Residual Municipal Solid Waste Research Articles

Comparative study of steam, organic Rankine cycle and supercritical CO2 power plants integrated with residual municipal solid waste gasification for district heating and cooling

Among the different waste-to-energy solutions, gasification is considered a promising option and an alternative to landfilling of residual municipal solid waste (RMSW). Therefore, the potential of RMSW air gasification in combination with three different power cycles for district cooling and heating applications is investigated. The model of a fluidized bed air gasifier developed in Aspen Plus is integrated with the models of steam turbine (ST), organic Rankine cycle (ORC), and supercritical CO2 (sCO2) Brayton cycle power plants for the combined cooling, heating, and power production in district networks.The results of the numerical study show that the ST power plant provides higher electrical power compared to the other systems, while sCO2 exhibits better thermal power and the maxima combined energy conversion efficiency. In between, ORCs prove to be a reliable and flexible solution for varying RMSW compositions and temperature levels of the district network. The size of the district network strongly varies with scenarios and in the best case, more than 1,400 residential buildings can be connected to the trigeneration plant considering 20 ktons/year of RMSW input to the gasifier.

Energy Recovery from Residual Municipal Solid Waste: State of the Art and Perspectives within the Challenge to Climate Change

Among the technologies for the recovery of energy from waste, in particular residual municipal solid waste (rMSW), combustion is the most widely used thermo-chemical treatment process associated with thermal and electric power production by a steam cycle, named, shortly, Waste to Energy (WtE). Today, more than 500 WtE plants in the EU, about 400 in China and 76 in the USA are in operation, based on efficient technologies and advanced air pollution control systems. Energy recovery can be accomplished also by means of gasification; however, the presence of impurities together with the atmospheric pressure, at which syngas is normally produced, impose the feeding of syngas to a conventional steam cycle, leading to generally lower performances than WtE. The energy recovered by WtE offsets traditional energy sources such as fossil fuels and related emissions, providing savings in term of climate change. However, the savings obtainable by replacing electricity and/or heat will diminish as the energy systems will hopefully become increasingly renewable. Over this medium–long-term horizon, one possibility is to capture the CO2 from WtE flue gases and to store/use it. From the life cycle assessment perspective, it has been calculated that the introduction of CO2 capture and storage in WtE, despite energy penalties, is able to reduce the impact on climate change. The alternative approach, proposed to contain the emissions of greenhouse gases in the thermal treatment of waste, is using the carbon contained in it to produce commonly used chemical compounds (waste to chemicals). The benefits, in terms of reductions of greenhouse gases, are expected from the possibility of obtaining chemicals that can replace their analogue normally produced from fossil sources. To date, only one WtC demonstration plant is operating by being fed by rMSW-derived waste, and some similar initiatives are planned, but still adequate assurances in terms of robust knowledge of the involved complex processes, above all, if applied to highly inhomogeneous feed streams such as those obtained from rMSW, are not available. Once the several initiatives come to completion, it will enable waste management professionals to assess performance and to begin to consider such a facility in their planning.

MSW Management in Two Italian Mountainous Areas

Abstract Two case studies are reported in the present work. They regard municipal solid waste (MSW) management trends in the last decades in two Italian provinces selected to analyse some issues of waste management in mountainous areas. The first case study refers to a selective collection (SC) rate expected to reach 80 % soon. This scenario assumes SC mainly in kerbside mode. The scenario is based on specific local conditions: the absence of a thermo-chemical plant in the territory (but with a part of the residual MSW burnt in a neighbour province), the presence of local plant of anaerobic, and a sanitary landfill for pre-treated residual MSW. The adopted tariff helped increasing the SC rate: indeed, since 2013, a tariff calculated at user level, depending on the behaviour of each user, has been adopted. This is called punctual tariff. The second case study concerns an area where SC reached about 75 %. The punctual tariff has been recently introduced. In this scenario, an incineration plant and a Solid Recovered Fuel (SRF) plant allow implementing an industrial symbiosis solution in conjunction with a cement factory. The work demonstrates that SC can be the core of a correct MSW management and that kerbside collection is fully compatible with mountainous area. However, other issues remain to be optimized yet: the low density of mountain areas makes difficult to implement enhanced solutions of SC (e.g. for diapers) and increases costs for light packaging collection; moreover, the presence of tourist fluxes can significantly affect SC efficiency.

Determination of Residual Municipal Solid Waste Composition from Rural and Urban Areas: A Step toward the Optimization of a Waste Management System for Efficient Material Recovery

Residual municipal solid waste (RMSW) is a rapidly expanding problem worldwide and a good waste management system could reduce concerns about its correct treatment. The purpose of this study was to characterize RMSW from urban and rural areas with the ultimate goal of estimating the recycling potential of the identified fractions and implementing waste collection and recovery methods according to the type of area that generates them. A direct sampling campaign of RMSW was performed. The results showed that the highest organic waste rate was found in the rural area (11.9%); urban-area-produced RMSW mainly constituted recyclable fractions such as plastic (26.3%), paper (21.8%), glass (3.5%) and metals (3.3%). The physical-chemical characteristics of RMSW showed levels of heavy metals below the detection threshold. The conditions necessary for composting could be met only for the organic fraction coming from rural areas as demonstrated by a pH value of 6.9 and a moisture content of 46.5%. These data will be extended to all the urban and rural areas to design appropriate disposal and/or recovery plants with profitable economic interventions that will lead to a reduction in costs in the planning of the integrated solid waste management.

Are carbon-storing soils more sensitive to climate change? A laboratory evaluation for agricultural temperate soils

A range of agroecological practices allow to increase soil organic carbon (SOC) stocks, which makes a positive impact on climate change mitigation and soil health, but the permanence of this additional SOC storage can be questioned, in particular in a climate change context. Increased temperatures, accentuated evaporation of terrestrial water and increased atmosphere moisture content are anticipated, resulting in more frequent droughts and heavy precipitation events. Understanding the SOC dynamics and assessing the sensitivity of carbon mineralization to these climatic events is necessary to anticipate future carbon losses in terrestrial ecosystems. To this respect, it seems relevant to investigate carbon-storing soils as increased carbon mineralization induced by climate change may limit the carbon storing potential in agricultural soils. Thus, we evaluated the sensitivity of SOC mineralization to increased temperature, decreased soil moisture and drying-rewetting cycles using soils from long-term field experiments. We performed an incubation experiment on topsoil (0–30 cm) samples from temperate luvisols that had been under 20 years under conservation agriculture (CA), organic agriculture (ORG) and conventional agriculture (CON-LC) at the La Cage experiment, and under organic waste products (OWPs) applications in QualiAgro experiment, including biowaste composts (BIOW), residual municipal solid waste composts (MSW), farmyard manure (FYM) and conventional agriculture without organic inputs (CON-QA). Soil samples were incubated in the lab for 3 months under different temperature conditions (20, 28 and 35 °C) or under different moisture conditions (matric potential: pF1.5; pF 2.5 and pF 4.2) or under several dry (pF 4.2)-wet (pF 1.5) cycles (DWC). The results shown that, whatever the agricultural practices, soil moisture regime and temperature significantly affect the SOC mineralization. Overall, the DWC did not stimulate soil carbon mineralization relative to wet controls (pF1.5 and pF2.5). Whatever the soil moisture regime and temperature, specific carbon mineralization was similar between agricultural practices at La Cage, while at QualiAgro, specific carbon mineralization was lower in soils receiving organic waste products (OWPs) compared to the baseline soil. These results suggest a strong carbon stabilization by OWPs in soils as assessed by laboratory incubation experiments. Within each long-term experiment, we observed no significant difference between the carbon-storing soils (CA, ORG, MSW, FYM and BIOW) and their respective baseline soils (CON-LC and CON-QA) in the delta SOC mineralized whatever the soil moisture regime. The Q10 also indicated no significant difference between carbon-storing soils and their respective baseline soils. These results indicate that the SOC mineralization in carbon-storing soils had a similar sensitivity to the soil moisture regime and temperature as the baseline ones. Hence, the implementation of these agroecological practices appears beneficial for climate change mitigation, even in the context of extreme climatic events.

A general model for air gasification of heterogenous municipal solid waste

Sustainable management of municipal solid waste (MSW) is crucial due to its huge volume and cash flow. Among the different waste-to-energy solutions, gasification is considered an interesting option compared to incineration, which is the most common technology to valorise MSW, because of higher efficiency, lower environmental impacts, and producing hydrogen or other biofuel and biochemical products. However, mechanical–biological treatment of MSW results in heterogenous materials mainly composed of plastics, paper, and textiles, which troubles a reliable study of gasification. Hence, a flexible model of a fluidized bed air gasifier is developed in Aspen Plus in this work based on the experimental data from the literature to estimate the syngas properties from residual MSW of composting facilities.The developed model gives a low heating value (LHV) of the syngas in the range 4.2–7.3 MJ/Nm3 considering the characteristics of the residual MSW from a real composting facility, which is in line with the experimental values reported in the literature. Furthermore, a sensitivity analysis is performed varying the composition of the residual waste from the mechanical–biological treatment to support preliminary feasibility analyses of energy production from heterogeneous materials. The results showed a good capability of the model in predicting the energy performance of the fluidized bed gasifiers varying feedstock materials and equivalence ratios.

A Systematic Review on the Synthesis of Silicon Carbide: An Alternative Approach to Valorisation of Residual Municipal Solid Waste

Over the past several decades, industrialised and developing nations have attempted to enhance sustainability. Demands for energy and the acceleration in environmental deterioration are the two primary obstacles to progress. The daily generation of municipal solid waste has been a significant factor in the deterioration of the ecology. To address this issue, a considerable amount of municipal solid waste may be used to synthesise SiC nanomaterials from organic and inorganic fractions and use them as carbon and silica sources. Nanomaterials have progressively received widespread prominence as the development of particulate materials accelerates at an incredible rate. One such material is silicon carbide (SiC), which has garnered considerable interest due to its remarkable performance and wide variety of applications. This review article discusses the SiC polytypes, including cubic, hexagonal, and rhombohedral SiC. The characteristics of silicon carbide, such as its biomimetic, surface, and thermal properties, are also discussed. In addition, the synthesis of silicon carbide was described in depth, including microwave sintering, the calcination method, the carbothermal redox reaction, and much more. The final section describes the applications of silicon carbide, including wastewater treatment, medical implants, and gas detection.

Municipal Solid Waste as a Long-Term Source for Generating Energy

This article provides a summary of the strategies currently in use to extract energy from municipal solid waste. Special trash is ignored since its characteristics greatly vary from type to type and from region to region. However, municipal solid waste has properties that make it amenable to a more standardized investigation of its energy potential. The initial part examines the methods for extracting usable energy from garbage. The second part discusses energy availability in the context of the changing qualitative and quantitative characteristics of Municipal Solid Waste (MSW). The third section takes a look at selective collection and how it serves the larger goal of energy recovery. In the fourth part, the significance of Directive 1999/31/CE and its effect on energy recovery strategies are discussed in the context of the current trend in the use of residual municipal solid waste. A mandatory pre-treatment makes less interesting the option of landfilling, moving the energy exploitation of residual municipal solid waste towards thermal treatments. Also, research shows how thermal treatments and anaerobic digestion could work together to provide for a local resident's energy needs.

Characterization of Municipal Solid Waste and Assessment of Its Potential for Refuse-Derived Fuel (RDF) Valorization

Reuse and recycling are preferred strategies in waste management to ensure the high position of waste resources in the waste management hierarchy. However, challenges are still pronounced in many developing countries, where disposal as a final solution is prevalent, particularly for municipal solid waste. On the other hand, refuse-derived fuel as a means of energy recovery provides a sustainable option for managing mixed, contaminated and residual municipal solid waste (MSW). This study provides one of the earliest assessments of refuse-derived fuel (RDF) from MSW in Ghana through a case study in the cities of Accra and Kumasi. The residual/reject fractions (RFs) of MSW material recovery were characterized for thermochemical energy purposes. The studied materials had the potential to be used as RDF. The combustible portions from the residual fractions formed good alternative fuel, RDF, under the class I, II-III classification of the EN 15359:2011 standards. The RDF from only combustible mixed materials such as plastics, paper and wood recorded a significant increase in the lower heating value (28.66–30.24 MJ/kg) to the mass RF, with the presence of organics (19.73 to 23.75 MJ/kg). The chlorine and heavy metal content met the limits set by various standards. An annual RDF production of 12 to 57 kilotons is possible from the two cities. This can offset 10–30% of the present industrial coal consumption, to about 180 kiloton/yr CO2 eq emissions and a net cost saving of USD 8.7 million per year. The market for RDF as an industrial alternative fuel is developing in Ghana and similar jurisdictions in this context. Therefore, this study provides insights into the potential for RDF in integrated waste management system implementation for socioeconomic and environmental benefits. This supports efforts towards achieving the Sustainable Development Goals (SDGs) and a circular economy.

The Use of Residual Municipal Solid Waste as an Alternative Fuel

Abstract The relevance of the work is determined by the war of the Russian Federation in Ukraine and the decision of the leading countries of the world, the EU and Ukraine to abandon energy dependence on energy from the Russian Federation. An analysis is provided of the main directions for reducing the European Union's dependence on Russian natural gas by a third by the end of 2022, in particular, the development of the Waste-to-Energy market in the EU and other leading countries of the world. The main ways are presented and computational investigations of the possibility of substitution of certain amounts of natural gas with artificial fuel from residual MSW are carried out. Based on the performed calculations, the authors formulated proposals for the feasibility of constructing facilities for energy use of residual MSW in different regions of Ukraine, as well as connecting them to the systems of centralized heating in Ukraine. The paper proves the necessity of building Waste-to-Energy power plants in the largest, large and big cities of the country. The ecological expediency of recovery of residual waste is shown.

Perspectives of decentralised gasification of residual municipal solid waste

In the European Union (EU), the dominant technology for high-temperature thermal treatment of residual Municipal Solid Waste (i.e., the unsorted waste where source separation is performed) is the moving grate incineration. The process of combustion in this sector has been optimised thanks to the introduction of stringent criteria of operation both in the combustion chamber and in the treatment of the generated off-gas. However, the costs of treatment can be sustainable only if the tariff to be applied for the service is coherent with the average value found in the sector. The literature demonstrates that, under a capacity threshold, the grate system is out of market, thus limiting the implementation of small decentralised plants. This paper discusses the potential benefits of small-scale and decentralised thermo-chemical treatment plants replacing a single large-scale one. In addition, the present article analyses the consequences of the results of a recent survey that zoomed in on the availability of small-scale gasifiers for implementing such a strategy. The results of this analysis show that small-scale gasification is preferable to other technologies (e.g., incineration and pyrolysis) in terms of scale effect and flexibility/modularity. Compared to other thermal treatments, the local environmental impact could be reduced by converting syngas into fuels or chemicals rather than burning it for direct energy recovery. The paper also shows that small-scale gasification is able to respond to different needs in both EU and non-EU countries, like the management of progressively lower amounts of residual waste requiring treatment/management of uncontrolled dump sites.

A consequential approach to life cycle sustainability assessment with an agent‐based model to determine the potential contribution of chemical recycling to UN Sustainable Development Goals

Chemical recycling (CR) could support a circular approach for municipal solid waste (MSW) treatment. In promoting the recirculation of recyclable carbon-containing waste as secondary feedstock for chemical production, it could contribute to resource conservation, emissions reduction, and supply security. To evaluate CR's contribution to the transition from a linear to a circular carbon economy—and correspondingly to the achievement of environmental, economic, and social sustainability as indicated in the UN Sustainable Development Goals (UN-SDGs)—this study builds on extant literature of life cycle sustainability assessment (LCSA) to investigate consequential environmental, economic, and social CR impacts. Specifically, an integrated approach whereby process-based life cycle assessment, techno-economic analysis, and social indicators are linked in the framework of an agent-based model is developed to investigate sustainability consequences of CR via gasification of residual MSW in Germany. Results suggest that CR contributes to reducing climate change and to addressing terrestrial acidification and fossil resource scarcity. However, its deployment will be associated with significant system costs. Hence, to promote CR implementation, measures such as obliging direct waste incineration to trade CO2 certificates—provided that certificate prices increase sharply in the future—as well as implementing a recycling rate are found to be necessary to gap economic disadvantages. This study not only contributes to extending life cycle approaches for LCSA methodologically, it furthermore provides valuable insights into temporal and spatial interactions in waste management systems to inform science, industry, and politics about the sustainability impacts of CR on the achievement of the UN-SDGs. This article met the requirements for a gold-gold JIE data openness badge described at http://jie.click/badges.

Constructing carbon sink-oriented waste management system towards reduction and maximum recovery via high-precision packaging waste inventory

Towards circular economy and carbon neutrality, the low-valued recyclable packaging in residual municipal solid waste (rMSW) should be transformed from incineration to recycling and non-recyclables should be reduced. This study confirmed that small amount of packaging plastic recycling in rMSW could contribute to great carbon sink. We firstly investigated high-resolution rMSW composition inventory including the used product types and polymers. Then the environmental performance of low-valued recyclables recycling and non-recyclables reduction was accurately assessed. Lastly, for contaminated plastic packaging, the trade-offs between cleaning resource consumption and recovery rate were quantified. Although recyclable plastic and Al-PE-Paper packaging only accounted for 7.7% and 2.0% in rMSW, compared with incineration, recycling low-valued recyclables and further restricting non-recyclables decreased greenhouse gas from +153.8 to -112.7 and -196.2 CO2-eq/t rMSW, respectively. This study revealed the significance of packaging waste recycling and indicated the path for recycling-oriented waste management in the further.

Environmental Comparison of Different Mechanical–Biological Treatment Plants by Combining Life Cycle Assessment and Material Flow Analysis

The role of Mechanical–Biological Treatment (MBT) is still of the utmost importance in the management of residual Municipal Solid Waste (MSW). These plants can cover a wide range of objectives, combining several types of processes and elements. The aim of this work is to assess and compare, from an environmental point of view, the performance of seven selected MBT plants currently operating in different countries, which represent the main MBT layout and processes. For the scope, a combined Life Cycle Assessment (LCA) and Material Flow Analysis (MFA) approach has been adopted to assess plant-specific efficiencies in materials and energy recovery. Metals recovery was a common and high-efficiency practice in MBT; further recovery of other types of waste was often performed. Each assessed MBT plant achieved environmental benefits: among them, the highest environmental benefit was achieved when the highest amount of waste was recovered (not only with material recycling). Environmental results were strongly affected by the recycling processes and the energy production, with a little contribution from the energy requirement. The impacts achieved by the MBT process were, on average, 14% of the total one. The main condition for a suitable MBT process is a combination of materials recovery for the production of new raw materials, avoiding disposal in landfill, and refuse-derived fuel production for energy recovery. This work can be of help to operators and planners when they are asked to define MBT schemes.

MBT Organic Waste Treatment: Lessons Learnt

Treating organic wastes using a combination of mechanical biological treatment (MBT) and anaerobic digestion (AD) is an established process in Europe. In 2010 the UK was considered under resourced with respect to its per capita AD capacity, suggesting a significant prospect for plants in the UK. The ratio of plants then treating municipal solid waste (MSW) compared to biowaste, has changed in the past 10-15 years from favouring biowaste plants to plants treating residual MSW (rMSW). Contractors need to be aware of the parameters that impact on the performance of an MBT AD plant. To identify the key parameters, a review of available information on plant operational performance was undertaken using a wide range of sources. Operational parameters for AD processes are well-documented and provide key process design factors when designing a plant. Consolidation of the information obtained was assessed and a list of problems/solutions compiled that could be reviewed when considering a potential EPC contract. The 2010 list of identified problems has been compared to the current literature discussing the operational performance of MBT AD plants, to see if the issues have been resolved, continue to be a problem, or new issues have arisen.

Mini-review of waste sector greenhouse gas and short-lived climate pollutant emissions in Tyre Caza, Lebanon, using the Solid Waste Emissions Estimation Tool ('SWEET').

In 2020, International Solid Waste Association's (ISWA) Task Force on Closing Dumpsites completed a study of waste sector short-lived climate pollutants (SLCPs) and other greenhouse gas (GHG) emissions in Tyre Caza, Lebanon, using the Solid Waste Emissions Estimation Tool (SWEET). SWEET model runs used data on municipal solid waste (MSW) generation, collection, disposal, and diversion under existing and potential alternative management scenarios proposed in an Integrated Waste Management Plan (IWMP) for Tyre Caza. Waste sector emissions reductions exceeding 45% of baseline levels are achievable by 2030 if all dumpsites are closed and remediated, waste burning stopped, and a new sanitary landfill developed with 60% methane collection and combustion. Additional emissions reduction accrues from implementing the IWMP and upgrading existing waste treatment facilities to increase waste diversion rates from current levels (22% including informal sector recycling) to 40%. Estimates of all of Lebanon's waste sector emissions using SWEET were developed for this mini-review article using published data on the amounts of MSW collected, disposed, and diverted, with adjustments to account for indirect GHG reductions from composting and anaerobic digestion (AD). A 50% reduction in emissions from baseline levels can be achieved by 2034, if by 2025 diversion of collected wastes to recycling, composting, and AD facilities is increased from 14% to 28%, and all residual MSW is disposed in sanitary landfills with 65% methane recovery.

Residual municipal solid waste as co-substrate at wastewater treatment plants: An assessment of methane yield, dewatering potential and microbial diversity

Separately collected organic fraction of municipal solid waste, also known as biowaste, is typically used to fill the available capacity of digesters at wastewater treatment plants. However, this approach might impair the use of the ensuing digestate for fertilizer production due to the presence of sewage sludge, a contaminated substrate. Worldwide, unsorted municipal solid household waste, i.e. residual waste, is still typically disposed of in landfills or incinerated, despite its high content of biodegradables and recyclables. Once efficiently separated from residual waste by mechanical processes, the biodegradables might be appropriate to substitute biowaste at wastewater treatment plants. Thus, the biowaste would be available for fertilizer production and contribute to a reduction in the demand on non-renewable fertilizers. This study aimed at determining the technical feasibility of co-digesting the mechanically separated organic fraction of residual waste with sewage sludge. Further, key parameters for the implementation of co-digestion at wastewater treatment plants were determined, namely, degradation of the solids and organics, specific methane production, flocculant demand, and dewatered sludge production. The microbial community and diversity in both mono- and co-digestion was also investigated. Semi-continuous laboratory scale experiments showed that the co-substrate derived from the residual waste provided a stable anaerobic co-digestion process, producing 206 to 245 L of methane per kg of volatiles solids added to the digester. The dewaterability of the digestate increased by 4.8 percentage points when the co-substrate was added; however, there was also an increase in the flocculant demand. The specific dewatered sludge production was 955 kg per ton of total solids of co-substrate added to the digester. Amplicon sequencing analysis provided a detailed insight into the microbial communities, which were primarily affected by the addition of co-substrate. The microbiota was fully functional and no inhibition or problems in the anaerobic digestion process were observed after co-substrate addition.

Global warming potential and economic performance of gasification-based chemical recycling and incineration pathways for residual municipal solid waste treatment in Germany

Chemical recycling could facilitate the transition from a linear to a circular carbon economy, where carbon-containing waste is channeled back into the production cycle as a chemical feedstock instead of being incinerated or landfilled. However, the predominant focus on technological aspects of chemical recycling for plastic waste narrows evaluations of its potential in contributing to such a transition. Moreover, it leads to significant controversy about its role in the waste hierarchy as a possible competitor to mechanical recycling. To address these gaps in the literature, this study assesses ecological and economic impacts associated with chemical recycling of residual municipal solid waste in Germany. Combining approaches of life cycle assessment and techno-economic analysis, chemical recycling and conventional incineration-based treatment pathways are comparatively evaluated in terms of global warming potential and economic performance (i.e. fixed capital investment, net present value, dynamic payback period, and levelized cost of carbon abatement). Results indicate that compared to incineration-based conventional pathways, chemical recycling can contribute to reducing greenhouse gas emissions in low-emission energy systems. However, the economic performance of chemical recycling is highly dependent on its scale of operation. Additionally, a price premium for recycling products as well as economic instruments for penalizing CO2 emissions are identified to play important roles in the economic performance of chemical recycling.

Economic Feasibility and Sustainability Assessment of Residual Municipal Solid Waste Management Scenarios in NSW, Australia

This study evaluates the economic cost and sustainability of treating residual municipal solid waste (MSW) through five waste management scenarios. In the baseline scenario (Bsc), all waste was managed through landfilling, while in scenario 1 (Sc1) all waste was treated by incineration. Sc2 employed anaerobic digestion (AD) for food waste and landfilling, and Sc3 treated the waste through AD for food waste, incineration of combustible and plastic wastes, and landfilling. Sc4 treated the waste using AD, incineration, landfilling, and recycling of the plastic waste. The economic cost of waste management scenarios was estimated by calculating different economic variables, such as gate fees, including capital and operating costs, governmental incentives and levies, and also the potential of employed waste treatment technologies for resource recovery. The results revealed that Sc3 has the lowest economic cost of 238.1 mAUD/year, followed by Sc1 (261.9 mAUD/year), while Bsc proved to be the highest cost at 476.1 mAUD/year for MSW treatment. It was noticed that scenarios employing incineration had lower economic costs compared to Bsc and Sc2, mainly because incineration resulted in higher electricity generation and reduced greenhouse gas emissions. The sustainability assessment results confirmed that Sc3 had the lowest and Bcs the highest total economic cost and environmental damage.

Insight into the Composition of the Stabilized Residual from a Full-Scale Mechanical-Biological Treatment (MBT) Plant in Terms of the Potential Recycling and Recovery of Its Contaminants

There is a lack of knowledge about the composition and particle size distribution of the <80 mm fraction mechanically separated from residual municipal solid waste (rMSW) and the stabilized residual (SR) after aerobic stabilization in a full-scale MBT plant. Therefore, the composition of the particle size fractions (>60 mm, 60–40 mm, 40–10 mm) of the <80 mm fraction and SR, collected in all seasons (summer (S), autumn (A), winter (W), spring (Sp)), was determined. Biodegradable waste (vegetable waste, other organic waste, paper, cardboard) constituted from 44.1% (A) to 54.3% (Sp) of the <80 mm fraction and it decreased to 8.5% (W) to 17.1% (S) in the SR, after effective biodegradation. In SR, the smaller particle size fractions (up to 40 mm) predominated. The main contaminants in SR were plastic, glass, metal, and other waste. Hierarchical clustering indicated that the composition of the particle size fractions of SR was more similar across four seasons than that of the <80 mm fraction. After stabilization and separation, the share of contaminants increased in the SR size fractions, which means that their recovery before landfilling may be profitable. This suggests a new direction in waste management that would be consistent with the principles of a circular economy, in which a waste product, like SR, which previously could only be landfilled, becomes a source of secondary materials.