• Nuclear Engineering and Technology
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• 제48권6호
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• pp.1368-1375
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• 2016

A radiological safety assessment study was performed for the transportation of low level radioactive wastes which are temporarily stored in Korea Atomic Energy Research Institute (KAERI), Daejeon, Korea. We considered two kinds of wastes: (1) operation wastes generated from the routine operation of facilities; and (2) decommissioning wastes generated from the decommissioning of a research reactor in KAERI. The important part of the radiological safety assessment is related to the exposure dose assessment for the incidentfree (normal) transportation of wastes, i.e., the radiation exposure of transport personnel, radiation workers for loading and unloading of radioactive waste drums, and the general public. The effective doses were estimated based on the detailed information on the transportation plan and on the radiological characteristics of waste packages. We also estimated radiological risks and the effective doses for the general public resulting from accidents such as an impact and a fire caused by the impact during the transportation. According to the results, the effective doses for transport personnel, radiation workers, and the general public are far below the regulatory limits. Therefore, we can secure safety from the viewpoint of radiological safety for all situations during the transportation of radioactive wastes which have been stored temporarily in KAERI.

• 한국환경보건학회지
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• 제26권3호
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• pp.81-85
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• 2000

In order to reduce emission of air pollutants from spot incineration, it is required to develope the combustion chamber of small wastes incinerator having combustion efficiency. The characteristics of combustion of the incinerator with combustion chamber having tangential angels with surface of 45$^{\circ}$of air supply nozzles were studied in accordance with non-grate, fixed-grate and shaking-grate in the combustion chamber. Combustion conditions were evaluated with combustion efficiency, emission of hazardous gases, temperatures, ignition loss of ash and so on. Combustion efficiencies were shown 73.9% for non-gate, 81.1% for fixed-grate and 89.0% for shaking-grate. Emissions of CO were revealed 6.52 ppm for non-grate, 273 ppm for fixed-grate and 224 for shaking-grate. Comprehensively evaluated, combustion conditions got better in order of shaking-grate, fixed-grate and non-grate. This study suggests that small wastes incinerator should have shaking-or fixed-grate in combustion chamber to get better combustion condition even though at expensive cost of manufacturing.

• 콘크리트학회논문집
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• 제12권3호
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• pp.87-94
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• 2000

Disposal of casting foundry fly ash generally depends on reclamation up to the present. This is the great loss from a standpoint of saving resources and utilizing industrial wastes. Therefore, a study on the reuse of fly ash as a substitute material for construction is necessary in order to utilize industrial wastes, to reduce cost and improve quality in producing concrete products, and to protect environment from pollution. In this study, methods for the reuse of the casting foundry fly ash, industrial wastes products, as an admixture for concrete are discussed. For this purpose, fly ash was extracted from casting foundry and tests of physical and chemical properties are executed. Also, various characteristics of concrete using fly ash as an admixture are experimented. Finally, the reuse methods for casting foundry fly ash are presented.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.372-378
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• 2003

This study investigates the fractional composition and the leaching characteristics of heavy metals in polluted soils due to mining activities. The fractionated composition of heavy metals is classified into five fractions, adsorbed, carbonate, reducible, organic and residual fraction. The status of humic substances in mine wastes of most sites are polyhumic except tailing from Sangdong mine. According to the sequential extraction procedures (SEPs), leaching probabilities of Cd in coal wastes and tailing are relatively low due to high percentage of residual fraction. 46.4% of Ni in tailings from Sangdong mine is probably leached under oxidized environment, and 39.4% of Cu in these tailings is readily extracted under strongly oxidized environment by organic fraction. According to leaching condition of pH 3.0 and pH 5.6, the amount of heavy metals leached out of coal wastes and tailing increases to 1/2 hours. At pH 3.0 and pH 5.6, concentration of Ni in tailing increases up three times of the initial value. Heavy metals released from coal wastes and tailing were not influenced significantly by leaching time.

• 방사성폐기물학회지
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• 제6권4호
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• pp.347-356
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• 2008

처분시설 성능을 유지하고 안전성을 확보하기 위해서는 방사성폐기물의 처분 적합성 여부를 확인하기 위한 폐기물 인수기준이 필요하다. 국내 처분장 조건에 맞는 인수기준을 개발하기 위해 경주 처분부지와 유사한 해외 처분장 인수기준과 국내에서 발생되는 방사성폐기물 특성을 분석하여 심층 검토하였다. 방사성폐기물 인수기준은 국내 전문연구기관인 한국원자력 연구원과의 기술용역을 통하여 개발되었으며 국내 폐기물 발생기관별 폐기물특성, 발생자의견 등 국내여건을 반영하여 기준이 설정되었다. 또한 설정된 기준은 학계, 연구계, 산업계로 구성된 기술자문협의체를 통해 협의되고 검증되었다. 폐기물인수기준은 국내에서 발생되는 폐기물을 가능한 수용할 수 있도록 폐기물발생기관의 의견을 수용하고 방사성폐기물 처분시설의 안전성을 확보할 수 있는 수준에서 개발되었다. 그러나 개발된 폐기물인수기준은 현재 각 발생기관에서 발생된 폐기물 전량을 처분할 수 있는 기준이 아니므로 본 폐기물인수기준에 부적합한 폐기물은 각 발생기관에서 별도의 처리방안을 강구하여 처분의뢰될 것으로 예상된다. 앞으로 방사성폐기물 처분시설의 인수기준은 장기 안전성이 보장되도록 핵종별 처분농도 제한치 등 관련기준은 지속적으로 보완해 나갈 계획이다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.374-377
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• 2003

본 연구는 각종 유기성 폐기물의 혐기소화시 혐기성 분해 특성에 대해 알아보고자 하였다. 실험에 적용된 유기성 폐기물의 종류는 음식폐기물, 축산폐기물, 농산부산물 이었으며 기질과 접종액을 1:1로 혼합하여 회분식으로 실험을 수행하였고, 이때 발효조내의 TS, VS, sCOD 변화 및 가스발생량을 측정하였다. 음식폐기물의 경우 실험초기에 혐기성 분해가 일어났으며, 농산부산물의 경우 실험 종반부에 혐기성 분해가 일어났다. 반면 축산폐기물의 경우 실험초기에 한차례 혐기성 분해가 이루어지고 종반부에서 다시 혐기성 분해가 이루어짐을 알 수 있었다.

• 한국토양비료학회지
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• 제46권3호
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• pp.173-181
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• 2013

Livestock wastes are considered as major environmental pollutants because they contain high concentration of organic materials. In 2001, The Environmental Department reported that stock farmers were increasing as 5.1%/year, which resulted in a gradual increase in livestock wastes generation. The direct disposal of livestock wastes create several environmental problems. Thus, several countries banned the disposal of livestock wastes in environment including aquatic systems. Recently, aeration-based liquid fertilization was considered as potential way for the disposal of livestock wastes. In this study, next generation sequencing (NGS) analysis was used to understand the microbial community changes during liquid fertilization of livestock wastes. Microbial community was compared with liquid fertilizer physicochemical analysis such as $BOD_5$, $COD_{Mn}$ pH, N (Nitrogen), P (Phosphorus), K (Potassium) etc. The physicochemical parameters and bacterial community results pave the way for producing effective livestock-based fertilizer. By comparing the physical characteristics of the manure with microbial community changes, it is possible to optimize the conditions for producing effective fertilizer.

• 유기물자원화
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• 제16권1호
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• pp.70-78
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• 2008

본 연구에서는 경기도 B지역 학교 폐기물의 성상 및 물리 화학적 특성을 조사하였다. 이것은 폐기물 재활용 및 자원화시설 설계를 위한 기초자료로 활용할 수 있게 하고자 한다. 학교폐기물의 물리적 조성의 실험결과 음식 쓰레기 12.25%, 종이류 56.26%, 플라스틱과 비닐류 9.26%, 섬유 1.52%, 나무 3.70%, 고무 및 피혁류와 기타는 0.11%이다. 학교폐기물의 대부분은 종이류와 플라스틱류이고, 약 90%가 가연성분인 것으로 나타났다. 삼성분 분석 결과 수분 5.72%, 가연분 88.29%, 그리고 회분 5.98%로 나타났으며, 농촌지역 학교 폐기물 성분중 수분이 도시지역 학교보다 높게 나왔다. 건조된 폐기물의 원소 분석 결과 탄소, 산소, 수소가 높게 나왔으며 학교폐기물의 저위발열량은 3051.44kcal/kg로 조사되어졌다.

• 한국미생물·생명공학회지
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• 제25권6호
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• pp.623-629
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• 1997

The studies of isolation and physiological characteristics of mesophilic or thermophilic bacteria from thermophilic oxic process (TOP) treating Chinese restaurant wastes were conducted. Chinese restaurant wastes were consist of moisture; 75.8%, solids; 24.2% and ash; 0.49%. The volatile solid was about 99% of total dry solids. In wastes used in this experiment, there was content of crude protein; 4.47%, crude lipid; 3.56%, free sugar, 0.4% , crude starch; 10.34% and crude fiber 3.14%, respectively. And then it has about 4,970 kcal/kg-dry solid of Chinese restaurant wastes. From TOP treating the chinese restaurant wastes, 37 strains of mesophilic or thermophilic bacteria were primarily isolated using medium used for the isolation and among them 6 strains of thermophilic and 7 strains of mesophilic bacteria were selected by testing the activities of amylase, cellulase, protease and lipase. TB-1, TB-9 as thermophilic bacteria and MB-15-1, 15-2, MB23 as mesophilic bacteria having strong enzyme activity were selected among isolated strains. All selected strains reduced nitrate to nitrite and they utilized glucose, manose, manitol, and maltose as carbon source. From these MB15-2 was identified as Bacillus cereus, TB1, Bacillus licheniformis and TB9; Bacillus schlegelii.

• 방사성폐기물학회지
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• 제2권4호
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• pp.231-238
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• 2004

원자력 발전소에서 발생하는 고체 방사성 폐기물인 이온교환수지, 제올라이트, 활성탄 및 슬러지 에 포함된 성분 원소 분석을 위한 산분해 조건을 확립하였다. 방사성 폐기물의 분해 에는 흔합산을 이용한 밀폐형 극초단파 산분해법을 사용하였으며, 제안한 방법에 따른 산분해 후의 용액은 맑고 색이 없는 투명한 상태임을 확인할 수 있었다. 또한, 산분해 과정을 거친 각각의 용액 시료는 ICP-AES와 AAS를 사용하여 분석하였고, 모의 방사성 폐기물에 첨가한 5종의 금속 원소들은 $94{\%}$ 이상의 높은 회수율을 보여주었다. 화학적 특성을 고려하여 제안된 산분해 조건에 의해 용액화된 중${\cdot}$저준위 방사성 폐기물의 성분 원소 분석은 최적의 유리화 기술 개발을 위한 기초 자료로 유용하게 사용될 수 있을 것으로 판단된다.