Feixi County has made significant progress in promoting waste classification,such as establishing a comprehensive classification system,and effectively reducing environmental pollution and waste volume.However,with th...Feixi County has made significant progress in promoting waste classification,such as establishing a comprehensive classification system,and effectively reducing environmental pollution and waste volume.However,with the increase in waste generation,the county faces multiple challenges especially in the disposal of kitchen waste and improvement of residents environmental awareness.To address these issues,Feixi County has implemented various measures,such as strengthening the construction of infrastructure for waste classification,improving regulations and clearly defining responsibilities,enhancing residents environmental awareness to encourage their participation in waste classification through education and promotion,and increasing supervision to ensure effective implementation of the work.It emphasizes community governance,encourage all parties to participate in it,and strengthen publicity,education and training to enhance residents participation.Feixi County has achieved positive results,but efforts are needed to further improve facilities,raise awareness,enhance supervision,and ensure the continuous effectiveness of waste classification work to promote urban green sustainable development.展开更多
The unbalanced and inadequate use of fertilizers is one of the causes of soil degradation. Combined with the ever-increasing population, it is necessary to find sustainable agricultural production alternatives. The pr...The unbalanced and inadequate use of fertilizers is one of the causes of soil degradation. Combined with the ever-increasing population, it is necessary to find sustainable agricultural production alternatives. The present work aims to determine the effect of different rates and mixtutes of organic amendments on soil fertility and the performance of Sunflower (Helianthus annuus L.). In the field, treatments consisted of solid household waste and faecal sludge in the ratios of 3/5 (V1), and a mixture of faecal sludge and household waste in the ratio of 3/5 with 900 worms (V2). At the end of the composting process, V1, V2 composts and the poultry manure (PM) were applied at rates of 4, 5 and 6 t∙ha−1 in a randomized complete block design with three replications. Soil samples were collected before and after the experiment and analyzed. The main results revealed that at the end of the composting process, there was a progressive improvement in the physico-chemical properties of V1 and V2 composts. In particular, the C/N ratio, phosphorus (P) and total nitrogen (TN) initially at 16.49 ± 0.42 (V1, V2), 21.06 ± 0.07 mg∙kg−1 (V1, V2), 0.76% ± 0.08% (V1, V2) respectively, increased after 60 days to 12.40 ± 0.41 (V1), 9.74 ± 0.28 (V2) for C/N, 21.94 ± 0.63 mg∙kg−1 (V1) and 22.04 ± 0.04 mg∙kg−1 (V2) for P, 0.96% ± 0.0% (V1) and 1.22 ± 0.04 (V2) for TN. The application of 6 t∙ha−1of PM had the greatest influence on the diameter and weight of the flower heads (27.16 ± 4.01 t∙ha−1 and 230.83 ± 2.64 t∙ha−1), while 4 t∙ha−1 of V2 gave the tallest sunflower plants (110.07 ± 73.28 cm) as well as the diameter at the crown (19.30 ± 9.07 cm). However, CEC was most influenced by 4 t∙ha−1 of V1, while 4 t∙ha−1 of PM had the greatest effect on organic carbon and phosphorus. However, 5 t∙ha−1 of PM showed the highest sunflower production and yield (1.67 ± 0.21 t∙ha−1). The combination with 900 earthworms is recommended for composting and 5 t∙ha−1 of PM is recommended to obtain a better sunflower production.展开更多
The aim of this paper is to develop a Multi-Actor Geo-Collaborative Device to improve the processes of household waste collect (HWC) in urban areas. The proposed device will be tested in the Lamkansa district, in the ...The aim of this paper is to develop a Multi-Actor Geo-Collaborative Device to improve the processes of household waste collect (HWC) in urban areas. The proposed device will be tested in the Lamkansa district, in the southwestern part of Casablanca city, Morocco. The approach used is a systemic analysis of communication in order to act on a territory. We have been inspired by several methodological developments concerning multi-actor processes of land use planning. We focused our work on the involvement of the inhabitants in the process of household waste collect. The results show that the urban population can help and contribute to the development of complementary solutions to improve the urban environment and their living environment. Moreover, by integrating citizens in HWC processes, as well as decision communication, we can reduce household waste management costs and make it faster and more efficient, through a geo-collaborative, participatory and incentive logic. The approach described in this article is original, not only considering the technologies used to present and share the collected information, but also regarding the concept of integrating several actors in a collaborative/incentive mode. It arouses great interest by combining geomatics with communication and information sciences. It contributes to improve the participation of the inhabitants in the life of their urban environment in order to establish a reinforced dialogue on the future of their city and public health. Also, it involves the development and testing of new devices and tools for multi-actor collaboration.展开更多
Source separation is the basic premise for making effective use of household wastes. In eight cities of China, how- ever, several pilot projects of source separation finally failed because of the poor participation ra...Source separation is the basic premise for making effective use of household wastes. In eight cities of China, how- ever, several pilot projects of source separation finally failed because of the poor participation rate of residents. In order to solve this problem, identifying those factors that influence residents’ behavior of source separation becomes crucial. By means of questionnaire survey, we conducted descriptive analysis and ex- ploratory factor analysis. The results show that trouble-feeling, moral notion, environment protection, public education, environment value and knowledge deficiency are the main factors that play an important role for residents in deciding to separate their household wastes. Also, according to the contribution percentage of the six main factors to the total behavior of source separation, their influencing power is analyzed, which will provide suggestions on household waste management for policy makers and decision makers in China.展开更多
In order to enhance the production of biogas and to study the thermal behavior of waste, a numerical study of fluid flows and heat transfers within household waste was developed to predict the distributions of thermal...In order to enhance the production of biogas and to study the thermal behavior of waste, a numerical study of fluid flows and heat transfers within household waste was developed to predict the distributions of thermal fields. The mathematical model is based on the conservation of mass and energy equations. The resulting system of equations is discretized using the finite volume method and solved using the Thomas algorithm. The results of the model studied are compared with the numerical and site measurements results from other authors. The results have been found to be in good agreement. The results show that the mathematical model is able to reproduce the thermal behavior in anaerobic phase in landfills. The isotherms revealed that temperatures are lower in the upper part of the waste cell, very high in the core and decrease slightly in the bottom of the cell due to the biodegradation of waste.展开更多
Solid waste is a promising renewable fuel that can substitute conventional fuel. According to the researchers, thermoconversion of solid waste such as municipal solid waste or residual household waste (RHW) is benefic...Solid waste is a promising renewable fuel that can substitute conventional fuel. According to the researchers, thermoconversion of solid waste such as municipal solid waste or residual household waste (RHW) is beneficial to society. However, due to its heterogeneity, the gasification of RHW is more complex. This review article discusses the steps that RHW must undergo before its thermoconversion and the state of the art of solid waste gasification. First, characterisation methods of RHW are surveyed. Second, the properties of RHW, the production lines of refuse derived fuel (RDF) from RHW, the influence of RDF composition and operating parameters such as equivalence ratio and temperature are reviewed. Moreover, RDF gasification products, scientific barriers and proposed solutions are evaluated. In conclusion, concerning emissions, costs and technical aspects related to each thermochemical process, it can be said that gasification is a promising technique for the recovery of RHW. However, studies on cogasification of waste and biomass on a pilot-industrial scale are still scarce and synergistic effects of this cogasification need to be clarified.展开更多
Within the European Union (EU) a paradigm shift is currently occurring in the waste sector, where EU waste directives and national waste strategies are placing emphasis on resource efficiency and recycling targets. Th...Within the European Union (EU) a paradigm shift is currently occurring in the waste sector, where EU waste directives and national waste strategies are placing emphasis on resource efficiency and recycling targets. The most recent Danish resource strategy calculates a national recycling rate of 22% for household waste, and sets an ambitious goal of a 50% recycling rate by 2020. This study integrates the recycling target into the FRIDA model to project how much waste and from which streams should be diverted from incineration to recycling in order to achieve the target. Furthermore, it discusses how the existing technological, organizational and legislative frameworks may affect recycling activities. The results of the analysis show that with current best practice recycling rates, the 50% recycling rate cannot be reached without recycling of household biowaste. It also shows that all Danish municipalities will need to make efforts to recover all recyclable fractions, and that the increased recycling efforts of only selected municipalities will not be sufficient to reach the target.展开更多
This study explores household solid waste management (HSWM) practices and awareness among residents of Windhoek West, a rapidly urbanizing constituency in the Khomas Region of Namibia. Employing a descriptive methodol...This study explores household solid waste management (HSWM) practices and awareness among residents of Windhoek West, a rapidly urbanizing constituency in the Khomas Region of Namibia. Employing a descriptive methodology, the research investigates the interplay between public awareness, regulatory frameworks, and the availability of waste management facilities to assess their impact on waste management behaviors. Our findings indicate significant gaps in both knowledge and infrastructure that hinder effective waste management. The study reveals that while there is a high willingness among residents to engage in recycling and waste reduction, actual practices are limited due to inadequate facilities and lack of stringent enforcement of waste policies. This research identifies key factors that influence waste management practices, including demographic characteristics and access to waste management facilities. It also proposes actionable strategies such as expanding recycling and sorting facilities, enhancing educational campaigns tailored to local needs, and implementing regular enforcement mechanisms. These strategies are aimed at improving compliance with waste management protocols and fostering a culture of environmental responsibility. The results of this investigation show the critical role of ongoing education and infrastructural improvement in bridging existing knowledge gaps and facilitating effective waste management practices. This research lays a foundational step toward enhancing sustainable urban development and effective waste management in Windhoek, providing valuable insights for policymakers, community leaders, and stakeholders engaged in urban environmental management.展开更多
This research,carried out during September and October 2020 in the city of Kankan,made it possible to take stock of the city’s household waste management.The quantities of waste from the four main landfills in the ci...This research,carried out during September and October 2020 in the city of Kankan,made it possible to take stock of the city’s household waste management.The quantities of waste from the four main landfills in the city are assessed,namely:Sogbè(1350.3 m^(3)),Station(195.5 m^(3)),Station University of Kankan(2491.5 m^(3))and Salamani(369.6 m^(3)).Waste from three landfills/dumps was characterized for 26 days.This characterization covered 5,010.6 kg of waste,composed of 4263.9 kg of organic matter,462.1 kg of recyclable matter and 284.6 kg of inorganic matter.The survey concerned a target population of 403 inhabitants,which made it possible to determine a production ratio per habitant per day of(0.48 kg/habitant/d).Finally,a composting experiment of 2000 kg of organic matter was carried out.The results obtained during this study constitute the basic elements allowing defining a better policy of management of household solid waste in the city of Kankan.展开更多
Waste stream characteristics must be understood to tackle waste management problem in Tripoli city, Libya. It is recognized that information on both quantity and composition of generation waste is important for the ef...Waste stream characteristics must be understood to tackle waste management problem in Tripoli city, Libya. It is recognized that information on both quantity and composition of generation waste is important for the effective planning of household waste handling infrastructure. So, this study is aimed to evaluating the generation, composition and density of household solid waste in Tripoli city, Libya. The study is carried out according to the Annex 2.1 of: WHO 1996. It was conducted during one week in summer, autumn and winter 2011/2012. The daily household solid waste generation assessment has been carried out for 150 Libyan families where 947 people in three main parts of Tripoli city have been chosen randomly. A questionnaire was prepared according to Buenrostro et al. 2001 and Raje et al. 2001 using door-to-door surveying. The result showed that the average of total generation quantity, daily generation rate, total volume and density were 1415 kg, 0.64 kg/person/day, 19.3 m<sup>3 </sup>and 74.4 kg/m<sup>3</sup> respectively in Tripoli city. Household solid waste contains 36.3% organic matter and 32.5% recyclable materials (glass, paper, plastic, metals). The total generation quantity, daily generation rate, total volume and density were in Tripoli city agreed with those for African and Arabic countries. But the problem is that Tripoli suffers from insufficient municipal solid waste management and lack of sanitary landfills.展开更多
Mechanical pretreatment is an indispensable process in biological treatment plants that remove plastics and other impurities from household biogenic waste(HBW).However,the imperfect separation of plastics in these pre...Mechanical pretreatment is an indispensable process in biological treatment plants that remove plastics and other impurities from household biogenic waste(HBW).However,the imperfect separation of plastics in these pretreatment methods has raised concerns that they pose a secondary formation risk for microplastics(MPs).To validate this presumption,herein,quantities and properties of plastic debris and MPs larger than 50 μm were examined in the full chain of three different pretreatment methods in six plants.These facilities received HBW with or without prior depackaging at the source.The key points in the secondary formation of MPs were identified.Moreover,flux estimates of MPs were released,and an analysis of MPs sources was provided to develop an overview of their fate in HBW pretreatment.Pretreated output can contain a maximum of(1673±279) to(3198±263) MP particles per kilogram of wet weight(particles·kg^(-1)ww) for those undepackaged at source,and secondary MPs formation is primarily attributed to biomass crushers,biohydrolysis reactors,and rough shredders.Comparatively,HBW depackaged at the source can greatly reduce MPs by 8%-72%,regardless of pretreatment processes.Before pretreatment,4.6-205.6 million MP particles were present in 100 tonnes of HBW.MPs are produced at a rate of 741.11-33124.22 billion MP particles annually in anaerobic digester feedstock(ADF).This study demonstrated that HBW pretreatment is a competitive source of MPs and emphasized the importance of implementing municipal solid waste segregation at the source.Furthermore,depackaging biogenic waste at the source is recommended to substantially alleviate the negative effect of pretreatment on MPs formation.展开更多
This paper presents the results of batch anaerobic co-digestion of matooke, cassava, and sweet potato peels and vines. These agricultural wastes and others form the biggest portion of household wastes in developing co...This paper presents the results of batch anaerobic co-digestion of matooke, cassava, and sweet potato peels and vines. These agricultural wastes and others form the biggest portion of household wastes in developing countries. However, they have remained an unexploited resource amidst the ever increasing needs of clean energy and waste disposal challenges. Efforts to use them individually as biogas substrates have been associated with process acidification failure resulting from their fast hydrolysis. The aim of this work was to exploit agricultural wastes is co-digestion among themselves and assess their effect on methane yield and its kinetics, pH and hydraulic retention time (HRT). Sixteen ratios of Matooke peels (MP), cassava peels (CP) and sweet potato peels (SP) were assessed in duplicate. Methane yield and its kinetics, pH and HRT demonstrated dependence on the proportion of substrates in the mixture. Depending on the ratio mixture, HRT increased to 15 days compared to less than 5 days for single substrates, hydrolysis rate constant (k) reduced to a range of 0.1 - 0.3 d<sup>-1</sup> compared to single substrates whose k-values were above 0.5 d<sup>-1</sup>, pH was maintained in the range of 6.38 - 6.43 and CH<sub>4</sub> yield increased by 15% - 200%. Ratios 2:1:0, 2:0:1, 0:1:2, 1:1:1 and 1:1:4 were consistent all through in terms of model fitting, having a positive synergetic effect on HRT, hydrolysis rate constant, lag phase and methane yield. However, more research is needed in maintaining the pH near the neutral for process stability assurance if household wastes are to be used as standalone substrates for biogas production without being co-substrates with livestock manure.展开更多
A number of waste materials were studied on their application into asphalt mixtures. Materials tested were plastic waste as (soft) granular material,ceramic waste from electrical insulators,foundry sand and sintered g...A number of waste materials were studied on their application into asphalt mixtures. Materials tested were plastic waste as (soft) granular material,ceramic waste from electrical insulators,foundry sand and sintered granulate from burned household waste. Both plastic waste,crushed ceramics and large fractions of sintered household waste could be used as partial replacement for coarse aggregates. Foundry sand could partially replace natural sand in asphalt mixtures. The first step of the study was to find out if the waste materials could satisfy basic requirements and for some if their leaching behavior was acceptable. In the next phase mixtures were designed and mechanical tests were done on several mixtures with waste components to determine indirect tensile strength,stiffness,fatigue. In order to estimate the water sensitivity of some mixtures,retained indirect tension tests were done. The properties are reported and compared with each other and reference mixtures. From the research it becomes clear that it takes a lot of work to replace virgin materials in asphalt mixtures with waste materials.展开更多
基金Supported by the School-Level Natural Science Project of Anhui Xinhua University(2023zr008)Innovation and Entrepreneurship Training Program for College Students of Anhui Province(S202312216114)+1 种基金Natural Key Scientific Research Project of Anhui Provincial Department of Education(2022AH05187)Anhui University Natural Science Outstanding Research and Innovation Team Project(2023AH010059).
文摘Feixi County has made significant progress in promoting waste classification,such as establishing a comprehensive classification system,and effectively reducing environmental pollution and waste volume.However,with the increase in waste generation,the county faces multiple challenges especially in the disposal of kitchen waste and improvement of residents environmental awareness.To address these issues,Feixi County has implemented various measures,such as strengthening the construction of infrastructure for waste classification,improving regulations and clearly defining responsibilities,enhancing residents environmental awareness to encourage their participation in waste classification through education and promotion,and increasing supervision to ensure effective implementation of the work.It emphasizes community governance,encourage all parties to participate in it,and strengthen publicity,education and training to enhance residents participation.Feixi County has achieved positive results,but efforts are needed to further improve facilities,raise awareness,enhance supervision,and ensure the continuous effectiveness of waste classification work to promote urban green sustainable development.
文摘The unbalanced and inadequate use of fertilizers is one of the causes of soil degradation. Combined with the ever-increasing population, it is necessary to find sustainable agricultural production alternatives. The present work aims to determine the effect of different rates and mixtutes of organic amendments on soil fertility and the performance of Sunflower (Helianthus annuus L.). In the field, treatments consisted of solid household waste and faecal sludge in the ratios of 3/5 (V1), and a mixture of faecal sludge and household waste in the ratio of 3/5 with 900 worms (V2). At the end of the composting process, V1, V2 composts and the poultry manure (PM) were applied at rates of 4, 5 and 6 t∙ha−1 in a randomized complete block design with three replications. Soil samples were collected before and after the experiment and analyzed. The main results revealed that at the end of the composting process, there was a progressive improvement in the physico-chemical properties of V1 and V2 composts. In particular, the C/N ratio, phosphorus (P) and total nitrogen (TN) initially at 16.49 ± 0.42 (V1, V2), 21.06 ± 0.07 mg∙kg−1 (V1, V2), 0.76% ± 0.08% (V1, V2) respectively, increased after 60 days to 12.40 ± 0.41 (V1), 9.74 ± 0.28 (V2) for C/N, 21.94 ± 0.63 mg∙kg−1 (V1) and 22.04 ± 0.04 mg∙kg−1 (V2) for P, 0.96% ± 0.0% (V1) and 1.22 ± 0.04 (V2) for TN. The application of 6 t∙ha−1of PM had the greatest influence on the diameter and weight of the flower heads (27.16 ± 4.01 t∙ha−1 and 230.83 ± 2.64 t∙ha−1), while 4 t∙ha−1 of V2 gave the tallest sunflower plants (110.07 ± 73.28 cm) as well as the diameter at the crown (19.30 ± 9.07 cm). However, CEC was most influenced by 4 t∙ha−1 of V1, while 4 t∙ha−1 of PM had the greatest effect on organic carbon and phosphorus. However, 5 t∙ha−1 of PM showed the highest sunflower production and yield (1.67 ± 0.21 t∙ha−1). The combination with 900 earthworms is recommended for composting and 5 t∙ha−1 of PM is recommended to obtain a better sunflower production.
文摘The aim of this paper is to develop a Multi-Actor Geo-Collaborative Device to improve the processes of household waste collect (HWC) in urban areas. The proposed device will be tested in the Lamkansa district, in the southwestern part of Casablanca city, Morocco. The approach used is a systemic analysis of communication in order to act on a territory. We have been inspired by several methodological developments concerning multi-actor processes of land use planning. We focused our work on the involvement of the inhabitants in the process of household waste collect. The results show that the urban population can help and contribute to the development of complementary solutions to improve the urban environment and their living environment. Moreover, by integrating citizens in HWC processes, as well as decision communication, we can reduce household waste management costs and make it faster and more efficient, through a geo-collaborative, participatory and incentive logic. The approach described in this article is original, not only considering the technologies used to present and share the collected information, but also regarding the concept of integrating several actors in a collaborative/incentive mode. It arouses great interest by combining geomatics with communication and information sciences. It contributes to improve the participation of the inhabitants in the life of their urban environment in order to establish a reinforced dialogue on the future of their city and public health. Also, it involves the development and testing of new devices and tools for multi-actor collaboration.
文摘Source separation is the basic premise for making effective use of household wastes. In eight cities of China, how- ever, several pilot projects of source separation finally failed because of the poor participation rate of residents. In order to solve this problem, identifying those factors that influence residents’ behavior of source separation becomes crucial. By means of questionnaire survey, we conducted descriptive analysis and ex- ploratory factor analysis. The results show that trouble-feeling, moral notion, environment protection, public education, environment value and knowledge deficiency are the main factors that play an important role for residents in deciding to separate their household wastes. Also, according to the contribution percentage of the six main factors to the total behavior of source separation, their influencing power is analyzed, which will provide suggestions on household waste management for policy makers and decision makers in China.
文摘In order to enhance the production of biogas and to study the thermal behavior of waste, a numerical study of fluid flows and heat transfers within household waste was developed to predict the distributions of thermal fields. The mathematical model is based on the conservation of mass and energy equations. The resulting system of equations is discretized using the finite volume method and solved using the Thomas algorithm. The results of the model studied are compared with the numerical and site measurements results from other authors. The results have been found to be in good agreement. The results show that the mathematical model is able to reproduce the thermal behavior in anaerobic phase in landfills. The isotherms revealed that temperatures are lower in the upper part of the waste cell, very high in the core and decrease slightly in the bottom of the cell due to the biodegradation of waste.
文摘Solid waste is a promising renewable fuel that can substitute conventional fuel. According to the researchers, thermoconversion of solid waste such as municipal solid waste or residual household waste (RHW) is beneficial to society. However, due to its heterogeneity, the gasification of RHW is more complex. This review article discusses the steps that RHW must undergo before its thermoconversion and the state of the art of solid waste gasification. First, characterisation methods of RHW are surveyed. Second, the properties of RHW, the production lines of refuse derived fuel (RDF) from RHW, the influence of RDF composition and operating parameters such as equivalence ratio and temperature are reviewed. Moreover, RDF gasification products, scientific barriers and proposed solutions are evaluated. In conclusion, concerning emissions, costs and technical aspects related to each thermochemical process, it can be said that gasification is a promising technique for the recovery of RHW. However, studies on cogasification of waste and biomass on a pilot-industrial scale are still scarce and synergistic effects of this cogasification need to be clarified.
基金supported by the Danish Strategic Research Council as part of the TOPWASTE project
文摘Within the European Union (EU) a paradigm shift is currently occurring in the waste sector, where EU waste directives and national waste strategies are placing emphasis on resource efficiency and recycling targets. The most recent Danish resource strategy calculates a national recycling rate of 22% for household waste, and sets an ambitious goal of a 50% recycling rate by 2020. This study integrates the recycling target into the FRIDA model to project how much waste and from which streams should be diverted from incineration to recycling in order to achieve the target. Furthermore, it discusses how the existing technological, organizational and legislative frameworks may affect recycling activities. The results of the analysis show that with current best practice recycling rates, the 50% recycling rate cannot be reached without recycling of household biowaste. It also shows that all Danish municipalities will need to make efforts to recover all recyclable fractions, and that the increased recycling efforts of only selected municipalities will not be sufficient to reach the target.
文摘This study explores household solid waste management (HSWM) practices and awareness among residents of Windhoek West, a rapidly urbanizing constituency in the Khomas Region of Namibia. Employing a descriptive methodology, the research investigates the interplay between public awareness, regulatory frameworks, and the availability of waste management facilities to assess their impact on waste management behaviors. Our findings indicate significant gaps in both knowledge and infrastructure that hinder effective waste management. The study reveals that while there is a high willingness among residents to engage in recycling and waste reduction, actual practices are limited due to inadequate facilities and lack of stringent enforcement of waste policies. This research identifies key factors that influence waste management practices, including demographic characteristics and access to waste management facilities. It also proposes actionable strategies such as expanding recycling and sorting facilities, enhancing educational campaigns tailored to local needs, and implementing regular enforcement mechanisms. These strategies are aimed at improving compliance with waste management protocols and fostering a culture of environmental responsibility. The results of this investigation show the critical role of ongoing education and infrastructural improvement in bridging existing knowledge gaps and facilitating effective waste management practices. This research lays a foundational step toward enhancing sustainable urban development and effective waste management in Windhoek, providing valuable insights for policymakers, community leaders, and stakeholders engaged in urban environmental management.
文摘This research,carried out during September and October 2020 in the city of Kankan,made it possible to take stock of the city’s household waste management.The quantities of waste from the four main landfills in the city are assessed,namely:Sogbè(1350.3 m^(3)),Station(195.5 m^(3)),Station University of Kankan(2491.5 m^(3))and Salamani(369.6 m^(3)).Waste from three landfills/dumps was characterized for 26 days.This characterization covered 5,010.6 kg of waste,composed of 4263.9 kg of organic matter,462.1 kg of recyclable matter and 284.6 kg of inorganic matter.The survey concerned a target population of 403 inhabitants,which made it possible to determine a production ratio per habitant per day of(0.48 kg/habitant/d).Finally,a composting experiment of 2000 kg of organic matter was carried out.The results obtained during this study constitute the basic elements allowing defining a better policy of management of household solid waste in the city of Kankan.
文摘Waste stream characteristics must be understood to tackle waste management problem in Tripoli city, Libya. It is recognized that information on both quantity and composition of generation waste is important for the effective planning of household waste handling infrastructure. So, this study is aimed to evaluating the generation, composition and density of household solid waste in Tripoli city, Libya. The study is carried out according to the Annex 2.1 of: WHO 1996. It was conducted during one week in summer, autumn and winter 2011/2012. The daily household solid waste generation assessment has been carried out for 150 Libyan families where 947 people in three main parts of Tripoli city have been chosen randomly. A questionnaire was prepared according to Buenrostro et al. 2001 and Raje et al. 2001 using door-to-door surveying. The result showed that the average of total generation quantity, daily generation rate, total volume and density were 1415 kg, 0.64 kg/person/day, 19.3 m<sup>3 </sup>and 74.4 kg/m<sup>3</sup> respectively in Tripoli city. Household solid waste contains 36.3% organic matter and 32.5% recyclable materials (glass, paper, plastic, metals). The total generation quantity, daily generation rate, total volume and density were in Tripoli city agreed with those for African and Arabic countries. But the problem is that Tripoli suffers from insufficient municipal solid waste management and lack of sanitary landfills.
基金financially supported by the National Natural Science Foundation of China (22276140)the Shanghai Municipal Government State-Owned Assets Supervision and Administration Commission, China (2022028)the Key Research and Development Project of Zhejiang Province, China (2021C03024).
文摘Mechanical pretreatment is an indispensable process in biological treatment plants that remove plastics and other impurities from household biogenic waste(HBW).However,the imperfect separation of plastics in these pretreatment methods has raised concerns that they pose a secondary formation risk for microplastics(MPs).To validate this presumption,herein,quantities and properties of plastic debris and MPs larger than 50 μm were examined in the full chain of three different pretreatment methods in six plants.These facilities received HBW with or without prior depackaging at the source.The key points in the secondary formation of MPs were identified.Moreover,flux estimates of MPs were released,and an analysis of MPs sources was provided to develop an overview of their fate in HBW pretreatment.Pretreated output can contain a maximum of(1673±279) to(3198±263) MP particles per kilogram of wet weight(particles·kg^(-1)ww) for those undepackaged at source,and secondary MPs formation is primarily attributed to biomass crushers,biohydrolysis reactors,and rough shredders.Comparatively,HBW depackaged at the source can greatly reduce MPs by 8%-72%,regardless of pretreatment processes.Before pretreatment,4.6-205.6 million MP particles were present in 100 tonnes of HBW.MPs are produced at a rate of 741.11-33124.22 billion MP particles annually in anaerobic digester feedstock(ADF).This study demonstrated that HBW pretreatment is a competitive source of MPs and emphasized the importance of implementing municipal solid waste segregation at the source.Furthermore,depackaging biogenic waste at the source is recommended to substantially alleviate the negative effect of pretreatment on MPs formation.
文摘This paper presents the results of batch anaerobic co-digestion of matooke, cassava, and sweet potato peels and vines. These agricultural wastes and others form the biggest portion of household wastes in developing countries. However, they have remained an unexploited resource amidst the ever increasing needs of clean energy and waste disposal challenges. Efforts to use them individually as biogas substrates have been associated with process acidification failure resulting from their fast hydrolysis. The aim of this work was to exploit agricultural wastes is co-digestion among themselves and assess their effect on methane yield and its kinetics, pH and hydraulic retention time (HRT). Sixteen ratios of Matooke peels (MP), cassava peels (CP) and sweet potato peels (SP) were assessed in duplicate. Methane yield and its kinetics, pH and HRT demonstrated dependence on the proportion of substrates in the mixture. Depending on the ratio mixture, HRT increased to 15 days compared to less than 5 days for single substrates, hydrolysis rate constant (k) reduced to a range of 0.1 - 0.3 d<sup>-1</sup> compared to single substrates whose k-values were above 0.5 d<sup>-1</sup>, pH was maintained in the range of 6.38 - 6.43 and CH<sub>4</sub> yield increased by 15% - 200%. Ratios 2:1:0, 2:0:1, 0:1:2, 1:1:1 and 1:1:4 were consistent all through in terms of model fitting, having a positive synergetic effect on HRT, hydrolysis rate constant, lag phase and methane yield. However, more research is needed in maintaining the pH near the neutral for process stability assurance if household wastes are to be used as standalone substrates for biogas production without being co-substrates with livestock manure.
文摘A number of waste materials were studied on their application into asphalt mixtures. Materials tested were plastic waste as (soft) granular material,ceramic waste from electrical insulators,foundry sand and sintered granulate from burned household waste. Both plastic waste,crushed ceramics and large fractions of sintered household waste could be used as partial replacement for coarse aggregates. Foundry sand could partially replace natural sand in asphalt mixtures. The first step of the study was to find out if the waste materials could satisfy basic requirements and for some if their leaching behavior was acceptable. In the next phase mixtures were designed and mechanical tests were done on several mixtures with waste components to determine indirect tensile strength,stiffness,fatigue. In order to estimate the water sensitivity of some mixtures,retained indirect tension tests were done. The properties are reported and compared with each other and reference mixtures. From the research it becomes clear that it takes a lot of work to replace virgin materials in asphalt mixtures with waste materials.