In this study, the chemical flow of butadiene in the Korean chemical material industry was analyzed by chemical flow analysis. In addition, the atmospheric emissions estimation equation was calculated. The results of the product-specific material flow analysis showed that 1,450,076 tons of butadiene have been used in the domestic chemical material industry. Of that, 28.2% was used for SBR, 29% for BR, 21.2% for ABS, and 21.5% for the manufacture of other rubber products. In addition, butadiene has been used in the production of final products, such as automotive supplies and equipment, tires, shoes, and consumer electronics products. Among them, it was found that the major product at 39% in the production of tires. About 56.7 tons of butadiene found to have been emitted into the atmosphere by the calculated expression. The results of the regional analysis showed butadiene was treated in five cities and seven provinces, with the largest amount of butadiene used in Chungnam. The results of standard industrial classification showed that, among the 23 divisions of the standard industrial classification, butadiene flow in the manufacture of synthetic resins or other plastic materials was found to account for about 70% of the total.

Material flow analysis (MFA) of recycling material and of mercury from linear-type spent fluorescent lamps (SFLs was performed to estimate the material composition of the chain recycling process by an input-output approach. The recycling process system for linear-type SFLs was established using an end-cutting system, a hammer crusher, a screen separation system, a mercury distillation system, and an activated carbon adsorption component. From the results of the MFA of lineartype SFLs, 92% of materials used in linear-type SFLs such as glass, aluminum, and phosphor powder can be recycled. For MFA of mercury, the mercury content in the phosphor powder was the highest among material compositions tested and the total mercury amount in the recycling materials from 1 ton of SFLs was estimated to be 75.43 g. In the recycling process system for linear-type SFLs, the mercury amount in the vapor phase was analyzed and found to be 2228 mg in the endcutting system, 172 mg in the hammer crusher, and 2585 mg in the screen separation system. The total mercury amount in the vapor phase was estimated to be 4985 mg, which was only 6.22% of the total mercury amount emitted from the recycling process system. Hence, it was estimated that the MFA of the total mercury amount obtained from the vapor phase and the recycling materials of 1 ton of SFLs using the recycling process system was 80.175 g.

본 연구에서는 개량형 공압식 가동보를 대상으로 가동보의 기립 각도변화에 따른 잠김흐름 특성을 분석하고 유량계수를 산정하였다. 실험결과, 위어마루에서 하류수면까지의 높이와 위어마루에서 상류 수면고 높이의 비()에 대한 유량감소계수()의 변화는 가1에 가까울 수록 감소하였다. 따라서 보 하류에서의 수심은 상류보다 작지만 보를 통과하는 흐름으로 인해 하류 유속이 빠르게 나타났으며, 유량이 증가할수록 상·하류 수위차는 감소하는 것으로 나타났다. 또한 같은 유량조건인 경우 하류수두는 가클수록 크게 증가하였다. 개량형 공압식 가동보의 잠김흐름 유량계수는 가동보의 물리적 제원보다는 상류 접근흐름수두와 상·하류 흐름조건에 의하여 결정되었

In this study, the recycling processes of construction and demolition waste (C&D waste) were analyzed, and its national recycling rate was determined using material flow analysis (MFA). Available statistical data provided by Ministry of Environment and Korea Environment Corporation were used for the MFA study. The collected data were carefully examined and validated by field investigations. System boundary for MFA covered from waste generation from construction sites to final disposal in 2013. The field investigation showed that recycled aggregate is produced through mechanical shredding, separation, and screening processes of C&D waste. The production efficiency (or process yield) was estimated to be approximately 81.2% on average. The foreign materials in the waste accounted for 18.8% by weight. The separated impurities were sent to recycling facilities, incineration facilities, or landfill sites, depending on the physicochemical characteristics. Efficiency of recycling facilities and the statistical data were integrated to estimate the national actual recycling rate, which turned out to be 87.7% in 2013. Approximately 49.1% of the construction-related waste was recycled as recycled aggregate for concrete production and road base layer for asphalt pavement. Based on the result of MFA, there is 9.8% difference between the actual recycling rate in this study and reported recycling rate by national statistics. In the future, more various C&D waste treatment and disposal facilities, along with aggregate recycling facility, should be investigated to verify the actual recycling rate determined by this study. Statistical accuracy should be further refined through additional field investigations. Our findings can be applicable to development of recycling policies and best management practices for C&D waste streams.

This study, examines the flow characteristics of upstream channel depending on water gate operation of Nakdan Multi-fuctional weir. The specific purpose of this study are to simulate the variation of flow velocity depending on the operation of the weir using 1-dimensional hydraulic model, HEC-RAS, and compare it with observed velocity. For discharge conditions from 50 ㎥/s to 3,500 ㎥/s, it is observed that the velocity of upstream channel is almost constant, whereas for probability flood discharge, the velocity and froude number are increased as the discharge values are increased. The velocity values for downstream boundary condition EL, 40.0 m are more decreased than those for EL. 40.5m. From comparison on the variation of water stage depending on water gate operation, it is observed that the stage values are almost constant for discharges below 300 ㎥/s, whereas 5 cm to 20 cm for discharges over 700 ㎥/s. Flow velocity at streamflow gauging station. Nakdong, is decreased by more than 875% after installing the weir. The results obtained from this study indicate that the velocity of upstream channel is decreased and the discharge and velocity of downstream channel are significantly varied after installing the weir.

In this study we conducted a material flow analysis (MFA) of the four major types of waste electrical and electronic equipment (WEEE), namely refrigerators, TV sets, washing machines, and air conditioners, based on the most reliable data available from the Eco-Assurance System, other governmental sources, the literature, a field survey, and interviews. A MFA of six major components, iron, copper, aluminum, plastics, precious metals, and rare metals was also conducted. The estimated total generation of WEEE in 2013 amounted to 401.8 thousand tons, of which 3.8% (or, approximately 5% including printed circuit boards) was exported and 55.0% was recycled. The collection by the formal take-back system occupied 34.6% of the total generation, from which 83.9% was recovered as valuables. The six major components amounted to 299.7 thousand tons, among which 89.8% of iron, 91.4% of copper, 56.0% of aluminum, 27.1% of plastics, 37.1% of precious metals, and 6.2% of rare metals were recovered. A high positive correlation was found between the amount of WEEE flowing into the private recycling business and its economic value. Since the recovery ratio in the private sector was estimated to be much lower, while the potential environmental impact was higher, an optimal strategy was identified to enhance the collection by the public sector. Providing economic incentives should be an effective means to encourage private collection through the formal take-back system.

The purpose of this study is to analysis the materials flow of steel cans from producing to discarding, finding problems in materials flow diagram in performance recycling of steel cans, and improvement ways for relevant systems and policies. Through supply various statics in KECO, it was found that the amount of steel calculated in Korea is 80,555 thousand tons. This amounts is reused from steel scrap of 35,143 thousand tons. After that producing steel was manufactured to steel plate, and manufactured steel plate produced steel cans of 273 thousand tons. The steel cans of 103.2 thousand tons was released in Korea. The 89.5 thousand tons of wastes for recycling was 86.8% for total of 103.2 thousand tons for recycling. The amount of recycling was assumed that there is no loss in collection, sorting and packing stage. According to such studies, a materials flow diagram was drafted and the problems in recycling for each stage were reviewed. In consequence plan to improve consist of materials and structure in cans in production stage, plans to restrict inclusion of foreign particles in discardment and selection section, plan to provide different support in funding and granting quality ratings in the sorting and compression section was suggested.

The damage cases by debris flow and each investigation techniques used by the institutes associated with debris flow were analysed. It was concluded that considering urban debris flow characteristics and the purpose of investigation is essential to establish reasonable debris-flow damage investigation technique.

Environmental concerns regarding mercury-containing fluorescent lamps have been raised in many countries, especiallyafter International Minamata Convention on Mercury in 2014. Improper management and disposal of the waste such aslandfilling and incineration may pose serious threats to the environment and human health. In Korea, mercury-containinglamps have been regulated by the expanded producer responsibility (EPR) system since 2004. However, only less than30% of the lamps sold to consumers has been collected by municipalities. In order to provide additional measures relatedto proper management of fluorescent lamps, there is a need for a quantitative material flow study by life cycle stage. Inthis study, material flow analysis was conducted by collecting relevant data from literature review, available statistics,and field site visits to lamp recycling facilities. According to the results of this study, approximately 150 million unitsof fluorescent lamps were put on the market in 2013, while 36.9 million units of the lamps were recycled mainly fromhouseholds in the year. It is estimated that approximately 3.5 million units and 2.3 million units of lamps in disposalbags are disposed and treated in landfills and incineration facilities, respectively. This study also found that there weresignificant amounts of uncollected lamps that were present in industrial sectors. The material flow of the industrial sectorsare largely unknown and not properly regulated by government. Based on the mass flow of mercury in lamps, 1.6ton ofmercury in lamps came into consumer markets in 2013. Approximately 407kg of mercury was collected by the recyclingprocess at the fluorescent lamps recycling facility. The mercury disposed in landfills and treated in incinerators were foundto be 38.3kg and 25.5kg, respectively. Further study may be warranted to focus the material and mercury flow of lampsin industrial sectors in order to accurately determine the final destination and disposal of such waste in the environmentbecause there are very few available statistical data regarding distribution flow and treatment of lamps in the sectors.

Neodymium(Dysprosium)-permanent magnets (Nd(Dy)-Fe-B Magnets) have necessity and potential to be recycled given their high criticality and important roles in various high-tech fields as well as the characteristics of being selectively disengaged from the assemblies in which they are used. This study focused on secondary material flow (downstream) of Nd(Dy)-Fe-B Magnets in South Korea. The quantitative information includes the primary data of each category (Emission - Collection - Disengagement - Resource Recovery - Remanufacturing) with domestic recycling situations of the magnets, which can contribute to more effective policy-making. As a result of the material flow analysis, this study provides the primary data of Nd and Dy at each stage and inhibiting factors (bottleneck) of Nd-Fe-B Magnets recycling and suggests the method for improvement of recycling of rare earth magnet.

The depth of low permeable layer in Jeju Island was analyzed using the geologic columnar section data. The highest low permeable layer was found in center of Mt. Halla and the deepest area was in eastern part of Jeju Island. The study area, Seongsan watershed, is located in the eastern part of Jeju where the low permeable layer showing deep in a northward direction. Based on this analysis, the MODFLOW modeling was performed for groundwater flow of Seongsan watershed. The boundary of Seongsan watershed was set up as a no-flow and the modeling result showed the difference -0.26~0.62 m compared to the observed groundwater level. Meanwhile, MODFLOW model results considering low permeable layer showed -0.26~0.36 m differences compared to groundwater level and indicated more accurate than no-flow method result. Therefore, to interpret the groundwater flow over Seongsan watershed, comprehensive consideration including the low permeable layer distribution below the basalt layer is needed.

Environmental regulations on the management of waste electrical and electronic equipments (WEEE) have been strengthened in many developed countries. Improper management and disposal of such waste, especially in informal sectors, may pose serious threats to the environment and human health. In Korea, there are very few available statistical data regarding distribution flow and treatment of WEEE in informal sectors (i.e., unreported private collection and recycling facilities). In order to provide additional measures related to proper management of WEEE, there is an urgent need for a quantitative material flow study on the amount of the waste found in the sectors. This can be achieved by conducting a statistical analysis of the flow of WEEE in the sectors and by drawing significant results and implications of such analysis. In this study, the relevant data were collected from literature review and a number of field site visits to informal private collection and recycling sites with survey in Daejoen Metropolitan City. Statistical analysis of the survey related to the distribution of WEEE in informal sectors was conducted to determine the quantitative flow of WEEE in the sectors. According to the results of this study, 3.38 kg/person/year were introduced into informal sectors in 2013, while 2.48 kg/ person/year was recycled in formal sectors in 2012. This study implies that there are significant amounts of WEEE that are present and processed in the sectors, which are not regulated by government. Small private collectors of WEEE in informal sectors received approximately 60.6 unit/month on average. The results of this statistical study indicate that there are no significant differences among the factors such as the amount of treatment, the number of employee, and the degree of dismantle process. However, there is significant difference among the WEEE category large home appliance, small-sized home appliance, and audio-video equipment. Further study may be warranted to focus the flow of WEEE in informal sectors in more large scale in order to accurately determine the final destination and disposal of such waste in the environment.

In this study, we conducted a pilot basis for the census debris flow hazard zone is located on the roadside in some national road. Valley part by usage data for 154 points by calculating the risk and damage was also selected for the debris flow prevention research priorities. This databased to be able to systematically manage a debris flow that may occur on the national roadside.

최근 번번히 발생하는 이상기후로 인해 산지의 비율이 높은 우리나라에서 발생빈도가 높아지고 있다. 이러한 토사재해 방재를 위해 다양한 방법으로 연구가 진행되고 있다. 일반적으로 토사재해를 해석하는 프로그램으로 FLO-2D, RAMMS, DEBRIS-2D 등 다양한 프로그램이 개발되어 있다. 본 연구에서는 미연방재난관리청(FEMA)에서 토석류 해석에 권장하고 있는 프로그램인 FLO-2D를 이용하여 토석류 거동에 대한 연구를 수행하였다. FLO-2D는 정상류, 정수압 분포의 가정을 통해 유한차분법을 통해 토석류를 모의하는 2차원 해석 프로그램이다. 연구방법은 먼저 토석류 거동에 영향을 미치는 다양한 인자에 대한 토석류 흐름 특성을 분석하고 그 결과에 의한 통계적 추론 분석을 활용하여 주요 인자간의 민감도 분석을 수행하였다. 토석류 거동 영향인자로 흐름지형, 물성치, 전파면의 형상 등을 선정하였다. 흐름 지형은 실제 토석류 흐름 지형과 유사하게 나타낼 수 있도록 계곡형 형태로 구성하여 입력하여 모의하였고 물성치는 점성과 항복응력 값을 변화시켜 토석류의 물성에 따른 모의를 수행하고 전파면의 형상은 전파면의 경사를 변화시켜 도심지의 경사에 따른 흐름 분석을 수행하였다. FLO-2D를 이용하여 선정한 주요 인자에 대해 민감도 분석을 위한 수치모의를 수행한 결과, 토석류 흐름에 영향을 미치는 주요 인자의 변화에 따른 거동 특성을 파악할 수 있었다. 본 연구를 통해 선정된 토사재해 거동의 유효 인자에 대해 심도있는 연구를 수행한다면, 토사재해 관련 방재활용 및 계획수립에 활용할 수 있을 것이다. 또한 토사재해 발생 예상 지역의 지형, 토질분석 자료를 통해 토석류 거동 특성을 좀 더 정확히 분석할 수 있게 하여 토사재해로 인한 피해 저감에 도움을 줄 수 있을 것이다.

최근 전 지구적인 기후변화의 영향으로 집중호우가 증가하고 있어 산지가 많은 국내에서는 산지재해 발생 위험이 증가하고 있다. 특히 산지에서 발생하는 토석류의 경우는 산지계류를 따라 빠르게 이동하여 하류부에 위치한 도심지까지 피해를 주고 있다. 그러나 토석류 피해지역을 정확히 분석하고 대책을 수립하기 위한 연구는 매우 미진한 상태이다. 따라서 본 연구에서는 지상 LiDAR 장비를 활용하여 토석류 발생 및 피해지역에 대한 3차원 정밀지형정보를 구축하는 방법에 관해 연구를 수행하였다. 구축된 3차원 지형정보는 토석류 피해지역의 복구활동 및 시간경과에 따른 재해현장의 환경변화에 지장을 받지 않고 다양한 연구활동이 가능하다. 따라서 지상 LiDAR로 구축된 지형자료는 토석류 피해지역의 이동과 확산범위 산정을 위해 적용된 RAMMS 모형의 기본자료로 활용하였다.

본 연구는 도심지 지역에서 위험지역 선정 - 사회경제적 취약성 평가 - 고위험구역 정밀평가로 이어지는 토사재해 통합 취약성 평가 가이드라인을 작성하는 것을 목적으로 하며, 그 첫 단계로 국내·외 취약성 평가 관련 제도 및 법률을 분석하였다. 국내 토사재해 관련 법률은 관리 주체와 관리 대상에 따라 다양하게 구분되어 있는 것으로 나타났다. 토사재해는 국토해양부, 안전행정부, 소방방재청, 산림청 등 4개 행정부처가 관할하며 관련 법률도 14개가 있는 것으로 분석되었다. 국토의 개발과 관리 및 그에 따른 개발제한, 주택건설과 관련해서는 국토교통부가 관할하고 있으며, 재난, 재해 및 안전관리, 재해 피해저감을 위한 이주 등은 안전행정부와 소방방재청, 산림의 보호, 관리 및 사방사업은 산림청이 관할하고 있다. 2012년부터는‘국토의 계획 및 이용에 관한 법률’을 비롯하여 도시 개발을 위한 장기계획인 ‘광역 도시계획 수립지침’, ‘도시군 기본계획 수립지침’과 ‘도시군 관리계획 수립지침’에 매 5년마다 재해 취약성 분석을 수행하고, 계획 수립시 반영토록 하여, 피해를 사전에 방지하는 예방형 토지이용체계로의 변화가 있었다. 미국, 캐나다, 스위스, 아일랜드, 스웨덴 등에서도 토사재해를 저감하기 위한 토지이용의 제한 및 대책수립을 법으로 강제하고 있는 것으로 나타났다. 토사재해 통합 취약성 평가 가이드라인의 원활한 활용을 위해서는 관련 법에 취약성 분석 수행여부를 명시하고 관련 고시(또는 예규)에 토사재해 통합 취약성 평가 가이드라인을 포함하는 방안이 고려되고 있다. 그러나 토사재해 관리체계가 국토해양부, 산림청, 소방방재청 등 3개 부서로 나누어진 상황에서 전 부처에서 통합적으로 사용하기 위해서는 각 부처와의 사전 의견 조율 및 협의가 매우 중요할 것으로 판단된다.

우리나라는 국토의 70 %가 산지로 구성되어 있고 토심이 얕은 지형이 많아 토사재해 발생 위험지역이 많이 분포되어 있다. 이에 급격한 강우가 발생하게 되면 토사재해 발생 확률은 급격하게 증가하게 된다. 특히, 인구 밀집도가 높은 도심지에 토사재해 발생을 대처하지 못해 인명피해와 재산피해가 증가하지만 토사재해를 관리하는 연구는 아직 미흡한 실정이다. 기존 토사재해 거동을 해석하는 수치모의 시뮬레이터는 주로 외국기술에 의존하여 국내지형에 적용하기에는 적합하지 못한 부분이 있다. 본 연구는 도심지 대상 토사재해 해석을 수행하기 위해 천수방정식을 활용한 동수역학 기반 방정식을 유도하여 흐름 해석을 수행하였다. 실제 토석류 흐름을 잘 반영하는 흐름조건을 찾기 위해 9개의 흐름저항관계식을 적용하여 모의를 수행하였다. 모의를 검증하기 위해 Ritter solution으로 해석한 정확해와 비교하여 이상유체 거동과 비슷한 경향을 보이는 것을 확인하였다. USGS에서 Iverson(1994-2012)이 수행한 토석류 수리모형 실험 결과 값과도 비교·검증하여 실제 토석류 흐름과 비슷하게 모의를 하는지 확인하였다. 또한 상용 프로그램과 개발된 시뮬레이션을 비교하기 위하여 토석류 해석을 하는데 가장 많이 이용되고 있는 FLO-2D 수치모의 프로그램과 USGS 토석류 실험과 비교·검증을 수행하였다. 차후 정수압 가정, Non-Newtonian 유변학 모형, 추가 유입 토사 등을 고려하여 개선할 예정에 있으며, 최종적으로 토석류의 이송, 퇴적 과정을 정확히 모의하여 도심지 내 토석류로 인한 토사재해의 거동과 규모를 예측하려고 한다.

Food waste, a putrescible form of waste, comprised of 30% of the total municipal solid waste stream in Daejeon Metropolitan City (DMC) in 2012. Proper management of food waste is a challenging task for local government. This study was conducted to determine material flows when treated food waste in various recycling facilities. Material flows in the recycling processes were collected by site surveys, field trips and discussion with operators and governmental employees. Material flow analysis (MFA) was conducted to quantify the flow of food waste from generation to disposal for the year 2012. MFA along with its mass transfer coefficients were determined based on the inputs, outputs and waste fluxes. According to the mass transfer coefficient results, treatment efficiency for the dry and wet feed manufacturing facility was found to be higher than other treatment facilities. Water consumption was higher for the composting site, resulting in large volume of wastewater (mass transfer coefficient 1.539). While large amounts of screening materials such as plastic, chopsticks, aluminum foils, and bottle caps were generated at the composting site, mass transfer coefficients (0.312) at the dry and wet feed facility were relatively high, implying effective treatment of food waste occurring. The results of this study help to facilitate waste management policy decision-makers in developing effective food waste management techniques in DMC.

The purpose of this study is to identify the materials flow of aluminum cans from its production, manufacturing, distribution, consumption to its discarding, while finding problems in the materials flow diagram in carrying out recycling, and to present improvement measures for relevant systems and policies. Through various statistics, it was found that the actual amount of aluminum ingots distributed in Korea is 1,808,597 tons. From this 381,802 tons of aluminum plates were used for domestic uses, 75,070 tons were used to produce cans, and it was found that 50,073 tons of can products were produced and distributed in Korea. The 50,073 tons of wastes for separate collection was 96% and recycling was 76% for a total of 38,297 tons for recycling. Upon examining the recycling path, it was found that can-to-can was 35% equivalent to 13,403 tons, while 14,100 tons were melted for alloys and 10,794 tons were used as deoxidizing agents for blast furnaces. According to such studies, a materials flow diagram was drafted and the problems in recycling for each stage were reviewed. In result, plans to improve packaging materials and structures in the production stage, plans to restrict inclusion of foreign particles in the discard and selection stage, plans to provide different support in funding and granting quality ratings in the sorting and compression stages, and plans to apply as recycling designated business systems for high-value recycling in the resourcing stage were proposed.

본 연구에서는 하상변동 및 하상유지공 유실 문제가 발생했던 남한강과 금당천 합류부 지점을 대상으로 지류에서 유입되는 유량의 변화에 따른 흐름특성 및 하상변동 특성을 2차원 수치모형을 이용하여 분석하였다. 대상 구간의 수치모의 분석결과, 본류에서는 흐름집중 현상에 의해 지류 유입유량에 관계없이 합류 전에 비해 합류 후 유속이 더 큰 것으로 나타났다. 그러나 지류 유입유량이 클수록 지류하천의 하도 침식이 가속화되고 따라서 주하도가 형성되어 지류에서의 마름영역이 더 크게 나타났다. 이로 인한 지류에서의 하도 침식은 지류에서의 유사발생량을 증가시키고 침식된 유사는 합류부 구간에 퇴적되는 것으로 나타났다. 합류부 구간에서의 지류 유입부 퇴적은 본류 흐름을 좌안으로 집중시키고 좌안의 하상이 저하되는 현상을 야기하였다.