• 한국환경과학회지
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• 제14권1호
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• pp.23-32
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• 2005

Surface sediments (0$\~$4 cm) were sampled at 40 stations from Ulsan Bay and its adjacent areas of Korea, to evaluate the contamination by sewage-derived organic matters using fecal sterols. Some sterols were quantified by gas chromatography coupled to mass spectrometry (GC/MS). Total concentrations of eight sterols (co­prostanol, cholesterol, cholestanol, epicholestanol, epicoprostanol, ${\beta}-sitosterol,$ brassicasterol, and stigmasterol) in the sediments from Ulsan Bay and its vicinity varied from 929 to 23,444 ng/g dry weight. The most predom­inant sterols were cholesterol and coprostanol, accounting for $33\~72{\%}$ of total sterols. The concentration of coprostanol known as the indicator of human feces ranged from 141 to 8,257 ng/g dry weight. In particular, the coprostanol concentrations in the sediments from Jansaengpo Harbor and Taehwa River exceeded the value of 1,000 ng/g dry weight, suggesting that these areas could be considered as the hot-spot zones by municipal sewage contamination. Some molecular indices and multivariate data analysis were used to assess the origin of these sterols in the sediments. Results showed that the major routes of sewage contamination in Ulsan Bay and its vicinity were the input through Jansaengpo Harbor and Taehwa River.

• 펄프종이기술
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• 제47권3호
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• pp.40-46
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• 2015

For some Korean newsprint mill, addition level of aluminum sulfate has been reduced because sulfur from aluminum sulfate has detrimental effect on the efficiency of anaerobic water treatment. At this moment, an unexpected decrease in sizing degree of TMP mixed newspaper was occurred. The phenomena means that hydrophobic substance usually originated from TMP cannot be fixed on the paper. This study focused on effect of alum and PAC on sizing of paper and contamination. Also, substitutability of PAC was discussed as a possible alternatives of aluminum sulfate under anaerobic condition of water treatment. Evaluation of sizing degree and pitch deposit potential were performed at the varied addition level of PAC and aluminum sulfate. Hydrophobic substance mainly derived from TMP could be fixed on the surface of fiber by PAC. Fines retention was not changed by replacing aluminum sulfate with PAC. Additionally, fixing of hydrophobic substance without excessive agglomeration can be enhanced by PAC with low molecular weight. Consequently, sizing degree of newspaper and contamination of recycling process of ONP can be controlled by low molecular weighted PAC.

• 한국습지학회지
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• 제12권3호
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• pp.15-20
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• 2010

마산만유역의 창원시 수계에서 발생한 오염부하는 차집관로를 통하여 하수종말처리장으로 운반되거나 창원시 하천을 거쳐 봉암갯벌을 경유한 후 마산만으로 유입된다. 즉 마산만 하구 갯벌인 봉암갯벌은 도심에 위치하여 있고 민관산학의 협력으로 보존되어 생태학습장으로 이용되는 귀중한 갯벌이다. 특히 최근 몇 년 동안 조개류, 어류와 물새 등 다양한 생물이 관찰되고 있으며 우리나라 최초의 마산만특별관리해역 연안오염총량관리의 중심 지역에 해당한다. 1970년에 시작한 창원기계공업단지의 가동으로 마산만의 하구와 내만은 중금속으로 오염되었음이 보고되었다. 봉암갯벌의 저서생물의 서식지인 퇴적물에 존재하는 잔류성이 강한 주요 중금속 오염물질의 변화를 분석하였다. 아연, 구리, 납이 오염퇴적물 기준의 상위 기준 또는 심한 오염 기준을 초과하였고 인근 지점 별로도 95% 신뢰구간에서 차이를 보였다. 2006년과 2009년의 자료를 비교할 때 모든 중금속 농도가 점차 감소하고 있었다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2003년도 가을 학술논문집
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• pp.671-675
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• 2003

연구로 1,2호기 해체 사업이 본격적으로 착수하게 됨에 따라 2001년 8월부터 2002년 12월까지 연구로 2호기 부속시설인 동위원소 생산시설을 제염 및 해체하였다. 이 시설은 동위원소 생산용 콘크리트 핫셀, 납 핫셀 및 실험실로 구성되어 있다. 제염ㆍ해체의 대상물은 흄후드, 실험대, 씽크 및 오염된 내부 시설물이다. 안전한 해체 활동을 위해서 각종 지침서 및 절차서가 수립되었다. 해체 활동을 위해 총 20,933 man-hour의 인력이 소요되었고, 드릴링 머신 등 여러 장비가 투입되었다. 실험실에서의 최대 오염도는 유리성 오염도가 $\beta$ : 9.24 Bq/$\textrm{cm}^2$이였고, 고착성 오염도는 350,000 cpm이였다. 해체폐기물은 콘크리트류, 목재류 및 철재류 등으로 총 62.146 Ton이고, 작업자들의 피폭량은 0.33 mam-mSv로 나타났다.

• 한국축산식품학회지
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• 제34권6호
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• pp.792-798
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• 2014

The distribution channel of meat by-products from the pig farm to the final consumer can include a meat processor, wholesale market, wholesaler, retailer, and butcher shop. Bacterial contamination at any of these steps remains to be a serious public health concern. The aim of this study was to evaluate the distribution channel and microbial characteristics of pig by-products in Korea. Upon evaluation of pig by-products in cold storage, we found that the small and large intestine were significantly (p<0.05) higher in pH value compared to the heart and liver. The total plate counts were not significantly different among offals until cold storage for 7 d. The coliform count after 1 d of cold storage was significantly (p<0.05) higher in small and large intestine than in the other organs. The coliform count of heart, liver, and stomach showed a higher coliform count than small and large intestine until 7 d of cold storage. As determined by 16S rRNA sequencing, contamination of major pig by-products with Escherichia coli, Shigella spp., and other bacterial species occurred. Therefore, our results suggest that a more careful washing process is needed to maintain quality and hygiene and to ensure the safety of pig by-products, especially for small and large intestine.

• 멤브레인
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• 제27권1호
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• pp.104-107
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• 2017

역삼투막 운영에 있어서 유기물 오염에 대한 문제들을 해결하기 위해 많은 연구를 하고 있다. 현재 가성소다(NaOH)를 사용하여 유기물 오염 제거를 하고 있다. 본 연구는 지속적인 막오염 증가 문제를 해결하기 위한 물리/화학적 세정 기법으로서 기존에 사용하던 가성소다와 Micro-bubble를 이용하여 유기물 오염 제거 실험을 수행되었다. 멤브레인 강제 오염을 위해 Humic acid sodium, Bovine serum albumin, Sodium alginate 약품을 사용하여 유기물 오염을 시켰다. 유기물 오염에 따른 Flux를 관찰하였고, 가성소다와 Micro-bubble를 이용한 유기물 오염 제거 실험은 가성소다로만 사용했을 때보다 향상된 것을 관찰했다.

• 환경영향평가
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• 제19권2호
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• pp.107-116
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• 2010

In this research potential liquation of contaminants from surrounding soil to a reservoir in an island was studied to investigate the cause and route of contamination of Baengyeong-myeon reservoir. Soil of Baengyeong-myeon reservoir consists of $SiO_2$ and has a high iron content because of geological characteristics of its country rock. From the field investigation and simulation study it was found that highly accumulated carbon content in the reservoir sediment was incurred from ground water, which provides a good habitat for microbes. And the liquation, the cause of organics growth, occurs mainly on the bottom of the reservoir consisting marine clay layer once used as farmland. So dredging of the sediment of reservoir and replacing with valley soil is suggested to prevent continuous contamination of a reservoir in an island due to COD production.

• 대한의생명과학회지
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• 제28권3호
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• pp.195-199
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• 2022

The use of copper antibacterial films as an effective infection prevention method is increasing owing to its ability to reduce the risk of pathogen transmission. In this study, we evaluated the bacterial contamination of the antibacterial copper membrane attached to a door handle at a university over time. Six mounting locations with high floating population were selected. In three sites, the door handles with the antibacterial film were exposed, while the remaining three were not attached with the antibacterial films. On days 7 and 14, isolated bacterial strains were inoculated in BHI broth and agar, respectively. Colony-forming units (CFU) were determined after incubation. Strain identification was performed using bacterial 16s rRNA PCR and sequencing. Results showed that the bacterial population on day 14 significantly increased from 6 × 10⁹ CFU/mL (day 7) to 2 × 10¹⁰ CFU/mL. Furthermore, strain distribution was not different between the on and off the copper antibacterial film groups. In conclusion, although copper has an antibacterial activity, microbial contamination may occur with prolonged use.

• 한국환경과학회지
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• 제31권6호
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• pp.491-501
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• 2022

This study evaluated the contamination levels of inland pollution sources flowing into Taeanhaean National Park. The nutritional status of influents was assessed by analyzing water quality and trophic status index (TRIX) at 52 stations, and the contamination levels of sediments were evaluated by analyzing eutrophication cleanup index (CIET) and heavy metals at 36 stations. The results of the TRIX analysis showed that 26 of the 52 stations had influents with a TRIX value of 6-10 (poor water quality/very high trophic level), indicating atrocious water quality and high eutrophication levels. The results of the CIET analysis showed that 4 out of the 36 stations were highly contaminated with organic matter. Analysis of heavy metals showed that the copper (Cu) and zinc (Zn) levels exceeded the threshold effects level (TEL) and probable effects levels (PEL) at several stations. In addition, the arsenic (As) level exceeded the threshold effects level at one station, and the levels of the other heavy metals (Cd, Cr⁶⁺, Ni, Pb, and Hg) were lower. Most inland pollution sources have been identified as small-scale, but long-term and continuous exposure can negatively affect the marine ecosystem; therefore, it necessary to prepare inland pollution source management standards and measures suitable for the characteristics of the coastal area.

• Journal of Microbiology and Biotechnology
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• 제34권5호
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• pp.1101-1108
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• 2024

Earlier studies have validated the isolation of extended-spectrum beta-lactamase-producing Salmonella (ESBL-Sal) strains from food. While poultry is recognized as a reservoir for Salmonella contamination, pertinent data regarding ESBL-Sal remains limited. Consequently, the Ministry of Food and Drug Safety has isolated Salmonella spp. from retail meat and evaluated their antibiotic susceptibility and genetic characteristics via whole-genome sequencing. To further elucidate these aspects, this study investigates the prevalence, antibiotic resistance profiles, genomic characteristics, and homology of ESBL-Sal spp. obtained from livestock-derived products in South Korean retail outlets. A total of 653 Salmonella spp. were isolated from 1,876 meat samples, including 509 beef, 503 pork, 555 chicken, and 309 duck samples. The prevalence rates of Salmonella were 0.0%, 1.4%, 17.5%, and 28.2% in the beef, pork, chicken, and duck samples, respectively. ESBL-Sal was exclusively identified in poultry meat, with a prevalence of 1.4% in the chicken samples (8/555) and 0.3% in the duck samples (1/309). All ESBL-Sal strains carried the bla_CTX-M-1 gene and exhibited resistance to ampicillin, ceftiofur, ceftazidime, nalidixic acid, and tetracycline. Eight ESBL-Sal isolates were identified as S. Enteritidis with sequence type (ST) 11. The major plasmid replicons of the Enteritidis-ST11 strains were IncFIB(S) and IncFII(S), carrying antimicrobial resistance genes (β-lactam, tetracycline, and aminoglycoside) and 166 virulence factor genes. The results of this study provide valuable insights for the surveillance and monitoring of ESBL-Sal in South Korean food chain.