국내 3단계 매립형 처분시설은 2018년도 한국원자력환경공단의 중^저준위 방폐물관리시행계획에 의하면 주로 원전 해체 현장에서 발생하는 극저준위방폐물을 수용하기 위해 2019년 4월부터 2026년 2월까지 총 104,000드럼(2개 트렌치)을 수용 하기 위해 건설이 계획 중이다(총 2,246억원 투입). 이후 총 5개 트렌치에 260,000드럼이 총 34,076 m2의 면적에 단계적으로 수용되며 따라서 현재 한국원자력환경공단은 관련 인수기준을 마련 중에 있다. 극저준위방폐물 처분시설 인수기준의 경우 프랑스, 스페인 등이 전용 처분시설을 운영하면서 자국의 인수기준을 합리적으로 잘 준용하고 있으나 본 논문에서는 해체방 폐물의 처분에 가장 경험이 많은 미국의 처분시설을 고려하여 국내 매립형 처분시설에 우선적으로 반영되어야 할 사항이 있는지 분석하였고 이를 통하여 경주내 3단계 매립형 처분시설의 인수기준 마련에 도움이 되고자 하였다.

The validity of landfill gas models is an important problem considering that they are frequently used for landfill-site-related policy making and energy recovery planning. In this study, the Monte Carlo method was applied to an landfill gas generation model in order to enhance conformity. Results show that the relative mean deviation between measured data and modeled results (MD) decreased from 19.8% to 11.7% after applying the uncertainty range of Intergovernmental Panel on Climate Change (IPCC) to the methane-generation potential and reaction constants. Additionally, when let reaction constant adjust derived errors from all other modeling components, such as model logic, gauging waste, and measured methane data, MD decreased to 6.6% and the disparity in total methane generation quantity to 2.1%.

수도권매립지에서는 황량하고 척박한 폐기물매립장을 세계 최대의 환경명소로 탄생시키기 위하여 매립이 완 료된 지역을 중심으로 나무심기 사업을 지속적으로 추 진 중에 있다. 그간 추진된 수목식재 현황을 바탕으로 방문객의 인식을 통해 생태경관 개선효과를 조사하여 수도권매립지의 독창적인 경관 조성에 기여하기 위하여 본 연구가 추진되었다. 2002년부터 2014년까지 교목 239,203주, 묘목 2,125,408주, 관목 2,930,294주로 총 5,294,905주를 수 도권매립지에 식재한 것으로 집계되었다. 년도별로는 사 업초기년도인 2002∼2003년과 2009∼2010년에 각각 2,028,451주(38%), 1,574,172주(30%)로 식재가 집중되 었다. 위치별 식재량은 제1매립장 1,943,713주(37%), 제 2매립장 1,659,743주(31%), 외곽경계지역 1,067,455주 (20%), 녹색바이오단지 623,994주(12%) 순이며, 수목의 성상별로는 관목 2,930,294주(55%), 묘목 2,125,408주 (40%), 교목 239,203주(5%) 순으로 나타났다. 이는 식 재지반이 얕고 환경이 척박한 매립지임을 고려, 관목과 묘목이 주로 식재되었음을 보여준다. 수도권매립지 조경수림대(제 1,2매립장 사면, 차폐수림 대, 도로변, 구 시설지 등)에 식재된 수목을 2013년 기준 전수조사 한 결과 교목 302,481주(104종), 묘목 108,051주 (55종), 관목 143,447㎡(25종)으로 집계되었다. 성상별 주 요 수종으로 교목은 곰솔(21.4%), 상수리나무(11.4%), 이 팝나무(8.7%), 산벚나무(6.5%), 측백나무(6.5%) 순이며, 묘 목은 소나무(42.8%), 곰솔(15.6%), 왕벚나무(6.9%), 대왕 참나무(5.9%), 산벚나무(5.6%) 순, 관목은 개나리(37.9%), 철쭉(17.5%), 수수꽃다리(6.5%), 박태기나무(5.5%), 무궁 화(3.8%) 순으로 나타났다. 위치별로 세분화하여 살펴보면 제1매립장 사면에 식재된 교목은 곰솔, 산벚나무, 상수리 순, 관목은 개나리, 철쭉 순이며, 제2매립장 사면에 식재된 교목은 소나무, 곰솔, 상수리 순, 관목은 개나리, 땅비싸리 순이다. 차폐수림대에 식재된 교목은 느티나무, 곰솔, 산벚 나무 순, 관목은 철쭉, 수수꽃다리 순이며, 도로변에 식재된 교목은 소나무, 느티나무, 리기다소나무 순, 관목은 박태기, 무궁화 순이다. 이를 통해 그간 식재한 묘목이 교목으로 성장하였으며, 수도권매립지에 위치별로 다양한 수종의 수 목이 도입되었음을 알 수 있다. 수도권매립지 방문객을 대상으로 2014년 9월 22일부터 10월 12일까지 3주간 수도권매립지 환경개선 인식조사와 조경수림대 가치추정을 실시하였다. 방문객, 직원, 경력자 등을 대상으로 매립지 문답식 조사지에 의해 진행하였으며 일대일 면접조사와 인터넷(SNS) 설문을 병행하였다. 조사 결과 수도권매립지 주변 환경여건 중 경관생태, 쾌적도, 소 음은 양호하나 토양, 수질, 대기, 악취는 보통 수준으로 조사 되었다. 또한 최근에 방문할수록 매립지 환경이 양호한 것 으로 인식하는 경향을 보였다. 수목 선호기능은 환경개선, 생태적합, 녹음제공, 유지관리용이, 관상기능 순이었으며, 선호수종은 소나무, 느티나무, 벚나무, 참나무류, 단풍나무 순으로 나타났다. 2002년부터 식재된 수목의 누적식재량과 설문조사로 나 타난 환경인식의 상관관계를 분석해 보면, 누적식재량과 경 관생태는 식재량이 누적될수록 방문객의 인식이 심각(2.0) 에서 보통(3.5)으로 개선되어, 현재는 양호한 상태로 파악되 고 있다. 또한 식재량 누적에 따라 경관생태 인식이 단계적 으로 상승되고 있는데, 1단계 상승기인 2003년에서 2008년 은 누적식재량 200만~300만주 구간이며, 2단계 상승기인 2011년에서 2014년은 누적식재량 500만~530만주 구간으 로 파악되었다. 경관생태 인식이 개선되는 시기는 공사가 대대적인 식재사업을 추진한 시기인 2002년에서 2003년, 2009년에서 2010년과 유사하게 나타남을 알 수 있다. 누적 식재량과 전반적인 쾌적도는 경관생태와 유사한 패턴을 보이며, 식재량이 누적될수록 방문객 쾌적도 인식이 심각(1.5) 에서 보통(3.5)으로 상향되고 있으며, 현재 양호한 상태로 파악된다. 쾌적도도 식재량 누적에 방문객 쾌적도가 단계적 으로 상승하고 있으며, 2차에 걸쳐 인식이 개선되었다. 매립지 수목 식재 필요성과 관련해 필요하다(81%), 필요 없다(9%)로 나타났으며, 식재가 필요한 지역으로 매립지 전체 외곽경계(36%), 외부 주거지 인근(24%), 각 매립장 외곽경계(17%), 각 매립장 토양윗층(11%), 기타(12%) 순 으로 나타났다. 수도권매립지 조경수림대 가치추정을 위해 조건부가치 측정법(CVM)을 실시하였으며, 지불의사유도를 위해 이중 양분석택법(초기제시금액 : 1,000원, 2,000원, 3,000원)을 사용하였다. 응답한 236명의 설문조사 결과 매립지 조경수 림대의 주된 생태계서비스는 조절서비스(43%), 서식지서 비스(25%), 문화서비스(21%), 공급서비스(11%) 순으로 나 타났으며, 조경수림대 보전을 위한 가구당 지불의사는 평균 2,377원/월, 지불사유는 유산가치(41%), 존재가치(27%), 사용가치(20%), 선택가치(12%) 순으로 나타났다. 수도권 지역 가구수(1,011만)과 소득 200만원 이상 가구비중 (0.838)을 반영하여 산출한 결과 수도권매립지 조경수림대 의 가치는 연간 2,418억원으로 추산된다.

본 논문에서는 노은 생활 폐기물 매립장의 사전 환경 영향 평가 단계에서 수행되었고 주로 기반암 깊이와 침출수 분포를 조사하기 위해 굴절법 토모그래피 방법이 수행되었다. 본 탐사 방법은 토목 분야와 환경 분야에 응용되어왔다. 굴절법 토모그래피 방법을 수행하기 위해 침출수의 예상 유동방향과 직각으로 추정되는 3개의 측선을 설정하여 적용하였다. 본 연구 지역인 노은 생활 폐기물 매립장은 개략적으로 3층 구조로 구성되어 있고 하류에서 상류 지역으로 갈수록 기반암까지 깊이가 점진적으로 얕아지고 특히 하류 지역에서는 부분적으로 침출수 등이 충진되어 있는 지층이 존재하고 있음이 확인되었다. 따라서 생활 폐기물 매립장 하부 지반의 침출수의 분포 뿐만 아니라 매립장 하부의전체적인 지반 구조를 분석하기 위해 굴절법 토모그래피 탐사가 효과적인 방법으로 확인되었다.

주요 온실기체인 이산화탄소와 메탄의 농도를 난지도 매립장에 위치한 42개의 배출공으로부터 측정하였다. 그 결과에 의하면, 배출공의 출구에서 관측된 메탄은 부피기준으로 절반 그리고 이산화탄소는 28%에 가까운 수준으로 높은 농도를 유지하였다. 그러나 이들의 환경거동은 배출공의 위치 등과 같은 차이 외에도 가스성분에 따라 여러 가지차이를 보여 주었다. 본 연구의 결과는 이들 성분의 분포가 수은과 같은 미량성분의 분포특성과는 달리 대체로 균질한편이라는 것을 확인해 주었다.

A comprehensive water budget analysis considering the water consumed for landfill gas formation was performed for Sudokwon Landfill Site 2 (LS2) from October 2000 through December 2016. The weighted average mole ratios of carbon (C), hydrogen (H), and oxygen (O) of the total disposed waste were 30.4%, 48.8%, and 20.8% respectively. The total emitted H and O as CO2 and CH4 from landfill gas was 2,812×103 Mg, of which 28.6% (803×103 Mg) was supplied from water. The total emitted water quantity consisted of landfill gas at 8.4%, leachate at 90.2%, and vapor in landfill gas at 1.4%. The total supplied water quantity to LS2 was 22.0×106 Mg, and the quantity supplied from water included in disposed waste was 62.9%. Considering the supplied and emitted water quantity, the retained quantity in LS2 was estimated to be 12×106 Mg, and the emitted and retained quantities were 43.3% and 56.7%, respectively. Considering the retained quantity, the water content in LS2 was estimated to be 26.0%, far below the optimum level for landfill site stabilization.

Because methane-producing bacteria (MPB) and sulfate-reducing bacteria (SRB) compete for anaerobic utilization of organic matter, the methane generation potential (Lo) decreases logarithmically with the decrease in the COD/SO4 ratio. The Lo correction coefficient equals the Lo at a particular COD/SO4 ratio divided by the maximum Lo. An Lo correction coefficient was derived each year based on the COD/SO4 ratios of waste added to the landfill. The methane generation potential was multiplied by the Lo correction coefficient in order to correct the LFG (landfill gas) generation calculation. At the second Sudokwon landfill site (2000 ~ present), the COD/SO4 ratio decreased from 11.6 in 2000 to 4.8 in 2014. Thus, the Lo correction coefficient decreased from 0.89 in 2000 to 0.42 in 2014. The LFG 2008-2014 production correction was calculated using the model equation (Scholl canyon), and was almost the same (91 ~ 113%) as the quantity measured, including LFG that was collected, flared, or allowed to diffuse through the landfill. The methane oxidation correction factor, calculated from the concentrations of nitrogen and oxygen within the landfill gas, was between 0.92 and 1 for the first landfill site and between 0.96 and 1 for the second landfill site. Air ingress into the landfill had a negligible effect on gas generation.

Sulfate produced during anaerobic reduction limits the activity of methanogens but it is not reflected in the Intergovernmental Panel on Climate Change (IPCC) methodology for estimating CH4 emissions. In this study, CH4 emissions from the Sudokwon landfill site were estimated by adopting a methane correction factor, which was determined through the relationship between the COD/sulfate ratio and CH4 generation. Although the gas originating from the Sudokwon landfill site has not produced any environmental problems in recent years due to gas collection and soil cover maintenance activities, CH4 emissions estimated by the IPCC methodology indicated that only 60% of the CH4 was recovered and the remainder was emitted into the atmosphere, suggesting a potential environmental problem. Accordingly, CH4 estimates determined according to IPCC methodology must be modified by adopting the methane correction factor and considering the effect of sulfate concentration.

The objective of this study was to determine the CH4 oxidation factor (%) and the CH4 oxidation rate (g m−2 d−1) in landfill cover soil. To quantify in-situ rates of CH4 oxidation, CH4 and CO2 fluxes were measured on a landfill site using the static chamber technique. The CH4 oxidation factor obtained in this study through the mass balance method ranged between 41% and 61%, which is much higher than the Intergovernmental Panel on Climate Change (IPCC) default value of 10%. The higher CH4 oxidation factor derived in this study can be explained by the CH4 bottom flux in addition to the soil texture. The CH4 oxidation factors were observed to increase with decreases in CH4 bottom flux. Therefore, when CH4 bottom fluxes are high in a landfill, using a gas collection system can enhance CH4 oxidation factor. The CH4 oxidation rates were estimated to range from 16.6 g m−2 d−1 to 20.8 g m−2 d−1. In addition, this study was conducted to evaluate the effects of vegetation on the CH4 oxidation factor. The results showed that the CH4 oxidation factors for bare soil, vegetated soil, and soil adjacent to a gas well were 57%, 70%, and 44%, respectively. The results indicate that vegetation on landfill covers can increase the CH4 oxidation factor because of increasing soil porosity.

The purpose of this study is to investigate the regional waste discharge and characteristics in Incheon Metropolitan City, and to evaluate the potential energy recovery for combustible wastes being discharged from Incheon province as well as currently being landfilled in the Sudokwon Landfill Site. Approximately, 2,466 ton and 0.879 kg/(capita·day) were estimated for annual average discharge of domestic wastes and daily domestic waste discharge rate per person in Incheon during the period from 2007 to 2013. The least squares methodology indicates those values to decrease to 1,120 ton and 0.347 kg/(capita·day), respectively in year 2021. The assessment of potential energy recovery for the landfilled household solid wastes indicated that total energy of 1.00 × 107 GJ and 212 billion Won of electric charges could be recovered and saved each year. For the construction wastes, recoverable annual energy and electric charges were 1.04 × 107 GJ and 269 billion Won, respectively.

Mathematical models have been developed to evaluate methane emission from landfills. The Intergovernmental Panel on Climate Change (IPCC) and the US Environmental Protection Agency (USEPA) have provided first-order decay (FOD) models to estimate methane emission from landfills. The methane generation potential (L0) and the methane generation rate constant (k) are the two primary parameters in the FOD model. A major challenge in landfill gas modeling is estimating these parameters. The IPCC recommended that every country should develop country-specific emission factors appropriate for its circumstances and characteristics. The k value represents the rate constant associated with waste decomposition. In general, there are two different approaches for estimating a k value for a landfill. One uses actual field data in comparison with modeled data. However, this approach is limited by the spatial and temporal characteristics of landfill. Another approach is to collect samples of landfilled waste and then measure their biodegradability of waste as a function of waste age. As biodegradability is a surrogate for landfilling age, lower biodegradability would be expected in order samples. The objective of this study was to determine a k value using an anaerobic test (GB21). To achieve this objective, the GB21 which is used in Germany was conducted to estimate biodegradability of waste samples, and k value was determined based on FOD equation. Waste samples were collected at a landfill located in A City, Korea. The landfill is a valley-type landfill. It received municipal solid waste from 1990 to 2010. Food and paper wastes were the major fractions, constituting about 62.9% of the total amount disposed. However, the Ministry of Environment in Korea banned direct landfilling of food wastes in 2005, since then, food waste has no longer been disposed into landfills. In this study, the landfill site was separated into four areas based on landfilling age, and four samples were collected from each area. Cumulative biogas production for the waste excavated from the landfill varied from 6.9 to 35.8 Nl/kg-Dry Matter. Cumulative biogas production for landfilling age of 1 year was 35.8 Nl/kg-DM and it decreased to 6.9 Nl/kg-DM after 14 years. The k value obtained from this study was 0.156 yr-1 and was higher than the default k prescribed by the IPCC, which is 0.09 yr-1 in boreal and temperate climates. The higher k values obtained in this study can be explained by the high proportion of food waste disposed into the studied landfill. The default k values of rapidly degrading wastes including food waste and sludge are 0.185 yr-1. In addition a higher k value will result in predictions of more methane generation in the early years after waste burial, resulting in higher estimates of uncollected methane in greenhouse gas inventories. This work contributes to understanding decomposition rate of landfilled waste by examining biodegradability determination and providing k value for landfill.

Emissions of leachate, odor, and landfill gas(LFG) from an open-dumping landfill site do harm to public health by contaminating neighboring soil, underground water, and rivers. Particularly, methane(CH4) and carbon dioxide(CO2), the main components of LFG, are especially noted as the causing material of the global warming that become seriously recognized worldwide issue. As one of alternatives in managing LFG, incineration of inflammable wastes that are generated during excavation process at an open-dumping landfill has been evaluated. Standard on stabilization for evaluation, neither CH4 density nor CO2 density could not Because meet 'less than 5%' criterion and so it is right to install a gas collection system during landfill renewal to prevent diffusion of odor and collect it. Because it shows considerable heating value, incineration of inflammable wastes might be the reasonable solution from the result of our study.

Results for application of RDF(Refuse Derived Fuel) to selected wastes in metropolitan and small and medium cities are as follows. The physical characteristics of waste are paper, plastic, food waste, and so on. The proximate analysis in P city showed 20.2% of moisture, 71% of combustible material, and 8.8% of ash on annual average. That in G city showed 31.6% of moisture, 59.5% of combustible material, and 8.9% of ash. Ultimate analysis in P city showed 52.04% of carbon, 7.02% of hydrogen, 28.80% of oxygen, 0.66% of nitrogen, and 0.09% of sulfur. Heating value was 3,363 kcal/kg. Ultimate analysis in G city showed 50.85% of carbon, 6.56% of hydrogen, 29.86% of oxygen, 0.79% of nitrogen, and 0.12% of sulfur. Heating value in the G city was somewhat lower than that in the P city with 2,632 kcal/kg. Thus, application of RDF in metropolitan city was more effective than that in small and medium cities. Heating value in mixture for the P city was lower than that in waste of the volume rate waste charge system alone by 143 kcal/kg. In proximate analysis, moisture, and combustible material were likely to be more adequate to RDF.

The purpose of this study is to investigate weighted compaction density according to a loading density in truck, a compaction density of solid waste and composition ratios of solid waste for calculation of a capacity of the landfill sites. The experiments for calculations of in-place density at landfill site have been conducted in S landfill site at B City. The size of vessel for measuring the compaction density was 1m3(1m×1m×1m). The experiment tests have been carried out methods (1 time for bulldozer and 4 times for compactor) that do contain all of specification at the landfill site. Average of the loading density at the landfill site was 0.264 ton/m3 (0.113～0.487 ton/m³). When the loading density for each compositions was compared, the composition of the highest average loading density (0.474 ton/m³) was miscellaneous wastes. The composition of the lowest average loading density (0.120 ton/m³) was general solid waste. The reported results indicated that the compaction density at the landfill site was 0.538 ton/m³, which was calculated with weighted incoming ratios of compositions. The ranges of the density for each composition were from 0.021 ton/m³ to 0.221 ton/m³. When the compaction density for each composition was compared, the composition with the highest average compaction density (0.221 ton/m³) was miscellaneous wastes. The composition with the lowest average compaction density (0.021 ton/m³) was general solid wastes.

Characteristic of wastes in a unsanitary landfill at the residential development site in H city, Kyunggi-do was investigated for the disposal of huge amount of wastes. The total amount of wastes was estimated at 117,000 ton and construction solid wastes and municipal solid wastes were detected together. The portion of combustibles was very low and soils, concrete wastes, and pebbles were the major components in landfilled wastes. Because the site was the residential development site, the landfilled wastes should be removed immediately for the construction. Therefore the way that the unsanitary landfill was excavated and the wastes were sorted into three categories such as soils, noncombustibles and combustibles was selected as the best method. Soils and noncombustibles could be recycled and sorted combustibles could be re-landfilled in a smaller area or incinerated.

Most of methane gas result from waste matter in landfill, therefore the persons concerned take an increasing interest in management of gases in landfill. Infrared Gas Analyzer was used to measure components of gases, CH4, CO2, O2, through gas exhausted pipe. To measure amount of the gas flow meter(Portable Hot-Line Current Meter) was used and it was set at right angles with direction of the flow. In this research the total amount of methane gas produced in Beck-Suk Landfill was calculated through FOD method suggested by IPCC. This research found that in Chon-An Beck-Suk Landfill anaerobic resolution was made actively and the amount of methane gas produced there was 54.14%, which is higher than common figure, 50%, in other researches. The components of reclaimed waste matter, especially, organic waste matter can have a great effect of the amount of the greenhouse gases produced in landfill. We can expect that the amount of greenhouse gas will decrease from 2005, when it will be prohibited from carrying kitchen refuse and sludge into landfill.

In this study, sulfate reduction reaction was used to increase the decomposition of organics, which is the most critical factor for the stabilization of a landfill site. Composite of sewage sludge, papers, and incineration ashes was used in the column. The experimental results indicated that out of 10 reactors, the reactors 3, 4, 8, and 9 showed higher organics (i.e., TOC) removal rate than that in the absence of sulfate. The organics removal rates (K) in R3 and R9 were 8.65e-4/d and 3.82e-4/d, respectively. The times to reach 10% of initial concentrations in R3 and R9 was 7.3 and 16.5 years, respectively, showing faster organics decomposition rates in these reactors.

The odor removal of landfill site leachate was carried out using pyroligenous liquid. The constituent elements of pyroligenous liquid and leachate were also analysed, employing Atomic Absorption Spectroscopy(AAS). Before order removal, the heavy metal ions such as Pb, Zn, Cu, Mn, Fe and Ni, in pyroligenous liquid were detected with ultra trace level. However, in this liquid, other metal ions such as As, Hg and Cd were not observed. The optimum condition for removing odor from the leachate was observed in 15 times dilution of pyroligenous liquid. Also, the degree of outlet odor was 1. Furthermore, the concentration of odor constituent compounds, e.g. H2S, NH3, NH2 and CO2 in the leachate was remarkably reduced. Finally, water quality of the leachate was improved,