• 한국환경과학회지
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• 제14권10호
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• pp.965-972
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• 2005

This research studied the effect of factors that are able to form disinfection by-products (DBPs) of chlorination, including natural organic matter (NOM) with sewage, bromide ions, pH and contact time. Trihalomethane (THMs) yield of $0.95{\mu}mol/mg$ was higher than other DBPs yield for the chlorinated humic acid samples. THMs yield of sewage sample was $0.14{\mu}mol/mg$ and haloacetonitriles (HANs) yield in the sewage samples were $0.13{\mu}mol/mg$ but only $0.02{\mu}mol/mg$ for the humic acid samples. As the concentration of bromide ions increased, brominated DBPs increased while chlorinated DBPs decreased, because bromide ions produce brominated DBPs. THMs were highest $(55.55{\mu}g/L)$ at a pH of 7.9 and haloacetic acids (HAAs) were highest $(34.98{\mu}g/L)$ at a pH of 5. Also THMs increased with increasing pH while HAAs decreased with increasing pH. After chlorination, the rate of THMs and HAA formation are faster at initial contact time and then reaches a nearly constant value after 24 hours. This study considers ways to reduce DBP formation by chlorination.

• 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.

• 한국환경과학회지
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• 제21권8호
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• pp.1015-1021
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• 2012

Formation of disinfection by-products (DBPs) including trihalomethans (THMs), haloacetic acid (HAAs), haloacetonitriles (HANs) and others from chlorination of algogenic organic matter (AOM) of Microcystis sp., a blue-green algae. AOM of Microcystis sp. exhibited a high potential for DBPs formation. HAAs formation potential was higher than THMs and HANs formation potential. The percentages of dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) formation potential were 43.4% and 51.4% in the total HAAs formation potential. In the case of HANs formation potential, percentage of dichloroacetonitrile (DCAN) formation potential was 97.7%. Other DBPs were aldehydes and nitriles such as acetaldehyde, methylene chloride, isobutyronitrile, cyclobutanecarbonitrile, pentanenitrile, benzaldehyde, propanal, 2-methyl, benzyl chloride, (2-chloroethyl)-benzene, benzyl nitrile, 2-probenenitrile and hexanal.

• 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.

• 대한화학회지
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• 제18권4호
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• pp.278-288
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• 1974

P-dichlorobenzene을 출발물질로하여 니트로화 반응, 메톡시화 반응 및 환원반응을 거쳐서 2-amino-4-chloroanisole을 얻은 다음 이것에 연속적인 염소화반응을 시켜 2-amino-3,4,5-trichloroanisole 만을 순수하게 얻을 수 있었다. 한편 4-chloro-2-nitroanisole 을 촉매 존재하에서 염소화반응시켜 2,4-dichloro-6-nitroanisole을 간편하게 얻었으나 이 이상의 염소화 반응은 보통 압력에서는 성공되지 못하였다. 2-amino-4,6-dichloranisole의 연속적인 염소화 반응으로 2-amino-3,4,5,6,-tetrachloroanosole을 간편하게 얻을수 있었다. 한편 2-amino-4-chloranisole 및 2-amino4,6-dichloranisole의 Schiemann반응으로 2-fluoro-4-chloranisole 및 2-fluoro-4,6-dichloroanisole을 각각 얻은 다음 이들의 연속적인 염소화 반응으로 2-fluoro-3,4,5,6-tetrachloroanisole을 간편하게 합성할 수 있었다. 염소화반응생성물들의 확인에 NMR 분석방식을 사용하여 생성물을 분리하지 않고 연속 합성하는 방식을 택하였으며 이러한 방식의 간편성을 논의 하였다. 높은 합성수득률 및 반응조건의 간이성에 따르는 실용성에 관하여서도 각각 제언 하였다.

• 한국물환경학회지
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• 제20권3호
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• pp.275-280
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• 2004

This study was performed to investigate the disinfection efficiency and the formation characteristics of disinfection by-products(DBPs) by chlorination in the sewage effluent. The effluent was sampled from the sewage treatment plants operated in the activated sludge process and the advanced sewage process. The type of DBPs investigated were Trihalomethanes(THMs), Dichloroacetonitrile(DCAN), Chloral hydrate(CH), Dichloroacetic acid(DCAA), Trichloroacetic acid(TCAA). Major findings are as follows. First, the optimum injection concentration for chlorination in sewage effluent were found to be in the range $0.5{\sim}1.0mg\;cl_2/L$. Also, It was found that the chlorine dosage in the effluent of activated sludge process was higher than in the effluent of advanced sewage process. Second, the maximum formation concentration of THMs were $12.7{\mu}g/L$. The THMs formation reaction was finished in a short time of several seconds and chloroform was mainly formed. Also, it was found that the concentration of ammonium nitrogen is higher, the concentration of THMs is lower. Third, it was found that DCAA and TCAA were mainly formed as DBPs by disinfection.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 1998년도 추계 학술대회 발표 논문집
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• pp.83-83
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• 1998

• 대한화학회지
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• 제12권2호
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• pp.55-60
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• 1968

芳香族誘道體 化合物의 鹽素化反應을 紫外線照射 및 ${\gamma}$-線照射下에서 行하였던 바 ethyl,${\alpha} ,{\beta} -dichloro-{\beta}$-phenyl propionate의 境遇 紫外線下에서는 主로 p-chloro 化合物이 生成되었다. 같은 反應을 ${\gamma}$-線 照射下에서 行한 結果 에스텔과 鹽素의 몰比가 1:2일 때에는 p-chloro 化合物이 主로 生成되었으나 몰比가 1:8인 境遇에는 側鎖鹽素化物이라고 判斷되는 多鹽素化合物이 生成되었다. 反應生成物을 確認하기 爲하여서 ethyl , ${\alpha} ,{\beta} -dichloro-{\beta}$-(p-chlorophenyl) propionate 및 ethyl${\alpha} ,{\beta} -dichloro-{\beta}$ -($o$-chlorophenyl) propionate 를 各各 ${\gamma}$-線 照射下에서 鹽素化시켜 보았더니 p-chloro誘道體에서는 側鎖鹽素化物을, o-chloro誘道體에서는 o,p-dichlorophenyl 化合物에 各各 該當하는 鹽素化物을 生成하였다. 化合物 確認에는 放射化 thin layer chromatography를 利用 하였으며 鹽素含量을 放射化分析法을 分析하였다. 反應結果를 鹽素化反應에 對한 芳香族의 置換基의 效果와 關聯시켜 論議하였으며 實驗方法을 記述하였다.

• 환경위생공학
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• 제24권2호
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• pp.40-48
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• 2009

Unusual bloom of toxic cyanobacteria in water bodies have drawn attention of environmentalists world over. Major bloom of Anabaena, Microcystis in water storage reservoir, rivers and lake leading to adverse health effects have been reported from Australia, England and many part of the world. These cyanobacterial cells can release intercellular matter like toxin in water and these intercellular matter can increase the concentration of organic matter. Cellysis can occur when algal cells meet the disinfectants like chlorine in water treatment plant and the resultant rising up of DOC(Dissolved Organic Carbon) or TOC(Total Organic Carbon) can increase the formation of disinfection by products. Disinfectants that kill microorganisms react with the organic or inorganic matter in raw water. In general disinfectants oxidize the matter in raw water and the resultant products can be harmful to human. There are always conflict about which is more important, disinfection or minimizing disinfection by products. The best treatment process for raw water is the process of the lowest disinfection by products and also the the lowest microorganism. In this study the cultured cells, Microcytis Aeruginosa(MA), Anabaena Flos-aquae(AF), Anabaena Cylindrica(AC), and the cells obtained in Daechung Dam(DC) whose dominant species was Anabaena Cylindrica were subjected to chlorination. Chlorination oxidizes inorganic and organic compounds and destruct live cells in raw water. Chloroform was analyzed for the cultured cells which were treated with $20mg/\ell$ dose of chlorine. In general chloroform is easily formed when dissolved organic matter react with chlorine. The cultured cells contributes the concentration of dissolved organic carbon and also that of total organic carbon which might be potent precusors of chloroform formed. The correlations of the concentration of chloroform, DOC and TOC were investigate in this study.

• 대한환경공학회지
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• 제34권5호
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• pp.351-358
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• 2012

Microcystis sp.의 부패과정에서 수중으로 용출되는 AOM 특성과 염소 이들에서의 disinfection by-products (DBPs) 생성특성을 조사하였다. 수중으로 용출된 EOM과 cell + IOM에서의 염소 DBPs 생성특성을 조사한 결과, EOM은 보관기간 초기부터 지속적으로 증가하였으나 cell + IOM의 경우는 급격한 감소경향을 나타내었으며, 생성된 DBPs 중 HAAFP가 가장 높은 생성비율을 나타내었다. 또한, 이 때의 DBP 구성종들의 변화를 살펴본 결과, HAA 구성종들의 경우는 EOM에서는 di-HAA 구성종들의 비율은 점점 감소하였고 tri-HAA 구성종들의 비율은 점점 증가하였다. 그러나 cell + IOM의 경우는 EOM의 경우와는 반대 경향을 나타내었다. 또한, HAN 구성종들의 경우는 EOM과 cell + IOM 모두 di-HAN 구성종들의 생성비율이 월등히 높았다.