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The effects of oxytetracycline on Nitrogen Cycle in a model aquaculture system
Carl Angelo Medriano,Kartik Chandran,Samir Khanal,Jae Woo Lee(이재우),Sungpyo Kim(김성표) 한국산학기술학회 2014 한국산학기술학회 학술대회 Vol.- No.-
This study aims to investigate the effects of OTC in the response of a Nitrosomonas europaea, a model nitrifying bacterium. For this aim, the variations of nitrogen species in aquaculture water samples and Nitrosomonas europaea culture, as a function of OTC concentration, have been monitored. As a result, aquaculture samples show the nitrification level is lower by 23% from 5ppm, 43% from 50ppm, and 46% from 100ppm OTC as compared to a control (no added OTC). Also, the addition of 50ppm OTC to Nitrosomonas europaea culture showed 29% lower degradation level compared to a control. As compared to control, the 10ppm OTC showed increased nitrite level by 30% and nitrous oxide level by up to 29% after 80 hrs. RNA expression analysis was able correlate amoA expression to the reduced level of ammonia removal. The hao, nirK, and norB gene expressions did not show correlation to the oxytetracycline concentration, thus suggesting that the dose influenced in other ways perhaps somewhere during post-transcription to enzyme activity
하수 처리시설의 공간 및 운전인자에 따른 항생제 내성의 통계학적 분석
김성표,조윤철,김이형,Kartik Chandran 한국습지학회 2011 한국습지학회지 Vol.13 No.1
본 연구의 목적은 하수처리장의 공간적 그리고 운전인자에 따른 테트라싸이클린 내성균(TRB) 및 테트라 싸이클린 내성 유전자(TRG)들의 거동을 파악하는데 있다. 이를 위한 노력으로, 세 개의 실제 다른 하수처리장내에서 7개월 이상 각각의 반응조별로 시료를 채취하여 TRB 및 TRG가 분석되었다. 통계 기법은 주성분분석(PCA)을 통해 이들 간에 어떠한 일반적 관계식이 성립하는지 알아보려 노력하였다. 통계 분석결과, 활성슬러지내에 TRB 농도는 1차 침전 유입수에 있는 TRB 농도에 많은 영향을 받는 것을 알 수 있었다. 또한, 본 연구를 통해 TRB와 TRG의 내거동이 하수처리장 SRT 조건에 많이 영향을 받는 것을 알 수 있었다.
Pak, Gijung,Salcedo, Dennis Espineli,Lee, Hansaem,Oh, Junsik,Maeng, Sung Kyu,Song, Kyung Guen,Hong, Seok Won,Kim, Hyun-Chul,Chandran, Kartik,Kim, Sungpyo American Chemical Society 2016 Environmental science & technology Vol.50 No.14
<P>This study mainly evaluated the effectiveness of ozonation toward the enhancement of the removal efficiencies of antibiotic-resistant bacteria (ARB), pB10 plasmid transfer, and pB10 plasmids under different pH and suspended solids (SS) and humic acid concentrations. First, chlorination was tested as a reference disinfection process. Chlorination at a very high dose concentration of Cl-2 (75 mg L-1) and a long contact time (10 min) were required to achieve approximately 90% ARB and pB10 plasmid transfer removal efficiencies. However, even these stringent conditions only resulted in a 78.8% reduction of pB10 plasmid concentrations. In case of ozonation, the estimated CT (concentration x contact time) value (at C-0 = 7 mg L-1) for achieving 4-log pB10 plasmid removal efficiency was 127.15 mg.min L-1, which was 1.04- and 1.25-fold higher than those required for ARB (122.73 mg-min L-1) and a model nonantibiotic resistant bacterial strain, E. coli K-12, (101.4 mg.min L-1), respectively. In preventing pB10 plasmid transfer, ozonation achieved better performance under conditions of higher concentrations of humic acid and lower pH. Our study results demonstrated that the applicability of CT concept in practice, conventionally used for disinfection, might not be appropriate for antibiotic resistance control in the wastewater treatment process. Further studies should be conducted in wastewater engineering on how to implement multiple barriers including disinfection to prevent ARB and ARG discharge into the environment.</P>