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Microsized Corn-Oil Droplet (MOD)의 Trichloroethylene (TCE) 생물학적 탈염소화 분해 자연저감 완효성 촉진제 적용성 평가
한경진,김희윤,권수열,김영 한국물환경학회 2024 한국물환경학회지 Vol.40 No.1
Recently, enhanced in situ bioremediation using slow substrate release techniques has been actively researched for managing TCE-contaminated groundwater. This study conducted a lab-scale batch reactor experiment to evaluate the feasibility of natural attenuation for TCE dechlorination using microsized corn-oil droplet (MOD) as an activator considering the following three factors: 1) TCE dechlorination in the presence or absence of MOD; 2) TCE dechlorination in the presence or absence of inactivator of native microbial activity; and 3) MOD concentration effects on TCE dechlorination. Batch reactors were constructed using site groundwater and soil in which Dehalococcoides bacteria were present. Without MOD, TCE was decomposed into dichloroethylene (DCE). However, other by-products of TCE dechlorination were not detected. With MOD, DCE, vinyl chloride (VC), and ethylene (ETH) were sequentially observed. This result confirmed that MOD effectively supplied electrons to complete dechlorination of TCE to ETH. However, when an excess of MOD was provided, it formed unfavorable conditions for anaerobic digestion because dechlorination reaction did not proceed while propionic acid was accumulated after DCE was generated. Therefore, if an appropriate amount of MOD is supplied, MOD can be effectively used as a natural reduction activator to promote biodegradation in an aquifer contaminated by TCE.
완효성 탄소원 정제 내 citric acid의 생물학적 탈질소화 영향
한경진,염여훈,김영,권수열 한국지하수토양환경학회 2022 지하수토양환경 Vol.27 No.3
This study utilized citric acid as a floating agent in biological denitrification process and assessed its role under differentcarbon supplying conditions. Several microcosm tests including citric acid active (CAA), precipitating tablet release active(PTRA) and floating tablet release active (FTRA) were conducted to evaluate nitrate denitrification efficacy. In CAAreactors, nitrate removal was accompanied by the formation of denitrification by-products such as nitrite and nitrous oxide,with the extent of nitrate removal being proportional to citric acid concentration. These results suggest that citric acidinduced heterotrophic biological denitrification. PTRA reactor that incorporated CAA and the same electron donor showeda similar denitrification efficiency to CAA reactor. FTRA reactor, which contained the same amount of fumarate as PTRA,enhanced denitrification by 7% as compared to the PTRA reactor. The overall results of this work indicate that surpluscitric acid can be efficiently utilized in heterotrophic denitrification.
간외 담관 결석 환자에서 경피 경간 치료술의 유용성 및 안전성에 대한 연구
선한경 ( Han Gyung Seon ),권창일 ( Chang Il Kwon ),윤상필 ( Sang Pil Yoon ),유광호 ( Kwang Ho Yoo ),옥창수 ( Chang Su Ok ),김원희 ( Won Hee Kim ),고광현 ( Kang Hyun Ko ),홍성표 ( Sung Pyo Hong ),박필원 ( Pil Won Park ) 대한내과학회 2012 대한내과학회지 Vol.83 No.1
Background/Aims: Endoscopic retrograde cholangiopancreatography (ERCP) occasionally fails due to surgically altered anatomy, difficult cannulation, or poor general condition. This study evaluated the safety and effectiveness of percutaneous transhepatic papillary balloon dilatation (PTPBD) for managing extrahepatic bile duct stones. Methods: Between 2001 and 2010, 17 out of 509 patients with extrahepatic bile duct stones and acute cholangitis were enrolled retrospectively. After PTPBD of the sphincter, the stones were extracted using an occlusion balloon to push the stone over a guidewire into the duodenum. The procedure success was evaluated based on residual stones. In addition, the size and number of stones and complications were analyzed. Results: Of the 17 patients, nine had a previous gastrectomy, four had poor general condition, and four had unsuccessful cannulation, The stone diameter ranged from 8 to 25 mm, Seven, five, and five patients had one, two, or three or more stones, respectively. The results were successful in 16 out of 17 patients, with no residual stones. Treatment failed in one patient, who was then treated with the rendezvous technique with endoscopy. No procedure-related major complication occurred. Three patients had mild transient elevations of the serum amylase levels. Conclusions: PTPBD was safe and effective for managing extrahepatic bile duct stones in patients with unsuccessful or contraindicated ERCP.