Basic properties of fly ash samples from different urban waste combustion facilities in China were analyzed using as X-ray fluorescence （XRF）, scanning electron microscopy （SEM）, X-ray diffraction （XRD）. The lea...Basic properties of fly ash samples from different urban waste combustion facilities in China were analyzed using as X-ray fluorescence （XRF）, scanning electron microscopy （SEM）, X-ray diffraction （XRD）. The leaching toxicity procedure and some factors influencing heavy metals distribution in fly ash were further investigated. Experimental results indicate that the fly ash structures are complex and its properties are variable. The results of XRF and SEM revealed that the major elements （〉10000 mg/kg, listed in decreasing order of abundance） in fly ash are O, Ca, Cl, Si, S, K, Na, Al, Fe and Zn. These elements account for 93% to 97%, and the content of Cl ranges from 6.93% to 29.18 %, while that of SiO2 does from 4.48% to 24.84%. The minor elements （1000 to 10000 mg/kg） include Cr, Cu and Pb. Primary heavy metals in fly ash include Zn, Pb, Cr, Cu etc. According to standard leaching test, heavy metal leaching levels vary from 0 to 163.10 mg/L （Pb） and from 0.049 to 164.90 mg/L （Zn）, mostly exceeding the Chinese Identification Standard for hazardous wastes. Morphology of fly ash is irregular, with both amorphous structures and polycrystalline aggregates. Further research showed that heavy metals were volatilized at a high furnace temperature, condensed when cooling down during the post-furnace system and captured at air pollution control systems. Generally, heavy metals are mainly present in the forms of aerosol particulates or tiny particulates enriched on surfaces of fly ash particles. The properties of fly ash are greatly influenced by the treatment capacities of incinerators or the variation of waste retention time in chamber. Fly ash from combustors of larger capacities generally has higher contents of volatile component and higher leaching toxicity, while those of smaller capacities often produce fly ash containing higher levels of nonvolatile components and has lower toxicity. The content of heavy metals and leaching toxicity maybe have no convincing correlation, and high alkali content of CaO greatly contribute to leaching toxicity of heavy metal and acid neutralization capacity against acid rain.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
Corrosion of burning urban domestic wastes to alkali-resistant bricks and spalling-resistant high alumina bricks was researched by static crucible method and SEM in order to choose refractories for cement rotary kilns...Corrosion of burning urban domestic wastes to alkali-resistant bricks and spalling-resistant high alumina bricks was researched by static crucible method and SEM in order to choose refractories for cement rotary kilns for collaboratively disposing wastes. The result indicates that the main corrosion mechanism is slag permeation and corrosion ; the emitted high temperature gases containing alkali, sulfur and chlorine during burning the wastes re- act with refractories forming low melting point sulfate, chloride and compound salts, which metamorphose the refractories, and the loose metamorphic layer is easy to spall under thermal stress. So, corrosion resistance and spaUing resistance shall be taken into account when choosing refractories for cement rotary kilns for collaboratively disposing wastes. It is suggested that decomposition furnaces should adopt spaUing resistant high alumina bricks and anti-coating SiC castables, and preheating equipment should adopt high strength alkali-resistant bricks and castables.展开更多
Escalation in population over time triggered the abrupt exploitation of natural resources for human survival trough industrialization that ultimately caused splendid increase in the waste generation. This industrial d...Escalation in population over time triggered the abrupt exploitation of natural resources for human survival trough industrialization that ultimately caused splendid increase in the waste generation. This industrial development resulted in the migration of rural community toward urban areas. Management of urban waste is a great challenge for the urban administration. However, technologies have been developed to manage the waste in environmental friendly and sustainable manner. Sanitary landfill sites are one of the latest methods of disposing the municipal solid waste in an environment friendly and sustainable manner. Government and administrative authorities are adopting this technology for the management of urban solid waste. Present study is about identifying landfill sites for the Sahiwal city with an area of 1160 square kilometer and projected population of 1.57 million persons in 2016. Geographical Information System (GIS) is used for the identification of appropriate landfill site (LFS) that can fulfill the need of city in future and is selected based on the sustainable and eco-friendly criteria. The criteria are developed keeping in view the proximity from several land-use features i.e. water bodies, roads, settlements, agricultural land, bare land and existing disposal sites. The weights of the criteria are quantified using pair-wise comparison method in Analytic Hierarchy Process (AHP). The weights are incorporated in GIS spatial data environment and are assigned to proximity threshold of each criterion. Ultimately a map for each criterion is developed highlighting suitable, least suitable, less suitable and un-suitable areas with respect to each specific criterion. These maps are spatially overlaid which result in a final map that identifies most suitable landfill sites for solid waste disposal. The five identified sites are then prioritized based on their distances from the city center and area available. All identified sites are on the bare land and contain considerable buffer from environmentally sensitive receptors.展开更多
基金Project supported by the Hi-Tech Research and Development Program (863) of China (No. 2002AA644010) the National Tenth-Five Year Program of China (No. 2003BA604A-11-07).
文摘Basic properties of fly ash samples from different urban waste combustion facilities in China were analyzed using as X-ray fluorescence （XRF）, scanning electron microscopy （SEM）, X-ray diffraction （XRD）. The leaching toxicity procedure and some factors influencing heavy metals distribution in fly ash were further investigated. Experimental results indicate that the fly ash structures are complex and its properties are variable. The results of XRF and SEM revealed that the major elements （〉10000 mg/kg, listed in decreasing order of abundance） in fly ash are O, Ca, Cl, Si, S, K, Na, Al, Fe and Zn. These elements account for 93% to 97%, and the content of Cl ranges from 6.93% to 29.18 %, while that of SiO2 does from 4.48% to 24.84%. The minor elements （1000 to 10000 mg/kg） include Cr, Cu and Pb. Primary heavy metals in fly ash include Zn, Pb, Cr, Cu etc. According to standard leaching test, heavy metal leaching levels vary from 0 to 163.10 mg/L （Pb） and from 0.049 to 164.90 mg/L （Zn）, mostly exceeding the Chinese Identification Standard for hazardous wastes. Morphology of fly ash is irregular, with both amorphous structures and polycrystalline aggregates. Further research showed that heavy metals were volatilized at a high furnace temperature, condensed when cooling down during the post-furnace system and captured at air pollution control systems. Generally, heavy metals are mainly present in the forms of aerosol particulates or tiny particulates enriched on surfaces of fly ash particles. The properties of fly ash are greatly influenced by the treatment capacities of incinerators or the variation of waste retention time in chamber. Fly ash from combustors of larger capacities generally has higher contents of volatile component and higher leaching toxicity, while those of smaller capacities often produce fly ash containing higher levels of nonvolatile components and has lower toxicity. The content of heavy metals and leaching toxicity maybe have no convincing correlation, and high alkali content of CaO greatly contribute to leaching toxicity of heavy metal and acid neutralization capacity against acid rain.
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Corrosion of burning urban domestic wastes to alkali-resistant bricks and spalling-resistant high alumina bricks was researched by static crucible method and SEM in order to choose refractories for cement rotary kilns for collaboratively disposing wastes. The result indicates that the main corrosion mechanism is slag permeation and corrosion ; the emitted high temperature gases containing alkali, sulfur and chlorine during burning the wastes re- act with refractories forming low melting point sulfate, chloride and compound salts, which metamorphose the refractories, and the loose metamorphic layer is easy to spall under thermal stress. So, corrosion resistance and spaUing resistance shall be taken into account when choosing refractories for cement rotary kilns for collaboratively disposing wastes. It is suggested that decomposition furnaces should adopt spaUing resistant high alumina bricks and anti-coating SiC castables, and preheating equipment should adopt high strength alkali-resistant bricks and castables.
文摘Escalation in population over time triggered the abrupt exploitation of natural resources for human survival trough industrialization that ultimately caused splendid increase in the waste generation. This industrial development resulted in the migration of rural community toward urban areas. Management of urban waste is a great challenge for the urban administration. However, technologies have been developed to manage the waste in environmental friendly and sustainable manner. Sanitary landfill sites are one of the latest methods of disposing the municipal solid waste in an environment friendly and sustainable manner. Government and administrative authorities are adopting this technology for the management of urban solid waste. Present study is about identifying landfill sites for the Sahiwal city with an area of 1160 square kilometer and projected population of 1.57 million persons in 2016. Geographical Information System (GIS) is used for the identification of appropriate landfill site (LFS) that can fulfill the need of city in future and is selected based on the sustainable and eco-friendly criteria. The criteria are developed keeping in view the proximity from several land-use features i.e. water bodies, roads, settlements, agricultural land, bare land and existing disposal sites. The weights of the criteria are quantified using pair-wise comparison method in Analytic Hierarchy Process (AHP). The weights are incorporated in GIS spatial data environment and are assigned to proximity threshold of each criterion. Ultimately a map for each criterion is developed highlighting suitable, least suitable, less suitable and un-suitable areas with respect to each specific criterion. These maps are spatially overlaid which result in a final map that identifies most suitable landfill sites for solid waste disposal. The five identified sites are then prioritized based on their distances from the city center and area available. All identified sites are on the bare land and contain considerable buffer from environmentally sensitive receptors.
