• 한국환경과학회지
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• 제12권10호
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• pp.1079-1084
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• 2003

This study was carried out to check changes of components in the slaughter waste by the bacteria isolated from slaughter wastes from Gyungnam Province from May to June 2000, and to find usefu] organism for treatment of the waste. Bacteria used in this study were Aeromonas hydrophila, as the dominant of the waste. Optimum conditions for bacterial culture were obtained as the temperature of 35$^{\circ}C$, pH 6.5, and shaking of 120 rpm in nutrient broth. The mean values of dissolved oxygen was 4.14 mg/1; biochemical oxygen demand, 1731.21 mg/1; ratio of BOD/COD, 0.53-0.64; ratio of T-P/T-N, 1.0-1.41; and viable counts of the waste, 5.47${\times}$10$\^$7/ CFU. Little change in total nitrogen observed by 36 hr of the culture. The largest amount of increasing NH$_4$$\^$+/-N was observed in the sample that 10% of the waste added in nutrient broth with A. hydrophila showing the value of 29.19 mg/l at the beginning to 570.36 mg/1 by 36 hr of culture. However, the highest increasing ratio between initial amount and finals at 36 hr of culture showed as 41.6 times when 3% of the waste added. NO$_3$ -N was decreased showing the value of 71.27 mg/1 to 32.14 mg/1 by 24 hr of culture with the organism when 10% of the waste added in nutrient broth. Total phosphorus was decreased showing the value from 188.74 mg/1 to 101.41 mg/1 after 12 hr of culture with the organism when 5% of the waste added in nutrient broth, while T-P was decreased gradually by 24 hr of culture from 193.8 to 101.4 mg/1 when 10% of the waste added.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.516-522
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• 2023

The co-precipitation process plays a key role in the decontamination of radionuclides from low and intermediate levels of liquid waste. For that reason, the removal of Cs ions from waste solution by the co-precipitation method was carried out. A simulated liquid waste (¹³³Cs) was prepared from a 0.1 M CsCl solution, while wastewater generated by washing steel ash served as a representative of radioactive cesium solution (¹³⁷Cs). By co-precipitation, potassium ferrocyanide was applied for the adsorption of Cs ions, while nickel nitrate and iron sulfate were selected for supporting the precipitation. The amount of residual Cs ions in the CsCl solution after precipitation and filtration was determined by ICP-OES, while the radioactivity of ¹³⁷Cs was measured using a gamma-ray spectrometer. After cesium removal, the amount of cesium appearing in both XRD and SEM-EDS was analyzed. The removal efficiency of ¹³³Cs was 60.21% and 51.86% for nickel nitrate and iron sulfate, respectively. For the ash-washing solution, the removal efficiency of ¹³⁷Cs was revealed to be more than 99.91% by both chemical agents. This implied that the co-precipitation process is an excellent strategy for the effective removal of radioactive cesium in waste solution treatment.

• 방사선산업학회지
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• 제17권4호
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• pp.509-518
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• 2023

The Kori Unit 1 nuclear power plant, which is planned to be dismantled after permanent shutdown, is expected to generate a large amount of various types of radioactive waste during the dismantling process. For the disposal of Very-low-level waste, which is expected to account for the largest amount of generation, the Korea Radioactive waste Agency (KORAD) is in the process of detailed design to build a 3-phase landfill disposal facility in Gyeongju. In addition, a large container is being developed to efficiently dispose of metal and concrete waste, which are mainly generated as Very low-level waste of decommissioning. In this study, based on the design characteristics of the 3-phase landfill disposal facility and the large container under development, radiation exposure dose evaluation was performed considering the normal and accident scenarios of radiation workers during operation. The direct exposure dose evaluation of workers during normal operation was performed using the MCNP computer program, and the internal and external exposure dose evaluation due to damage to the decommissioning waste package during a drop accident was performed based on the evaluation method of ICRP. For the assumed scenario, the exposure dose of worker was calculated to determine whether the exposure dose standards in the domestic nuclear safety act were satisfied. As a result of the evaluation, it was confirmed that the result was quite low, and the result that satisfied the standard limit was confirmed, and the radiational disposal suitability for the 3-phase landfill disposal facility of the large container for dismantled radioactive waste, which is currently under development, was confirmed.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2017년도 춘계학술논문요약집
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• pp.281-282
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• 2017

• 유기물자원화
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• 제1권2호
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• pp.299-315
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• 1993

시민들의 생활폐기물에 대한 재활용활동을 알아보기 위하여 서울시 도봉구, 시흥시, 김포군을 선정하여 발생원별로 그 실태를 조사하였다. 3개 조사지역의 재활용량은 0.02 kg/인/일 -0.10 kg/인/일 범위에 있었으며, 회수율은 폐지가 42.7%로 가장 높고, 빈병, 유리류가 10.7%, 캔류가 14.8%, 플라스틱류가 2.8%로 가장 낮았다. 수집 및 판매되는 재활용품에서는 중량비나 판매금액의 구성비에 있어서 폐지가 60% 이상으로 가장 중요한 품목이었으며, 다음이 빈병류이었다. 재활용품의 판매금액은 주택지역이나 사무지역 모두 5원/인/일 이하로 미미한 액수였다. 시민조직의 일종인 재활용추진협의회의 구성을 보면 대부분이 통 반장 중심의 조직으로 구성되어 있었고 활동은 쓰레기의 재분류작업에 한정되어 있었다. 일반적으로 시민들의 참여도와 회원들의 만족도는 낮았으며 경제적 유인동기가 낮아서 가까스로 명맥을 유지하고 있었다. 이 논문에서는 재활용 활성화방안으로 분리수거지침의 제정, 적정 인구규모별 자생적 주민조직의 활성화, 유휴노동력의 활용, 민간수거업체의 육성에 대하여 검토하였다.

• 한국물환경학회지
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• 제23권2호
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• pp.216-221
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• 2007

The adsorption characteristics of malachite green on waste garnet have been investigated for its treatment from aqueous solution by employing waste garnet which is generated from the abrasive production process as an adsorbent. The influential factors examined were the initial concentration of malachite green in solution, reaction temperature, and the amount of adsorbent. Also, the effect of the modification of the surface of adsorbent on adsorption was examined. As the initial malachite green was increased with reaction temperature and the color removal of malachite green-containing solution was promoted with the amount of adsorbent. Finaly, increased adsorption of malachite green could be attained when the surface of glass was modified by hexamethyldisilazane.

• 대한지역사회영양학회지
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• 제5권2호
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• pp.316-323
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• 2000

This study was carried out to evaluate nutritional quality of the dosirak severed by 3 Dosirak manufacturing establishment in Kangnung. The subjects of this study came from 3 different male high schools in Kangnung. The portion amounts of Dosirak were weighed and the food intake was measured by substracting the leftover from the averaged portion amount. The leftover was measured by a modified aggregate selection plate waste measurement technique. The nutrient intakes were analyzed by a computer aided nutritional analysis program for professionals(CAN pro). The menu of the dosirak was too simple. The total amount of Dosirak was 714g and the percent of plate waste was 714g and the percent of plate waste was 7.2%. The male high school students were taking adequate energy, but the nutrients which did not meet 75% of the 1/3RDA(Recommended Dietary Allowances) were Ca, Fe, and vitamin B$_2$.

• KIEAE Journal
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• 제7권5호
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• pp.127-133
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• 2007

Each year the amount of construction wastes increases at a rapid pace. Particularly, wastes from apartment housing projects that make up 89.14% of the total construction projects have increased about 48% as compared with those of the year 2000. Construction wastes are therefore rising as an issue related to environmental problems and disposal costs. And there are ongoing studies of the disposal, control and recycling of construction wastes. Mitigation measures for the wastes, however, have been a rare subject of research that focuses on waste-generating factors by activity during apartment housing projects. Given that, the purpose of this study was to categorize construction wastes by work type and to identify the factors causing wastes in order to reduce them. This study investigated the amount of the wastes from apartment housing constructions by activity as related to disposal costs, and examined causes in the ordering, transport, material management and construction stage, respectively. The analysis results will likely bring about expectation effects that help reduce the generation of the wastes by establishing action plans.

• 한국분무공학회지
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• 제26권2호
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• pp.96-103
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• 2021

In order to improve the overall efficiency and meet the emission regulations of boiler systems, the heat exchanging methods between inlet air and exhaust gas have been used in boiler systems, named as the waste-heat-recovery condensing boiler. Recently, to further improve the overall efficiency and to reduce the NOx emission simultaneously, the concept of the water injection into the inlet air is introduced. This study suggests the models for the optimized design parameters of water injection for waste-heat-recovery condensing boilers and performs the analysis regarding the water injection amount and droplet sizes for the optimized water injection. At first, the required amount of the water injection was estimated based on the 1^st law of thermodynamics under the assumption of complete evaporation of the injected water. The result showed that the higher the inlet air and exhaust gas temperature into the heat exchanger, the larger the amount of injected water is needed. Then two droplet evaporation models were proposed to analyze the required droplet size of water injection for full evaporation of injected water: one is the evaporation model of droplet in the inlet air and the other is that on the wall of heat exchanger. Based on the results of two models, the maximum allowable droplet sizes of water injection were estimated in various boiler operating conditions with respect to the residence time of the inlet air in the heat exchanger.

• 한국환경과학회지
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• 제13권3호
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• pp.301-311
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• 2004

The purpose of this study was to examine teachers’ awareness of chemical waste produced in elementary school laboratory experimentation and how this awareness relates to collection and disposal of chemical waste. More specifically, the study looked at the correlation between the handling of chemical waste and factors such as years of teachers’ educational career, class size and amount of waste produced. The target population were 250 elementary school teachers in Gyeongnam area and 237 subjects were responded. Among the 237 responses, 37 cases that did not complete the questionnaire were eliminated. Therefore, 200 responses were analyzed in this study. The survey questionnaire consisted of 15 questions. The categories of the questionnaire were their skills of management and treatment of the chemical waste. The data collected were analyzed by SPSS 10.0, and the relations among variables such as class sizes and years of teaching experience were also analyzed by $x^2-test.$ The results in this study were as follows: First, there were no significant differences between the years of teaching and class sizes in the training experience of chemical waste disposal. Second, there was a significant difference between the science laboratory size and class sizes in the laboratory actual condition. In addition, in the relations between the number of times of experimentation and the years of teaching experience, there was a significant difference. Third, in terms of the discharge amount of chemical waste, there was a significant difference between the years of teaching and class sizes. Fourth, in the simple chemistry waste disposal process in the science laboratory, there also was a significant difference between the kinds of experimental equipments that used in the experimentation and the years of teaching. Based on this study, it was found that great amount of the chemical wastes produced in the science laboratory dumped into the drain and the treatment process of chemical waste was also inattentive. Even the importance of environmental education is emphasized in the elementary education, the basic problems occurred in the science laboratory is disregarded. Therefore, not only students but teachers have to pay attention to the disposal process of chemical waste in the laboratory in order to prevent environment pollution. Furthermore, the efforts of preventing environment pollution are needed such as opening the teacher training course about environment education, minimal use of chemicals, treatment of chemical waste, and so forth.