In order to realize the OY Smelting Furnace disposal of solid waste,municipal waste,form a model of steel enterprises and urban integration,through the production practice of smelting furnace,analyzes the mechanism of...In order to realize the OY Smelting Furnace disposal of solid waste,municipal waste,form a model of steel enterprises and urban integration,through the production practice of smelting furnace,analyzes the mechanism of solid waste disposal,and proposed the disposal of solid waste desulfurization agent and disposal method:According to the theory to guide the actual production process,the test ton of iron with 10-15kg of desulfurizer in the production process does not affect the quality of molten iron and slag quality.展开更多
Anaerobic digestion is a good method, which possesses the optimal combination of volume reduction, probability of success and potential for resource and energy recovery. However, relatively little research has been do...Anaerobic digestion is a good method, which possesses the optimal combination of volume reduction, probability of success and potential for resource and energy recovery. However, relatively little research has been done on the anaerobic digestion of organic solid wastes (OSW), especially in China. However, different substrates, start-up conditions, micro-organisms, processing technologies, pre-treatment methods could influence the result of anaerobic digestion. Anaerobic treatment of municipal OSW is less than that of wastewaters because some problems and obstructions need to be solved. Meanwhile, the application of anaerobic digestion of OSW is also discussed in the present paper.展开更多
Freetown which is the capital city of Sierra Leone is facing challenges with population growth, urbanization, and industrialization, leading to an increase in municipal solid waste (MSW) generation. The study aims to ...Freetown which is the capital city of Sierra Leone is facing challenges with population growth, urbanization, and industrialization, leading to an increase in municipal solid waste (MSW) generation. The study aims to evaluate MSW generation, composition, and disposal methods, as well as the impact of collection fees, policy implementation, and women’s participation in municipal solid waste management (MSWM). The study used both qualitative and quantitative methods for data collection and analysis. The study administered 393 structured questionnaires in three selected sections to collect data on variables such as family size, education, level of knowledge, etc. The study used door-to-door data collection to determine the rate of solid waste generation, composition, and disposal in 66 households from two of the selected sections and 34 households from the other section to evaluate the current situation of MSWM practices among households in Freetown. The study used a descriptive statistic to analyze the data collected using Origin-Pro9 and MS Excel software. The findings showed that with a 4.2% urban growth rate, Freetown had a population of 1,467,543 in 2023, generating 851 tons of MSW per day, with organic waste accounting for 78% of the total MSW generated. Plastic waste generation also increased from 7.6% in 2020 to 13% in 2023. The study emphasizes the need to sustain the MSWM system by prioritizing solid waste collection fees, policy enforcement, and women’s participation in the MSWM sector. It further suggests and provides recommendations for developing an efficient and sustainable MSWM system in Sierra Leone, including knowledge transfer from countries like China and the US.展开更多
Indiscriminate disposal of solid waste in dumpsites located within urban areas has proved to be a problem to nearby residents in most developing cities of the world, Freetown is no exception. Open dumps have environme...Indiscriminate disposal of solid waste in dumpsites located within urban areas has proved to be a problem to nearby residents in most developing cities of the world, Freetown is no exception. Open dumps have environmental safeguards;they can pose major public health threats and environmental effects in urban cities. Therefore, this paper presents the findings of a research carried out in Freetown municipal area in Sierra Leone to determine the environmental and health impacts of solid waste disposal at Granville Brook dumpsite on the surrounding human settlements. Data were collected from three hundred and ninety eight nearby dumpsite household residents (less than fifty metres) and two hundred and thirty three far away household residents (more than fifty metres) through the use of structured self-administered questionnaires. Interviews and personal observations were also used to collect some of the data. Descriptive statistics involving tables, graphs and figures were used to present and analyze the data. Results show that both nearby residents and far away residents suffered from related diseases such as malaria, chest pains, diarrhea and cholera, due to the location of the dumpsite closer to their settlements. As a result, this study highlights the need for the Freetown City Council to properly manage and relocate the dumpsite to a safe distance from all human settlements, and provide resettlement and environmental education programmes for all persons living less than fifty metres away from the dumpsite as interim measures.展开更多
To analyze the feasibility of utilization of thermal technology in fly ash treatment,thermal properties and microstructures of municipal solid waste incineration(MSWI) fly ash were studied by measuring the chemical el...To analyze the feasibility of utilization of thermal technology in fly ash treatment,thermal properties and microstructures of municipal solid waste incineration(MSWI) fly ash were studied by measuring the chemical element composition,specific surface area,pore sizes,functional groups,TEM image,mineralogy and DSC-TG curves of raw and sintered fly ash specimens.The results show that MSWI fly ash particles mostly have irregular shapes and non-typical pore structure,and the supersonic treatment improves the pore structure;MSWI fly ash consists of such crystals as SiO2,CaSO4 and silica-aluminates,and some soluble salts like KCl and NaCl.During the sintering process,mineralogy changes largely and novel solid solutions are produced gradually with the rise of temperature.Therefore,the utilization of a proper thermal technology not only destructs those persistent organic toxicants but also stabilizes hazardous heavy metals in MSWI fly ash.展开更多
Accumulating operational experience in both aerobic and anaerobic mechanical biological waste treatment (MBT) makes it increasingly obvious that controlled water management would substantially reduce the cost of MBT...Accumulating operational experience in both aerobic and anaerobic mechanical biological waste treatment (MBT) makes it increasingly obvious that controlled water management would substantially reduce the cost of MBT and also enhance resource recovery of the organic and inorganic fraction. The MBT plant at Gescher, Germany, is used as an example in order to determine the quantity and composition of process water and leachates from intensive and subsequent rotting, pressing water from anaerobic digestion and scrubber water from acid exhaust air treatment, and hence prepare an MBT water balance. The potential of, requirements for and limits to internal process water reuse as well as the possibilities of resource recovery from scrubber water are also examined. Finally, an assimilated process water management concept with the purpose of an extensive reduction of wastewater quantity and freshwater demand is presented.展开更多
Landfill leachate is mainly the result of precipitation of water into the layers of buried waste, and biochemical reactions of waste that has dangerous substances and pollutants that lead to the contamination of surfa...Landfill leachate is mainly the result of precipitation of water into the layers of buried waste, and biochemical reactions of waste that has dangerous substances and pollutants that lead to the contamination of surface and groundwater resources. Therefore, it must be collected and treated properly. The investigation of various biological methods in leachate treatment, their advantages and disadvantages, and their effect on reduction of COD (chemical oxygen demand) are the objectives of this study. Reviewed processes include anaerobic and aerobic sequencing batch reactor, up-flow anaerobic sludge blanket, moving-bed biofilm reactor, membrane bioreactor, and aerated lagoons, lead to reduction of biodegradability pollutants in different circumstances. The present study has indicated that the most and the least reduction of COD has been through aerated lagoon (95%) and moving-bed biofilm reactor (8%), respectively.展开更多
Solid waste such as “garbage” “trash” “refuse” “slug” and “rubbish” is disposed off or is required to be disposed off in accordance with national law. The study relies on primary and secondary sources of inf...Solid waste such as “garbage” “trash” “refuse” “slug” and “rubbish” is disposed off or is required to be disposed off in accordance with national law. The study relies on primary and secondary sources of information. The primary sources include the Constitution, statutes and subsidiary legislation. The secondary sources of information include books, journals, conference proceedings, newspapers, magazines and internet materials. The information obtained from these sources is subjected to content and contextual analysis. The study examines the Kwara State Environmental Protection Agency Law, 1992 and other laws on waste disposal and management in Kwara State, Nigeria. The study also examines the regulations and the agency i.e. the Kwara State Environmental Protection Agency created by the law with a view to determine the inadequacies in the law.展开更多
This paper describes a research project that has been conducted as part of the Kano Municipal waste management strategy. The aim is to quantify and to identify the existing locations of waste disposal sites by mapping...This paper describes a research project that has been conducted as part of the Kano Municipal waste management strategy. The aim is to quantify and to identify the existing locations of waste disposal sites by mapping their spatial distribution within the metropolitan Kano. QUICKBIRD satellite imageries;locations of existing waste disposal sites collected using Global Positioning System (GPS);and topographical map (1:5000 scale) of Kano metropolis were used to generate data for the study. The data were prepared and analysed using ArcMap 10.2.1 and Erdas Imagine 11 software to produce the spatial distribution maps for solid waste disposal sites within the metropolis. The result shows that out of the 300 existing waste disposal sites assessed, the city has fairly well-distributed waste disposal sites. Conversely, the disposal sites are more clustered in the centre of the metropolis than the outskirts. However, about 80 percent of the sites are either located very close to roads, settlements or water bodies. Also, while about 92 percent of the existing waste disposal locations are open space, only about 7 percent are containers (closed dumping sites). Correspondingly, about 89 percent are authorised dumping sites and only about 11 percent are unauthorised illegal. The study recommends that policymakers should intervene and relocate the existing unauthorized dump sites to more suitable areas.展开更多
Introduction: Treatment of solid medical waste (SMW) is a complex task requiring the proper practices with specific treatment methods corresponding to each type of SMW during pretreatment and final treatment. This stu...Introduction: Treatment of solid medical waste (SMW) is a complex task requiring the proper practices with specific treatment methods corresponding to each type of SMW during pretreatment and final treatment. This study targeted three treatment methods identified as the main used by the majority of health care facilities (HCFs) and treating a large amount of SMW. It aimed: 1) to evaluate the current practices by calculating the emergy investment and emergy costs that are required to treat one ton of SMW through the three treatment methods and 2) to evaluate and compare better technologies and provide policy suggestions for the final treatment of SMW in Burundi. Materials and Methods: This study used the emergy methodology to evaluate the relative efficiencies of three treatment methods used for to treat SMW in twelve HCFs in Bujumbura. Results and Conclusion: The total emergy input was 1.36E+20 seJ/yr, 3.54E+17 seJ/yr, and 1.681E+18 seJ/yr for low temperature incinerator, landfill and organic pit, respectively. Conclusion: Rapid improvement of organic pit by ensuring its maintenance, the gradual replacement of low temperature incinerator by high temperature incinerator with air control pollution and landfill by sanitary landfill are highly recommended by respecting its maintenance (fence, roof and monitoring evaluation) for reducing the risk.展开更多
Antibiotic fermentation residue(AFR)is nutrient-rich solid waste generated from fermentative antibiotic production process.It is demonstrated that AFR contains high-concentration of remaining antibiotics,and thus may ...Antibiotic fermentation residue(AFR)is nutrient-rich solid waste generated from fermentative antibiotic production process.It is demonstrated that AFR contains high-concentration of remaining antibiotics,and thus may promote antibiotic resistance development in receiving environment or feeding farmed animals.However,the dominate microorganisms and antibiotic resistance genes(ARGs)in AFRs have not been adequately explored,hampering understanding on the potential antibiotic resistance risk development caused by AFRs.Herein,seven kinds of representative AFRs along their production,storage,and treatment processes were collected,and multiple methods including amplicon sequencing,metagenomic sequencing,and bioinformatic approaches were adopted to explore the biological characteristics of AFRs.As expected,antibiotic fermentation producer was found as the predominant species in raw AFRs,which were collected at the outlet of fermentation tanks.However,except for producer species,more environment-derived species persisted in stored AFRs,which were temporarily stored at a semi-open space.Lactobacillus genus,classified as Firmicutes phylum and Bacilli class,became predominant bacterial taxa in stored AFRs,which might attribute to its tolerance to high concentration of antibiotics.Results from metagenomic sequencing together with assembly and binning approaches showed that these newly-colonizing species(e.g.,Lactobacillus genus)tended to carry ARGs conferring resistance to the remaining antibiotic.However,after thermal treatment,remaining antibiotic could be efficiently removed from AFRs,and microorganisms together with DNA could be strongly destroyed.In sum,the main risk from the AFRs was the remaining antibiotic,while environment-derived bacteria which tolerate extreme environment,survived in ARFs with high content antibiotics,and may carry ARGs.Thus,hydrothermal or other harmless treatment technologies are recommended to remove antibiotic content and inactivate bacteria before recycling of AFRs in pharmaceutical industry.展开更多
The clayish crushed stone was used for making aerated concrete. Through studying hydro-thermal synthesis reaction, mix ratio, gas-forming and performance analysis, Grade-B05 and Grade-B06 aerated concrete were prepare...The clayish crushed stone was used for making aerated concrete. Through studying hydro-thermal synthesis reaction, mix ratio, gas-forming and performance analysis, Grade-B05 and Grade-B06 aerated concrete were prepared successfully. The proper mix ratio and key processing parameters were achieved. The microstructure of aerated concrete with crush stone was analyzed by means of XRD and SEM. The experimental results indicate that the hydration products are poorly crystalline C- S- H ( B ), tobermorite and hydrogarnet. No componeat of clay was found. Unreacted SiO2 cart be in existence, and the structure system of aerated concrete is homogencous and dense.展开更多
Babylon Governorate covers an area of 5315 km2 with a population that reaches about 1,974,490 inhabitants in the central part of Iraq. Iraq produced 31,000 tons/day solid waste in 2013. The Governorate of Babylon prod...Babylon Governorate covers an area of 5315 km2 with a population that reaches about 1,974,490 inhabitants in the central part of Iraq. Iraq produced 31,000 tons/day solid waste in 2013. The Governorate of Babylon produces annual 483,221 tons of solid waste. Management of collection and disposal of waste in Babylon Governorate is done through open dumping of waste and poor collection process. These sites do not conform to the scientific and environmental criteria applied in the selection of landfill sites. To find out how much solid waste is expected in the future, two methods were used to calculate the population growth in Babylon Governorate to the year 2030. The results showed that the total waste in 2030 will be 761,104 tons and 943055 tons while the cumulated quantity of solid waste expected till 2030 was 12,494,521 tons and 14,095,437 tons according to the first and second methods respectively.展开更多
Investigations on the recycling plasma pyrolysis technique are presented in 25 kW was employed for the experiments. of oyster shells and bone waste treatment using the this paper. A arc based plasma torch operated at ...Investigations on the recycling plasma pyrolysis technique are presented in 25 kW was employed for the experiments. of oyster shells and bone waste treatment using the this paper. A arc based plasma torch operated at Fresh oyster shells were recycled using the plasma torch to convert them to a useful product such as CaO. Bone waste was treated to remove the infectious organic part and to vitrify the inorganic part. The time required for treatment in both cases was significantly short. Significant reduction in the weight of the samples was observed in both cases.展开更多
Daily meat consumption produces a lot of bone waste, and dumped bone waste without treatment would result in environmental hazards. Conventional treatment methods of waste bones have some disadvantages. Herein, an inv...Daily meat consumption produces a lot of bone waste, and dumped bone waste without treatment would result in environmental hazards. Conventional treatment methods of waste bones have some disadvantages. Herein, an investigation of bone waste treated using thermal plasma technology is presented. A high-temperature plasma torch operated at 25.2 kW was used to treat bone waste for seven minutes. The bone waste was finally changed into vitric matter and lost 2/3 of its weight after the treatment. The process was highly efficient, economical, convenient, and fuel-free. This method could be used as an alternative for disposal of bone waste, small infectious animals, hazardous hospital waste, etc.展开更多
Among Brazilian soils orders, there are some of it classified as acid soils, which need correction to guarantee crop productivity. Currently, limestone is the most used soil corrective and wood ash has been a sustaina...Among Brazilian soils orders, there are some of it classified as acid soils, which need correction to guarantee crop productivity. Currently, limestone is the most used soil corrective and wood ash has been a sustainable alternative to this process. Thus, the objective was to evaluate the effect of two correctives of soil acidity on an Oxisol collected in the Brazilian Cerrado area using limestone and wood ash and the effect of soil correction on initial growth of cowpea. Two greenhouse experiments were carried out: 1) with limestone, using base saturation levels (V%) of 0, 20, 40, 60 and 80;and 2) wood ash, with doses of 0, 8, 16, 24 and 32 g⋅dm−3, both in five randomized blocks. At 40 days after sowing, it was verified that pH values were within the range considered ideal for soil (pH of 5 to 7), according to the increase of base saturation levels and wood ash doses, but limestone provided faster results. Initial growth of cowpea was positively influenced by soil correction with use of both correctives. Wood ash and limestone increased soil pH to adequate values and resulted in better initial crop development.展开更多
The purpose of this article is to present the key elements for best performance and profitability of Municipal Solid Waste (MSW) management in a low-income city. The research provides an overview of methods and models...The purpose of this article is to present the key elements for best performance and profitability of Municipal Solid Waste (MSW) management in a low-income city. The research provides an overview of methods and models for integrated planning of a two-phase program: MSW collection and transportation, and MSW treatment. We present the case study of Matadi (the Democratic Republic of Congo) that has a low level of the MSW management compared to other African cities. We develop a spreadsheet model for collection and transportation of MSW which is relevant for low-income cities and enables determining the waste collection fee. A CDM decay model is used to predict the GHG emissions in disposal site. The MSW treatment plant in case of Matadi is evaluated. For the anaerobic digestion technology selected as appropriate for this plant, the key factors that ensure profitability of the plant are as follows: tipping fee from the municipality (19% of total revenue), amount of carbon credits which can sum up to 16% of the total revenue, expansion of waste collection range from 25 to 50 km. The methods of this study can be used for solving waste problem in other low-income cities where the budget for municipal services is scanty, particularly when starting from a very low level of MSW management.展开更多
文摘In order to realize the OY Smelting Furnace disposal of solid waste,municipal waste,form a model of steel enterprises and urban integration,through the production practice of smelting furnace,analyzes the mechanism of solid waste disposal,and proposed the disposal of solid waste desulfurization agent and disposal method:According to the theory to guide the actual production process,the test ton of iron with 10-15kg of desulfurizer in the production process does not affect the quality of molten iron and slag quality.
基金Granted by the Chongqing Municipal 2004’ Academician Funds(2004-8260).
文摘Anaerobic digestion is a good method, which possesses the optimal combination of volume reduction, probability of success and potential for resource and energy recovery. However, relatively little research has been done on the anaerobic digestion of organic solid wastes (OSW), especially in China. However, different substrates, start-up conditions, micro-organisms, processing technologies, pre-treatment methods could influence the result of anaerobic digestion. Anaerobic treatment of municipal OSW is less than that of wastewaters because some problems and obstructions need to be solved. Meanwhile, the application of anaerobic digestion of OSW is also discussed in the present paper.
文摘Freetown which is the capital city of Sierra Leone is facing challenges with population growth, urbanization, and industrialization, leading to an increase in municipal solid waste (MSW) generation. The study aims to evaluate MSW generation, composition, and disposal methods, as well as the impact of collection fees, policy implementation, and women’s participation in municipal solid waste management (MSWM). The study used both qualitative and quantitative methods for data collection and analysis. The study administered 393 structured questionnaires in three selected sections to collect data on variables such as family size, education, level of knowledge, etc. The study used door-to-door data collection to determine the rate of solid waste generation, composition, and disposal in 66 households from two of the selected sections and 34 households from the other section to evaluate the current situation of MSWM practices among households in Freetown. The study used a descriptive statistic to analyze the data collected using Origin-Pro9 and MS Excel software. The findings showed that with a 4.2% urban growth rate, Freetown had a population of 1,467,543 in 2023, generating 851 tons of MSW per day, with organic waste accounting for 78% of the total MSW generated. Plastic waste generation also increased from 7.6% in 2020 to 13% in 2023. The study emphasizes the need to sustain the MSWM system by prioritizing solid waste collection fees, policy enforcement, and women’s participation in the MSWM sector. It further suggests and provides recommendations for developing an efficient and sustainable MSWM system in Sierra Leone, including knowledge transfer from countries like China and the US.
文摘Indiscriminate disposal of solid waste in dumpsites located within urban areas has proved to be a problem to nearby residents in most developing cities of the world, Freetown is no exception. Open dumps have environmental safeguards;they can pose major public health threats and environmental effects in urban cities. Therefore, this paper presents the findings of a research carried out in Freetown municipal area in Sierra Leone to determine the environmental and health impacts of solid waste disposal at Granville Brook dumpsite on the surrounding human settlements. Data were collected from three hundred and ninety eight nearby dumpsite household residents (less than fifty metres) and two hundred and thirty three far away household residents (more than fifty metres) through the use of structured self-administered questionnaires. Interviews and personal observations were also used to collect some of the data. Descriptive statistics involving tables, graphs and figures were used to present and analyze the data. Results show that both nearby residents and far away residents suffered from related diseases such as malaria, chest pains, diarrhea and cholera, due to the location of the dumpsite closer to their settlements. As a result, this study highlights the need for the Freetown City Council to properly manage and relocate the dumpsite to a safe distance from all human settlements, and provide resettlement and environmental education programmes for all persons living less than fifty metres away from the dumpsite as interim measures.
基金Project(50808184) supported by the National Natural Science Foundation of China
文摘To analyze the feasibility of utilization of thermal technology in fly ash treatment,thermal properties and microstructures of municipal solid waste incineration(MSWI) fly ash were studied by measuring the chemical element composition,specific surface area,pore sizes,functional groups,TEM image,mineralogy and DSC-TG curves of raw and sintered fly ash specimens.The results show that MSWI fly ash particles mostly have irregular shapes and non-typical pore structure,and the supersonic treatment improves the pore structure;MSWI fly ash consists of such crystals as SiO2,CaSO4 and silica-aluminates,and some soluble salts like KCl and NaCl.During the sintering process,mineralogy changes largely and novel solid solutions are produced gradually with the rise of temperature.Therefore,the utilization of a proper thermal technology not only destructs those persistent organic toxicants but also stabilizes hazardous heavy metals in MSWI fly ash.
文摘Accumulating operational experience in both aerobic and anaerobic mechanical biological waste treatment (MBT) makes it increasingly obvious that controlled water management would substantially reduce the cost of MBT and also enhance resource recovery of the organic and inorganic fraction. The MBT plant at Gescher, Germany, is used as an example in order to determine the quantity and composition of process water and leachates from intensive and subsequent rotting, pressing water from anaerobic digestion and scrubber water from acid exhaust air treatment, and hence prepare an MBT water balance. The potential of, requirements for and limits to internal process water reuse as well as the possibilities of resource recovery from scrubber water are also examined. Finally, an assimilated process water management concept with the purpose of an extensive reduction of wastewater quantity and freshwater demand is presented.
文摘Landfill leachate is mainly the result of precipitation of water into the layers of buried waste, and biochemical reactions of waste that has dangerous substances and pollutants that lead to the contamination of surface and groundwater resources. Therefore, it must be collected and treated properly. The investigation of various biological methods in leachate treatment, their advantages and disadvantages, and their effect on reduction of COD (chemical oxygen demand) are the objectives of this study. Reviewed processes include anaerobic and aerobic sequencing batch reactor, up-flow anaerobic sludge blanket, moving-bed biofilm reactor, membrane bioreactor, and aerated lagoons, lead to reduction of biodegradability pollutants in different circumstances. The present study has indicated that the most and the least reduction of COD has been through aerated lagoon (95%) and moving-bed biofilm reactor (8%), respectively.
文摘Solid waste such as “garbage” “trash” “refuse” “slug” and “rubbish” is disposed off or is required to be disposed off in accordance with national law. The study relies on primary and secondary sources of information. The primary sources include the Constitution, statutes and subsidiary legislation. The secondary sources of information include books, journals, conference proceedings, newspapers, magazines and internet materials. The information obtained from these sources is subjected to content and contextual analysis. The study examines the Kwara State Environmental Protection Agency Law, 1992 and other laws on waste disposal and management in Kwara State, Nigeria. The study also examines the regulations and the agency i.e. the Kwara State Environmental Protection Agency created by the law with a view to determine the inadequacies in the law.
文摘This paper describes a research project that has been conducted as part of the Kano Municipal waste management strategy. The aim is to quantify and to identify the existing locations of waste disposal sites by mapping their spatial distribution within the metropolitan Kano. QUICKBIRD satellite imageries;locations of existing waste disposal sites collected using Global Positioning System (GPS);and topographical map (1:5000 scale) of Kano metropolis were used to generate data for the study. The data were prepared and analysed using ArcMap 10.2.1 and Erdas Imagine 11 software to produce the spatial distribution maps for solid waste disposal sites within the metropolis. The result shows that out of the 300 existing waste disposal sites assessed, the city has fairly well-distributed waste disposal sites. Conversely, the disposal sites are more clustered in the centre of the metropolis than the outskirts. However, about 80 percent of the sites are either located very close to roads, settlements or water bodies. Also, while about 92 percent of the existing waste disposal locations are open space, only about 7 percent are containers (closed dumping sites). Correspondingly, about 89 percent are authorised dumping sites and only about 11 percent are unauthorised illegal. The study recommends that policymakers should intervene and relocate the existing unauthorized dump sites to more suitable areas.
文摘Introduction: Treatment of solid medical waste (SMW) is a complex task requiring the proper practices with specific treatment methods corresponding to each type of SMW during pretreatment and final treatment. This study targeted three treatment methods identified as the main used by the majority of health care facilities (HCFs) and treating a large amount of SMW. It aimed: 1) to evaluate the current practices by calculating the emergy investment and emergy costs that are required to treat one ton of SMW through the three treatment methods and 2) to evaluate and compare better technologies and provide policy suggestions for the final treatment of SMW in Burundi. Materials and Methods: This study used the emergy methodology to evaluate the relative efficiencies of three treatment methods used for to treat SMW in twelve HCFs in Bujumbura. Results and Conclusion: The total emergy input was 1.36E+20 seJ/yr, 3.54E+17 seJ/yr, and 1.681E+18 seJ/yr for low temperature incinerator, landfill and organic pit, respectively. Conclusion: Rapid improvement of organic pit by ensuring its maintenance, the gradual replacement of low temperature incinerator by high temperature incinerator with air control pollution and landfill by sanitary landfill are highly recommended by respecting its maintenance (fence, roof and monitoring evaluation) for reducing the risk.
基金supported by the National Natural Science Foundation of China (No.32141002)。
文摘Antibiotic fermentation residue(AFR)is nutrient-rich solid waste generated from fermentative antibiotic production process.It is demonstrated that AFR contains high-concentration of remaining antibiotics,and thus may promote antibiotic resistance development in receiving environment or feeding farmed animals.However,the dominate microorganisms and antibiotic resistance genes(ARGs)in AFRs have not been adequately explored,hampering understanding on the potential antibiotic resistance risk development caused by AFRs.Herein,seven kinds of representative AFRs along their production,storage,and treatment processes were collected,and multiple methods including amplicon sequencing,metagenomic sequencing,and bioinformatic approaches were adopted to explore the biological characteristics of AFRs.As expected,antibiotic fermentation producer was found as the predominant species in raw AFRs,which were collected at the outlet of fermentation tanks.However,except for producer species,more environment-derived species persisted in stored AFRs,which were temporarily stored at a semi-open space.Lactobacillus genus,classified as Firmicutes phylum and Bacilli class,became predominant bacterial taxa in stored AFRs,which might attribute to its tolerance to high concentration of antibiotics.Results from metagenomic sequencing together with assembly and binning approaches showed that these newly-colonizing species(e.g.,Lactobacillus genus)tended to carry ARGs conferring resistance to the remaining antibiotic.However,after thermal treatment,remaining antibiotic could be efficiently removed from AFRs,and microorganisms together with DNA could be strongly destroyed.In sum,the main risk from the AFRs was the remaining antibiotic,while environment-derived bacteria which tolerate extreme environment,survived in ARFs with high content antibiotics,and may carry ARGs.Thus,hydrothermal or other harmless treatment technologies are recommended to remove antibiotic content and inactivate bacteria before recycling of AFRs in pharmaceutical industry.
文摘The clayish crushed stone was used for making aerated concrete. Through studying hydro-thermal synthesis reaction, mix ratio, gas-forming and performance analysis, Grade-B05 and Grade-B06 aerated concrete were prepared successfully. The proper mix ratio and key processing parameters were achieved. The microstructure of aerated concrete with crush stone was analyzed by means of XRD and SEM. The experimental results indicate that the hydration products are poorly crystalline C- S- H ( B ), tobermorite and hydrogarnet. No componeat of clay was found. Unreacted SiO2 cart be in existence, and the structure system of aerated concrete is homogencous and dense.
文摘Babylon Governorate covers an area of 5315 km2 with a population that reaches about 1,974,490 inhabitants in the central part of Iraq. Iraq produced 31,000 tons/day solid waste in 2013. The Governorate of Babylon produces annual 483,221 tons of solid waste. Management of collection and disposal of waste in Babylon Governorate is done through open dumping of waste and poor collection process. These sites do not conform to the scientific and environmental criteria applied in the selection of landfill sites. To find out how much solid waste is expected in the future, two methods were used to calculate the population growth in Babylon Governorate to the year 2030. The results showed that the total waste in 2030 will be 761,104 tons and 943055 tons while the cumulated quantity of solid waste expected till 2030 was 12,494,521 tons and 14,095,437 tons according to the first and second methods respectively.
文摘Investigations on the recycling plasma pyrolysis technique are presented in 25 kW was employed for the experiments. of oyster shells and bone waste treatment using the this paper. A arc based plasma torch operated at Fresh oyster shells were recycled using the plasma torch to convert them to a useful product such as CaO. Bone waste was treated to remove the infectious organic part and to vitrify the inorganic part. The time required for treatment in both cases was significantly short. Significant reduction in the weight of the samples was observed in both cases.
基金supported by the Regional Research Center for Environmental Technology of Thermal Plasma (ETTP) at Inha University designated by Ministry of Commerce,Industry and Energy (MOCIE) of South Korea (2006)
文摘Daily meat consumption produces a lot of bone waste, and dumped bone waste without treatment would result in environmental hazards. Conventional treatment methods of waste bones have some disadvantages. Herein, an investigation of bone waste treated using thermal plasma technology is presented. A high-temperature plasma torch operated at 25.2 kW was used to treat bone waste for seven minutes. The bone waste was finally changed into vitric matter and lost 2/3 of its weight after the treatment. The process was highly efficient, economical, convenient, and fuel-free. This method could be used as an alternative for disposal of bone waste, small infectious animals, hazardous hospital waste, etc.
文摘Among Brazilian soils orders, there are some of it classified as acid soils, which need correction to guarantee crop productivity. Currently, limestone is the most used soil corrective and wood ash has been a sustainable alternative to this process. Thus, the objective was to evaluate the effect of two correctives of soil acidity on an Oxisol collected in the Brazilian Cerrado area using limestone and wood ash and the effect of soil correction on initial growth of cowpea. Two greenhouse experiments were carried out: 1) with limestone, using base saturation levels (V%) of 0, 20, 40, 60 and 80;and 2) wood ash, with doses of 0, 8, 16, 24 and 32 g⋅dm−3, both in five randomized blocks. At 40 days after sowing, it was verified that pH values were within the range considered ideal for soil (pH of 5 to 7), according to the increase of base saturation levels and wood ash doses, but limestone provided faster results. Initial growth of cowpea was positively influenced by soil correction with use of both correctives. Wood ash and limestone increased soil pH to adequate values and resulted in better initial crop development.
文摘The purpose of this article is to present the key elements for best performance and profitability of Municipal Solid Waste (MSW) management in a low-income city. The research provides an overview of methods and models for integrated planning of a two-phase program: MSW collection and transportation, and MSW treatment. We present the case study of Matadi (the Democratic Republic of Congo) that has a low level of the MSW management compared to other African cities. We develop a spreadsheet model for collection and transportation of MSW which is relevant for low-income cities and enables determining the waste collection fee. A CDM decay model is used to predict the GHG emissions in disposal site. The MSW treatment plant in case of Matadi is evaluated. For the anaerobic digestion technology selected as appropriate for this plant, the key factors that ensure profitability of the plant are as follows: tipping fee from the municipality (19% of total revenue), amount of carbon credits which can sum up to 16% of the total revenue, expansion of waste collection range from 25 to 50 km. The methods of this study can be used for solving waste problem in other low-income cities where the budget for municipal services is scanty, particularly when starting from a very low level of MSW management.