A simulated landfill anaerobic bioreactor was used to characterize the anaerobic biodegradation and biogas generation of organic waste which was mainly composed of residuals of vegetables and foods. We investigated th...A simulated landfill anaerobic bioreactor was used to characterize the anaerobic biodegradation and biogas generation of organic waste which was mainly composed of residuals of vegetables and foods. We investigated the dynamics of the coenzyme F420 activity and determined correlations between biogas yields, methane yields, methane concentration and coenzyme F420 activity. The experiment was carded out under different conditions from control without any treatment, addition of Fe^3＋, microorganism inoculation to a combination of Fe3＋ addition and inoculation at a temperature of 36±2℃. The experiment was lasted 120 d and coenzyme F420 activity was analyzed using ultraviolet spectrophotornetry. Experimental results indicated that activity of the coenzyme F420 treated by Fe and microorganism inoculation increased substantially. The waste treated by inoculation had the greatest increase. When the waste was treated by Fe^3＋, inoculation and the combination of Fe^3＋ and inoculation, biogas yields increased by 46.9%, 132.6% and 153.1%, respectively; while the methane yields increased 4, 97 and 98 times. Methane concentration varied between 0 and 6% in the control reactor, from 0 to 14% for waste treated by the addition of Fe^3＋, from 0 to 59% for waste treated by inoculation and from 0 to 63% for waste treated by Fe^3＋ addition and inoculation. Correlations between coenzyme F420 activity and biogas production, methane production and methane concentration proved to be positively significant （p〈0.05）, except for the control. Consequently, coenzyme F420 activity could be used as an index for monitoring the activity of methanogens during anaerobic biodegradation of the organic fraction of municipal solid waste.展开更多
Municipal solid waste （MSW） and its disposal are gaining significant importance in geotechnical and geoenvironmental engineering. However, conventional research is primarily focused on fresh MSW or MSW that is compa...Municipal solid waste （MSW） and its disposal are gaining significant importance in geotechnical and geoenvironmental engineering. However, conventional research is primarily focused on fresh MSW or MSW that is compacted under its own weight in the landfill. In this work, a series of tests to study the properties of a densified MSW after ground treatment were presented. The tests involved oedometer test, simple shear test, triaxial shear test, and permeability test, which were conducted to investigate the compressibility, shear strength, creep behavior and permeability of the MSW. The results show that the compressibility modulus of the MSW increases as the dry density increases. However, the influence of density on modulus decreases once the density reaches a certain value. Like most soils, the stress-strain curve of the densified MSW can be approximated by a hyperbola in the triaxial shear test. Fibrous components provide additional cohesion for MSW, but have a relatively smaller effect on friction angle. Permeability is also found to be closely related to the dry density of the MSW, i.e., MSW with a higher dry density has a smaller permeability. The permeability coefficient may be less than 10 7 cm/s if the density is high enough.展开更多
waste dam is one of the most important infrastructures in the project of valley sanitary landfill. On one hand, it forms the landfill capacity required. On the other hand, it improves the slope stability of waste body...waste dam is one of the most important infrastructures in the project of valley sanitary landfill. On one hand, it forms the landfill capacity required. On the other hand, it improves the slope stability of waste body. Consequently, I think it is very significant to maintain the stability of waste dana for the whole sanitary landfill. Combining with a project example, aiming at the special geological conditions, we have made three plans of waste dam structure, calculation and analysis comparison respectively. Reinforced concrete frame waste dam is highlighted in the project for its advantages, smoothly solving the three problems in the engineering.展开更多
The valley shaped Tianziling landfill of Hangzhou in China built in 1991 to dispose of municipal solid waste (MSW) was designed for a service life of 13 years. The problem of waste landfill slope stability and expansi...The valley shaped Tianziling landfill of Hangzhou in China built in 1991 to dispose of municipal solid waste (MSW) was designed for a service life of 13 years. The problem of waste landfill slope stability and expansion must be considered from the geotechnical engineering point of view, for which purpose, it is necessary to understand the geotechnical properties of the MSW in the landfill, some of whose physical properties were measured by common geotechnical tests, such as those on unit weight, water content, organic matter content, specific gravity, coefficient of permeability, compressibility, etc. The mechanical properties were studied by direct shear test, triaxial compression test, and static and dynamic penetration tests. Some strength parameters for engineering analysis were obtained.展开更多
This paper summarizes the situation of e-waste recycling in China, points out several key problems, identify the causes and draw lessons and experiences abroad about e-waste management, propose systematic suggestions ...This paper summarizes the situation of e-waste recycling in China, points out several key problems, identify the causes and draw lessons and experiences abroad about e-waste management, propose systematic suggestions from the production side, the recovery side, consumers side, government departments and thelegislation.展开更多
A new type of refuse derived fuel (RDF) for pyrolysis and gasification was prepared from municipal solid waste (MSW) in the presence of a small quantity of coal by bindless high pressure technology at room temperature...A new type of refuse derived fuel (RDF) for pyrolysis and gasification was prepared from municipal solid waste (MSW) in the presence of a small quantity of coal by bindless high pressure technology at room temperature. The physicochemical property of RDF was tested. Orthogonal experiment method was used to optimize the process parameters using dropping strength (mechanical strength) and thermal stability of the RDF as indices for quality of RDF. The result shows that the mixture of MSW and coal with a total moisture ranging from 5% to 17% can be easily compressed into RDF briquettes at a pressure above 70 MPa. When the briquetting pressure is higher than 100 kN and moisture content is about 10%, the qualified RDF can be obtained. The orthogonal experiment shows that the moisture can greatly affect the mechanical strength of RDF, while all the technique parameters have no obvious influence on thermal stability of RDF. The optimal parameters are a shaping pressure of 106 MPa, a moisture content of 10%, and a coal content of 20%.展开更多
The management of municipal solid waste （MSW） is currently one of the major environmental concerns in Mexico. Therefore, municipalities must develop local programs for prevention and integrated management of MSW bas...The management of municipal solid waste （MSW） is currently one of the major environmental concerns in Mexico. Therefore, municipalities must develop local programs for prevention and integrated management of MSW based on the data of MSW generation; however, these are scarce and diffuse. It is known that the MSW generation is affected by many factors, including life level. Given the importance of having reliable data, the objective of this study was to determine the per capita MSW generation of a small urban locality in the state of Veracruz and test whether there were significant statistic differences of per capita M SW generation among the life levels. The households were randomly sampled according to the Mexican standard of reference and were classified as popular, middle and residential. The per capita MSW generation determined was 0.355 kg·inhab^-1.day^-1. This value was lower than the value estimated by the national reference, suggesting that it might be overestimated and consequently lead to errors in estimating installations costs for the MSW treatment. The result of the experimental design revealed that there were significant statistic differences in the per capita MSW generation among the three socioeconomic strata. This study will allow the municipality to establish better strategies within the municipal program and differential rate for the provision of public clean service and it also provides a solid basis for future research under similar conditions.展开更多
A field study was conducted in the paddy soil amended with municipal solid waste （MSW） and sewage sludge （SS） to find out total, DTPA extractable nickel （Ni） and chrome （Cr） in soil and their uptake by rice pl...A field study was conducted in the paddy soil amended with municipal solid waste （MSW） and sewage sludge （SS） to find out total, DTPA extractable nickel （Ni） and chrome （Cr） in soil and their uptake by rice plant as split-plot arrangement based on randomized complete block design with three replications. The results indicated that the most available Ni （2.10 ppm） measured under 3 years application of 40 ton.ha~ MSW＋I/2 chemical fertilizer （CF）. Also, with 3 application of 40 ton-ha＂l MSW concluded the highest available Cr. The most accumulation of Ni in root （14.51 ppm） and grain （8.89 ppm） happened under 3 years application of 40 ton.ha-1 SS and 20 ton ha-1 MSW＋I/2 CF, respectively. With application of 40 ton.ha-1 SS and 40 ton SS＋1/2 CF, respectively happened the maximum Cr uptake by root and grain （12.43 and 3.65 ppm, respectively）.展开更多
The purpose of this study was to analyze the migration pathways of contaminants from closed landfills and to estimate health risks based on soil characteristics. The health risks were estimated using Framework for Ris...The purpose of this study was to analyze the migration pathways of contaminants from closed landfills and to estimate health risks based on soil characteristics. The health risks were estimated using Framework for Risk Analysis Multimedia Environmental Systems （FRAMES） software. The sensitivity of human health risks and hazard indices due to vinyl chloride contamination in groundwater were performed in relation to soil characteristics such as Darcy velocity, thickness of soil layer, mass of contaminant present in the aquifer. Based on the analysis, Darcy velocity showed no effect on estimated risks. Since soil layer thickness had a significant effect on the estimated health risks, effects of different soil types on estimated risks were analyzed. The results showed that soils from the least appropriate to the most appropriate for risk management due to groundwater contamination were sand, sandy clay, sandy loam, loam and clay loam. FRAMES model was suitable for assessing the health risks due to vinyl chloride contamination in groundwater originating from a municipal solid waste landfill. The model showed the changes in both carcinogenic and non carcinogenic risks over time. The estimated health risks were directly correlated with the levels of vinyl chloride detected in groundwater.展开更多
General as well as the municipal solid waste （MSW） management in Thailand is reviewed in this paper. Topics include the MSW generation, sources, composition and trends. The review, then, moves to sustainable solutio...General as well as the municipal solid waste （MSW） management in Thailand is reviewed in this paper. Topics include the MSW generation, sources, composition and trends. The review, then, moves to sustainable solutions for MSW management and sustainable alternative approaches with an emphasis on an integrated MSW management. Information of waste in Thailand is also given at the beginning of this paper for better understanding of later contents. It is clear that no one single method of MSW disposal can deal with all materials in an environmentally sustainable way. As such, a suitable approach in MSW management should be an integrated approach that could deliver both environmental and economic sustainability. With increasing environmental concerns, the integrated MSW management system has a potential to maximize the useable waste materials as well as produce energy as a by-product. In Thailand, the compositions of waste （86%） are mainly organic waste, paper, plastic, glass and metal. As a result, the waste in Thailand is suitable for an integrated MSW management. Currently, the Thai national waste management policy starts to encourage the local administrations to gather into clusters, to establish central MSW disposal facilities with suitable technologies and reducing the disposal cost based on the amount of MSW generated.展开更多
This article reviews the literature on thermochemical processing of municipal solid waste as the final disposal in Brazil, explores recent publications in the field of solid waste generated, its origin, characteristic...This article reviews the literature on thermochemical processing of municipal solid waste as the final disposal in Brazil, explores recent publications in the field of solid waste generated, its origin, characteristics and removal mechanisms currently employed, in the same way, available technologies for the thermochemical treatment of MSW with an emphasis on gasification and clean technology are evaluated, highlighting the current technical and reported in the literature in order to identify indicators of efficiency and flexibility of the technology. From the review it is concluded that gasification is a technically feasible option for the thermochemical conversion of municipal solid waste and subsequent power generation, besides being a technology that meets the applicable emission limits. Some of the main advantages of gasification of municipal solid waste are： （a） the sharp reduction in the waste mass （about 70-80%） and volume （approximately 80-90%）; （b） the drastic reduction in land use, 1：3000; （c） destruction of organic pollutants and other halogenated hydrocarbons; （d） concentration and immobilisation of inorganic contaminants so that they can be used effectively and safely removed; （e） use recyclables, such as ferrous metals, ferrous ash and slag materials; （f） reducing emissions of greenhouse gases by anaerobic decomposition of organic waste and （g） power generation.展开更多
基金Projects 40372069 supported by the National Natural Science Foundation of ChinaNCET-05-0479 by the Program for New Century Excellent Talents in University0F4506 by the Science and Technology Foundation of China University of Mining and Technology
文摘A simulated landfill anaerobic bioreactor was used to characterize the anaerobic biodegradation and biogas generation of organic waste which was mainly composed of residuals of vegetables and foods. We investigated the dynamics of the coenzyme F420 activity and determined correlations between biogas yields, methane yields, methane concentration and coenzyme F420 activity. The experiment was carded out under different conditions from control without any treatment, addition of Fe^3＋, microorganism inoculation to a combination of Fe3＋ addition and inoculation at a temperature of 36±2℃. The experiment was lasted 120 d and coenzyme F420 activity was analyzed using ultraviolet spectrophotornetry. Experimental results indicated that activity of the coenzyme F420 treated by Fe and microorganism inoculation increased substantially. The waste treated by inoculation had the greatest increase. When the waste was treated by Fe^3＋, inoculation and the combination of Fe^3＋ and inoculation, biogas yields increased by 46.9%, 132.6% and 153.1%, respectively; while the methane yields increased 4, 97 and 98 times. Methane concentration varied between 0 and 6% in the control reactor, from 0 to 14% for waste treated by the addition of Fe^3＋, from 0 to 59% for waste treated by inoculation and from 0 to 63% for waste treated by Fe^3＋ addition and inoculation. Correlations between coenzyme F420 activity and biogas production, methane production and methane concentration proved to be positively significant （p〈0.05）, except for the control. Consequently, coenzyme F420 activity could be used as an index for monitoring the activity of methanogens during anaerobic biodegradation of the organic fraction of municipal solid waste.
基金Foundation item： Project（50979047） supported by the National Natural Science Foundation of China Project（2010CB732103） supported by the National Basic Research Program of China Project（2012-KY-02） supported by the State Key Laboratory of Hydroscience and Engineering （Tsinghua University）, China
文摘Municipal solid waste （MSW） and its disposal are gaining significant importance in geotechnical and geoenvironmental engineering. However, conventional research is primarily focused on fresh MSW or MSW that is compacted under its own weight in the landfill. In this work, a series of tests to study the properties of a densified MSW after ground treatment were presented. The tests involved oedometer test, simple shear test, triaxial shear test, and permeability test, which were conducted to investigate the compressibility, shear strength, creep behavior and permeability of the MSW. The results show that the compressibility modulus of the MSW increases as the dry density increases. However, the influence of density on modulus decreases once the density reaches a certain value. Like most soils, the stress-strain curve of the densified MSW can be approximated by a hyperbola in the triaxial shear test. Fibrous components provide additional cohesion for MSW, but have a relatively smaller effect on friction angle. Permeability is also found to be closely related to the dry density of the MSW, i.e., MSW with a higher dry density has a smaller permeability. The permeability coefficient may be less than 10 7 cm/s if the density is high enough.
文摘waste dam is one of the most important infrastructures in the project of valley sanitary landfill. On one hand, it forms the landfill capacity required. On the other hand, it improves the slope stability of waste body. Consequently, I think it is very significant to maintain the stability of waste dana for the whole sanitary landfill. Combining with a project example, aiming at the special geological conditions, we have made three plans of waste dam structure, calculation and analysis comparison respectively. Reinforced concrete frame waste dam is highlighted in the project for its advantages, smoothly solving the three problems in the engineering.
文摘The valley shaped Tianziling landfill of Hangzhou in China built in 1991 to dispose of municipal solid waste (MSW) was designed for a service life of 13 years. The problem of waste landfill slope stability and expansion must be considered from the geotechnical engineering point of view, for which purpose, it is necessary to understand the geotechnical properties of the MSW in the landfill, some of whose physical properties were measured by common geotechnical tests, such as those on unit weight, water content, organic matter content, specific gravity, coefficient of permeability, compressibility, etc. The mechanical properties were studied by direct shear test, triaxial compression test, and static and dynamic penetration tests. Some strength parameters for engineering analysis were obtained.
文摘This paper summarizes the situation of e-waste recycling in China, points out several key problems, identify the causes and draw lessons and experiences abroad about e-waste management, propose systematic suggestions from the production side, the recovery side, consumers side, government departments and thelegislation.
基金Foundation of Education Departmentof Jiangsu Government for Commercialization of High Technology Developed in Universities
文摘A new type of refuse derived fuel (RDF) for pyrolysis and gasification was prepared from municipal solid waste (MSW) in the presence of a small quantity of coal by bindless high pressure technology at room temperature. The physicochemical property of RDF was tested. Orthogonal experiment method was used to optimize the process parameters using dropping strength (mechanical strength) and thermal stability of the RDF as indices for quality of RDF. The result shows that the mixture of MSW and coal with a total moisture ranging from 5% to 17% can be easily compressed into RDF briquettes at a pressure above 70 MPa. When the briquetting pressure is higher than 100 kN and moisture content is about 10%, the qualified RDF can be obtained. The orthogonal experiment shows that the moisture can greatly affect the mechanical strength of RDF, while all the technique parameters have no obvious influence on thermal stability of RDF. The optimal parameters are a shaping pressure of 106 MPa, a moisture content of 10%, and a coal content of 20%.
文摘The management of municipal solid waste （MSW） is currently one of the major environmental concerns in Mexico. Therefore, municipalities must develop local programs for prevention and integrated management of MSW based on the data of MSW generation; however, these are scarce and diffuse. It is known that the MSW generation is affected by many factors, including life level. Given the importance of having reliable data, the objective of this study was to determine the per capita MSW generation of a small urban locality in the state of Veracruz and test whether there were significant statistic differences of per capita M SW generation among the life levels. The households were randomly sampled according to the Mexican standard of reference and were classified as popular, middle and residential. The per capita MSW generation determined was 0.355 kg·inhab^-1.day^-1. This value was lower than the value estimated by the national reference, suggesting that it might be overestimated and consequently lead to errors in estimating installations costs for the MSW treatment. The result of the experimental design revealed that there were significant statistic differences in the per capita MSW generation among the three socioeconomic strata. This study will allow the municipality to establish better strategies within the municipal program and differential rate for the provision of public clean service and it also provides a solid basis for future research under similar conditions.
文摘A field study was conducted in the paddy soil amended with municipal solid waste （MSW） and sewage sludge （SS） to find out total, DTPA extractable nickel （Ni） and chrome （Cr） in soil and their uptake by rice plant as split-plot arrangement based on randomized complete block design with three replications. The results indicated that the most available Ni （2.10 ppm） measured under 3 years application of 40 ton.ha~ MSW＋I/2 chemical fertilizer （CF）. Also, with 3 application of 40 ton-ha＂l MSW concluded the highest available Cr. The most accumulation of Ni in root （14.51 ppm） and grain （8.89 ppm） happened under 3 years application of 40 ton.ha-1 SS and 20 ton ha-1 MSW＋I/2 CF, respectively. With application of 40 ton.ha-1 SS and 40 ton SS＋1/2 CF, respectively happened the maximum Cr uptake by root and grain （12.43 and 3.65 ppm, respectively）.
文摘The purpose of this study was to analyze the migration pathways of contaminants from closed landfills and to estimate health risks based on soil characteristics. The health risks were estimated using Framework for Risk Analysis Multimedia Environmental Systems （FRAMES） software. The sensitivity of human health risks and hazard indices due to vinyl chloride contamination in groundwater were performed in relation to soil characteristics such as Darcy velocity, thickness of soil layer, mass of contaminant present in the aquifer. Based on the analysis, Darcy velocity showed no effect on estimated risks. Since soil layer thickness had a significant effect on the estimated health risks, effects of different soil types on estimated risks were analyzed. The results showed that soils from the least appropriate to the most appropriate for risk management due to groundwater contamination were sand, sandy clay, sandy loam, loam and clay loam. FRAMES model was suitable for assessing the health risks due to vinyl chloride contamination in groundwater originating from a municipal solid waste landfill. The model showed the changes in both carcinogenic and non carcinogenic risks over time. The estimated health risks were directly correlated with the levels of vinyl chloride detected in groundwater.
文摘General as well as the municipal solid waste （MSW） management in Thailand is reviewed in this paper. Topics include the MSW generation, sources, composition and trends. The review, then, moves to sustainable solutions for MSW management and sustainable alternative approaches with an emphasis on an integrated MSW management. Information of waste in Thailand is also given at the beginning of this paper for better understanding of later contents. It is clear that no one single method of MSW disposal can deal with all materials in an environmentally sustainable way. As such, a suitable approach in MSW management should be an integrated approach that could deliver both environmental and economic sustainability. With increasing environmental concerns, the integrated MSW management system has a potential to maximize the useable waste materials as well as produce energy as a by-product. In Thailand, the compositions of waste （86%） are mainly organic waste, paper, plastic, glass and metal. As a result, the waste in Thailand is suitable for an integrated MSW management. Currently, the Thai national waste management policy starts to encourage the local administrations to gather into clusters, to establish central MSW disposal facilities with suitable technologies and reducing the disposal cost based on the amount of MSW generated.
文摘This article reviews the literature on thermochemical processing of municipal solid waste as the final disposal in Brazil, explores recent publications in the field of solid waste generated, its origin, characteristics and removal mechanisms currently employed, in the same way, available technologies for the thermochemical treatment of MSW with an emphasis on gasification and clean technology are evaluated, highlighting the current technical and reported in the literature in order to identify indicators of efficiency and flexibility of the technology. From the review it is concluded that gasification is a technically feasible option for the thermochemical conversion of municipal solid waste and subsequent power generation, besides being a technology that meets the applicable emission limits. Some of the main advantages of gasification of municipal solid waste are： （a） the sharp reduction in the waste mass （about 70-80%） and volume （approximately 80-90%）; （b） the drastic reduction in land use, 1：3000; （c） destruction of organic pollutants and other halogenated hydrocarbons; （d） concentration and immobilisation of inorganic contaminants so that they can be used effectively and safely removed; （e） use recyclables, such as ferrous metals, ferrous ash and slag materials; （f） reducing emissions of greenhouse gases by anaerobic decomposition of organic waste and （g） power generation.
