• Nuclear Engineering and Technology
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• 제51권3호
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• pp.746-754
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• 2019

Vitrification of radioactive liquid waste (RLW) provides a feasible solution for isolating radionuclides from the biosphere for an extended period. In vitrification, base glass and radioactive waste are added simultaneously into the melter. Determination of heat and mass transfer rates is necessary for rational design and sizing of melter. For obtaining an assured product quality, knowledge of reaction kinetics associated with the thermal decomposition of waste constituents is essential. In this study Thermogravimetry (TG) - Differential Thermogravimetry (DTG) of eight kinds of nitrates and two oxides, which are major components of RLW, is investigated in the temperature range of 298-1273 K in the presence of base glasses of five component (5C) and seven component (7C). Studies on thermal behavior of constituents in RLW were carried out at heating rates ranging from 10 to $40\;K\;min^{-1}$ using TG - DTG. Thermal behavior and related kinetic parameters of waste constituents, in the presence of 5C and 7C base glass compositions were also investigated. The activation energy, pre-exponential factor and order of the reaction for the thermal decomposition of 24% waste oxide loaded glasses were estimated using Kissinger method.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 봄 학술발표회 논문집
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• pp.521-528
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• 1999

As the size of our industry and population inclose, the byproducts such as municipal solid wastes, industrial wastes are in the increasing phase. The treatment of such things is rising as a social problem. Today, the final disposal of these wastes depends mostly on the landfill, and the sanitary landfill is required and designed for preventing soil and groundwater contamination. Clays have been used for a liner material of a sanitary landfill, however, the high quality clay is hard to come by and quite expensive as a lining material in our country. Using the waste lime produced abundantly every year from chemical processes was studied here, made from the proper mixing of the bentonite and the waste lime meets the regulations from the USEPA. The soil property index tests (sieve analysis, specific gravity test Atterberg limit test) were performed, and at last to confirm the sorption characteristics of the bentonite and the waste lime the sorption isotherm equilibrium test and the sorption isotherm were performed with Toluene and Ethylbenzene which are the main components of the leachate from the landfill.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.94-97
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• 2003

Recently, owing to the deterioration of reconstruction and the construction, much of the construction waste is discharged in our construction field, and the amount of construction waste are rapidly increased. These waste are raised to financial and environmental problems, so the method of reusing waste concretes has been studied and carried out many direction. Especially being want of resources, if waste concrete could be recycled as aggregate for concrete, it will contribute to solve the exhaustion of natural aggregate, in terms of saving resources and protecting environment. This study is that the floating properties of concrete with recycled coarse aggregate were investigated for the substitution of recycled coarse aggregate. The result of this study, in case of water reducing, the property of harden concrete for the substitution ratio of recycled coarse aggregate was increased. The Quality of recycled coarse aggregate concrete was improved by water reducing.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.1248-1251
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• 2000

Recently, the yearly amount of remicon used in Korea is approximately one hundred million cubic meter, and it caused a by-product, remicon waste sludge. The sludge produced by washing mixers or drums of remicon trucks is restrained by the law for waste disposal because its pH is over 12, so the expense for waste disposal is needed. Until now, the waste sludge water has been recycled and used for concrete materials as sludge water which is limited to 3% of cement unit weight. However, the study on the properties of the concrete mixed with this waste sludge is so insufficient that the quality of them can be hardly trusted. Therefore, the study on that will be discussed.

• 에너지공학
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• 제21권3호
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• pp.315-324
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• 2012

폐기물 저감 재활용 에너지화 기술은 27대 중점 녹색기술 중 하나로, 2012년까지 정부 R&D 투자가 증가해야 함에도 불구하고, 2008년~2010년 기간 동안 연평균 증가율이 오히려 감소하였다. 이에 따라 동 분야의 정부 R&D 투자 현황을 상세히 분석하였고, 그 결과 총 정부 R&D 투자는 감소하였지만, 동 분야에서 정의하는 전략제품 서비스 기술에 대한 투자는 증가하고 집중화 되는 추세로 나타나 투자의 질적인 측면은 양호했다고 판단된다. 특히 2010년에는 전략제품 서비스 기술 중 3개 기술군((1) 폐기물 에너지화설비, (2) 폐기물자원순환시설, (3) 폐기물기반 물질생산시설)의 비중이 24 ~ 28%로 비교적 균등하게 투자되어, 정부 R&D 투자는 질적으로 적절했다고 판단되어 진다. 이러한 분석틀은 향후 녹색기술 R&D 정책 추진점검에서 활용할 수 있을 것이다.

• 한국지반환경공학회 논문집
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• 제14권1호
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• pp.61-68
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• 2013

본 연구에서는 지반보강재로서 폐타이어 사용에 따른 환경영향을 평가하기 위하여 실내실험 및 현장시험시공을 수행하였다. 실내실험을 통하여 폐타이어의 용출특성에 가장 큰 영향을 미치는 폐타이어의 입경과 배수조건을 변화시켜가며 유출수의 pH, 탁도, TOC, Zn 농도를 분석하였다. 또한, 현장시험시공을 통하여 폐타이어를 이용한 보강토 옹벽 시공 후 하부 집수정의 수질을 분석하였다. 입경에 따른 용출실험 결과 폐타이어 입경이 증가할수록 용출농도가 감소하는 것을 확인할 수 있었으며, 이는 비표면적의 차이 때문으로 판단된다. 배수조건에 따른 용출실험 결과 배수조건인 경우 시간이 경과할수록 용출농도가 감소하여 주변 환경에 큰 영향을 미치지 않을 것으로 판단되나, 비배수 조건인 경우 시간이 경과할수록 용출농도가 증가하는 현상을 발견할 수 있었다. 1년간의 현장모니터링 결과 폐타이어로 보강된 옹벽으로부터 발생되는 침출수는 전반적으로 용출농도가 높지 않은 것으로 나타났으며, 침출수 발생 초기에 농도가 증가하다가 이후 점점 감소하여 원수인 우수와 비슷해지는 경향을 나타내었다. 따라서 폐타이어를 지반보강재로 사용함에 따라 발생하는 환경적 영향은 무시할 수 있는 수준임을 알 수 있었다.

• 농업과학연구
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• 제47권2호
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• pp.375-380
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• 2020

The high intrinsic water content and salinity of food waste prevent a smooth composting process and consequently cause social, economic and environmental problems. In this study, we investigated the distribution of the water content and salinity in food wastes to obtain useful primary data to ensure adequate and quality recycling. A total of 300 food waste (FW) samples were collected from residential apartments (home generated FW), a wide range of restaurants, i.e., restaurant generated FW that included Korean, Chinese, Japanese and western FWs, and several places that included food waste processing facilities (dehydrated FW cakes). The collected food wastes were oven dried for 48 hours at 80℃ after which the water and salinity contents were analyzed. The results show that the average water content of the FWs was 72.45 ± 10.51%, and the average salinity content was 2.03 ± 0.57%. Furthermore, the salinity of the collected FWs was characterized by where the FW was generated. By location, the salinity concentration of home generated FW was 2.30% while western food had the lowest salinity concentration of 1.18%. However, dehydrated cakes had the highest salinity concentration of 2.84%. Especially, the distribution of the salinity content in food wastes can form the basis for improving the compost quality in food waste recycling.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.529-532
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• 2006

In this study, recently it has to be solved urgently the unbalance of demand and supply about the fine aggregate because the sea sand is restricted by exhaustion of river sand and intensification of environmental law. In this background, manufacturing technology which can produce recycled sand from construction and demolition waste concrete mass is developed. However, the existed washing method has the problem which not only impurities but also many other things make poor quality. Therefore, it tries to conform in time necessity, the objective of this study is to develop the Sand Flux system which can product the high-quality recycled sand from wast concrete and high value-added technology of the high-quality recycled sand as basic materials for mortar and concrete. At the same time it will be able to improve the quality of recycled sand products as an experiment of the physical nature and a quality present condition the products of recycled sand from construction waste.

• 유기물자원화
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• 제9권2호
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• pp.77-86
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• 2001

As construction and expansion of wastewater treatment works is continuing, generation of sludge is increasing. Bur most sludge is not used appropriately but disposed by landfill dumping to sea. Furthermore direct landfilling of sludge cake containing moisture content over 75% has been legally prohibited since 2001 that's enforcement will be more strict in 2003. Such a situation means nowadays recycling of organic waste such as sludge and food waste is necessary. Composting is one of recycling methods commonly and used as an effective means of stabilizing organic waste and then compost can be used as fertilizer. However fertilizer law management which include standard of compost products and other fertilizers applied all sludge products indiscriminiately and was not flexible. So MOE has graded organic composts according to land applications to improve recycle of organic wastes. The classified organic compost which contains low contaminants has been possible to use as various purpose. This study enalyzed 30 samples which were raw materials for compost and compost products management well and to estimate the quality of compost products. Heavy metals were measured in Raw materials and OM/N, NaCl and VS were tested in compost products as well as heavy metals. As a result, approximate 10% of raw materials was not suitable to the grade A and 6.7% over the grade B of the regulation on raw materials for compost. In the case of 30 produced compost propducts approximate, 57% of composts was not compatible with the grade A and B of the regulation on composting product. The qualities of compost products were worse than raw materials, because the compost products have more regulation item raw materials have.

• 한국물환경학회지
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• 제22권5호
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• pp.895-904
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• 2006

The improved MLE (modified Ludzack-Ettinger) process was operated for piggery waste treatment in full-scale public livestock waste treatment plant. The treated waste from bioreactor was suitable for the strict effluent standard of 200 mgCOD/L and 60 mgTN/L as it was dewatered chemically without settling tank and passed through filtration process. Though this treatment method produced a great deal of sludge ($6.4m^3\;per\;m^3$ dewatered piggery waste) it was able to accomplish predominant effluent quality by removing non-biodegradable COD and color without advanced oxidation process as ozone, fenton and etc.. The nitrogen removal efficiency of bioreactor was rapidly declined from March to May (from 0.016 to 0.005 kgN/kgVSS-day) when disinfection is in earnest as well as from warm season when reactor temperature rises higher than $35^{\circ}C$(from 0.016 to 0.008 kgN/kgVSS-day). This study proves that counterplanes for infection residuals, bioreactor temperature and dewatering sludge reduction are necessary for piggery waste treatment.