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1.
Environ Monit Assess ; 196(6): 537, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38730190

RESUMO

Selecting an optimal solid waste disposal site is one of the decisive waste management issues because unsuitable sites cause serious environmental and public health problems. In Kenitra province, northwest Morocco, sustainable disposal sites have become a major challenge due to rapid urbanization and population growth. In addition, the existing disposal sites are traditional and inappropriate. The objective of this study is to suggest potential suitable disposal sites using fuzzy logic and analytical hierarchy process (fuzzy-AHP) method integrated with geographic information system (GIS) techniques. For this purpose, thirteen factors affecting the selection process were involved. The results showed that 5% of the studied area is considered extremely suitable and scattered in the central-eastern parts, while 9% is considered almost unsuitable and distributed in the northern and southern parts. Thereafter, these results were validated using the area under the curve (AUC) of the receiver operating characteristics (ROC). The AUC found was 57.1%, which is a moderate prediction's accuracy because the existing sites used in the validation's process were randomly selected. These results can assist relevant authorities and stakeholders for setting new solid waste disposal sites in Kenitra province.


Assuntos
Lógica Fuzzy , Sistemas de Informação Geográfica , Eliminação de Resíduos , Marrocos , Eliminação de Resíduos/métodos , Resíduos Sólidos/análise , Monitoramento Ambiental/métodos , Instalações de Eliminação de Resíduos , Gerenciamento de Resíduos/métodos
2.
Environ Monit Assess ; 196(6): 544, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38740657

RESUMO

A comprehensive analysis of municipal solid plastic waste (MSPW) management while emphasizing plastic pollution severity in coastal cities around the world is mandatory to alleviate the augmenting plastic waste footprint in nature. Thus, decision-makers' persuasion for numerous management solutions of MSPW flow-control can be met through meditative systematic strategies at the regional level. To forecast solutions focused on systematic policies, an agent-based system dynamics (ASD) model has been developed and simulated from 2023 to 2040 while considering significant knit parameters for MSPW management of Khulna City in Bangladesh. Baseline simulation results show that per-capita plastic waste generation will increase to 11.6 kg by 2040 from 8.92 kg in 2023. Eventually, the landfilled quantity of plastic waste has accumulated to 70,000 tons within 18 years. Moreover, the riverine discharge has increased to 834 tons in 2040 from a baseline quantity of 512 tons in 2023. So the plastic waste footprint index (PWFI) value rises to 24 by 2040. Furthermore, the absence of technological initiatives is responsible for the logarithmic rise of non-recyclable plastic waste to 1.35*1000=1350 tons. Finally, two consecutive policy scenarios with baseline factors such as controlled riverine discharge, increased collection and separation of plastic waste, expansion of recycle business, and locally achievable plastic conversion technologies have been simulated. Therefore, policy 2, with 69% conversion, 80% source separation, and 50% riverine discharge reduction of MSPW, has been found adequate from a sustainability perspective with the lowest PWFI ranges of 3.97 to 1.07 alongside a per-capita MSPW generation of 7.63 to 10 kg from 2023 till 2040.


Assuntos
Cidades , Plásticos , Resíduos Sólidos , Gerenciamento de Resíduos , Bangladesh , Plásticos/análise , Resíduos Sólidos/análise , Resíduos Sólidos/estatística & dados numéricos , Gerenciamento de Resíduos/métodos , Eliminação de Resíduos/métodos , Previsões , Política Ambiental , Monitoramento Ambiental/métodos , Reciclagem
3.
Waste Manag ; 181: 34-43, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38581750

RESUMO

The main disposal method for municipal solid waste (MSW), including the growing worldwide volumes of kitchen waste, involves transport to landfills. Because kitchen waste is mainly composed of organic matter and has a high moisture content, large amounts of leachate and landfill gas are generated when it is sent to landfills. Therefore, rapid waste stabilization is essential. In this study, four semi-aerobic bioreactors (named NS, SS, MS, and LS) were established with void fractions of 33.76%, 39.84%, 44.62%, and 41.31%, respectively. The results showed that the void fractions of landfill directly affected the gas flow path. When the landfill void fraction was small (e.g., NS), most airflow traveled directly through the pipeline and minimal airflow entered the waste layer. When the landfill void fraction was large (e.g., MS), air easily entered the waste layer and some air flowed into the gas vent with the landfill gas. As the reaction proceeded, the void fraction gradually decreased due to gravity-induced sedimentation. During the water addition experiment, the voids were occupied by water, leading to formation of an anaerobic area. Among the four bioreactors, only MS had negligible formation of an anaerobic zone in the center. Methane (CH4) generation was detected only at the connection between the gas vent and the leachate collection pipe. A larger void fraction led to formation of a smaller anaerobic zone. The ratio of air flowing in pipeline was lowest in MS. These results indicated that a large void fraction promotes the decomposition of organic matter.


Assuntos
Reatores Biológicos , Eliminação de Resíduos , Instalações de Eliminação de Resíduos , Eliminação de Resíduos/métodos , Aerobiose , Resíduos Sólidos/análise
4.
Waste Manag ; 181: 145-156, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38608529

RESUMO

Landfill disposal is a major approach of disposing municipal solid waste (MSW) in China. In order to explore the impact of volatile organic compounds (VOCs) generated by landfill on the air quality of regional environment, Jiangcungou landfill in Xi'an and its surrounding area were taken as a research object to analyze the spatial distribution and seasonal variation patterns of non-methane hydrocarbon (NMHC) and VOCs components through seasonal sampling of regional NMHC concentration and VOCs concentration (116 species). CALPUFF model was adopted to analyze the regional dispersion characteristics of NMHC on landfill. In addition, propylene equivalent concentration (PEC) and maximum incremental reactivity (MIR) methods were used to estimate O3 formation potential of the landfill, while fraction aerosol coefficient (FAC) and SOA potential (SOAP) methods were used to estimate SOA formation potential of the landfill. It was indicated that, the component with the highest concentration of VOCs on the working surface and the surrounding area of landfill was p + m-xylene (41.0 µg/m3) and halohydrocarbon (111.2 µg/m3-156.3 µg/m3), respectively. The component with the greatest impact on the surrounding air was acetone, which accounts for 75 %-87 % of the corresponding substance concentration on the landfill. In summer, the surrounding area was affected most by NMHC from landfill, whose emissions contributed 9.5 mg/m3 to the surrounding area. The component making the largest contribution to O3 formation was p + m-xylene (8 %-24 %), while ethylbenzene was the component making the largest contribution to SOA formation (20 %-24 %).


Assuntos
Poluentes Atmosféricos , Monitoramento Ambiental , Eliminação de Resíduos , Resíduos Sólidos , Compostos Orgânicos Voláteis , Instalações de Eliminação de Resíduos , Compostos Orgânicos Voláteis/análise , China , Resíduos Sólidos/análise , Poluentes Atmosféricos/análise , Eliminação de Resíduos/métodos , Estações do Ano , Hidrocarbonetos/análise
5.
Waste Manag ; 181: 211-219, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38648723

RESUMO

Complex organic matter represents a suitable substrate to produce hydrogen through dark fermentation (DF) process. To increase H2 yields, pretreatment technology is often required. The main objective of the present work was to investigate thermo-acid pretreatment impact on sugar solubilization and biotic parameters of DF of sorghum or organic fraction of municipal solid waste (OFMSW). Biochemical hydrogen potential tests were carried out without inoculum using raw or thermo-acid pretreated substrates. Results showed an improvement in sugar solubilization after thermo-acid pretreatments. Pretreatments led to similar DF performances (H2 and total metabolite production) compared to raw biomasses. Nevertheless, they were responsible for bacterial shifts from Enterobacteriales towards Clostridiales and Bacillales as well as metabolic changes from acetate towards butyrate or ethanol. The metabolic changes were attributed to the biomass pretreatment impact on indigenous bacteria as no change in the metabolic profile was observed after performing thermo-acid pretreatments on irradiated OFMSW (inactivated indigenous bacteria and inoculum addition). Consequently, acid pretreatments were inefficient to improve DF performances but led to metabolic and bacterial community changes due to their impact on indigenous bacteria.


Assuntos
Biomassa , Fermentação , Bactérias/metabolismo , Resíduos Sólidos/análise , Hidrogênio/metabolismo , Sorghum/metabolismo , Eliminação de Resíduos/métodos
6.
J Environ Manage ; 357: 120825, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38579472

RESUMO

Alkali-activation is an effective municipal solid waste incineration fly ash (MSWIFA) solidification/stabilization (S/S) technology. However, the characteristics of calcium-rich silica-poor aluminum phase in MSWIFA easily cause the structural instability and contamination of alkali activated MSWIFA S/S bodies. Therefore, the aluminosilicate solid wastes are used in this work to optimize the immobilization and structural properties. Results showed that incorporation of aluminosilicate solid wastes significantly improved the compressive strength and heavy metals pollution toxicity of MSWIFA S/S bodies. Compared to alkali activated MSWIFA, the compressive strength of S/S bodies with addition of coal fly ash, silica fume and granulated blast furnace slag improved by 31.0%, 47.6% and 50.8% when the curing time was 28 days, respectively. Leachability of Pb, Zn and Cd in these alkali activated MSWIFA S/S bodies was far below the threshold value specified in Standard GB16889. Aluminosilicate solid wastes provided abundant Si/Al structural units, and some new phases such as ettringite(AFt, 3CaO⋅Al2O3⋅3CaSO4⋅32H2O), calcium sulfoaluminate hydrate (3CaO⋅Al2O3⋅CaSO4⋅12H2O) and Friedel's salt (CaO⋅Al2O3⋅CaCl2⋅10H2O) can be detected in S/S matrix with aluminosilicate solid wastes, along comes increased the amount of the amorphous phases. Lower Ca/Si molar ratio tended to form the network structure gel similar to tobermorite with higher polymerization degree. Meanwhile, the silica tetrahedron of the gels changed from the oligomerization state like island to the hyperomerization state like chain, layer network or three-dimensional structure, and average molecular chain length increased. These findings provide theoretical basis for structural properties optimization and resource utilization of MSWIFA S/S matrices.


Assuntos
Silicatos de Alumínio , Metais Pesados , Eliminação de Resíduos , Cinza de Carvão/química , Resíduos Sólidos/análise , Incineração/métodos , Dióxido de Silício , Álcalis/química , Metais Pesados/análise , Carbono/química , Material Particulado , Eliminação de Resíduos/métodos
7.
J Environ Manage ; 357: 120783, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38579475

RESUMO

The rapid development of the economy and society is causing an increase in the amount of municipal solid waste (MSW) produced by people's daily lives. With the strong support of the Chinese government, incineration power generation has steadily become the primary method of treating MSW, accounting for 79.86%. However, burning produces a significant amount of municipal solid waste incineration fly ash (MSWI-FA), which contains heavy metals, soluble chlorine salts, and dioxins. China's MSWI-FA yield increased by 8.23% annually to 7.80 million tons in 2022. Besides, the eastern region, especially the southeastern coastal region, has the highest yield of MSWI-FA. There are certain similarities in the chemical characteristics of MSWI-FA samples from Northeast, North, East, and South China. Zn and CaO have the largest amounts of metals and oxides, respectively. The Cl content is about 20 wt%. This study provides an overview of the techniques used in the thermal treatment method, solidification and stabilization, and separation and extraction of MSWI-FA and compares their benefits and drawbacks. In addition, the industrial applications and standard requirements of landfill treatment and resource utilization of MSWI-FA in China are analyzed. It is discovered that China's resource utilization of MSWI-FA is insufficient through the study on the fly ash disposal procedures at a few MSW incineration facilities located in the economically developed Guangdong Province and the traditional industrial city of Tianjin. Finally, the prospects for the disposal of MSWI-FA were discussed.


Assuntos
Metais Pesados , Eliminação de Resíduos , Humanos , Cinza de Carvão/química , Resíduos Sólidos/análise , Material Particulado/análise , Carbono/análise , Incineração , Metais Pesados/análise , China
8.
Chemosphere ; 357: 142077, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38643843

RESUMO

Organic fraction of municipal solid waste (OFMSW) and waste activated sludge (WAS) are the most produced organic waste streams in urban centres. Their anaerobic co-digestion (AcoD) allows to generate methane (CH4) and digestate employable as renewable energy source and soil amendment, respectively, fully in accordance with circular bioeconomy principles. However, the widespread adoption of such technology is limited by relatively low CH4 yields that fail to bridge the gap between benefits and costs. Among strategies to boost AcoD of OFMSW and WAS, use of conductive materials (CMs) to promote interspecies electron transfer has gained increasing attention. This paper presents one of the few experimental attempts of investigating the effects of four different carbon(C)-based CMs (i.e., granular activated carbon - GAC, graphite - GR, graphene oxide - GO, and carbon nanotubes - CNTs) separately added in semi-continuous AcoD of OFMSW and thickened WAS. The presence of C-based CMs has been observed to improve CH4 yield of the control process. Specifically, after 63 days of operation (concentrations of GAC and GR of 10.0 g/L and of GO and CNTs of 0.2 g/L), 0.186 NL/gVS, 0.191 NL/gVS, 0.203 NL/gVS, and 0.195 NL/gVS of CH4 were produced in reactors supplemented with GAC, GR, GO, and CNTs, respectively, compared to 0.177 NL/gVS produced in the control process. Likewise, at the end of the test (i.e., after 105 days at concentrations of C-based CMs half of the initial ones), CH4 yields were 0.193 NL/gVS, 0.201 NL/gVS, 0.211 NL/gVS, and 0.206 NL/gVS in reactors supplemented with GAC, GR, GO, and CNTs, respectively, compared to 0.186 NL/gVS of the control process. Especially with regard to GR, GO, and CNTs, results obtained in the present study represent a significant advance of the knowledge on the effects of such C-based CMs to realistic and scalable AD process conditions respect to previous literature.


Assuntos
Carbono , Metano , Eliminação de Resíduos , Esgotos , Resíduos Sólidos , Esgotos/química , Anaerobiose , Metano/análise , Resíduos Sólidos/análise , Carbono/química , Carbono/análise , Eliminação de Resíduos/métodos , Grafite/química , Reatores Biológicos , Nanotubos de Carbono/química , Carvão Vegetal/química
9.
Waste Manag ; 182: 21-31, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38631177

RESUMO

This research investigates the formation mechanism of soot and particulate matter during the pyrolysis and gasification of waste derived from Municipal Solid Waste (MSW) in a laboratory scale drop tube furnace. Compared with CO2 gasification atmosphere, more ultrafine particles (PM0.2, aerodynamic diameter less than 0.2 µm) were generated in N2 atmosphere at 1200℃, which were mainly composed of polycyclic aromatic hydrocarbons (PAHs), graphitic carbonaceous soot and volatile alkali salts. High reaction temperatures promote the formation of hydrocarbon gaseous products and their conversion to PAHs, which ultimately leads to the formation of soot particles. The soot particles generated by waste derived from MSW pyrolysis and gasification both have high specific surface area and well-developed pore structure. Compared with pyrolysis, the soot generated by gasification of waste derived from MSW had smaller size and higher proportion of inorganic components. The higher pyrolysis temperature led to the collapse of the mesoporous structure of submicron particles, resulting in a decrease in total pore volume and an increase in specific surface area. Innovatively, this research provides an explanation for the effect of reaction temperature/ CO2 on the formation pathways and physicochemical properties of soot and fine particulate matter.


Assuntos
Temperatura Alta , Material Particulado , Pirólise , Resíduos Sólidos , Fuligem , Material Particulado/análise , Material Particulado/química , Resíduos Sólidos/análise , Fuligem/análise , Fuligem/química , Eliminação de Resíduos/métodos , Incineração/métodos , Dióxido de Carbono/análise , Dióxido de Carbono/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/química , Tamanho da Partícula
10.
Waste Manag ; 182: 74-90, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38643525

RESUMO

To understand which are the best strategies for textile waste management and to analyse the effects on the environment of applying circular economy practices to textile products, a review of 45 publications where life cycle assessment (LCA) is applied to these topics has been carried out. The separate collection of textiles, followed by reuse and recycling brings relevant environmental benefits, with impacts related to reuse resulting lower than those of recycling. At the opposite, when mixed municipal solid waste is addressed to energy recovery, the textile fraction is the second most impacting on climate change, right after plastics, while for landfill disposal impacts textiles directly follow the more biodegradable fractions. Textiles manufacturing using recycled fibres generally gives lower impacts than using virgin ones, with a few exceptions in some impact categories for cotton and polyester. The circular practices with the lowest impacts are those that ensure the extension of the textiles service life. Another aim of this review is to identify the main variables affecting the life cycle impact assessment (LCIA). These resulted to be the yield and material demand of recycling processes, the use phase variables, the assumptions on virgin production replaced by reuse or recycling, the substitution factor in reuse, and transportation data in business models based on sharing. Thus, in LCA modelling, great attention should be paid to these variables. Future research should address these aspects, to acquire more relevant data, based on industrial-scale processes and on people habits towards the circular economy strategies applied to textiles.


Assuntos
Reciclagem , Têxteis , Gerenciamento de Resíduos , Reciclagem/métodos , Gerenciamento de Resíduos/métodos , Indústria Têxtil , Resíduos Sólidos/análise
11.
Waste Manag ; 182: 113-123, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38648689

RESUMO

The research pertaining to solid waste is undergoing extensive advancement, thereby necessitating a consolidation and analysis of its research trajectories. The existing biblio-studies on solid waste research (SWR) lack thorough analyses of the factors influencing its trends. This article presents an innovative categorization framework that categorizes publications from six SWR journals utilizing Source Latent Dirichlet Allocation. First analyse changes in publication numbers across main categories, subcategories, journals, and regions, providing a macro-level study of SWR. Temporal analysis of keywords supplements a micro-level study of SWR, which highlights that emerging technologies with low Technology Readiness Level receive significant attention, while studies on widespread technologies are diminishing. Additionally, this study demonstrates the substantial influence of socioeconomic factors and previous SWR publications on current and future SWR trends. Finally, the article confirms the impact of global events on SWR trends by examining the structural breakpoints of SWR and their correlation with global events.


Assuntos
Resíduos Sólidos , Resíduos Sólidos/análise , Publicações Periódicas como Assunto/estatística & dados numéricos , Gerenciamento de Resíduos/métodos , Classe Social , Eliminação de Resíduos/métodos , Eliminação de Resíduos/estatística & dados numéricos , Pesquisa , Fatores Socioeconômicos
12.
Waste Manag ; 182: 164-174, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38653044

RESUMO

The current study introduces an innovative methodology by utilizing treated wastewater (TWW) from an effluent treatment plant as a washing agent to enhance the characteristics of incineration bottom ash (IBA). This approach addresses sustainability concerns and promotes the circular economy by reusing wastewater generated in municipal solid waste incineration facilities. Previous research has underscored the challenges of open IBA reuse due to elevated leaching of chlorides, sulfates, and trace metal(loid)s. Thus, the experimental setup explores various combinations of washing, with or without screening, to optimize the properties of soil-like material (SLM < 4.75 mm) and overall material (OM < 31.5 mm) fractions of IBA for unrestricted applications. Batch leaching tests were conducted on treated samples, and leaching characteristics were evaluated in accordance with regulatory standards, primarily the Dutch standard for unrestricted IBA reuse. The findings reveal that washing in isolation proves insufficient to enhance IBA properties; however, washing followed by screening, specifically for removing fines (<0.15 mm), proves effective in reducing contamination. The study identifies that multiple steps of washing and screening (with recirculation) process render OM and SLM fractions suitable for unrestricted reuse with a cumulative liquid-to-solid ratio of 6 L/kg and a total washing time of 15 min. The multi-step treatment was found effective in reducing sulfate contamination by 65-74 % and chloride contamination by 83-89 % in IBA fractions. This approach offers a promising solution for overcoming the limitations associated with IBA leaching, thereby promoting sustainable waste reuse practices.


Assuntos
Incineração , Águas Residuárias , Incineração/métodos , Águas Residuárias/química , Resíduos Sólidos/análise , Reciclagem/métodos , Cinza de Carvão/análise , Cinza de Carvão/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise
13.
Waste Manag ; 182: 197-206, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38670003

RESUMO

The significant increase in antibiotic resistance genes (ARGs) in organic solid wastes (OSWs) has emerged as a major threat to the food chain. Aerobic composting is a widely used technology for OSW management, with the potential to influence the fate of AGRs. However, the variability of the ARG elimination effects reported in different studies has highlighted the uncertainty regarding the effects of composting on ARGs. To identify the potential of composting in reducing ARG and the factors (e.g., composting technologies and physiochemical properties) influence ARG changes, a meta-analysis was conducted with a database including 4,232 observations. The abundances of ARGs and mobile genetic elements (MGEs) can be substantially reduced by 74.3% and 78.8%, respectively, via aerobic composting. During composting, the ARG levels in chicken and swine manure tended to be reduced more significantly (81.7% and 78.0%) compared to those in cattle manure (52.3%) and sewage sludge (32.6%). The reduction rate of sulfonamide resistant genes was only 35.3%, which was much lower than those of other types. MGEs and composting duration (CD) were identified as the most important factors driving ARG changes during composting. These findings provide a comprehensive insight into the effects of composting on ARG reduction, which may help prevent the transmission in food systems.


Assuntos
Compostagem , Resistência Microbiana a Medicamentos , Esterco , Compostagem/métodos , Resistência Microbiana a Medicamentos/genética , Esterco/microbiologia , Animais , Aerobiose , Resíduos Sólidos/análise , Bovinos , Galinhas , Genes Bacterianos , Antibacterianos , Eliminação de Resíduos/métodos , Suínos
14.
Waste Manag ; 182: 207-214, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38670004

RESUMO

The objective of this paper is to evaluate the feasibility of co-processing wind turbine blade (WTB) material in cement manufacturing to provide an end-of-life means to divert the solid waste of decommissioned WTBs from landfills. Many WTBs consist primarily of glass fiber reinforced thermoset polymers that are difficult to recover or recycle. Portland cement is produced world-wide in large quantities, requiring immense quantities of raw materials (mostly calcium oxide and silicon oxide) and kiln temperatures approaching 1,450 °C. This work contributes analyses of WTB material composition, and predicts the energy provided through the combustible components of the WTBs and raw material contributions provided by incorporating the incombustible components of the WTBs to produce cement. Approximately 40 to 50 % of the WTB material will contribute as fuel to cement production, and approximately 50 to 60 % of the WTB material is expected to be incombustible. One tonne of WTB material can displace approximately 0.4 to 0.5 tonne of coal, while also contributing approximately 0.1 tonne of calcium oxide and 0.3 tonne of silicon oxide as raw material to the cement production process. The glass fiber WTB tested had an average boron content of 4.5 % in the ash. The effects of this high boron content on the cement and its production process should be evaluated. Co-processing WTBs in cement plants will slightly reduce combustion-related CO2 emissions due to avoided calcination. It seems feasible to co-process glass-fiber reinforced WTBs in cement production as WTBs provide suitable raw materials and compatible fuel for this process.


Assuntos
Materiais de Construção , Materiais de Construção/análise , Reciclagem/métodos , Vento , Compostos de Cálcio/química , Gerenciamento de Resíduos/métodos , Resíduos Sólidos/análise , Vidro , Óxidos
16.
J Environ Manage ; 358: 120831, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38603850

RESUMO

Municipal solid waste incineration (MSWI) fly ash contains large amounts of Ca, Si, and other elements, giving it the potential to be used as a raw material for cement production. However, fly ash often contains a high content of salts, which greatly limits its blending ratio during cement production. These salts are commonly removed via water washing, but this process is affected by the nature and characteristics of fly ash. To clarify the influence of the ash characteristics on salt removal, a total of 60 fly ash samples from 13 incineration plants were collected, characterized, and washed. The ash characterization and cluster analysis showed that the incinerator type and flue gas purification technology/process significantly influenced the ash characteristics. Washing removed a high percentage of salts from fly ash, but the removal efficiencies varied significantly from each other, with the chlorine removal efficiency ranging from 73.76% to 96.48%, while the sulfate removal efficiency ranged from 6.92% to 51.47%. Significance analysis further revealed that the salt removal efficiency varied not only between the ash samples from different incinerators, but also between samples collected at different times from the same incinerator. The high variance of the 60 ash samples during salt removal was primarily ascribed to their different mineralogical and chemical characteristics. Mineralogical analysis of the raw and washed ash samples showed that the mineralogical forms and proportion of these salts in each ash sample greatly influenced their removal. The presence of less-soluble and insoluble chloride salts (e.g., CaClOH, Ca2Al(OH)6(H2O)2Cl etc.) in fly ash significantly affected the chlorine removal efficiency. This study also found that Fe, Mn, and Al in fly ash were negatively correlated with the dechlorination efficiency of fly ash. In summary, the different physical and chemical properties of fly ash caused great discrepancies in salt removal. Consequently, it is suggested to consider the potential impact of the ash source and ash generation time on salt removal to ensure a reliable treatment efficiency for engineering applications.


Assuntos
Cinza de Carvão , Incineração , Resíduos Sólidos , Cinza de Carvão/química , China , Resíduos Sólidos/análise , Sais/química
17.
PLoS One ; 19(3): e0300707, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38512927

RESUMO

The circular economy is a way of eliminating the shortage of raw materials that Europe is currently facing. However, it is necessary to explicitly identify the problems that prevent greater involvement in the CE. This article is focused on consumers and how they treat discarded or non-functional items. The aim was to fill the research gap, i.e. to compile a suitable CE model and define a methodology that would ensure the efficient disposal of non-functional or unsuitable items by consumers. An original methodology was drawn up to conduct the representative research, designed to lead to the practical application of the proposed CE model. The research explored how consumers treat non-functional or unsuitable items, the costs they incur in discarding, renovating, reusing, and recycling such items, and the alternative costs of unsorted municipal waste. After the data had been implemented into the model the circular economy was proven to have an economic benefit for the national economy in all groups. However, the economic disadvantage for consumers was also calculated, where the cost of involvement in the CE is higher than the cost of unsorted municipal waste. This means that people are motivated to play a part in the CE more by their own responsible approach to life, or social pressure from those around them. Based on this research it may be said that economic aspects are one reason that consumers tend to be reluctant to get more involved in the CE. Unless there is a significant rise in the cost of municipal waste that would motivate consumers to move towards the CE for financial reasons, in order to support the CE consumers need to be better stimulated, educated and informed as much as possible through the media.


Assuntos
Eliminação de Resíduos , Gerenciamento de Resíduos , Humanos , Resíduos Sólidos/análise , Comportamento do Consumidor , Reciclagem , Caquexia
18.
J Environ Manage ; 355: 120226, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38430876

RESUMO

This study aims to evaluate the feasibility and safety of using municipal solid waste incineration fly ash (MSW-IFA) in the development of geopolymer-based solidification/stabilization (S/S) treatments. Geopolymers have garnered attention as a sustainable alternative to traditional cement, owing to their high strength, stability, and minimal CO2 emissions. In this study, a combination of experimental and simulation calculations was used to investigate the setting time, mechanical properties, environmental risks, hydration mechanisms and processes of municipal solid waste incineration fly ash-based polymeric functional cementitious materials (GFCM). The results demonstrate that the mechanical properties of GFCM are related to the changes in the mineral phases and the degree of compactness. Quantum chemical calculations indicate that the hydration products may be [Si(OH)4], [Al(OH)3(OH2)] and [Al(OH)4]-. It is possible that the heavy metals are embedded in the hydrated silica-aluminate by electrostatic interaction or chemisorption. Heavy metals may be embedded in hydrated silica-aluminate by electrostatic action or chemisorption. This study provides a feasible method for resource utilization and heavy metal stabilization mechanism of MSW-IFA.


Assuntos
Metais Pesados , Eliminação de Resíduos , Cinza de Carvão , Resíduos Sólidos/análise , Material Particulado , Carbono/química , Incineração , Metais Pesados/análise , Dióxido de Silício , Eliminação de Resíduos/métodos
19.
J Environ Manage ; 355: 120514, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38460330

RESUMO

With improvements in urban waste management to promote sustainable development, an increasing number of waste types need to be sorted and treated separately. Due to the relatively low amount of waste generated in small- and medium-sized cities, separate treatment facilities for each waste type lack scale, waste is treated at a high cost and low efficiency. Therefore, industrial symbiosis principles are suggested to be used to guide collaborative waste treatment system of multi-source solid wastes, and co-incineration is the most commonly used technology. Most existing studies have focused on co-incineration of one certain waste type (such as sludge or medical waste) with municipal solid waste (MSW), but the systematic design and the comprehensive benefits on a whole city and park level have not been widely studied. Taking the actual operation of a multi-source waste co-incineration park in south-central China as an example, this study conducted a detailed analysis of the waste-energy-water metabolism process of MSW, sludge, food waste, and medical waste co-incineration. The environmental and economic benefits were evaluated and compared with the single decentralized waste treatment mode. The results showed that the multi-source waste co-incineration and clustering park operating model was comprehensively superior to the single treatment mode, greenhouse gases and human toxicity indicators were decreased by 11.87% and 295.74%, respectively, and the internal rate of return of the project was increased by 29.35%. This mainly benefits from the synergy of technical system and the economies of scale. Finally, this research proposed policy suggestions from systematic planning and design, technical route selection, and an innovative management mode in view of the potential challenges.


Assuntos
Resíduos de Serviços de Saúde , Eliminação de Resíduos , Gerenciamento de Resíduos , Humanos , Esgotos/análise , Cidades , Alimentos , Incineração , Resíduos Sólidos/análise , Resíduos de Serviços de Saúde/análise , China
20.
Waste Manag ; 178: 339-350, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38430748

RESUMO

Leaching of potentially hazardous substances, especially the heavy metals from Incineration Bottom Ash (IBA) is a major problem in its recyclable usage. To address this concern, treatment of IBA is indispensable before it can be reused. IBA subjected to laboratory-scale treatment typically yields clearer conclusions in terms of leaching behaviors, benefiting from the controlled laboratory environment. However, the leaching behaviors of commercially treated IBA appear to be more ambiguous due to the complex and comprehensive nature of industrial-scale treatments, where multiple treatment techniques are involved concurrently. Furthermore, treatment efficiencies vary among different plants. In this study, three types of commercially treated IBA were sampled from leading waste treatment companies in Singapore. Characterization and leaching tests were performed on the treated IBAs in both standardized and modified manners to simulate various scenarios. Besides deionized water, artificial seawater was used as a leachant in leaching tests for simulating seawater intrusion. The results reveal the promoting effect of seawater on the leaching levels of several elements from three types of treated IBA, which may require special attention for IBA application and landfill near the coast. Furthermore, the elements examined in these three types of commercially treated IBA generally comply with the non-hazardous waste acceptance criteria outlined in Council Decision, 2003/33/EC (2003), except Sb. By combining two leaching tests, the elements were categorized into different types of leaching behavior, making it possible to prepare and respond to the concerning leaching scenarios in future engineering applications.


Assuntos
Cinza de Carvão , Metais Pesados , Singapura , Incineração , Metais Pesados/análise , Conservação dos Recursos Naturais , Resíduos Sólidos/análise
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