Assessment of Methane Flux from Municipal Solid Waste (MSW) Landfill Areas of Delhi, India

Carbon dioxide, methane and nitrous oxide are the major Greenhouse Gases (GHG’s), which emit from landfill areas and contribute significantly to global warming. Moreover, that the global warming potential of methane is 21 times higher than that of carbon dioxide and it has highest generation (60%) than other gases. Therefore, there is immense concern for its abatement or utilization from landfill areas. Compared to the west, the composition of municipal solid waste (MSW) in developing countries has higher (40% - 60%) organic waste. This would have potential to emit higher GHG’s from per ton of MSW compared to developed world. Beside that landfills areas in India are not planned or en- gineered generally low lying open areas, where MSW is indiscriminate disposed. This leads to uncontrolled emission of trace gases, foul smell, bird menace, ground and surface water pollution etc. Due to scarcity of land in big cities, mu- nicipal authorities are using same landfill for nearly 10 - 20 years. Hence, the possibility of anaerobic emission of GHG’s further increases. In the present paper we had quantified the methane emission from three MSW landfill areas of Delhi i.e., Gazipur, Bhalswa and Okhla. The results showed that the range of methane emission various in winter from 12.94 to 58.41 and in Summer from 82.69 - 293 mg/m2/h in these landfill areas. The paper has also reviewed the literature on methane emission from India and the status of landfill areas in India.

Estimation of Methane Emissions from Municipal Solid Waste Landfills in China Based on Point Emission Sources

The methane(CH4) emissions from municipal solid waste(MSW) landfills in China in 2007 were estimated based on database of the three-dimensional emission factors matrix and point sources, by an IPCC recommended FOD(firstorder decay) model. The location, capacity and age of landfills constitute the three dimensions of the emission factors matrix, which were obtained by laboratory analysis and in situ investigation. Key parameters such as waste composition,degradable organic carbon ratio, CH4 correction factor, oxidation factor and recovery rate, were carefully analyzed in terms of these three dimensions. The point sources database consists of 2,107 MSW landfills in cities and towns of China in 2007. The results show that the CH4 emissions from MSW landfills were 1.186 Mt in 2007. Compared with the CH4 emissions of 2.20 Mt in 2005, the significant discrepancy mainly comes from statistical data of landfills, e.g., number of landfills and amount of waste disposed in landfills. CH4 emissions were lower than 700 t for most of the landfills, whereas there were 279 landfills with emissions larger than 1,000 t, and only 10 landfills with emissions larger than 10,000 t.Jiangsu province ranks the largest emitter with 98,700 t while Tibet is the smallest emitter with 2,100 t. In general,the emissions from eastern provinces, such as Jiangsu, Guangdong and Zhejiang, were larger than those from western provinces, such as Ningxia, Tibet and Qinghai.

A perspective analysis on municipal solid waste(MSW) energy recovery in China

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Technology of comprehensive disposal and utilization of municipal solid waste (MSW)

The project for treating MSW of 200 tons each day was built in Yibin, Sichuan Province of China. The disposal processes are: separation and selection of usable resources; compost and fermentation of “heavy” organic waste (kitchen, garden composting rubbish); incineration of “light” waste (plastic, paper, wood and bamboo etc.) and landfill of inorganic waste. The thermal energy generated in the process can be used as 1/3 of the whole energy for drying fertilizers. In the process, there is no wastewater drainage, and air emissions can be effectively controlled by a series of measures. The sanitary and environmental indicators of disposal site meet the national standards. This project has worked well for two years. It not only disposes of and reduces the MSW, but also retrieves the resource effectively. The organic fertilizer has been applied in the ten thousand acres of fields, with productivity increase by more than 10%.

Minimizing N2O fluxes from full-scale municipal solid waste landfill with properly selected cover soil

市政的稳固的废物垃圾堆发射极氧化亚氮(N2O ) 气体。假设土壤盖住是从垃圾堆的主要 N2O 来源，测试的这研究在一个四年的工程期间，有好质地的选择土壤的合适的使用最小化的假设 N2O 排出物。照原尺寸的清洁的垃圾堆，照原尺寸的生物反应器垃圾堆和一个房间与 Nerium 种了 indicum 或 Festuca arundinacea Schreb，在 Hangzhou Tianziling 垃圾堆在 Hangzhou 城市是测试地点。从所有测试地点的 N2O 排放率比那些在出版报告报导更加低。明确地， N2O 排放率在苗床营养土依赖于土壤水分含量和硝酸盐集中。效果沥滤吃了再通行，灌溉是最小的。用于垃圾堆的适当地选择的苗床营养土减少了 N2O 流动。

Microbiological indication of municipal solid waste landfill non-stabilization

Accidental collapse resulted from unstable factors is an important technological problem to be solved in sanitary landfill. Microbiological degradation of organic matters in landfilled solid waste are an important unstable factor. A landfill reactor was thus manufactured and installed to examine quantitative and population dynamics of microorganisms during degradation of landfilled solid waste. It was showed that unstable landfill can be reflected and indicated by microbiological features such as rapidly decreased growth amount of microorganisms, no detection of fungi and actinomyces, and changing the dominant population into methanogenic bacteria and Acinotobacter.

Porous Structure of Municipal Solid Waste Incineration Bottom Ash in Initial Stage of Landfill

For quantitative estimation of the intra-layer porous structure in the initial stage of landfill formation with municipal solid waste incineration (MSWI) bottom ash, the water absorption of individual MSWI bottom ash particles was measured under still-water, degassed, and agitated conditions. The ratio of the water absorption rate found for the still-water procedure to the effective absorption capacity which was the one under degassing was 35.2%. In the water flow experiment of a column filled with MSWI bottom ash, the true density of the bottom ash was higher after water flow than before, which indicated that dissolution of the soluble components of the bottom ash particle surfaces resulted in a loss of apparent particle volume that more than offset the accompanying weight loss. The volume-based water absorption rate found for the bottom ash particles following 50 mL/h water flow through the column, as a ratio to the effective absorption capacity was about 51.8% of the effective absorption capacity. In a landfill layer comprised of MSWI bottom ash, it was suggested that some regions of the ash particle interiors underwent almost no contact with water.

Municipal solid waste degradation and landfill gas resources characteristics in self-recirculating sequencing batch bioreactor landfill

Based on the degradation characteristics of municipal solid waste(MSW)in China,the traditional anaerobic sequencing batch bioreactor landfill(ASBRL)was optimized,and an improved anaerobic sequencing batch bioreactor landfill(IASBRL)was put forward on the basis of leachate self-recirculation.By monitoring MSW composition,leachate characteristics variation and landfill gas(LFG)generation,the effect of IASBRL was comparatively studied by simulation landfill.Based on the adjusting,scouring and carrying effects of leachate self-recirculation,IASBRL can rapidly decrease Eh value to about-500mV and form a suitable biochemical environment for methanogens,which provides a precondition for stable cooperation between non-methanogens and methanogens.IASBRL can avoid the accumulation of organic acids,make VFA(volatile fatty acid)concentration and CODCr decrease along with the small range fluctuations,and form a stable decomposition-consumption synergy during MSW degradation,therefore,the hydrolysis rate of easy hydrolyze material reaches 71.2% in IASBRL.From the viewpoint of LFG resources in IASBRL,the cumulative LFG production increases to 2327.0L,CH4 mass fraction stabilizes at about 50%,and these provide a favorable precondition for LFG development.

基于Aspen Plus的MSW气化熔融工艺全流程模拟研究

城市固体废物(MSW)气化熔融工艺能够减少二噁英的生成和熔融固化重金属,是一种清洁高效的固体废物处理方式。已有研究多针对MSW的热解特性以及污染物的生成与排放,而对气化熔融工艺系统模块之间的影响和各反应器间物质流、能量流的联动变化过程研究不足。利用Aspen Plus模拟平台,基于吉布斯自由能最小化原理,对MSW气化熔融工艺进行了全流程模拟研究,分析了垃圾干燥温度、垃圾含水率、气化温度、气化介质以及灰熔点对工艺流程节点参数、物质流和能量流的影响,并提出了优化的工艺流程和运行参数。结果表明:在垃圾热解模拟时,垃圾含水率为9%,通过烟气循环能达到能量自给;在相同条件下,以水蒸气作为气化介质的气化效率最高,且在气化温度为850℃,水蒸气当量比为50%时,达到最佳工艺效果;当气化后产生的焦炭在熔融炉内燃烧刚满足灰熔点温度时,灰熔点的升高使气化剂比例、气化气有效气体摩尔流量和碳转化率不断降低。不同工况下的物质流、能量流的变化对实际工程具有指导意义。

Engineering properties for high kitchen waste content municipal solid waste

Engineering properties of municipal solid waste(MSW) depend largely on the waste's initial composition and degree of degradation.MSWs in developing countries usually have a high kitchen waste content(called HKWC MSW).After comparing and analyzing the laboratory and field test results of physical composition,hydraulic properties,gas generation and gas permeability,and mechanical properties for HKWC MSW and low kitchen waste content MSW(called LKWC MSW),the following findings were obtained:(1) HKWC MSW has a higher initial water content(IWC) than LKWC MSW,but the field capacities of decomposed HKWC and LKWC MSWs are similar;(2) the hydraulic conductivity and gas permeability for HKWC MSW are both an order of magnitude smaller than those for LKWC MSW;(3)compared with LKWC MSW,HKWC MSW has a higher landfill gas(LFG) generation rate but a shorter duration and a lower potential capacity;(4) the primary compression feature for decomposed HKWC MSW is similar to that of decomposed LKWC MSW,but the compression induced by degradation of HKWC MSW is greater than that of LKWC MSW;and(5) the shear strength of HKWC MSW changes significantly with time and strain.Based on the differences of engineering properties between these two kinds of MSWs,the geo-environmental issues in HKWC MSW landfills were analyzed,including high leachate production,high leachate mounds,low LFG collection efficiency,large settlement and slope stability problem,and corresponding advice for the management and design of HKWC MSW landfills was recommended.

Environmental monitoring and fuzzy synthetic evaluation of municipal solid waste transfer stations in Beijing in 2001-2006

Transfer station(TS)is an integral part of present-day municipal solid waste(MSW)management systems.To provide information for the incorporation of waste facilities within the current integrated waste management system,the authors measured the existing environmental quality at five MSW TSs.Discharged wastewater,air,and noise were monitored and assayed at the five TSs in Beijing in 2001-2006 during rainy seasons(RSs)and dry seasons(DSs).Except Ammonia(NH_3)and hydrogen sulfide(H_2S),the analytical results...

Selection of Landfill Sites for Solid Waste Treatment in Damaturu Town-Using GIS Techniques

Landfill has been recognized as the cheapest form for the final disposal of municipal solid waste and as such has been the most used method in the world. However, siting landfill is an extremely complex task mainly due to the fact that the identification and selection process involves many factors and strict regulations. For proper identification and selection of appropriate sites for landfills careful and systematic procedures need to be adopted and followed. Wrong siting of landfill many result in environmental degradation and often time public opposition. In this study, attempts have been made to determine sites that are appropriate for landfill siting in Damaturu town Nigeria, by combining geographic information system (GIS) and a multi-criteria decision making method (MCDM) known as the analytic network process (ANP) for the determination of the relative importance weights of factors (criteria). The land suitability output is presented from less suitable to the most suitable areas. The final map produced show areas that are suitable for landfill siting. Based on the analysis fourteen sites were identified to fulfill the required criteria, however, only seven met the land availability criteria of twenty hectares and above. The results showed the efficacy of GIS and multi-criteria decision making method in decision making.

水泥窑协同处置MSW环境负荷与性能耦合评价

基于中国某水泥厂2022~2023年生产数据及近3年国家/行业统计数据进行生命周期评价,核算水泥窑协同处置城市生活垃圾(MSW)生产不同品种水泥的环境负荷;联合数据质量指标评估和蒙特卡洛模拟来综合评估最终结果的不确定度.与常规工艺相比,水泥窑协同处置工艺生产每吨熟料的综合环境负荷降幅为7.82%;4种水泥中,P·O 52.5水泥的综合环境负荷最大,但其单位强度的环境负荷相对较小.综合考虑,采用水泥窑协同处置工艺生产P·C 42.5水泥与采用常规工艺生产P·O 42.5水泥相比,其综合环境负荷降幅为16.87%.

CH4 emission and recovery from Municipal Solid Waste in China

Methane (CH4) is an important greenhouse gas and a major environmental pollutant, second only to carbon dioxide (CO2) in its contribution to potential global wanning. In many cases, methane emission from landfills otherwise emitted to the atmosphere can be removed and utilized, or significantly reduced in quantity by using cost-effective management methods. The gas can also be used as a residential, commercial,or industrial fuel. Therefore, emission reduction strategies have the potential to become low cost, or even profitable. The annual growth rate of Municipal Solid Waste (MSW) output in China is 6.24% , with the highest levels found in South China, Southwest China and East China. Cities and towns axe developing quickly in these regions. MSW output was only 76.36 Mt in 1991 and increased to 109.82 Mt in 1997, registering an average increase of 43.8% . In China, methane emission from landfills also increased from 5.88 Mt in 1991 to 8.46 Mt in 1997; so the recovery of methane from landfills is a profitable project.

Laboratory testing of a densified municipal solid waste in Beijing

市政的稳固的废物(MSW ) 和它的处理在 geotechnical 和 geoenvironmental 工程正在获得重要重要性。然而，常规研究首先集中于在垃圾堆在它的自己的重量下面被压缩的新鲜 MSW 或 MSW。在这个工作，在地面处理以后学习使增加密度的 MSW 的性质的一系列测试被介绍。测试包含了 oedometer 测试，简单砍测试， triaxial 砍测试，和渗透测试，被进行调查压缩的可能性，砍力量，爬 MSW 的行为和渗透。当干燥密度增加，结果证明 MSW 的压缩的可能性模量增加。然而，一旦密度到达某个价值，模量上的密度的影响减少。象大多数土壤一样，使增加密度的 MSW 的压力紧张曲线能被一条双曲线在 triaxial 接近砍测试。含纤维的部件为 MSW 提供另外的结合，但是在磨擦角度上有相对更小的效果。渗透也被发现是仔细与 MSW 的干燥密度有关，即，有更高干燥的密度的 MSW 有更小的渗透。如果密度足够高，渗透系数可以是不到 10-7 cm/s。

Impact of open dumping of municipal solid waste on soil properties in mountainous region

This paper presents the effect of open dumping of municipal solid waste(MSW) on soil characteristics in the mountainous region of Himachal Pradesh, India. The solid waste of dumpsite contains various complex characteristics with organic fractions of the highest proportions. As leachate percolates into the soil, it migrates contaminants into the soil and affects soil stability and strength. The study includes the geotechnical investigation of dump soil characteristics and its comparison with the natural soil samples taken from outside the proximity of dumpsites. The geochemical analysis of dumpsite soil samples was also carried out by scanning electron microscopy(SEM) and energy dispersive X-ray spectroscopy(EDS).Visual inspection revealed that the MSW consists of high fraction of organics, followed by paper. The soil samples were collected from five trial pits in the dumpsites at depths of 0.5 m, 1 m and 1.5 m. Then the collected soil samples were subjected to specific gravity test, grain size analysis, Atterberg's limit test,compaction test, direct shear test, California bearing ratio(CBR) test and permeability analysis. The study indicated that the dumpsite soils from four study regions show decreasing trends in the values of maximum dry density(MDD), specific gravity, cohesion and CBR, and increasing permeability as compared to the natural soil. The results show that the geotechnical properties of the soils at all four study locations have been severely hampered due to contamination induced by open dumping of waste.

Modeling Environmental Susceptibility of Municipal Solid Waste Disposal Sites: A Case Study in São Paulo State, Brazil

The large excess of solid waste generated in cities is a result of population growth and economic development. Properly managing this municipal solid waste (MSW) is a challenge, mainly in underdeveloped and developing countries where financial concerns are an added problem. From the environmental point of view, a major issue is properly disposing MSW taking into consideration a wide range of factors, and working with different spatial data. In this study, we used geographic information system (GIS) to perform multi-criteria decision analysis (MCDA) conducted by analytical hierarchy process (AHP). The development of the environmental impact susceptibility model (EISM) for municipal solid waste disposal sites (MSWDS) applied to the state of Sao Paulo, Brazil considered factors such as geology, pedology, geomorphology, water resources, and climate represented by fifteen associated sub-factors. The results indicated that more than 82% of Sao Paulo’s territory is situated in areas with very low, low, and medium environmental impact susceptibility categories. However, in the remaining 18% of the state land area, 85 landfills are located in areas with high and very high environmental impact susceptibility categories. These results are alarming because these 85 landfills receive approximately 17,886 tons of MSW on a daily basis, which corresponds to 46% of all municipal solid waste disposed in Sao Paulo state. Therefore, decision makers, urban planners and policymakers could use the findings of the EISM towards mitigating the environmental impacts caused by MSWDS.