlorine more than ozone. The seasonal variation of DBPs concentration for the year needs to be investigated to study the temperature effect because DBPs strongly depend on temperature among various efficient factors.

• 한국환경과학회지
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• 제21권9호
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• pp.1031-1041
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• 2012

This study was carried out to investigate the characteristics of disinfection by-products (DBPs-trihalomethanes (THMs), haloacetic acids (HAAs) and haloacetonitriles (HANs) formation in chlorination of principal raw waters used for drinking water on Jeju Island, Korea. The domestic water supply of other area and humic acid solution (HA) were used as a reference point. The effects of chlorine contact time, solution temperature and pH on DBPs formation potential (DBPFP) were investigated for raw waters. In addition, the effect of $Br^-$ was studied for HA. The DBPFP (THMFP, HAAFP and HANFP) were increased with increasing chlorine contact time. Comparing the individual DBPFPs for raw waters, they decreased in the order of HAAFP > THMFP ${\geq}$ HANFP. As the solution temperature was increased, the THMFP, HAAFP and HANFP increased. With increasing the solution pH, the THMFP was increased, but HAAFP and HANFP were decreased. With the addition of 0.3 mg/L $Br^-$ for HA, the DBPFP was increased and the major chemical species changed: from trichloromethane to dibromochloromethane and tribromomethane for THMs; from dichloroacetic acid and trichloroacetic acid to tribromoacetic acid for HAAs; and from dichloroacetonitrile to dibromoacetonitrile for HANs.

• 한국물환경학회지
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• 제21권6호
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• pp.676-681
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• 2005

This study was researched for disinfection by-products (DBPs) by preozonation, prechlorination and/or postchlorination. DBPs including trihalomethanes (THMs), haloacetic acids (HAAs), halonitriles, and aldehydes were analyzed by the treatment steps of prechlorination, preozonation, sedimentation, filtration, and postchlorination comparatively. THMs were detected as $52.20{\mu}g/L$ after prechlorination and decreased during sedimentation and filtration process. The HAAs and aldehydes increased more during preozonaiton than prechlorination. However, chlorinated DBPs and aldehydes increased more by postchlorination. Chlorinated DBPs formed by preozonation increased 26% more than the chlorination process. If aldehydes were included in the total DBPs, DBPs increased up to 39% by preozonation. Preozonation could increase the removal efficiency of organic carbon during the coagulation and sedimentation processes. Ozonation might produce aldehydes that are not permitted for drinking water regulations. Also, DBPs were produced by preozonation than by chlorination. These results would bring a need for alternative disinfection studies to decrease DBPs.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2006년도 춘계학술발표논문집
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• pp.596-598
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• 2006

본 논문에서는 수지 조성비 및 수지탑 배열이 이온교환 특성에 미치는 영향을 조사하기 위하여 전해질 농도는 $Na^+\;125ppm$, $Cl^-\;315ppm$ 유속은 500ml/min, 이온교환 수지는 ROHM&HAAS IR 120 양이온 수지와 ROHM&HAAS IRA 402 음이온 수지를 사용하였고, 수지탑 배열은 혼상-혼상-음이온, 혼상-음이온-혼상, 음이온-혼상-혼상 수지탑 순으로, 이온교환 수지탑의 양 음이온교환 수지의 조성 비율은 1:1, 1:2, 1:3 로 변화하여 실험한 결과 이온교환 수지의 조성비 변화에서는 양 음이온교환 수지 조성비 1:2의 경우 1:1, 1:3의 경우보다 파과시간이 연장되었다. 수지탑 배열이 음이온-혼상-혼상 수지탑인 경우 혼상-혼상-음이온 수지탑 배열과 파과시간을 비교해보면 약 60% 파과시간이 연장되었다. 따라서 수지탑 배열은 음이온-혼상-혼상 수지탑 순으로, 수지 조성비는 1:2일 때 가장 효율적인 것으로 나타났다.

• 대한환경공학회지
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• 제38권2호
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• pp.63-70
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• 2016

수돗물 공급과정에서의 소독부산물 발생현황과 이와 관련된 수질 인자와의 상관성을 조사하여 소독부산물 발생특성을 규명하고자 K-water에서 관리하는 정수장의 수돗물 공급과정 5개 계통에 대하여 조사를 실시하였다. 수돗물 공급과정에서의 공급계통별 Water age 및 노후관 공급계통을 구분하여 조사대상을 선정하였으며, 소독부산물인 트리할로메탄 (THMs) 및 할로아세틱에시드 (HAAs), 유기물 항목으로서 BDOC 및 DOC를 포함하여 7개 항목에 대해 월 1회 조사하였다. 조사결과 노후관계통 및 Water age가 길수록 공급과정 내 유기물 농도가 높아지는 경향성을 확인할 수 있었다. 소독부산물과 관련 영향인자들의 상관관계를 분석한 결과 계통별 잔류염소 감소와 Water age간 상관관계가 매우 높은 것으로 나타났다. 또한 Water age와 THMs 생성간의 결정계수값이 매우 높아 THMs 생성에 Water age가 중요한 인자임을 알 수 있었다. 잔류염소 감소율이 THMs 증가에 미치는 영향 또한 매우 높게 나타났으며, Water age가 길어질수록 수온과 THMs 생성에 미치는 영향은 증가하는 것으로 나타났다. 이와 반면 HAAs는 THMs와는 달리 Water age, 잔류염소, 수온과의 상관관계 조사결과 결정계수 값이 낮게 나타났다.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.263-272
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• 2005

Chlorine disinfection has been used in drinking water supply to disinfect the water-borne microbial disease which may cause to serious human disease. it is still the least costly, relatively easy to use, Chlorination is the primary means to disinfect portable water supplies and control bacterial growth in the distribution system. However, chlorine reacts with natural organic matter(NOM), that presents in nearly all water sources, and then produces disinfection by-products(DBPs), that have adverse health effects. Although the existent DBPs have been reported in drinking water supplies, it is not feasible to predict the levels of the various DBPs due to the complex chemistry reaction involved. 1. The objectives of this study is to investigate seasonal variation difference concentration of DBPs in the plant to tap water. The average concentration of THMs was 20.04 ${\mu}g/{\ell}$ , HAAs 8-15 ${\mu}g/{\ell}$ , HANs 2-4.5 ${\mu}g/{\ell}$ respectively. 2. Distant variation of DBPs furmation by the distance is that THMs concentration increased by 17% at 2km point from the plant and by 28% at 7km and HAAs, HANs also increase each by 16%, 32% at 2 km from the plant and 35%, 56% at 7 km. DBPs increase in water supply pipe continually, 3. The seasonal occurrence of BBPs is that in May and August DBPs concentration is very higher than in march, in May DBPs concentration is highest. The temperature is main factor of DBPs formation, precursor also. 4. Precursor which was accumulated for winter flowed into the raw water by flooding in spring and summer and produced DBPs. 5. Therefore for the supply of secure drinking water, it is required to protect precursor of flowing into raw water and to add to BCAA and DBAA to drinking water standards.

• 대한환경공학회지
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• 제35권11호
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• pp.769-775
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• 2013

본 연구에서는 두 가지 기원의 표준 휴믹물질 혼합 시료와 Suwannee River fulvic acid (SRFA)을 사용하여 광분해로 인한 용존 유기물질의 스펙트럼 특성 변화와 이에 따른 소독 부산물 생성능의 변화를 조사하였다. 혼합시료의 염소소독부산물 발생잠재력(DBPFP)은 specific UV absorbance (SUVA) 값에 비례하여 증가하였다. 7일간 광분해 후 혼합시료의 SUVA 값은 모두 감소하였다. 그러나 동일 시료에서 DBPFP 값은 SUVA 감소폭보다 적었다. 비록 두 변수 사이에 직선성은 유지되었으나 같은 SUVA 범위 내에서의 DBPFP 값은 오히려 감소하는 경향을 보였다. 이 결과는 광분해로 인해 염소소독부산물 전구체 역할을 하는 비방향족 물질이 생성될 수 있음을 시사하였다. SRFA 시료에 대해 4일과 13일 광분해하여 각각 저분자와 고분자 부분에서의 DBPFP 값을 비교한 결과 광분해 후 유기탄소 당 염소소독부산물 발생량 변화양상은 염소소독부산물 종류에 따라 다르게 나타났다. 유기탄소 당 trihalomethenes (THMs) 발생은 광분해 후 고분자 부분에서 더 높았으나 haloacetic acids(HAAs)의 경우 고분자와 저분자 부분 사이의 유의한 차이가 관찰되지 않았다. 광분해 시간에 따른 유기탄소 당 DBPFP 값 변화 패턴도 용존 유기물 분자량에 따라 다르게 나타났다. THMs의 경우 고분자 부분에서는 광분해 시간에 따라 증가하는 경향을 보였으나 저분자에서는 큰 변화를 보이지 않았다. 반면 HAAs은 고분자에서 지속적인 감소 경향을, 저분자 부분에서는 증가 후 다시 감소하는 경향을 보였다. 본 연구결과 수중 유기물질은 전반적으로 광분해에 따라 소독부산물 생성능이 초기에 오히려 증가할 수 있으며 광분해 시간이 충분히 지속된 후에야 감소함을 보여주었다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.1459-1460
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• 2004

An AHP-based framework for comprehensive comparison of several power technologies haas been developed. A questionnaire has been designed and is about to surveyed for extracting boty weight vectors and subjective evaluation values. The attitude of evaluator groups will be incorporated into these two types of quantification.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.404-407
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• 2009

HYPOLED is a collaborative European project that commenced in 2008. It is targeted toward "High-Performance OLED-Microdisplays for Mobile Multimedia HMD and Projection Applications". In this paper, we describe the initial objectives and present draft specifications for devices, the personal display system and micro-projection unit. Initial results are shown and discussed.

• Animal Systematics, Evolution and Diversity
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• 제22권2호
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• pp.139-143
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• 2006

From the result of this study for the materials collected in Mt. Changbai-shan, six species of the family Noctuidae, Pangrapta marmorata Staudinger, P. griseola Staudinger, Ctenostola sparganoides (Bang-Haas), Cucullia amota Alpheraky, Xestia albonigra (Kononenko), and X. speciosa $(H\ddot{u}bner)$, are reported for the first time from China.