In order to promote the resource circulation and upcycling of waste refrigerators, it is necessary to analyze the material flow of recovered valuable resources and low-value residues after they are discharged. This study divided the flow of waste refrigerators into the five steps of discharge, collection, pretreatment, resource recovery, and sale/export/disposal and conducted material flow analysis (MFA) in each step. Waste refrigerators are treated via official (formal sectors, 65.6% of total amount) and unofficial (informal sectors, 34.4% of total amount) channels. Officially, waste refrigerators are collected through free collection by national and local governments, recovery by product producers and distributors, and waste collection·transportation·recycling companies and are recycled at public and private recycling centers. Unofficially, waste refrigerators are collected through junk shops and individual collectors. Waste refrigerators recycled in the formal sectors undergo pretreatment processes such as the disassembly, shredding, and separation and recovery of resources such as scrap irons, plastics, PCB (printed circuit board), cables, glasses, waste refrigerants, urethane, etc. Waste refrigerators recycled in informal sector treated through disassembly of the exterior, the shredding process by the excavators in illegal facilities and recovered waste refrigerants, plastics, glasses, scrap irons, copper, nickel silver, PCB, urethane, etc. MFA results show that in 2015, the amount of waste refrigerators collected from formal sectors reached 121,642 ton/year, the amount of recycling was 107,684 ton/year, and the amount of residues was 13,955 ton/year respectively. Thus, actual recycling rate per a waste refrigerator was estimated 88.15% in 2015. To promote the resource circulation and upcycling of waste refrigerators, it is necessary to find a way to improve the recycling of urethane, which accounts for 10.8% of the total weight of a refrigerator.

With the increase in food consumption, the amount of animal and plant residues in food manufacturing has continued to increase. In particular, the residues generated from food manufacturing industries have a high recycling value because they are generated in large quantities, are homogeneous, and their recycling costs are less than that of households or small restaurants. In this study, we selected industries that produce large amounts of homogeneous animal and plant residues, including manufacturers of animal oils and fats, vegetable oils and fats, starches and glucose or maltose, and conducted material flow analysis using statistical data, field surveys, and questionnaires. In the results of material flow analysis, the amount of raw materials used in the surveyed industries was 3,029,830 tons per year, and 8,487 tons of animal and plant residues were generated through manufacturing and processing. In addition, the import substitution effect of recycling byproducts from industries into animal feed or similar was estimated to be ₩847,007 million KRW per year.

The most common types of refrigerants used in automobiles today usually include HCFCs and HFCs, which have the potential of ozone depletion or the greenhouse effect. Although environmentally friendly refrigerants are being developed, there is still a lack of safety and high-cost problems for new refrigerants. This study was conducted to determine the flow of refrigerants from automotive air conditioners and examine their potential problems and a proper management plan. The number of automobiles manufactured, the number of automobiles in use, and end-of-vehicle flow were examined through available statistics and reports. The material flow of refrigerants has been determined by the life cycle of automobiles and the unit requirements of the refrigerants used in automobiles. Based on the results, in 2014, there were approximately 1,017 tons of refrigerants introduced from the manufacturing stage of automobiles, and about 395 tons of refrigerants leaked from the use stage. After the use stage, only 13 tons of refrigerants were delivered to treatment facilities and 195 tons were emitted into the atmosphere during the dismantling process. As a result, in South Korea in 2014, a large amount of refrigerants (590 tons) was estimated to have been leaked into the atmosphere from automotive air conditioners during the use and dismantlement stage. Several preventive measures for refrigerants should be properly enforced by introducing economic incentives as well as a monitoring system with strengthened laws and policies.

The objective of the current study was to analyze the current safety status of formaldehyde. More than 670 manufacturers in 15 business sectors were enrolled. A MFA of the manufacturers showed that manufacturer M, which specializes in the manufacture of basic organic chemicals, used the most formaldehyde (120,000 tons), and manufacturer B, which specializes in the manufacture of general varnish and related products, used the least (8 tons). The results of this study can be used to collect scattered material flow and identify different parts of the country where a nationally produced substance, such as formaldehyde, can be stored. The details of the toxicity reflected in the composition and the amount of formaldehyde are likely to be utilized to produce personal protective equipment.

수은은 온도계, 혈압계, 치과용 아말감, 전지, 형광등과 의약품 등 많이 사용되고 산업적으로도 전기 스위치, 촉매 등으로 중요하게 사용된다. 수은은 증기 흡입 시 폐렴을 유발하고 중추신경계와 신장에 영향을 줄 수 있을 정도로 매우 위험하여 수은과 수은 화합물의 사용이 금지되거나 제한을 받고 있으며, 대체물질과 대체 공정의 개발을 위한 노력이 행해지고 있다. 최근 연이은 병원, 학교 등의 혈압계, 온도계의 수은 누출사고와 형광등 생산시설인 (주)남영전구 광주공장의 해체 및 철거 중 수은 누출로 인한 근로자의 수은 중독 및 환경오염 사고와 비철금속업체의 수은 폐기물 처리문제가 대두되었다. 전국 병원 2,500개소 설문조사 결과, 143개 병원에서 혈압 및 체온계의 약 4천여개(수은량 : 약 140 kg)가 회수와 폐기가 필요한 것으로 조사되었다. 또한 미나마타 협약에서 요구되는 수은 수출･입, 공급원 파악, 임시보관 및 유통･보관, 회수, 처리 등 단계별 수은의 회수, 유통, 관리에 대한 체계 구축이 미흡하다. 수은폐기물은 미나마타협약에 의하여 ‘수은 구성 폐기물’, ‘수은 함유 폐기물’, ‘수은 오염 폐기물’로 나눠지고 본 연구에서는 ‘수은 함유 폐기물과 오염 폐기물’의 수입, 유통, 회수, 폐기 등 전과정 단계별 흐름 분석을 통하여 수은의 국내 흐름을 파악하고 관련 법 제도의 문제점을 분석하고자 함에 있다. 또한 수은 관련 유통량을 조사하고 폐기물의 처리 공정을 파악하여 대상 물질, 원료 사용량, 시스템 경계 설정, 데이터 수집 및 분석, 계산과 검증 등의 절차를 걸쳐 물질수지에 근거하여 ‘물질흐름도’를 작성하여 도출하였다. 물질흐름분석을 보다 쉽게 활용하고 적용할 수 있도록 ‘물질흐름분석 소프트웨어(STAN 2.5)를 활용하여 공정 내의 데이터 유입과 유출을 Shankey diagram 형태로 표현하였다. 연구 결과, 원자재 수은의 국내 유통량은 2014년 기준 국내 유입량은 약 3톤(제조량: 1 ton, 수입량: 2 ton)으로 집계되고 수입된 수은은 대부분 형광램프 제조(2.01 ton), 시약(0.76 ton), 촉매(0.12 ton) 등의 용도로 사용된 것으로 나타났다. 회수량은 문헌 조사 결과 수은 함유 부산물 및 폐기물 관리를 위해 도입되는 시나리오별 두 가지 기준을 적용하여 회수 가능량을 추정하였다. 시나리오에 따라 27.3 ton/yr, 25.4 ton/yr으로 예측하였다. 원자재 수은의 국내 재고량은 대략 0.5 ton/yr으로 보인다.

The flow of products containing valuable metal resources after discharging to waste means that it is necessary to form a plan to improve resource circulation to enhance the circulation of metal resources. In this study, waste resource circulation flow analysis of products containing cobalt and palladium after disposal was performed by classifying five stages: (1) discharge/import, (2) collection/discarding, (3) pretreatment, (4) resource recovery, and (5) product production/export. The mobile phone was one of products which were the most generating cobalt. Discharged cobalt was kept for processing or was produced as pure cobalt, cobalt oxide, or cobalt sulfate, and was used as a raw material for locks, speakers, AlNiCo magnets, tire, batteries, etc. The total amount of cobalt in the waste products was 994 tons and the recycling rate was 53.7%, indicating that 543 ton of cobalt was recycled. Palladium was discharged from waste electrical and electronic products, precious metals, petrochemical catalysts, vehicles catalysts at the end of their life, and medical equipment (dental). The palladium recovered by pre-treatment and resource recovery was recycled as a metal resource or exported. The amount of palladium recycled was 2.412 tons, of which a total of 2.512 or 96% tons is estimated to be recycled. Future research may be necessary to suggest institutional improvements, including the waste resource classification and market expansion for the recycling in the five steps based on the results of this study.

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.