• 식물병연구
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• 제21권3호
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• pp.193-200
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• 2015

Gray mold caused by Botrytis cinerea is one of the most important postharvest fungal pathogens of cut flowers. Here, gamma irradiation, an alternative for phytosanitary purposes, and sodium dichloroisocyanurate (NaDCC) were used to control B. cinerea in a cut chrysanthemum (Chrysanthemum morifolium Ramat.) cultivar, 'Baekma', one of the cultivars susceptible to B. cinerea. Spore germination and mycelium growth of B. cinerea were inhibited by gamma irradiation in an inversely dose-dependent manner. A dose of 4 kGy completely inhibited the mycelium growth of B. cinerea. A significant change in flower quality (physical properties) on chrysanthemum was shown from gamma irradiation at over 0.2 kGy (p<0.05). Therefore, in this study, the integration of gamma ray (below 0.2 kGy) and NaDCC, an eco-friendly form of chlorine, was investigated to control the disease with low dose of gamma irradiation dose. Interestingly, the gamma irradiated flowers showed more disease severity than the non-irradiated flowers. The combined treatment of gamma irradiation and NaDCC does not affect the severity of the fungal disease, whereas only 70 ppm of NaDCC treatment showed a significantly reduced severity. These results suggest that only chlorination treatment can be applied to control B. cinerea in cut chrysanthemum flowers.

• 한국물환경학회지
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• 제20권5호
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• pp.409-414
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• 2004

Pilot-scale experiments were performed for the treatment of bank filtrate contammg high manganese concentration around 2mg/L using rapid manganese sand filtration to investigate effects of oxidant dose and pH control on the removal efficiency of manganese. For theoretical dose ranges of oxidant (sodium hypochlorite) between 3 and 4mg/L, the manganese concentration of effluent was 0.57 mg/L, which corresponded to 72.5% removal and was higher than drinking water quality standards of 0.3mg/L. For excess dose ranges of oxidant between 4 and 8mg/L, the manganese concentration of effluent was reduced to 0.14mg/L, which corresponded to 94.5% removal, but the residual chlorine concentration was over 1.0mg/L. On the other hand, manganese removal efficiency drastically increased up to the value of 98.0%, which is equivalent to the effluent concentration of 0.03mg/L by controling pH to the range between 7 and 8 for the theoretical dose of oxidant. Consequently, these results indicated that appropriate dose of chemicals, such as oxidant and alkali, and continuous monitoring of manganese should be necessary to obtain efficient removal of manganese and to optimize the maintenance of treatment facilities for the treatment of bank filtrate with high concentration of manganese.

• 분석과학
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• 제11권6호
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• pp.452-459
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• 1998

수산계 폐기물로부터 분리한 chitin을 epichlorohydrin과 반응시켜 가교 chitin을 제조한 후 탈아세틸화하여 가교 chitosan을 제조하였다. 가교 chitosan-OH를 가교 chitosan-Cl로 전환시킨 뒤 킬레이트 시약인 2,2'-Iminodibenzoic acid 염과 반응시켜 킬레이트 흡착제인 2,2'-Iminodibenzoic acid-가교 chitosan을 합성하였다. 그리고 합성된 흡착제를 이용하여 Pb(II), Cu(II), Cd(II)의 흡착과 회수 특성을 연구하였다. 흡착특성에 대한 실험 결과, pH가 증가할수록 흡착되는 금속 이온의 양이 증가함을 알 수 있었다. 최적 반응시간은 1시간, 흡착력은 Cu(II)

• Korean Chemical Engineering Research
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• 제50권1호
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• pp.83-87
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• 2012

활성탄소섬유를 사용하여 염소소독 후 수돗물 내에 부산물로 존재하는 4종 트리할로메탄을 제거하였다. THMs의 종류별 농도 및 용액의 온도를 달리하면서 흡착실험을 수행하고 활성탄소섬유의 표면특성에 따른 흡착능력과 흡착메카니즘을 살펴본 결과, 4종의 THMs은 모두 Langmuir 타입의 흡착등온곡선을 보이면서 매우 신속하게 활성탄소섬유에 흡착되었다. THMs의 흡착은 활성탄소섬유의 표면에 균일하게 발달된 미세공의 입구에 물리적 및 화학적 수소결합으로 이루어졌다고 판단된다. Langmuir 타입은 특히 저농도 오염원 일때 제거효율이 높기 때문에 수돗물 내에 약 $30{\mu}g/L$ 수준으로 존재하는 THMs의 제거에는 활성탄소섬유가 매우 효과적임을 알 수 있다. 4종 THMs 종류별 흡착량은 큰 차이는 없으나 chloroform, bromodichloromethane, dibromochloromethane, 및 bromoform 의 순서로 증가하였다. 이는 brom 원자수의 증가와 일치하며 극성의 감소로 용해도가 낮아짐에 따라 흡착량이 증가한 것이다.

• 한국물환경학회지
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• 제28권5호
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• pp.754-761
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• 2012

Several drinking water treatment plants (DWTPs) produce the bottled tap waters (BTWs) as pilot production and provide them for noncommercial use. In 2008, acetaldehyde and chloral hydrate were detected in some BTWs and the public worry over the safety of the water. In this study, the BTWs produced from 7 DWTPs were tested for 13 chemicals including disinfection byproducts (DBPs). The level of four trihalomethanes (THMs) were increased up to 15 days. The average concentration of them was 0.0075 mg/L at the time of bottling and it was increased to 0.0214 mg/L after 15 days. The average acetaldehyde concentration was 0.0406 mg/L at the time of bottling but it was went up to 0.2251 mg/L after 11 days and then decreased. Although the initial concentrations of DBPs were below the drinking water standard, we also traced them at different storage conditions. Temperature affected the formations of THMs and acetaldehyde concentrations significantly. While the average concentration of THMs ranged from 0.0113 to 0.0182 mg/L at $25^{\circ}C$, it was increased to 0.0132 ~ 0.0256 mg/L at $50^{\circ}C$. In case of acetaldehyde, concentration ranged from 0.0901 to 0.2251 mg/L at $25^{\circ}C$, it was increased to 0.3394 ~ 1.0591 mg/L at $50^{\circ}C$. Throughout the tests with 7 BTWs samples, none of the chemicals was exceeded the drinking water standard of Korea. Therefore, it is recommended to avoid the exposure of BTWs to sunlight or high temperature during distribution and storage.

• 상하수도학회지
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• 제30권5호
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• pp.587-596
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• 2016

This study attempts to draw factors for an analysis of the operation effect of a rechlorination facility and autodrain equipment for residual chlorine equalization by installing and operating a rechlorination facility and autodrain equipment in P City and analyzing the practical evaluation method and operation effect. For this purpose, this study selected three indicators for an analysis of the effectiveness of residual chlorine equalization and conducted a comparative analysis before and after the implementation of the residual chlorine equalization. As a result of estimation, (1) the reduction of the residual chlorine concentration range from a water treatment plant to the pipe end was 16.0%; (2) the total reduction of chlorination input was 18.0%; and (3) the reduction of the generation of disinfection by-products was 19.5%. In addition, this achieved enough residual chlorine equalization in the supply process and shows that it could successfully achieve the economic feasibility of investment in equipment and the reduction of the generation of disinfection by-products. Like this, it is judged that the three indicators suggested in this study will be used sufficiently as indicators of an analysis of the effectiveness of residual chlorine equalization according to the operations of the rechlorination facility and autodrain equipment.

• 한국습지학회지
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• 제16권2호
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• pp.269-274
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• 2014

본 연구의 목적은 항생제 내성 균과 유전자 및, 항생제 내성 전달을 제어하는데 필요한 살균능 (CT, 농도 * 접촉 시간)을 서로 비교하는데 있다. 이를 위하여, 이를 위해 각기 다른 염소 주입농도(C)와 접촉시간(T)에 따라 각각의 항생제 내성 제거를 산정하였다. 그 결과 항생제 내성균 90%(1 log)이상 제어를 위해서는 CT 값(176~353 mg min/L)이 필요하였으며, 항생제 내성 유전자의 제거를 위한 CT 값은 195~372 mg min/L 이었다. 또한 항생제 내성 유전자의 전이 90% 이상 제거를 위한 CT 값은 187~489 mg min/L이었다. 따라서, 본 연구조건에서는 항생제 내성 유전자 및 유전자의 전이에 대한 제어를 위해서는 항생제 내성균 제어보다 더 높은 소독능이 필요함을 알 수 있었다.

• Environmental Engineering Research
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• 제11권4호
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• pp.217-231
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• 2006

The gas-phase formation of polychlorinated naphthalenes (PCNs) and dibenzofurans (PCDFs) was experimentally investigated by slow combustion of the three chlorophenols (CPs): 2-chlorophenol (2-CP), 3-chlorophenol (3-CP) and 4-chlorophenol (4-CP), in a laminar flow reactor over the range of 550 to $750^{\circ}C$ under oxidative condition. Contrary to the a priori hypothesis, different distributions of PCN isomers were produced from each CP. To explain the distributions of polychlorinated dibenzofuran (PCDF) and PCN congeners, a pathway is proposed that builds on published mechanisms of PCDF formation from chlorinated phenols and naphthalene formation from dihydrofulvalene. This pathway involves phenoxy radical coupling at unsubstituted ortho-carbon sites followed by CO elimination to produce dichloro-9, 10-dihydrofulvalene intermediates. Naphthalene products are formed by loss of H and/or Cl atoms and rearrangement. The degree of chlorination of naphthalene and dibenzofuran products decreased as temperature increased, and, on average, the naphthalene congeners were less chlorinated than the dibenzofuran congeners. PCDF isomers were found to be weakly dependent to temperature, suggesting that phenoxy radical coupling is a low activation energy process. Different PCN isomers, on the other hand, are formed by alternative fusion routes from the same phenoxy radical coupling intermediate. PCN isomer distributions were found to be more temperature sensitive, with selectivity to particular isomers decreasing with increasing temperature.

• 대한화학회지
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• 제37권7호
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• pp.677-682
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• 1993

방출조절성 약제를 개발하기 위한 방법으로 polyacrylic acid와 polymethacrylic acid에 thionylchloride로 chlorination하여 cephalexine을 반응시켜 Polyacryloylcephalexine 과 polymethacryloylcephalexine을 합성하였다. Polyacryloylcephalexine 중합체약에 대한 최소 발육 저지 농도로서 항균력은 Micrococcus luteus ATCC 9341과 Escherichia coli ESS이 우수하고, Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 25923, Mycobacterium phlei IFO 3158, Klebsiella pueumouiae KCTC 1560, Escherichia coli KCTC 1039, Salmonella typhimurium KCTC 1925 균주들에 대해서도 항균성이 대체적으로 우수하였다. polymethacryloylcephalexine 중합체약에 대한 최소 발육 저지 농도는 Micrococcus luteus ATCC 9341과 Klebsiella pueumouiae KCTC 1560이 우수하고, Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 25923, Mycobacterium phlei IFO 3158, Escherichia coli KCTC 1039, Escherichia coli ESS, Salmonella typhimurium KCTC 1925 균주들에 대해서는 항균력이 양호하였다.

• 한국환경과학회지
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• 제1권1호
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• pp.53-68
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• 1992

In order to research the adsorption removal characteristics of trace organic by-products in disinfection of drinking water by biological activated carbon(BAC), water samples disinfect- ted with $Cl_2$, $O_3$ and $ClO_2$ after treatment by fluidized-bed system with water added with humic acid(10mg/L) were investigated the formation and the removal of trihalomethanes (THMs), and the trace organic by-products by gas chromatography(GC) II gas chromatography/mass selective detector(GC/MSD). Control was used by activated carbon(AC) and water added with humic acid(HA). The results were summarized as follow : The THMs removal effect of BAC by chlorination was in lower 90 % than that of control(HA), the sorts of oxidants formed by $Cl_2$ , $O_3$ and $ClO_2$ were that $O_3$ was very fewer than $Cl_2$ or $ClO_2$, and that $ClO_2$ was fewer than $Cl_2$. The trace organic by-products were esters and phthalates etc. Based on results above, it is concluded that BAC was appeared the more desirable adsorbtion-degradation removal characteristics than that of AC.