This investigation is focused on conducting a thorough analysis of Municipal Solid Waste Management (MSWM). MSWM encompasses a range of interdisciplinary measures that govern the various stages involved in managing un...This investigation is focused on conducting a thorough analysis of Municipal Solid Waste Management (MSWM). MSWM encompasses a range of interdisciplinary measures that govern the various stages involved in managing unwanted or non-utilizable solid materials, commonly known as rubbish, trash, junk, refuse, and garbage. These stages include generation, storage, collection, recycling, transportation, handling, disposal, and monitoring. The waste materials mentioned in this context exhibit a wide range of items, such as organic waste from food and vegetables, paper, plastic, polyethylene, iron, tin cans, deceased animals, byproducts from demolition activities, manure, and various other discarded materials. This study aims to provide insights into the possibilities of enhancing solid waste management in the Farmgate area of Dhaka North City Corporation (DNCC). To accomplish this objective, the research examines the conventional waste management methods employed in this area. It conducts extensive field surveys, collecting valuable data through interviews with local residents and key individuals involved in waste management, such as waste collectors, dealers, intermediate dealers, recyclers, and shopkeepers. The results indicate that significant amounts of distinct waste categories are produced daily. These include food and vegetable waste, which amount to 52.1 tons/day;polythene and plastic, which total 4.5 tons/day;metal and tin-can waste, which amounts to 1.4 tons/day;and paper waste, which totals 5.9 tons/day. This study highlights the significance of promoting environmental consciousness to effectively shape the attitudes of urban residents toward waste disposal and management. It emphasizes the need for collaboration between authorities and researchers to improve the current waste management system.展开更多
Waste production rises in tandem with population growth and increased utilization.The indecorous disposal of waste paves the way for huge disaster named as climate change.The National Environment Agency(NEA)of Singapo...Waste production rises in tandem with population growth and increased utilization.The indecorous disposal of waste paves the way for huge disaster named as climate change.The National Environment Agency(NEA)of Singapore oversees the sustainable management of waste across the country.The three main contributors to the solid waste of Singapore are paper and cardboard(P&C),plastic,and food scraps.Besides,they have a negligible rate of recycling.In this study,Machine Learning techniques were utilized to forecast the amount of garbage also known as waste audits.The waste audit would aid the authorities to plan their waste infrastructure.The applied models were k-nearest neighbors,Support Vector Regressor,ExtraTrees,CatBoost,and XGBoost.The XGBoost model with its default parameters performed better with a lower Mean Absolute Percentage Error(MAPE)of 8.3093(P&C waste),8.3217(plastic waste),and 6.9495(food waste).However,Grid Search Optimization(GSO)was used to enhance the parameters of the XGBoost model,increasing its effectiveness.Therefore,the optimized XGBoost algorithm performs the best for P&C,plastics,and food waste with MAPE of 4.9349,6.7967,and 5.9626,respectively.The proposed GSO-XGBoost model yields better results than the other employed models in predicting municipal solid waste.展开更多
Air pollution control poses a major problem in the implementation of municipal solid waste incineration(MSWI).Accurate prediction of nitrogen oxides(NO_(x))concentration plays an important role in efficient NO_(x)emis...Air pollution control poses a major problem in the implementation of municipal solid waste incineration(MSWI).Accurate prediction of nitrogen oxides(NO_(x))concentration plays an important role in efficient NO_(x)emission controlling.In this study,a modular long short-term memory(M-LSTM)network is developed to design an efficient prediction model for NO_(x)concentration.First,the fuzzy C means(FCM)algorithm is utilized to divide the task into several sub-tasks,aiming to realize the divide-and-conquer ability for complex task.Second,long short-term memory(LSTM)neural networks are applied to tackle corresponding sub-tasks,which can improve the prediction accuracy of the sub-networks.Third,a cooperative decision strategy is designed to guarantee the generalization performance during the testing or application stage.Finally,after being evaluated by a benchmark simulation,the proposed method is applied to a real MSWI process.And the experimental results demonstrate the considerable prediction ability of the M-LSTM network.展开更多
Unorganized municipal solid waste (MSW) disposal system leads to stress on ecosystems and disturbs various nature cycles and human health. Solid waste management all over world is looked as a major challenge to civil ...Unorganized municipal solid waste (MSW) disposal system leads to stress on ecosystems and disturbs various nature cycles and human health. Solid waste management all over world is looked as a major challenge to civil bodies, especially in developing countries like Bangladesh. The proper management system of municipal solid waste depends on various factors like social, cultural, financial, political, environmental, physical and institutional and so on. The purpose of this study is to explore the leading factors that affect the solid waste management in Barishal city. For achieving this purpose, this research first has identified the socio-economic, cultural, physical and technical, institutional and environmental factors and then analyzed the factors which affect the solid waste management system in the study area. To achieve the purpose of the study, quantitative method has been used in this research. As a sample of this study, 150 household heads from total household members of the city have been selected randomly by using lottery method. A structured questionnaire has been constructed for collecting quantitative data. The quantitative data have been analyzed in this study by using SPSS Program, and Microsoft Excel. The findings of the study show that all city people know solid waste and solid waste management stakeholders present in the city and waste pickers collect all types of waste in the city and socio-economic, cultural, physical and technical, institutional factors affect the effective solid waste management in the study area where environmental factors have no influence on effective solid waste management in the study area. The study people have a bad impression of the current existing management system of the solid waste and they express their expectations where they mention that if municipal authorities improve the condition of the infrastructure, roads and vehicles;allow more budgets to manage waste;take proper strategies and planning to manage waste smartly like imposing fines, set up rules, then the municipal authorities will be able to manage solid waste properly. Finally, this research has proposed some recommendations that might be helpful for the policy-makers in the study area for making policies and further research regarding solid waste management.展开更多
This article describes MSW(Municipal Solid Waste)management with APG(Arc Plasma Gasification)technology.First,a brief description of the process and reactor configurations is presented,listing some advantages and disa...This article describes MSW(Municipal Solid Waste)management with APG(Arc Plasma Gasification)technology.First,a brief description of the process and reactor configurations is presented,listing some advantages and disadvantages.Then,alternatives for producing electrical energy with the residue of synthesis gas are addressed.Finally,this technology is proposed as an alternative to face the significant problem of eliminating MSW on a large scale.展开更多
The high water content of municipal solid waste(MSW)will reduce the effciency of mechanical sorting,consequently unfavorable for beneficial utilization.In this study,a combined hydrolytic-aerobic biodrying technology ...The high water content of municipal solid waste(MSW)will reduce the effciency of mechanical sorting,consequently unfavorable for beneficial utilization.In this study,a combined hydrolytic-aerobic biodrying technology was introduced to remove water from MSW.The total water removals were proved to depend on the ventilation frequency and the temporal span in the hydrolytic stage. The ventilation frequency of 6 times/d was preferable in the hydrolytic stage.The hydrolytic span should not be prolonged more than 4 d.At this optimal scenario,the final water content was 50.5%reduced from the initial water content of 72.0%,presenting a high water removal effciency up to 78.5%.A positive correlation was observed between the organics losses and the water losses in both hydrolytic and aerobic stages(R=0.944,p<0.01).The evolutions of extracellular enzyme activities were shown to be consistent with the organics losses.展开更多
Transfer station(TS)is an integral part of present-day municipal solid waste(MSW)management systems.To provide information for the incorporation of waste facilities within the current integrated waste management syste...Transfer station(TS)is an integral part of present-day municipal solid waste(MSW)management systems.To provide information for the incorporation of waste facilities within the current integrated waste management system,the authors measured the existing environmental quality at five MSW TSs.Discharged wastewater,air,and noise were monitored and assayed at the five TSs in Beijing in 2001-2006 during rainy seasons(RSs)and dry seasons(DSs).Except Ammonia(NH_3)and hydrogen sulfide(H_2S),the analytical results...展开更多
Dioxins, which are of the most toxic materials on the earth, are principal emitted from waste incineration process. The molecular structures, toxicity parameters, such as toxicity equivalency factor, tolerable daily i...Dioxins, which are of the most toxic materials on the earth, are principal emitted from waste incineration process. The molecular structures, toxicity parameters, such as toxicity equivalency factor, tolerable daily intake and physic-chemical properties of dioxins are briefly summarized. Three formation mechanisms of dioxins in waste incineration process, namely as de novo synthesis, mechanisms involving small organic molecular as precursors and homogenous gas phase reaction mechanism are alto reviewed. The influencing factors for dioxins formation during waste incineration process are also discussed. Three major methods for reducing dioxins emission from waste incineration process are discussed based upon the formation mechanisms and influencing factors. A new waste incineration process with low dioxins emission and low hydrogen chloride corrosion has been proposed based on multi- stage unit operation principal according to formation mechanisms of dioxins and potential production location in waste incinerators.展开更多
The concentrations of As, Cd, Cr, Cu, Ni, Pb, Fe and Zn in selected dumpsites in Potiskum were determined with Buck Scientific 210VGB Atomic Absorption Spectrometer (AAS) AVG 210. One-way ANOVA was deployed at p < ...The concentrations of As, Cd, Cr, Cu, Ni, Pb, Fe and Zn in selected dumpsites in Potiskum were determined with Buck Scientific 210VGB Atomic Absorption Spectrometer (AAS) AVG 210. One-way ANOVA was deployed at p < 0.05 level of significance for obtained triplicate values. It was found that the concentration (mg<span style="white-space:nowrap;">·</span>kg<sup>-1</sup>) of studied heavy metals in Potiskum dumpsites ranged from 0.108 ± 0.02 - 262.536 ± 0.68 with pattern of accumulation Pb (262.536 ± 0.02) > Zn (183.369 ± 0.58) > Fe (159.453 ± 0.50) > Cu (111.382 ± 0.62) > Cr (43.523 ± 0.36) > Ni (6.419 ± 0.26) > Cd (0.679 ± 0.01) > As (0.108 ± 0.02) mg<span style="white-space:nowrap;">·</span>kg<sup>-1</sup>. The concentrations of As, Cr, Ni, Fe and Zn fell below the WHO standards while those of Pb, Cd and Cu were above set limits by WHO. High acidity corresponds markedly with high levels of Cd, Cu, Cr and Zn and requires urgent attention as this trend is capable of groundwater contamination that will cause public health concern in affected areas.展开更多
The population of Turkey has increased rapidly in parallel with the risein technology and industrialization. The increasing population of thecountry has triggered urbanization, and environmental problems havedrawn att...The population of Turkey has increased rapidly in parallel with the risein technology and industrialization. The increasing population of thecountry has triggered urbanization, and environmental problems havedrawn attention. One of the issues resulting from urbanization is municipalsolid waste (MSW). Every object we use in our daily life is transformedinto solid waste when its economic life has ended. The processes fromthe storage of these wastes to their disposal, often referred to as MSWmanagement, come under the municipalities' authority and responsibility.MSW must be processed with the most negligible environmental impact.This study aimed to investigate MSW management systems in Turkey,including the quantity, composition, and disposal methods of MSWgenerated and populations served by MSW, MSW per capita per day.Results from the study showed that the mean MSW generated in Turkeywas 26.74 Mton/yr and increased in the following order by region;EasternAnatolia < South East Anatolia < Black Sea < Mediterranean < Aegean< Central Anatolia < Marmara. This order/ranking was in line with theregions' population. The population explained 84 to 95% of the variation inMSW. Results from the study could be used in MSW management.展开更多
Engineering properties of municipal solid waste(MSW) depend largely on the waste's initial composition and degree of degradation.MSWs in developing countries usually have a high kitchen waste content(called HKWC M...Engineering properties of municipal solid waste(MSW) depend largely on the waste's initial composition and degree of degradation.MSWs in developing countries usually have a high kitchen waste content(called HKWC MSW).After comparing and analyzing the laboratory and field test results of physical composition,hydraulic properties,gas generation and gas permeability,and mechanical properties for HKWC MSW and low kitchen waste content MSW(called LKWC MSW),the following findings were obtained:(1) HKWC MSW has a higher initial water content(IWC) than LKWC MSW,but the field capacities of decomposed HKWC and LKWC MSWs are similar;(2) the hydraulic conductivity and gas permeability for HKWC MSW are both an order of magnitude smaller than those for LKWC MSW;(3)compared with LKWC MSW,HKWC MSW has a higher landfill gas(LFG) generation rate but a shorter duration and a lower potential capacity;(4) the primary compression feature for decomposed HKWC MSW is similar to that of decomposed LKWC MSW,but the compression induced by degradation of HKWC MSW is greater than that of LKWC MSW;and(5) the shear strength of HKWC MSW changes significantly with time and strain.Based on the differences of engineering properties between these two kinds of MSWs,the geo-environmental issues in HKWC MSW landfills were analyzed,including high leachate production,high leachate mounds,low LFG collection efficiency,large settlement and slope stability problem,and corresponding advice for the management and design of HKWC MSW landfills was recommended.展开更多
The methane(CH4) emissions from municipal solid waste(MSW) landfills in China in 2007 were estimated based on database of the three-dimensional emission factors matrix and point sources, by an IPCC recommended FOD(fir...The methane(CH4) emissions from municipal solid waste(MSW) landfills in China in 2007 were estimated based on database of the three-dimensional emission factors matrix and point sources, by an IPCC recommended FOD(firstorder decay) model. The location, capacity and age of landfills constitute the three dimensions of the emission factors matrix, which were obtained by laboratory analysis and in situ investigation. Key parameters such as waste composition,degradable organic carbon ratio, CH4 correction factor, oxidation factor and recovery rate, were carefully analyzed in terms of these three dimensions. The point sources database consists of 2,107 MSW landfills in cities and towns of China in 2007. The results show that the CH4 emissions from MSW landfills were 1.186 Mt in 2007. Compared with the CH4 emissions of 2.20 Mt in 2005, the significant discrepancy mainly comes from statistical data of landfills, e.g., number of landfills and amount of waste disposed in landfills. CH4 emissions were lower than 700 t for most of the landfills, whereas there were 279 landfills with emissions larger than 1,000 t, and only 10 landfills with emissions larger than 10,000 t.Jiangsu province ranks the largest emitter with 98,700 t while Tibet is the smallest emitter with 2,100 t. In general,the emissions from eastern provinces, such as Jiangsu, Guangdong and Zhejiang, were larger than those from western provinces, such as Ningxia, Tibet and Qinghai.展开更多
硫混合物(包括的硫，硫化物，亚硫酸盐和硫酸盐) 的效果，重金属的起始的集中和在市政的固体的 Cd 排放上的操作条件浪费(MSW ) 焚化用一个模仿的管状的炉子被调查并且模仿了与 Cd 刺的 MSW。Cd 的集中被诱导地联合的血浆原子的排放 spe...硫混合物(包括的硫，硫化物，亚硫酸盐和硫酸盐) 的效果，重金属的起始的集中和在市政的固体的 Cd 排放上的操作条件浪费(MSW ) 焚化用一个模仿的管状的炉子被调查并且模仿了与 Cd 刺的 MSW。Cd 的集中被诱导地联合的血浆原子的排放 spectrometry (ICP-AES ) 在根据相关 USEPA 方法包括底部灰，苍蝇灰和烟道气体消化样品以后测量。结果证明 S 和 Na2S 趋于增加在底部灰划分的 Cd，而 Na2SO3 和 Na2SO4 趋于减少在底部灰划分的 Cd。在底部灰划分的 Cd 上的硫混合物的效果在 Na2 S 】
S 】
Na2SO3 】
Na2SO4 的顺序。化学平衡分析也被执行在 Cd 吸附上决定吸着剂的效果。计算证明 S 为 Cd 介绍强壮的亲密关系并且，当温度升起到时，由 SiC2 制止 Cd 吸附在 830 ° C 和 1030 ° C 之间， SiO2 的 Cd 吸附效率是超过 80% ， Al2O3 的效率直到 85% 。展开更多
Three treatments were tested to investigate the release concentrations of volatile organic compounds (VOCs) during the bio-drying of municipal solid waste (MSW) by the aerobic and combined hydrolytic-aerobic processes...Three treatments were tested to investigate the release concentrations of volatile organic compounds (VOCs) during the bio-drying of municipal solid waste (MSW) by the aerobic and combined hydrolytic-aerobic processes.Results showed that VOCs were largely released in the first 4 days of bio-drying and the dominant components were:dimethyl disulfide,dimethyl sulfide,benzene,2-butanone,limonene and methylene chloride.Thus,the combined hydrolytic-aerobic process was suggested for MSW bio-drying due to fewer aeration quantities in this phase when compared with the aerobic process,and the treatment strategies should base on the key properties of these prominent components.Malodorous sulfur compounds and terpenes were mainly released in the early phase of bio-drying,whereas,two peaks of release concentrations appeared for aromatics and ketones during bio-drying.Notably,for the combined hydrolytic-aerobic processes there were also high concentrations of released aromatics in the shift from hydrolytic to aerobic stages.High concentrations of released chlorinateds were observed in the later phase.For the VOCs produced during MSW bio-drying,i.e.,malodorous sulfur compounds,terpenes and chlorinateds,their release concentrations were mainly determined by production rates;for the VOCs presented initially in MSW,such as aromatics,their transfer and transport in MSW mainly determined the release concentrations.展开更多
The project for treating MSW of 200 tons each day was built in Yibin, Sichuan Province of China. The disposal processes are: separation and selection of usable resources; compost and fermentation of “heavy” organic ...The project for treating MSW of 200 tons each day was built in Yibin, Sichuan Province of China. The disposal processes are: separation and selection of usable resources; compost and fermentation of “heavy” organic waste (kitchen, garden composting rubbish); incineration of “light” waste (plastic, paper, wood and bamboo etc.) and landfill of inorganic waste. The thermal energy generated in the process can be used as 1/3 of the whole energy for drying fertilizers. In the process, there is no wastewater drainage, and air emissions can be effectively controlled by a series of measures. The sanitary and environmental indicators of disposal site meet the national standards. This project has worked well for two years. It not only disposes of and reduces the MSW, but also retrieves the resource effectively. The organic fertilizer has been applied in the ten thousand acres of fields, with productivity increase by more than 10%.展开更多
Utilisation of Municipal Solid Waste is important to curb the ever rising demand of scarce land for its disposal. Changing life style patterns, particularly in urban areas, has led to increase in generation of MSW. Mu...Utilisation of Municipal Solid Waste is important to curb the ever rising demand of scarce land for its disposal. Changing life style patterns, particularly in urban areas, has led to increase in generation of MSW. Municipal solid waste from Indian cities estimated to have 40% - 60% organic matter, which could be recycled as compost. The most suitable way to recycle it with low investment is aerobic composting using windrow method. With the compliance of Municipal Solid Waste (Management and Handling) Rules 2000, many cities in India are making compost with organic portion of MSW. Before applying MSWC for agricultural uses, it is important to inventories heavy metals in compost to assess its toxicity. In the present study the compost samples were quantified for its toxicity from three highly populated cities of India, i.e., Delhi (Capital of India), Ahmedabad (Gujarat) and Bangalore (Karnataka). The MSWC samples were analysed for total heavy metals and in extractable fractions. Few samples were found with higher concentration of metals then the prescribed limits for its application as compost in Indian MSW rules, whereas, samples have not showed significant heavy metals concentration in extractable fractions. Therefore, studied MSW compost samples had demonstrated its suitability to use as green compost.展开更多
The solidifying effect of cement addition on municipal solid waste incineration fly ash (MSWFA for short,collected from the gas exhaust system of MSW incinerator),the interaction of MSWFA with cement and water and the...The solidifying effect of cement addition on municipal solid waste incineration fly ash (MSWFA for short,collected from the gas exhaust system of MSW incinerator),the interaction of MSWFA with cement and water and the leaching of heavy metals from cement solidified MSWFA are investigated.The main results show that:(1) when MSWFA is mixed with cement and water,H 2 evolution,the formation and volume expansion of AFt will take place,the volume expansion can be reduced by ground rice husk ash addition;(2) heavy metals do leach from cement solidified MSWFA and at lower pH more leaching will occur;(3) compared with cement-solidified fly ash,the leachate of solidified MSWFA is with higher heavy metal contents;(4) with the increment of cement addition leached heavy metals are decreased;and (5) concentrations of Zn,Mn,Cu and Cd in all the leachates can meet the relevant Standards of Japan,but as the regulations for soil and groundwater protection of Japan are concerned,precautions against the leaching of Pb,Cl - and Cr 6+ and so on are needed.展开更多
Possibility of combustible gas production from municipal solid waste (MSW) using hot blast furnace (BF) slag has been studied.The objective of this work is to generate combustible gas from MSW using heated BF slag.In ...Possibility of combustible gas production from municipal solid waste (MSW) using hot blast furnace (BF) slag has been studied.The objective of this work is to generate combustible gas from MSW using heated BF slag.In this experiment,the thermal stability of the MSW was analyzed by thermogravimetric analysis,and effects of temperature,gasifying agent (air,N2,steam) and BF slag on the gas products were investigated at 600?900 ?C.The thermogravimetric analysis indicates that the weight loss of MSW includes four stages:evaporation of the moisture,combustion of volatile materials,burning of carbon residue and burnout of ash.The contents of the combustible gas increase with increasing temperature,and the lower calorific value (LCV) increases rapidly at 600?900 ?C.It is found that volume fraction of CO,H2 and CH4 at different atmospheres increases in the order N2<air<steam.It is believed that BF slag acts as the catalyst and the heat carrier,which promotes the gasification reactivity of MSW.展开更多
Hydration heat behavior and kinetics of blended cement containing up to 20% MSWI fly ash were investigated based on its hydration heat evolution rate measured by isothermal calorimeter. Kinetics parameters, N and K, a...Hydration heat behavior and kinetics of blended cement containing up to 20% MSWI fly ash were investigated based on its hydration heat evolution rate measured by isothermal calorimeter. Kinetics parameters, N and K, and hydration degree, Ca(OH)2 content, were also calculated and analyzed. According to the experimental results, the induction period was elongated, the second heat evolution peak was in advance, and the third hydration heat peak could be detected due to MSWI fly ash pozzolanic reaction. The hydration reaction rate was controlled by nucleation kinetics in the acceleration period and then by diffusion in the decay period, but in the deceleration period, the hydration experienced a dual controlling reaction of autocatalytic chemical reaction and diffusion. The hydration rate of blended cement was faster. Ca(OH)2 content increased before 14 days.展开更多
文摘This investigation is focused on conducting a thorough analysis of Municipal Solid Waste Management (MSWM). MSWM encompasses a range of interdisciplinary measures that govern the various stages involved in managing unwanted or non-utilizable solid materials, commonly known as rubbish, trash, junk, refuse, and garbage. These stages include generation, storage, collection, recycling, transportation, handling, disposal, and monitoring. The waste materials mentioned in this context exhibit a wide range of items, such as organic waste from food and vegetables, paper, plastic, polyethylene, iron, tin cans, deceased animals, byproducts from demolition activities, manure, and various other discarded materials. This study aims to provide insights into the possibilities of enhancing solid waste management in the Farmgate area of Dhaka North City Corporation (DNCC). To accomplish this objective, the research examines the conventional waste management methods employed in this area. It conducts extensive field surveys, collecting valuable data through interviews with local residents and key individuals involved in waste management, such as waste collectors, dealers, intermediate dealers, recyclers, and shopkeepers. The results indicate that significant amounts of distinct waste categories are produced daily. These include food and vegetable waste, which amount to 52.1 tons/day;polythene and plastic, which total 4.5 tons/day;metal and tin-can waste, which amounts to 1.4 tons/day;and paper waste, which totals 5.9 tons/day. This study highlights the significance of promoting environmental consciousness to effectively shape the attitudes of urban residents toward waste disposal and management. It emphasizes the need for collaboration between authorities and researchers to improve the current waste management system.
文摘Waste production rises in tandem with population growth and increased utilization.The indecorous disposal of waste paves the way for huge disaster named as climate change.The National Environment Agency(NEA)of Singapore oversees the sustainable management of waste across the country.The three main contributors to the solid waste of Singapore are paper and cardboard(P&C),plastic,and food scraps.Besides,they have a negligible rate of recycling.In this study,Machine Learning techniques were utilized to forecast the amount of garbage also known as waste audits.The waste audit would aid the authorities to plan their waste infrastructure.The applied models were k-nearest neighbors,Support Vector Regressor,ExtraTrees,CatBoost,and XGBoost.The XGBoost model with its default parameters performed better with a lower Mean Absolute Percentage Error(MAPE)of 8.3093(P&C waste),8.3217(plastic waste),and 6.9495(food waste).However,Grid Search Optimization(GSO)was used to enhance the parameters of the XGBoost model,increasing its effectiveness.Therefore,the optimized XGBoost algorithm performs the best for P&C,plastics,and food waste with MAPE of 4.9349,6.7967,and 5.9626,respectively.The proposed GSO-XGBoost model yields better results than the other employed models in predicting municipal solid waste.
基金the financial support from the National Natural Science Foundation of China(62021003,61890930-5,61903012,62073006)Beijing Natural Science Foundation(42130232)the National Key Research and Development Program of China(2021ZD0112301,2021ZD0112302)。
文摘Air pollution control poses a major problem in the implementation of municipal solid waste incineration(MSWI).Accurate prediction of nitrogen oxides(NO_(x))concentration plays an important role in efficient NO_(x)emission controlling.In this study,a modular long short-term memory(M-LSTM)network is developed to design an efficient prediction model for NO_(x)concentration.First,the fuzzy C means(FCM)algorithm is utilized to divide the task into several sub-tasks,aiming to realize the divide-and-conquer ability for complex task.Second,long short-term memory(LSTM)neural networks are applied to tackle corresponding sub-tasks,which can improve the prediction accuracy of the sub-networks.Third,a cooperative decision strategy is designed to guarantee the generalization performance during the testing or application stage.Finally,after being evaluated by a benchmark simulation,the proposed method is applied to a real MSWI process.And the experimental results demonstrate the considerable prediction ability of the M-LSTM network.
文摘Unorganized municipal solid waste (MSW) disposal system leads to stress on ecosystems and disturbs various nature cycles and human health. Solid waste management all over world is looked as a major challenge to civil bodies, especially in developing countries like Bangladesh. The proper management system of municipal solid waste depends on various factors like social, cultural, financial, political, environmental, physical and institutional and so on. The purpose of this study is to explore the leading factors that affect the solid waste management in Barishal city. For achieving this purpose, this research first has identified the socio-economic, cultural, physical and technical, institutional and environmental factors and then analyzed the factors which affect the solid waste management system in the study area. To achieve the purpose of the study, quantitative method has been used in this research. As a sample of this study, 150 household heads from total household members of the city have been selected randomly by using lottery method. A structured questionnaire has been constructed for collecting quantitative data. The quantitative data have been analyzed in this study by using SPSS Program, and Microsoft Excel. The findings of the study show that all city people know solid waste and solid waste management stakeholders present in the city and waste pickers collect all types of waste in the city and socio-economic, cultural, physical and technical, institutional factors affect the effective solid waste management in the study area where environmental factors have no influence on effective solid waste management in the study area. The study people have a bad impression of the current existing management system of the solid waste and they express their expectations where they mention that if municipal authorities improve the condition of the infrastructure, roads and vehicles;allow more budgets to manage waste;take proper strategies and planning to manage waste smartly like imposing fines, set up rules, then the municipal authorities will be able to manage solid waste properly. Finally, this research has proposed some recommendations that might be helpful for the policy-makers in the study area for making policies and further research regarding solid waste management.
文摘This article describes MSW(Municipal Solid Waste)management with APG(Arc Plasma Gasification)technology.First,a brief description of the process and reactor configurations is presented,listing some advantages and disadvantages.Then,alternatives for producing electrical energy with the residue of synthesis gas are addressed.Finally,this technology is proposed as an alternative to face the significant problem of eliminating MSW on a large scale.
基金supported by the National Key Technolo-gy R&D Program(No.2006BAC06B04,2006BAC02A03)the Key Grant Project of Shanghai Committee of Science and Technology(No.06dz12308).
文摘The high water content of municipal solid waste(MSW)will reduce the effciency of mechanical sorting,consequently unfavorable for beneficial utilization.In this study,a combined hydrolytic-aerobic biodrying technology was introduced to remove water from MSW.The total water removals were proved to depend on the ventilation frequency and the temporal span in the hydrolytic stage. The ventilation frequency of 6 times/d was preferable in the hydrolytic stage.The hydrolytic span should not be prolonged more than 4 d.At this optimal scenario,the final water content was 50.5%reduced from the initial water content of 72.0%,presenting a high water removal effciency up to 78.5%.A positive correlation was observed between the organics losses and the water losses in both hydrolytic and aerobic stages(R=0.944,p<0.01).The evolutions of extracellular enzyme activities were shown to be consistent with the organics losses.
文摘Transfer station(TS)is an integral part of present-day municipal solid waste(MSW)management systems.To provide information for the incorporation of waste facilities within the current integrated waste management system,the authors measured the existing environmental quality at five MSW TSs.Discharged wastewater,air,and noise were monitored and assayed at the five TSs in Beijing in 2001-2006 during rainy seasons(RSs)and dry seasons(DSs).Except Ammonia(NH_3)and hydrogen sulfide(H_2S),the analytical results...
文摘Dioxins, which are of the most toxic materials on the earth, are principal emitted from waste incineration process. The molecular structures, toxicity parameters, such as toxicity equivalency factor, tolerable daily intake and physic-chemical properties of dioxins are briefly summarized. Three formation mechanisms of dioxins in waste incineration process, namely as de novo synthesis, mechanisms involving small organic molecular as precursors and homogenous gas phase reaction mechanism are alto reviewed. The influencing factors for dioxins formation during waste incineration process are also discussed. Three major methods for reducing dioxins emission from waste incineration process are discussed based upon the formation mechanisms and influencing factors. A new waste incineration process with low dioxins emission and low hydrogen chloride corrosion has been proposed based on multi- stage unit operation principal according to formation mechanisms of dioxins and potential production location in waste incinerators.
文摘The concentrations of As, Cd, Cr, Cu, Ni, Pb, Fe and Zn in selected dumpsites in Potiskum were determined with Buck Scientific 210VGB Atomic Absorption Spectrometer (AAS) AVG 210. One-way ANOVA was deployed at p < 0.05 level of significance for obtained triplicate values. It was found that the concentration (mg<span style="white-space:nowrap;">·</span>kg<sup>-1</sup>) of studied heavy metals in Potiskum dumpsites ranged from 0.108 ± 0.02 - 262.536 ± 0.68 with pattern of accumulation Pb (262.536 ± 0.02) > Zn (183.369 ± 0.58) > Fe (159.453 ± 0.50) > Cu (111.382 ± 0.62) > Cr (43.523 ± 0.36) > Ni (6.419 ± 0.26) > Cd (0.679 ± 0.01) > As (0.108 ± 0.02) mg<span style="white-space:nowrap;">·</span>kg<sup>-1</sup>. The concentrations of As, Cr, Ni, Fe and Zn fell below the WHO standards while those of Pb, Cd and Cu were above set limits by WHO. High acidity corresponds markedly with high levels of Cd, Cu, Cr and Zn and requires urgent attention as this trend is capable of groundwater contamination that will cause public health concern in affected areas.
文摘The population of Turkey has increased rapidly in parallel with the risein technology and industrialization. The increasing population of thecountry has triggered urbanization, and environmental problems havedrawn attention. One of the issues resulting from urbanization is municipalsolid waste (MSW). Every object we use in our daily life is transformedinto solid waste when its economic life has ended. The processes fromthe storage of these wastes to their disposal, often referred to as MSWmanagement, come under the municipalities' authority and responsibility.MSW must be processed with the most negligible environmental impact.This study aimed to investigate MSW management systems in Turkey,including the quantity, composition, and disposal methods of MSWgenerated and populations served by MSW, MSW per capita per day.Results from the study showed that the mean MSW generated in Turkeywas 26.74 Mton/yr and increased in the following order by region;EasternAnatolia < South East Anatolia < Black Sea < Mediterranean < Aegean< Central Anatolia < Marmara. This order/ranking was in line with theregions' population. The population explained 84 to 95% of the variation inMSW. Results from the study could be used in MSW management.
基金Financial support provided by the National Basic Research Program of China(973 Project)(Grant No.2012CB719806)
文摘Engineering properties of municipal solid waste(MSW) depend largely on the waste's initial composition and degree of degradation.MSWs in developing countries usually have a high kitchen waste content(called HKWC MSW).After comparing and analyzing the laboratory and field test results of physical composition,hydraulic properties,gas generation and gas permeability,and mechanical properties for HKWC MSW and low kitchen waste content MSW(called LKWC MSW),the following findings were obtained:(1) HKWC MSW has a higher initial water content(IWC) than LKWC MSW,but the field capacities of decomposed HKWC and LKWC MSWs are similar;(2) the hydraulic conductivity and gas permeability for HKWC MSW are both an order of magnitude smaller than those for LKWC MSW;(3)compared with LKWC MSW,HKWC MSW has a higher landfill gas(LFG) generation rate but a shorter duration and a lower potential capacity;(4) the primary compression feature for decomposed HKWC MSW is similar to that of decomposed LKWC MSW,but the compression induced by degradation of HKWC MSW is greater than that of LKWC MSW;and(5) the shear strength of HKWC MSW changes significantly with time and strain.Based on the differences of engineering properties between these two kinds of MSWs,the geo-environmental issues in HKWC MSW landfills were analyzed,including high leachate production,high leachate mounds,low LFG collection efficiency,large settlement and slope stability problem,and corresponding advice for the management and design of HKWC MSW landfills was recommended.
基金funded by the Project Study on Key Issues of China City Carbon Emission Inventory (No. 41101500)supported by National Natural Science Foundation of China
文摘The methane(CH4) emissions from municipal solid waste(MSW) landfills in China in 2007 were estimated based on database of the three-dimensional emission factors matrix and point sources, by an IPCC recommended FOD(firstorder decay) model. The location, capacity and age of landfills constitute the three dimensions of the emission factors matrix, which were obtained by laboratory analysis and in situ investigation. Key parameters such as waste composition,degradable organic carbon ratio, CH4 correction factor, oxidation factor and recovery rate, were carefully analyzed in terms of these three dimensions. The point sources database consists of 2,107 MSW landfills in cities and towns of China in 2007. The results show that the CH4 emissions from MSW landfills were 1.186 Mt in 2007. Compared with the CH4 emissions of 2.20 Mt in 2005, the significant discrepancy mainly comes from statistical data of landfills, e.g., number of landfills and amount of waste disposed in landfills. CH4 emissions were lower than 700 t for most of the landfills, whereas there were 279 landfills with emissions larger than 1,000 t, and only 10 landfills with emissions larger than 10,000 t.Jiangsu province ranks the largest emitter with 98,700 t while Tibet is the smallest emitter with 2,100 t. In general,the emissions from eastern provinces, such as Jiangsu, Guangdong and Zhejiang, were larger than those from western provinces, such as Ningxia, Tibet and Qinghai.
文摘硫混合物(包括的硫，硫化物，亚硫酸盐和硫酸盐) 的效果，重金属的起始的集中和在市政的固体的 Cd 排放上的操作条件浪费(MSW ) 焚化用一个模仿的管状的炉子被调查并且模仿了与 Cd 刺的 MSW。Cd 的集中被诱导地联合的血浆原子的排放 spectrometry (ICP-AES ) 在根据相关 USEPA 方法包括底部灰，苍蝇灰和烟道气体消化样品以后测量。结果证明 S 和 Na2S 趋于增加在底部灰划分的 Cd，而 Na2SO3 和 Na2SO4 趋于减少在底部灰划分的 Cd。在底部灰划分的 Cd 上的硫混合物的效果在 Na2 S 】
S 】
Na2SO3 】
Na2SO4 的顺序。化学平衡分析也被执行在 Cd 吸附上决定吸着剂的效果。计算证明 S 为 Cd 介绍强壮的亲密关系并且，当温度升起到时，由 SiC2 制止 Cd 吸附在 830 ° C 和 1030 ° C 之间， SiO2 的 Cd 吸附效率是超过 80% ， Al2O3 的效率直到 85% 。
基金financially supported by the National Key Technology R&D Program of China (No.2006BAC06B04,2008BAJ08B13)
文摘Three treatments were tested to investigate the release concentrations of volatile organic compounds (VOCs) during the bio-drying of municipal solid waste (MSW) by the aerobic and combined hydrolytic-aerobic processes.Results showed that VOCs were largely released in the first 4 days of bio-drying and the dominant components were:dimethyl disulfide,dimethyl sulfide,benzene,2-butanone,limonene and methylene chloride.Thus,the combined hydrolytic-aerobic process was suggested for MSW bio-drying due to fewer aeration quantities in this phase when compared with the aerobic process,and the treatment strategies should base on the key properties of these prominent components.Malodorous sulfur compounds and terpenes were mainly released in the early phase of bio-drying,whereas,two peaks of release concentrations appeared for aromatics and ketones during bio-drying.Notably,for the combined hydrolytic-aerobic processes there were also high concentrations of released aromatics in the shift from hydrolytic to aerobic stages.High concentrations of released chlorinateds were observed in the later phase.For the VOCs produced during MSW bio-drying,i.e.,malodorous sulfur compounds,terpenes and chlorinateds,their release concentrations were mainly determined by production rates;for the VOCs presented initially in MSW,such as aromatics,their transfer and transport in MSW mainly determined the release concentrations.
文摘The project for treating MSW of 200 tons each day was built in Yibin, Sichuan Province of China. The disposal processes are: separation and selection of usable resources; compost and fermentation of “heavy” organic waste (kitchen, garden composting rubbish); incineration of “light” waste (plastic, paper, wood and bamboo etc.) and landfill of inorganic waste. The thermal energy generated in the process can be used as 1/3 of the whole energy for drying fertilizers. In the process, there is no wastewater drainage, and air emissions can be effectively controlled by a series of measures. The sanitary and environmental indicators of disposal site meet the national standards. This project has worked well for two years. It not only disposes of and reduces the MSW, but also retrieves the resource effectively. The organic fertilizer has been applied in the ten thousand acres of fields, with productivity increase by more than 10%.
文摘Utilisation of Municipal Solid Waste is important to curb the ever rising demand of scarce land for its disposal. Changing life style patterns, particularly in urban areas, has led to increase in generation of MSW. Municipal solid waste from Indian cities estimated to have 40% - 60% organic matter, which could be recycled as compost. The most suitable way to recycle it with low investment is aerobic composting using windrow method. With the compliance of Municipal Solid Waste (Management and Handling) Rules 2000, many cities in India are making compost with organic portion of MSW. Before applying MSWC for agricultural uses, it is important to inventories heavy metals in compost to assess its toxicity. In the present study the compost samples were quantified for its toxicity from three highly populated cities of India, i.e., Delhi (Capital of India), Ahmedabad (Gujarat) and Bangalore (Karnataka). The MSWC samples were analysed for total heavy metals and in extractable fractions. Few samples were found with higher concentration of metals then the prescribed limits for its application as compost in Indian MSW rules, whereas, samples have not showed significant heavy metals concentration in extractable fractions. Therefore, studied MSW compost samples had demonstrated its suitability to use as green compost.
文摘The solidifying effect of cement addition on municipal solid waste incineration fly ash (MSWFA for short,collected from the gas exhaust system of MSW incinerator),the interaction of MSWFA with cement and water and the leaching of heavy metals from cement solidified MSWFA are investigated.The main results show that:(1) when MSWFA is mixed with cement and water,H 2 evolution,the formation and volume expansion of AFt will take place,the volume expansion can be reduced by ground rice husk ash addition;(2) heavy metals do leach from cement solidified MSWFA and at lower pH more leaching will occur;(3) compared with cement-solidified fly ash,the leachate of solidified MSWFA is with higher heavy metal contents;(4) with the increment of cement addition leached heavy metals are decreased;and (5) concentrations of Zn,Mn,Cu and Cd in all the leachates can meet the relevant Standards of Japan,but as the regulations for soil and groundwater protection of Japan are concerned,precautions against the leaching of Pb,Cl - and Cr 6+ and so on are needed.
基金supported by the Applied Basic Research Key Project of Yunnan Province (No.2007E0014Z)
文摘Possibility of combustible gas production from municipal solid waste (MSW) using hot blast furnace (BF) slag has been studied.The objective of this work is to generate combustible gas from MSW using heated BF slag.In this experiment,the thermal stability of the MSW was analyzed by thermogravimetric analysis,and effects of temperature,gasifying agent (air,N2,steam) and BF slag on the gas products were investigated at 600?900 ?C.The thermogravimetric analysis indicates that the weight loss of MSW includes four stages:evaporation of the moisture,combustion of volatile materials,burning of carbon residue and burnout of ash.The contents of the combustible gas increase with increasing temperature,and the lower calorific value (LCV) increases rapidly at 600?900 ?C.It is found that volume fraction of CO,H2 and CH4 at different atmospheres increases in the order N2<air<steam.It is believed that BF slag acts as the catalyst and the heat carrier,which promotes the gasification reactivity of MSW.
基金Funded by the National Natural Science Foundation of China(No.51172164)
文摘Hydration heat behavior and kinetics of blended cement containing up to 20% MSWI fly ash were investigated based on its hydration heat evolution rate measured by isothermal calorimeter. Kinetics parameters, N and K, and hydration degree, Ca(OH)2 content, were also calculated and analyzed. According to the experimental results, the induction period was elongated, the second heat evolution peak was in advance, and the third hydration heat peak could be detected due to MSWI fly ash pozzolanic reaction. The hydration reaction rate was controlled by nucleation kinetics in the acceleration period and then by diffusion in the decay period, but in the deceleration period, the hydration experienced a dual controlling reaction of autocatalytic chemical reaction and diffusion. The hydration rate of blended cement was faster. Ca(OH)2 content increased before 14 days.
