• 유기물자원화
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• 제15권1호
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• pp.123-133
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• 2007

항생제 사용의 증가와 무분별한 사용으로 인한 항생제 오남용은 항생제 내성균 증가와 더불어 미생물 종의 변화 및 수질환경에 독성물질로써 작용할 수 있다. 특히 항생제는 생물학적 폐수처리 공정에서 미생물에 의한 하 폐수 처리의 효율성 문제를 가져올 수 있다. 본 연구에서는 축산업에서 가장 많이 사용되는 항생제로 조사된 Oxytetracycline(OTC) 항생제가 축산폐수의 생물학적 처리과정에서 질산화와 유기물 제거효율에 미치는 영향을 살펴보았다. 항생제가 축산폐수의 처리효율에 미치는 영향을 살펴보기 위해서 회분식 시험과 $A_2/O$(Anoxic-Anoxic-Oxic) 시스템을 이용하였다. 향후 항생제를 다량 함유하고 있는 축산폐수를 처리할 수 있는 축산폐수처리시스템에 대해서 연구하고자 한다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.343-347
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• 2003

황토볼을 이용하여 폐수처리를 한 결과 다음과 같은 결과를 보였다. 흐름도 A에서는 T-P 0.5ppm이하, T-N 1.0 ppm이하, COD 10ppm 이하였으며, 흐름도 B에서는 T-P 0.3ppm이하, T-N 5.0 ppm이하, COD 15 ppm 이하의 결과를 보여 주었다. 흐름도 C에서는 T-P 0.6ppm이하, T-N 10 ppm이하, COD 15 ppm 이하였으며, 흐름도 D에서는 T-P 1 ppm, T-N 8 ppm이하, COD 20ppm 이하의 결과를 보여 주었다. BOD는 각 흐름도 A, B, C, D에서 COD보다 높은 경우에는 6 ppm, 낮은 경우에는 3 ppm 정도의 차이를 보였다. SS는 각 공정에 따라 그다지 큰 차이를 보이고 있지 않으며, 1.0 처리 용량 Ton/day으로 계산 할 경우에 5 - 20 g/day 정도를 보이고 있다. 이러한 결과치는 하수종말처리장(특별대책지역 및 잠실수중보권지역)의 2 ppm 및 폐수처리시설(농공단지, 오${\cdot}$폐수처리시설 포함)의 T-P 8 ppm, T-N 질소성분 60 ppm이내의 탄소원 COD 40 ppm 이내의 기준에 해당하는 수치의 좋은 결과로 황토볼을 이용한 폐수처리 시스템의 가능성을 보여주고 있다.

• 대한환경공학회지
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• 제22권10호
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• pp.1757-1763
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• 2000

본 연구는 토양미생물을 활성화한 영양염류 제거 공정의 질소, 인 제거 특성을 Denitrifying Phosphorus removing Bacteria(DPB)의 영향에 의한 관점에서 파악하고자 행하였으며, 또한 DPB의 무산소 상태 하에서의 탈질 및 인 섭취 특성에 대해서도 연구가 진행되었다. Batch test 결과, 토양미생물을 이용한 영양염류 제거 공정에서의 질소, 인 제거는 무산소 상태에서 탈질과 동시에 인을 섭취하는 DPB(Denitrifying Phosphorus removing Bacteria)의 영향이 상당한 것으로 나타났으며 무산소 상태에서의 DPB에 의한 인 섭취 속도가 호기상태에서의 약 50%에 달하였고 초기 nitrate 농도가 DPB의 인 섭취 속도에 대한 영향인자임을 알 수 있었다. 그리고 영양염류 제거 공정에서의 DPB의 존재는 전체 공정의 효율을 증대시키는 것으로 판단되었다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권5호
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• pp.2115-2120
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• 2012

The presence of lung cancer cells in anoxic zones is a key cause od chemotherapeutic resistance. Thus, it is necessary to enhance the sensitivity of such lung cancer cells. However, loss of efficient gene therapeutic targeting and inefficient objective gene expression in the anoxic zone in lung cancer are dilemmas. In the present study, a eukaryotic expression plasmid pUC57-HRE-JAB1 driven by a hypoxia response elements promoter was constructed and introduced into lung cancer cell line A549. The cells were then exposed to a chemotherapeutic drug cis-diamminedichloroplatinum (C-DDP). qRT-PCR and western blotting were used to determine the mRNA and protein level and flow cytometry to examine the cell cycle and apoptosis of A549 transfected pUC57-HRE-JAB1. The results showed that JAB1 gene in the A549 was overexpressed after the transfection, cell proliferation being arrested in G1 phase and the apoptosis ratio significantly increased. Importantly, introduction of pUC57-HRE-JAB1 significantly increased the chemotherapeutic sensitivity of A549 in an anoxic environment. In conclusion, JAB1 overexpression might provide a novel strategy to overcome chemotherapeutic resistance in lung cancer.

• Biomolecules & Therapeutics
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• 제20권6호
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• pp.544-549
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• 2012

To examine the neuroprotective effects of ginsenoside R0, we investigated the effects of ginsenoside R0 in PC12 cells under an anoxic or oxidative environment with Edaravone as a control. PC12 neuroendocrine cells were used as a model target. Anoxic damage or oxidative damage in PC12 cells were induced by adding sodium dithionite or hydrogen peroxide respectively in cultured medium. Survival ratios of different groups were detected by an AlamarBlue assay. At the same time, the apoptosis of PC12 cells were determined with flow cytometry. The putative neuroprotective effects of ginsenoside R0 is thought to be exerted through enhancing the activity of antioxidant enzymes Superoxide dismutases (SOD). The activity of SOD and the level of malondialdehyde (MDA) and intracellular reactive oxygen species (ROS), were measured to evaluate the protective and therapeutic effects of ginsenoside R0. Ginsenoside R0 treated cells had a higher SOD activity, lower MDA level and lower ROS, and their survival ratio was higher with a lower apoptosis rate. It is suggested that ginsenoside R0 has a protective effect in the cultured PC12 cells, and the protection efficiency is higher than Edaravone. The protective mechanisms of these two are different. The prevent ability of ginsenoside R0 is higher than its repair ability in neuroprotection in vitro.

• 한국물환경학회지
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• 제23권1호
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• pp.19-26
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• 2007

The lab-scale BNR processes fed with Municipal Wastewater Before or After Primary Clarifier (MWBPC or MWAPC) were operated to observe the behavior of particle organic matter in terms of nitrification and denitrification efficiency. As a result of the fractionation of the COD from MWBPC or MWAPC using an aerobic respirometric serum bottle reactor, the total mass of biodegradable organic matter from MWBPC is about 52% greater than the mass from MWAPC. Batch reactors were operated to observe the effect of the Particulate Organic Matter (POM) on substrate utilization for denitrification. Although the consumption of POM for denitrification was observed, the increment of the Specific Denitrification Rate (SDNR) was not great. In terms of the effect of POM on nitrification at different HRTs, activate sludge reactors were operated to determine the optimal HRT when MWBPC and MWAPC were fed relatively. All reactors showed a great organic matter removal efficiency. Reactors fed with MWAPC had obtained the nitrification efficiency above 90% when the HRT of 4 hr, at least, was maintained, while reactors fed with MWBPC had same efficiency when the HRT longer than 5 hr was kept. Three parallel $A^2/O$ systems fed with MWBPC or MWAPC relatively were operated to investigate the effects of POM on BNR processes with varying the HRT of an anoxic reactor. For all systems, the efficiency of organic matter removal and denitrification, respectively, was great and about the same. In case of denitrification efficiency, system with MWAPC had 1.5% lower than system with MWBPC at the same HRT of anoxic reactor of 2 hr, and the increasing the HRT of the anoxic reactor by 1 hr in systems fed with MWBPC resulted in a 3.5% increment. The denitrification rate was similar while the consumption of organic matter in systems fed with MWBPC was higher than system fed with MWBPC. It suggests that POM in MWBPC was not be used significantly as a substrate for denitrification in system with the HRT of 3 hr of an anoxic reactor.

• 한국물환경학회지
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• 제24권5호
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• pp.563-568
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• 2008

In petroleum refining industry, caustic (NaOH) solution is used to remove $H_2S$ from hydrocarbon streams in naphtha cracking process. Once $H_2S$ is absorbed in caustic solution, the solution becomes known as spent sulfidic caustic (SSC), which contains high concentrations of hydrogen sulfide and alkalinity. This study was focused on the evaluation of autotrophic denitrification by SSC in a hybrid Bardenpho process. SSC was injected to the anoxic (1) and anoxic (2) tank at different S/N ratio. In a previous lab-scale study, as we operated a modified Ludzack-Ettinger process, it was observed that the COD increment of effluent and nitrification failure happened because of non-biodegradable matters in SSC and high pH, respectively. Thus cilia media was packed at 2.4%(v/v) in all aerobic tanks and the pH of SSC was neutralized from 13.3 to 11.5 with addition of sulphuric acid ($H_2SO_4$). Consequently, these strategies were successful because no COD increment of effluent was observed and nitrification failure did not happen. The maximum TN removal efficiency was 77.5% when SSC was injected to both the anoxic (1) and anoxic (2) tanks. The mean TN concentration of effluent in this condition was 5.8 mg/L.

• 한국환경보건학회지
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• 제31권4호
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• pp.340-348
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• 2005

Laboratory scale experiments were conducted to compare the performance of two types of sequencing batch reactor(SBR) systems, anoxic-oxic-anoxic-oxic $((AO)_2)$ SBR and anoxic-oxic-anoxic $(A_2O)$ SBR on the biological nitrogen and phosphorus removal. Also, the profiles of DO and pH in reactors were used to monitor the biological nutrient removal in two SBRs. The break point in the pH and DO curves at the oxic period coincided with the end of nitrifying activity at about 1 h 30 min in oxic phase, and the change in pH appears to be related to nitrate concentration. The TOC removal efficiency in $A_2O$ SBR was higher than that in $(AO)_2$ SBR. The denitrification was completed at the influent period. The 2nd non-aeration and aeration periods were not necessary for the nitrogen and phosphorus removal because of the low influent TOC concentration in this study. The release and uptake of phosphorus in $AO_2$ SBR was much higher than that in $(AO)_2SBR.$ In order to uptake more phosphorus, the 1st aeration period in $A_2O$ SBR should be prolonged.

• 한국물환경학회지
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• 제22권3호
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• pp.444-450
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• 2006

This study was carried out to compare the performance of two types of sequencing batch biofilm reactors (SBBRs), anoxic-oxic-anoxic-oxic $(AO)_2$ SBBR and anoxic-oxic-anoxic $A_2O$ SBBR, on the biological nutrient removal. The TOC removal efficiency in $A_2O$ SBBR was higher than that in $(AO)_2$ SBBR. At the 1st non-aeration period, the release of ${PO_4}^{3-}-P$ in $A_2O$ SBBR was higher than that in $(AO)_2$ SBBR because of the high TOC removal. At the 1st aeration-period, the nitrification was not completed in $(AO)_2$ SBBR, however, it was completed in $A_2O$ SBBR and the nitrification rate in $A_2O$ SBBR was higher than that in $(AO)_2$ SBBR. The release and uptake of ${PO_4}^{3-}-P$ in $A_2O$ SBBR was much higher than in $(AO)_2$ SBBR. Also, the profiles of DO and pH in reactors were used to monitor the biological nutrient removal in two SBBRs. The break point in DO and pH curves at the aeration period coincided with the end of nitrification.

• Journal of Microbiology
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• 제43권4호
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• pp.319-324
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• 2005

Estuarine sediments are frequently polluted with hydrocarbons from fuel spills and industrial wastes. Polycyclic aromatic hydrocarbons (PAHs) are components of these contaminants that tend to accumulate in the sediment due to their low aqueous solubility, low volatility, and high affinity for particulate matter. The toxic, recalcitrant, mutagenic, and carcinogenic nature of these compounds may require aggressive treatment to remediate polluted sites effectively. In petroleum-contaminated sediments near a petrochemical industry in Gwangyang Bay, Korea, in situ PAH concentrations ranged from 10 to 2,900 ${\mu}g/kg$ dry sediment. To enhance the biodegradation rate of PAHs under anaerobic conditions, sediment samples were amended with biostimulating agents alone or in combination: nitrogen and phosphorus in the form of slow-release fertilizer (SRF), lactate, yeast extract (YE), and Tween 80. When added to the sediment individually, all tested agents enhanced the degradation of PAHs, including naphthalene, acenaphthene, anthracene, fluorene, phenanthrene, fluoranthene, pyrene, chrysene, and benzo [a] pyrene. Moreover, the combination of SRF, Tween 80, and lactate increased the PAH degradation rate 1.2-8.2 times above that of untreated sediment (0.01-10 ${\mu}g$ PAH/ kg dry sediment/day). Our results indicated that in situ contaminant PAHs in anoxic sediment, including high molecular weight PAHs, were degraded biologically and that the addition of stimulators increased the biodegradation potential of the intrinsic microbial populations. Our results will contribute to the development of new strategies for in situ treatment of PAH-contaminated anoxic sediments.