Municipal Solid Waste Research Articles

Numerical Simulation and Intelligent Prediction of Effects of Primary Air Proportion and Moisture Content on MSW Incineration

As the core process of the thermal treatment of municipal solid waste (MSW), incineration process optimization has become a frontier topic in the field of environmental engineering. This study took a 500 t/d incinerator for engineering application as the research object. Based on a two-fluid model, a three-dimensional transient model of a proportional incinerator was established. The effects of primary air proportion and moisture content on the combustion state in the incinerator were verified and discussed using field test data, and the dynamic changes in flue gas temperature were predicted by a BPNN (Backpropagation Neural Network). The results show that the increase in air volume in the drying section promotes water evaporation but inhibits the devolatilization and combustion of fixed carbon. The position where complete devolatilization and fixed carbon combustion begins was delayed by 1.5 m~3 m. The moisture content (M) is negatively correlated with the devolatilization and combustion of fixed carbon. From M = 25% to M = 40%, the flue gas outlet temperature decreased by 140 K. In addition, a dynamic combustion BP neural network model with the movement of the grate under rated conditions was constructed, with the MSE (Mean Squared Error) being 1.629%. The model can learn data characteristics well and has a good prediction effect. This study provides a scientific basis for optimizing the operating parameters of municipal solid waste incinerators, helps to optimize the incineration process, and is of great significance to the thermal treatment of MSW.

Sustainable Reuse and Characterization of Soil-Like Material from Landfill Mining in Indian Cities

Abstract This study investigates the physicochemical properties of Soil-Like Material (SLM) recovered from aged Municipal Solid Waste (MSW) dumps in Anantapur, Andhra Pradesh, India, and assesses its potential for use in earth-fillings. The SLM, which constitutes 68-75% of the excavated waste, was analyzed for key parameters including total dissolved solids (TDS), chemical oxygen demand (COD), electrical conductivity (EC), and heavy metal concentrations. Results revealed that the organic content of SLM ranged from 6% to 20%, significantly higher than that of local soils (1.5%). The leachate produced from SLM showed elevated levels of TDS (500-1,200 mg/L), COD (150-270 mg/L), and heavy metals such as copper (Cu), lead (Pb), chromium (Cr), and zinc (Zn). Cu and Pb concentrations were found to be 27 and 26 times higher than those in local soil extracts, posing substantial risks to groundwater and soil quality. Other metals, including nickel (Ni), arsenic (As), and cadmium (Cd), also exceeded permissible limits. These findings suggest that while SLM has potential for reuse, its high contamination levels require treatment methods such as soil washing, heating, or stabilization with additives like lime or fly ash to reduce environmental risks. Without proper treatment, the direct use of SLM could result in significant ecological damage. The study highlights the importance of sustainable landfill site rehabilitation and the development of safe strategies for the reuse of SLM to mitigate potential environmental impacts.

Comparative Study on the Catalytic Ozonation of Biotreated Landfill Leachate Using γ-Al2O3-Based Catalysts Loaded with Different Metals

Global municipal solid waste (~2B tons/year) affects sustainability, as landfill and incineration face persistent leachate contamination, demanding effective management to advance water recycling and circular economies. Accelerated investigation of hybrid biocatalytic ozonation systems is imperative to enhance contaminant removal efficiency for stringent discharge compliance. This study investigates the catalytic ozonation effects of γ-Al2O3-based catalysts loaded with different metals (Cu, Mn, Zn, Y, Ce, Fe, Mg) on the biochemical effluent of landfill leachate. The catalysts were synthesized via a mixed method and subsequently characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Pseudo-second-order kinetics revealed active metal loading’s impact on adsorption capacity, with Cu/γ-Al2O3 and Mg/γ-Al2O3 achieving the highest Qe (0.85). To elucidate differential degradation performance among the catalysts, the ozone/oxygen gas mixture was introduced at a controlled flow rate. Experimental results demonstrate that the Cu/γ-Al2O3 catalyst, exhibiting optimal comprehensive degradation performance, achieved COD and TOC removal efficiencies of 84.5% and 70.9%, respectively. UV–vis absorbance ratios revealed the following catalytic disparities: Mg/γ-Al2O3 achieved the highest aromatic compound removal efficiency; Ce/γ-Al2O3 excelled in macromolecular organics degradation. EEM-PARAFAC analysis revealed differential fluorophore removal: Cu/γ-Al2O3 exhibited broad efficacy across all five components, while Mg/γ-Al2O3 demonstrated optimal removal of C2 and C4, but showed limited efficacy toward C5. These findings provide important insights into selecting catalysts in practical engineering applications for landfill leachate treatment. This study aims to elucidate catalyst formulation-dependent degradation disparities, guiding water quality-specific catalyst selection to ultimately enhance catalytic ozonation efficiency.

Risk of overestimating odor control performance with the removal efficiency of a single odorant: Odorant interactions during the chemical absorption

ABSTRACT Odor is a serious issue for municipal solid waste treatment process, and chemical absorption is a common technology for odor control. Interactions among odorants will influence the performance of chemical absorption, and they are still not fully understood. This work took the common and important odorants, including hydrogen sulfide (H2S), methanethiol, propanethiol and acetaldehyde, as examples, to investigate the removal performance of mixed odorants by sodium hypochlorite (NaClO) solution at different concentrations, and interactions among the odorants. The absorption experiments were conducted in gas-washing bottles with single or mixture of H2S, methanethiol, propanethiol and acetaldehyde as the inlet gases, and NaClO solutions at different concentrations as the absorption solutions. The thermodynamic equilibrium was simulated. Acetaldehyde was eliminated mainly by physical absorption, and the removal efficiency was not affected by the other three odorants. The removal efficiencies of H2S, methanethiol, and propanethiol increased with the chlorine concentration ([Cl2]), and reached nearly 100% by the NaClO solution of pH = 12.19, [Cl2] = 158.00 mg/L. H2S, methanethiol, and propanethiol competed for reacting with NaClO. H2S was more effectively removed than methanethiol and propanethiol due to its lower pKa value. The removal efficiency of methanethiol decreased linearly with the increase in methanethiol and H2S concentrations mainly due to the consumption of NaClO. Propanethiol removal was decreased by both methanethiol and H2S, and methanethiol had more influence than H2S due to the higher consumption of NaClO. The odor control performance could be overestimated when there are several important odorants, and only the removal efficiency of a single odorant was considered. Correspondingly, suggestions for chemical scrubber operation were provided, including the consideration of odorant interactions, the selection of monitoring odorants, and the optimization of operating parameters (pH and [Cl2]) using machine learning methods. Implications Chemical absorption is widely applied for odor control, and the interaction between odorants is an important influencing factor of the performance. Hydrogen sulfide, methanethiol, propanethiol and acetaldehyde are common and important odorants emitted during municipal solid waste treatment. This work investigated the removal performance of chemical absorption for the single and mixture of these odorants, and revealed the interaction between them, as well as the risk of overestimating odor performance with the removal efficiency of a single odorant, which can provide insights into optimizing odor control technologies.

Smart Compression Bin

Abstract The exponential growth of urban populations has led to an increasing volume of municipal solid waste, challenging traditional waste management practices in terms of efficiency, cost, and environmental sustainability. The Smart Compression Bin presents an innovative solution that integrates real-time monitoring, automated waste compression, and wireless communication to improve public waste collection systems. The bin uses ultrasonic sensors to detect fill levels, triggering a compression mechanism when capacity thresholds are reached. This not only maximizes storage space by reducing the volume of waste by up to 60%, but also minimizes the frequency of collection trips, reducing fuel consumption and labour costs. A microcontroller coordinates system functions and communicates bin status to a central dashboard via wireless modules, enabling timely and data-driven collection strategies. Powered by a rechargeable battery supported by solar panels, the system emphasizes energy efficiency and low maintenance. Field testing confirmed the system’s reliability, responsiveness, and effectiveness in various operational conditions. This paper contributes to smart city development by offering a scalable, eco-friendly approach to waste management, addressing key urban challenges through intelligent automation and IoT integration

Recent advancements in the treatments of the organic fraction of municipal solid waste towards circular economy

Recent advancements in the treatments of the organic fraction of municipal solid waste towards circular economy

Refuse-Derived Fuel with the Addition of Peanut Shells: An Evaluation Using a Decision-Making Support Algorithm

Brazil has made progress in Municipal Solid Waste (MSW) management through national legislation focused on integrated waste handling. However, challenges persist, particularly regarding MSW overproduction. A sustainable alternative is Refuse-Derived Fuel (RDF), generated from MSW with or without biomass addition. To be viable for combustion, RDF must meet established energy and environmental quality standards. In this context, a mathematical model based on fuzzy logic was developed to classify RDF quality and support decision-making. Five RDF samples were tested, evaluating their Lower Heating Value (LHV), chlorine, and mercury contents using calorimetry, atomic absorption, and X-ray fluorescence. Results indicate that RDF produced solely from MSW tends to have inadequate LHV, necessitating drying pretreatment. Even with the addition of peanut shells, the highest classification achieved was “Regular”, suggesting limited suitability for combustion in furnaces or boilers without pretreatment. Since the general composition of MSW in Brazil is consistent with the characteristics analyzed, RDF may remain unviable for energy recovery under similar conditions. Economic feasibility studies on drying are recommended, especially in urban centers with limited landfill space.

The Caloric Value of Municipal Solid Waste Generated in Georgia for Energy Recovery

Waste management approaches such as prevention, reuse, recycling, and recovery are key objectives, which stand in a Waste hierarchy of priority. The same Waste Hierarchy is a basic principle of the waste management policy of Georgia. Waste recovery is a priority approach over landfilling. In this case, it should be noted that more than 90 % of waste generated in Georgia is landfilled, which has negative social, economic, and environmental impacts. Thus, along with reusing and recycling, Waste-to-Energy (WtE) should be a solution for sustainable WM systems. Municipal waste generation in Georgia is characterized by increasing dynamics. For example, in 2015–2023, waste generation per capita increased from 207.8 kg to 302.2 kg. Accordingly, the amount of municipal waste disposed of in landfills has significantly increased. According to data from the National Statistics Office of Georgia, in 2015, 774.4 thousand tons were placed in landfills, and in 2023 – 1116.6 thousand tons, which is more than 90 % of the municipal waste generated annually. On the other hand, the calorific value of municipal waste generated in Georgia is of interest in terms of energy recovery, taking into account the experience of many developed countries, in particular Sweden and Denmark. As is known, for the effective use of municipal waste for energy recovery, it is necessary that the average lower calorific value of waste should be at least 7 MJ/kg and must never fall below 6 MJ/kg. Plastic waste is characterized by the highest calorific value, paper and textiles are also acceptable for energy recovery. Organic waste has a rather low calorific value (4 MJ/kg), which is not recommended for Waste-to-Energy technologies. Plastics such as Polypropylene PP, Polyethylene HDPE, and Polyethylene Terephthalate PET have a high calorific value. In this regard, it should be noted that municipal waste generated in Georgia consists of about 13–14 % plastic, 10–11 % of paper and cardboard, and more than 4 % of textiles. Organic waste constitutes the largest portion of municipal waste generated in Georgia (over 54 %), however, this type of waste is not of interest in terms of energy recovery, as the calorific value of organic waste is very low (4 MJ/kg).

Comprehensive experiences on the operation of a full-scale continuous dry anaerobic digestion plant treating mechanically sorted OFMSW

ABSTRACT Anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) is a crucial waste management method for the diversion of organics from landfills to decrease greenhouse gas emissions while enabling energy recovery. A number of dry AD systems treating OFMSW have notably increased over the last two decades. In this study, mono-digestion of mechanically sorted OFMSW and co-digestion of OFMSW, chicken manure and WWTP sludge were evaluated using triplicate full-scale digesters. Results demonstrated that 5–6.6 m3biogas/m3reactor.day biogas could be produced at an OLR of 10.5–12 kg TVS/m3.day, with an HRT of 16–18 days. Beyond this threshold, further increases in OLR resulted in reduced gas production due to ammonia inhibition as a result of broiler chicken manure overload. Biogas yield decline started when the chicken manure content of the feed was increased to 10% (w/w) and accompanied with the VFA/TA ratio rising above 0.8. Process instability and a sharp drop in biogas productivity were observed above 20% (w/w) of chicken manure, where VFA/TA ratio exceeded 1.0. Results underline the importance of balancing different properties (e.g., degradability, carbon to nitrogen ratio) of co-substrates to optimize the biogas yield and to ensure process stability.

Characterization of Municipal Solid Waste and Estimation of Al Nabai Landfill Gas Emissions in Baghdad with LandGEM Model and Field Measurements

Characterization of Municipal Solid Waste and Estimation of Al Nabai Landfill Gas Emissions in Baghdad with LandGEM Model and Field Measurements

Preparation and physicochemical characterization of cracking oil from waste plastics

The aim of this paper is to systematically explore the preparation process of waste plastic cracking oil from municipal solid waste and its physicochemical properties, and to study the composition and properties of waste plastic crack-ing oil in depth through characterization techniques such as organic ele-mental analysis (EA), capillary viscometer, flash point and ignition temperature test, so as to provide theoretical basis and technical support for the resource utilization of low value waste plastics in municipal solid waste.

Mechanical Strength of Waste Materials: A Cone Penetration Testing-Based Geotechnical Assessment for the Reclamation of Landfills.

The stability and mechanical properties of municipal solid waste (MSW) deposits in closed landfills are critical for safe land reclamation and infrastructure development. This study employs Cone Penetration Testing (CPT) to evaluate the geotechnical parameters of aged waste at three closed landfill sites in central Poland. Key parameters, including shear strength, internal friction angle, density, and liquidity index, were assessed to determine slope stability and bearing capacity for future redevelopment. Due to the heterogeneous nature of MSW, CPT results were analyzed in conjunction with empirical correlations and nomograms to improve accuracy, so the parameters can be used for future numerical modeling and proposing new computational approaches for landfill body elastic and mechanical behavior predictions. The findings indicate significant variability in landfill waste mechanical properties, influenced by waste composition, decomposition stage, and compaction history. The study highlights CPT's reliable detremination of geotechnical parameters for landfill restoration projects, particularly for infrastructure, creating the potential for green energy and sustainable development. The results contribute to improving engineering practices in landfill restoration and ensuring the long-term stability of post-closure land use. This study also contributes to obtaining reliable results on anthropogenic waste material mechanical parameters at both the material point and at the overall structural scale, benefiting future computational methods and modeling approaches for analyzing structural and geotechnical safety of such complex and demanding structures as landfills.

Fermentation of the organic fraction of municipal solid waste under different pH values and composition of microbial communities

ABSTRACT The organic fraction of municipal solid waste (OFMSW) must be stored for hours or days before being fed to the anaerobic digestion reactors. This storage leads to spontaneous lactic acid fermentation, and volatile fatty acids (VFAs) and ethanol are produced by naturally occurring microorganisms. This research deals with fermentation and hydrolysis by controlling the OFMSW storage (silage) conditions. Using only naturally occurring microorganisms as inoculum, OFMSW fermentation in a semi-continuous reactor at pH values of 4, 5, and 6 was performed. During 6 days, samples were collected and analyzed daily for VFAs, ethanol, and lactic acid. At pH 4, the main products were ethanol, lactic acid, and acetic acid; at pH 5, lactic acid predominated, decreasing after day 4; at pH 6, acetic acid formed rapidly and after day one, the concentration remained constant. At pH 6, butyric acid reached the highest concentration of all VFAs. The microbial diversity increased with pH. Metataxonomic analysis supports the possibility that the fungus of the Pichia genus is responsible for ethanol production and that various bacteria are responsible for VFAs, lactic acid production, and acetogenesis. Acetogenesis was the main pathway for the decrease in lactic acid and ethanol over time.

Comprehensive Evaluation of Sustainable Municipal Solid Waste Management (SMSWM) Practices in Rourkela

Abstract Effective management of municipal solid waste (MSW) is essential for ensuring sustainable urban development, especially in rapidly industrializing cities like Rourkela. This review paper provides a comprehensive evaluation of current municipal solid waste management (MSWM) practices in Rourkela, Odisha, with a focus on sustainability. Drawing upon a combination of local case studies, technological assessments, and comparative global frameworks, the study highlights the status, challenges, and opportunities for enhancing MSWM in the region. Particular emphasis is given to the recycling and utilization of industrial waste from the Rourkela Steel Plant, fly ash management, and the potential role of green technologies such as mechanical-biological treatment. The review also explores institutional frameworks, policy initiatives, stakeholder involvement, and public-private collaborations. It identifies critical gaps in waste segregation, informal sector integration, and long-term planning while proposing strategic interventions aligned with sustainable development goals (SDGs). This paper aims to contribute to the formulation of more efficient, inclusive, and environmentally sound waste management policies in Rourkela and similar Indian cities. Keywords Rourkela, Municipal Solid Waste Management (MSWM), Sustainability, Recycling, Industrial Waste, Green Technology, Urban Planning, Fly Ash, Smart City, Circular Economy

Sustainable Management of the Organic Fraction of Municipal Solid Waste: Microbiological Quality Control During Composting and Its Application in Agriculture on a Pilot Scale

Within the Life-NADAPTA project (LIFE16 IPC/ES/000001), and in the framework of sustainable waste management, a study was carried out on the microbiological evolution during the composting process of the organic fraction of municipal solid waste (FORSU) using aerated static piles and their agricultural application on a pilot scale. This is necessary to ensure effective sanitization of the compost and that its application does not pose any risk. The microbiological parameters considered were as follows: Salmonella sp., Escherichia coli, total coliforms, and Enterococcus sp. The physicochemical parameters moisture, total solids, organic matter, nitrogen, phosphorus, and heavy metals were also evaluated. Salmonella sp. was not detected throughout the process, and the concentration of the three microbiological indicators decreased to the sanitary conditions recommended by legislation. As a result, the compost obtained complied with the requirements set out in the regulations on fertilizer products and was highly stabilized and mature for application on agricultural land. Tests were carried out on the soil before, during and after the vegetative cycle of the crop and on the irrigation water. The soil results showed that the addition of the organic amendment did not alter the populations of the tested micro-organisms at the end of the crop growing cycle. Thus, an adequate treatment of the residues allows them to be used in a sustainable way, but an adequate monitoring of the operational parameters is necessary to ensure this.

Exploring municipal solid waste management practices and public perceptions in north coastal Andhra Pradesh, India

Municipal solid waste management (MSWM) presents a critical challenge in rapidly urbanizing regions, particularly in developing nations, where population growth and migration place increasing strain on infrastructure. This study examines MSWM practices and public perceptions in north coastal Andhra Pradesh, India, with a focus on waste collection, transportation, generation and reduction, reuse and recycling, composition, and separation. The research aims to assess the effectiveness of current MSWM strategies, identify gaps, and propose improvements based on best management practices. Through an analysis of existing regulations and levels of public engagement, this study provides insights into optimizing waste management approaches within the regulatory framework. The findings contribute to the development of sustainable waste management solutions that enhance environmental quality and urban livability. This research identifies key practices that improve waste management systems and offers recommendations for municipal bodies seeking to enhance efficiency and promote sustainability in waste reduction and resource recovery. The results underscore the importance of integrated solid waste management strategies and public participation in effectively addressing the growing challenges of urban waste management.

Arthropod assemblages in municipal solid waste landfills: decomposers or hidden hazards?

Landfills represent a cost-effective method for waste disposal but pose significant environmental and public health risks, including the spread of arthropod-borne diseases, if not properly managed. This study investigated arthropod assemblages in two municipal solid waste landfills in Maluti-a-Phofung, Free State, South Africa, and compared them with adjacent control sites. Arthropods were sampled using pitfall traps deployed in active and dormant landfill sites, as well as in adjacent pristine grassland biotopes, during both wet and dry seasons. The study identified 11 arthropod groups in the landfills, including collembolans (48%), Diptera (25%), Hymenoptera (8%), Coleoptera (8%), and spiders (6%). Results showed that landfills support significantly higher arthropod abundance and diversity compared to control sites. In the wet season, landfills recorded a total of 9,354 individuals, compared to 3,684 in control sites, while in the dry season, 1,193 individuals were recorded in landfills versus 788 in control areas. Detritivores and predatory arthropods were notably more abundant in landfills. Dipteran families such as Muscidae and Calliphoridae were particularly prevalent in landfills during the wet season, playing key roles as decomposers while also serving as potential disease vectors. The findings highlight that landfill conditions, including waste accumulation and seasonal variations, promote diverse arthropod communities crucial for waste degradation. However, the high abundance of arthropods, especially dipterans, may indicate inadequate landfill management. To mitigate potential health risks, improved waste containment, moisture control, and remediation practices are recommended. This study is the first documented investigation of arthropod assemblages in South African landfill sites, and future research should further explore the role of detritivores in waste degradation and pollution remediation in landfills.

Characterization of Municipal Solid Waste as Potential Fuel for Energy Needs.

The continued expansion of cities in economic, population and geographical terms leads to significant environmental and infrastructural pressures, including the need for efficient municipal solid waste (MSW) management. This research focuses on the characterization of MSW generated in the city of Skopje and the investigation of its thermo-physical properties and energy utilization potential. The analyses cover physical and chemical properties, including density, moisture content, volatile matter, ash, and higher heating value, using adequate testing methods. The results indicate that MSW has a relatively high gross calorific value, surpassing typical MSW ranges comparable to those of solid fossil fuels. With approximately 79.42% volatile matter and a low ash content of 7.76%, the considered MSW demonstrates excellent combustibility. Chemical analysis reveals high carbon (53.12%) and hydrogen (7.69%) levels, supporting high energy value, while low nitrogen (0.84%) and sulfur (0.26%) levels ensure minimal NOx and SOx emissions. These characteristics position MSW as a suitable feedstock for energy production in incineration facilities. However, the heterogeneous composition of MSW presents challenges to process stability, necessitating prior waste preparation. The research concludes that harnessing waste energy potential could contribute to sustainability, reduce reliance on fossil fuels, and improve the environmental conditions in large urban areas.

Application of high-resolution site characterisation tools and sampling methods for assessing microplastic migration beneath MSW dumpsites.

Application of high-resolution site characterisation tools and sampling methods for assessing microplastic migration beneath MSW dumpsites.

Distribution, removal and potential factors affecting antibiotics occurrence in leachate from municipal solid waste incineration plants in China.

Distribution, removal and potential factors affecting antibiotics occurrence in leachate from municipal solid waste incineration plants in China.