• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2003년도 가을 학술논문집
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• pp.701-706
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• 2003

A study on the electrosorption of U(VI) onto porous activated carbon fibers (ACFs) was performed to treat uranium-containing lagoon sludge. Effective U(Ⅵ) removal is accomplished when a negative potential is applied to the activated carbon fiber(ACF) electrode. For a feed concentration of 100mg/L, the concentration of U(VI) in the cell effluent is reduced to less than 1mg/L. The adsorbed uranium could be deserted from the ACF by passing a 1M NaCl solution through the cell and applying a positive potential onto the electrode. The regeneration of ACF from the cycling experiments was confirmed.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.283-296
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• 2020

A numerical model is established to investigate the run-up of a solitary wave after propagating over a triangular saw-tooth-shaped submerged breakwater. A rectangular-shaped submerged breakwater is simulated for comparison. Several factors, including the submerged depth, the lagoon length and the beach slope, are selected as independent variables. The free surface motions and velocity fields of the solitary wave interacting with the submerged breakwater are discussed. The results show that the submerged depth and lagoon length play significant roles in reducing the run-up. The influence of the beach slope is not significant. At the same submerged depth, the triangular saw-tooth-shaped submerged breakwater has only a slightly better effect than the rectangular-shaped submerged breakwater on the run-up reduction. However, a calmer reflected wave profile could be obtained with the rougher surface of the saw-tooth-shaped submerged breakwater. The study conclusions are expected to be useful for the conceptual design of saw-tooth-shaped submerged breakwaters.

• 생태와환경
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• 제48권1호
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• pp.1-11
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• 2015

본 연구에서는 동해안에서 10개의 석호들을 대상으로 어류군집의 조성의 차이를 파악하였고, 갈대 줄기의 탄소와 질소안정동위원소분석을 통하여 각 석호생태계의 유역환경을 예측하였다. 석호들 사이에서 어류의 조성(특히, 회유성 어류) 및 섭식기능군은 지형학적인 특성에 따라 분포의 차이를 보였다. 10곳의 석호들에서 갈대 줄기 ${\delta}^{13}C$과 ${\delta}^{15}N$값 각각 $-28.40{\pm}0.11$‰에서 $-26.87{\pm}0.25$‰과 $-1.09{\pm}1.45$‰에서 $12.08{\pm}0.53$‰의 범위를 보였다. 이들 석호에서의 갈대의 줄기 ${\delta}^{15}N$ 값의 차이는 토지 이용에 따른 인위적인 오염원의 차이와 석호의 지형학적인 특성 등과 관련이 있음을 보였다. 이 연구는 어류의 서식지 확보, 석호생태계에서의 생물다양성의 보전과 유역의 오염원에 대한 관리를 위한 유용한 정보를 제공할 수 있다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 학술논문집
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• pp.238-238
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• 2004

우라늄 변환시설은 중수로용 $UO_2$ 분말 제조 시설로서 2001년도부터 제염 해체를 통한 변환시설 환경복원사업을 시작하였다. 변환 공정의 운전 중 발생하여 라군(lagoon)에 저장되어 있는 방사성 슬러지 폐액의 처리는 시설의 해체과정에서 매우 중요한 업무중의 하나이다. 라군 슬러지의 주성분은 $NH_4NO_3$, $NaNO_3$, $Ca(NO_3)_3$, $CaCO_3$ 및 U 화합물과 소량의 Fe, Mg, Al, Si 및 P 화합물로 구성되어 있다.(중략)

• 한국제4기학회:학술대회논문집
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• 한국제4기학회 2003년도 제4기학회 제33차 학술발표대회
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• pp.39-40
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• 2003

• 한국해안해양공학회지
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• 제14권3호
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• pp.192-200
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• 2002

자연상태의 오염된 퇴적물과 준설과정을 거친 오염 퇴적물 사이에는 퇴적물이 안정상태에서 교란되어 다시 침강되기 때문에 체적변화가 발생한다. 또한, 부유물질의 침강을 촉진하기 위하여 투입되는 응결제 및 응집제의 영향에 따라 오염된 준설토의 체적변화가 다른 경향을 보인다. 본 연구는 약품투입량에 따른 오염된 준설토의 부피변화 분석에 중점을 두어 수행되었다. 퇴적물 시료는 동해안에 위치한 석호의 오염된 퇴적물(준설오니)을 이용하였으며. 함니율 변화, 응집제 및 응결제 투입량 변화에 따른 준설오니의 체적변화는 실내실험을 통하여 정량적으로 분석하였다. 적정 응집제 및 응결제 투입량은 체적변화가 가장 적은 값을 보이는 경우로 선정하였다. 분석결과, 준설오니의 체적은 평균 1.68배 증가하는 것으로 파악되었으며, 약품을 투입한 경우 함니율 증가에 따라 체적변화율이 증가하는 경향을 보이고 있으나 그 크기는 미미한 것으로 파악되었다.

• Environmental Engineering Research
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• 제12권4호
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• pp.129-135
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• 2007

This study evaluated microbial risk that could develop within soil microbial communities after amended with organic fertilizers from stabilized swine manure waste. For this purpose, we assessed the occurrences and competitiveness of antibiotic resistance and pathogenicity in soil microbial communities that were amended with swine manure wastes stabilized by a traditional lagoon fermentation process and an autothermal thermophilic aerobic digestion process, respectively. According to laboratory cultivation detection analysis, soil applications of the stabilized organic fertilizers resulted in increases in absolute abundances of antibiotic resistant bacteria and of two tested pathogenic bacteria indicators. The increase in occurrences might be due to the overall growth of microbial communities by the supplement of nutrients from the fertilizers. Meanwhile, the soil applications were found to reduce competitiveness for various types of antibiotic resistant bacteria in the soil microbial communities, as indicated by the decrease in relative abundances (of total viable heterotrophic bacteria). However, competitiveness of pathogens in response to the fertilization was pathogens-specific, since the relative abundance of Staphylococcus was decreased by the soil applications, while the relative abundance of Salmonella was increased. Further testes revealed that no MAR (multiple antibiotic resistance) occurrence was detected among cultivated pathogen colonies. These findings suggest that microbial risk in the soil amended with the fertilizers may not be critical to public health. However, because of the increased occurrences of antibiotic resistance and pathogenicity resulted from the overall microbial growth by the nutrient supply from the fertilizers, potential microbial risk could not be completely ruled out in the organic-fertilized soil samples.

• Asian-Australasian Journal of Animal Sciences
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• 제17권8호
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• pp.1168-1176
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• 2004

Intensive animal industries create large volumes of nutrient rich effluent, which, if untreated, has the potential for substantial environmental degradation. Aquatic plants in aerobic lagoon systems have the potential to achieve inexpensive and efficient remediation of effluent, and to recover valuable nutrients that would otherwise be lost. Members of the family Lemnaceae (duckweeds) are widely used in lagoon systems, but despite their widespread use in the cleansing of sewage, only limited research has been conducted into their growth in highly eutrophic media, and little has been done to systematically distinguish between different types of media. This study examined the growth characteristics of duckweed in abattoir effluent, and explored possible ways of ameliorating the inhibitory factors to growth on this medium. A series of pot trials was conducted to test the tolerance of duckweed to abattoir effluent partially remediated by a sojourn in anaerobic fermentation ponds, both in its unmodified form, and after the addition of acid to manipulate pH, and the addition of bentonite. Unmodified abattoir effluent was highly toxic to duckweed, although duckweed remained viable and grew sub optimally in media with total ammonia nitrogen (TAN) concentrations of up to 100 mg/l. Duckweed also grew vigorously in effluent diluted 1:4 v/v, containing 56 mg TAN/L and also modified by addition of acid to decrease pH to 7 and by adding bentonite (0.5%).

• Ocean and Polar Research
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• 제34권3호
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• pp.297-304
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• 2012

Pylaiella littoralis was collected in the Chuuk lagoon of the Federated States of Micronesia (FSM). The FSM has a variety of coral reef ecosystems, which provide essential materials, such as minerals, vitamins, essential amino acids, for marine organisms. In this study, the antioxidant activities of ethanol and enzymatic extracts of P. littoralis were evaluated by measuring their scavenging activities on DPPH free radical, Alkyl radical, hydroxyl radical and cell viability. The enzymatic extracts were hydrolyzed to prepare water soluble extracts by using five carbohydrate degrading enzymes (AMG, Celluclast, Termamyl, Ultraflo, and Viscozyme) and five proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase, and Protamex). As a result, the enzymatic extracts prepared by Flavourzyme, Ultraflo, and Kojizyme exhibited the greatest effects in DPPH free radical, alkyl radical scavenging activity and cell viability. Also, these enzymatic extracts had a higher antioxidant effect then commercial antioxidants in DPPH free radical and Alkyl radical scavenging activity. This study suggests that P. littoralis might be a useful source of natural antioxidants for the development of dietary supplements.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2003년도 가을 학술논문집
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• pp.665-670
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• 2003

우라늄 변환시설 내의 lagoon 슬러지의 처리 공정에서 발생하는 고농도 질산염 폐액의 처리를 위해 질산염 폐액의 열역학 및 열분해 특성을 조사하였다. 열역학적 특성은 고농도 질산염 폐액의 조성을 바탕으로 COACH와 GEMINKI II를 사용하여 조사하였으며, 열분해 특성은 TG/DTA, XRD 분석을 통하여 실제 질산염 폐액에 대하여 조사하였다. 폐액 내 함유 성분 중 $NH_4NO_3$는 $^250{\circ}C$에서 모두 분해되었으며, 잔류물의 대부분을 차지하는 $NaNO_3$는 $730^{\circ}C$에서 분해되는 것으로 나타났다. $NaNO_3$의 분해생성물인 불안정한 $Na_2O$를 안정한 화합물로 변화시켜 주기 위하여 $Al_2O_3$를 첨가할 경우 $NaNO_3$는 $450^{\circ}C$의 낮은 온도에서 분해 가능하였다. 이 같은 열역학 및 열분해 특성을 바탕으로 고농도 질산염 폐액의 처리 공정도를 제시하였으며, 특성 자료는 공정 모사의 기초 자료로 활용될 것이다.