Search Results (186)

Automated classification of municipal solid waste remains challenging due to high variability in object appearance, deformation, contamination, and inconsistent consumer disposal behavior, creating a need for representative multimodal datasets that enable robust machine-learning models. In this work, we developed a custom edge-node reverse-vending-machine (RVM) data-collection station equipped with multimodal sensors (RGB-D and microphone array) to co-record RGB-D video streams and impact audio on a single local compute node within the same acquisition window. Strict data acquisition protocols were designed to ensure a consistent environment, controlled illumination, and uniform background conditions while capturing realistic variations associated with everyday Greek consumer waste. The resulting dataset comprises 3300 multimodal samples corresponding to 721 distinct household waste items. Each sample is fully annotated across six categories addressing features critical for recycling: Material (18 classes), Hue (16 classes), Top/Cap, Label, Contamination, and Deformation. In addition, Common Objects in Context (COCO) annotations were added to support segmentation and object detection problems. This dataset is intended to support research on multimodal waste recognition, sensor fusion, and resource-efficient classification, and to serve as a foundation for evaluating models targeting edge-deployed recycling systems. Full article

The growing pressure of municipal waste generation and its associated environmental consequences has turned household participation into a central challenge for sustainable waste governance and circular-economy transition. This study adopts Cultural Additivity Theory and employs Bayesian Mindsponge Framework (BMF) analytics to examine how interactions between environmental–cultural and governance value bundles shape household willingness to pay (WTP) for improved urban waste management services, using survey data from 352 households in Hai Phong City, Vietnam. The results show that both the perceived importance of Commune Authorities and Women’s Unions are positively associated with WTP. More importantly, environmental perception and behavior further strengthen these governance–WTP associations, indicating that household financial support for improved waste management is greater when governance values interact with stronger environmental–cultural values. In contrast, higher environmental service satisfaction tends to weaken the positive association between governance importance and WTP. These findings suggest that household WTP is better understood as a relational outcome of interacting value bundles rather than as the product of isolated determinants operating independently. This study makes three contributions. First, it extends Cultural Additivity Theory into the field of urban environmental governance by demonstrating how interactions among value bundles shape household environmental decision-making. Second, it advances the waste-management literature by showing that environmental perception and environmental behavior become more influential when embedded within supportive governance and community structures. Third, it provides empirical evidence for developing community-based urban waste-management policies that integrate environmental communication, source-separation initiatives, local governance, and women-led community engagement to strengthen public participation and support sustainable urban waste-management systems. Full article

Municipal organic waste is one of the types of waste generated mainly in households but also by other producers. The key to managing this waste is to use appropriate treatment processes to reduce its negative impacts on the environment. The composting process involves the decomposition of persistent organic pollutants and their binding with the organic fraction. This study involved quantitative and qualitative research and analyses of organic waste contained in mixed municipal waste and selectively collected waste in Poland between 2020 and 2024. The aim of the study was to compare the final parameters of two types of organic waste after biological treatment, assess their potential management pathways within the circular economy, and discuss their potential relevance to greenhouse gas mitigation. The research results showed that, after applying the same biological processes to the two analyzed organic waste streams, the final products exhibited significant differences in physicochemical parameters, which necessitates the use of different management methods. The first end product can be classified as compost—a potential fertilizer—and must meet quality requirements for an organic soil improver. The second end product can be used for land reclamation if it meets all three criteria: an AT₄ (four-day aerobic respiration activity of the material) value of <10 mgO₂/g dry weight, loss on ignition of less than 35%, and organic carbon content of less than 20% dry weight. The products of the biological treatment of organic waste include fertilizers and stabilized waste intended for further processing. Full article

Municipal waste composition is commonly measured at a single point, even though recovery, mixing and handling can alter the stream before disposal. This study examined municipal solid waste in Sialkot, Pakistan, during an eight-day campaign from 27 December 2021 to 3 January 2022. A total of 672 physical-characterization samples was obtained from residential, commercial, institutional, industrial and street-sweeping sources. Household generation was 0.42, 0.46 and 0.51 kg per person per day in low-, middle- and high-income proxy areas, respectively. Kitchen waste declined from 45.91% at the source to 34.20% at communal storage and 23.45% at the dumpsite. Recyclable paper and plastic also declined, whereas dust and fines increased from 2.05% at the source to 19.60% at storage and 21.78% at disposal. Six mixed-waste composites showed moisture contents of 30.72–53.06%, ash contents of 15.85–45.04% and gross calorific values of 2924–12,530 kcal kg⁻¹. The results demonstrate that monitoring location materially affects estimated recycling and treatment potential. A multi-point monitoring protocol is therefore recommended for cities with mixed collection and informal material recovery. Full article

São Paulo is the largest city in Brazil and the second in Latin America. Its domestic waste production reached 3,515,678.96 tons in 2024. Historically, the city has a low recycling rate, and several laws and policies have been implemented to reverse this situation. The objective of this study was to investigate whether there have been advances in the recycling of household solid waste in São Paulo 15 years after the National Solid Waste Policy, from municipal and intra-urban perspectives. The extended period studied and segregated data by regional administration represent the innovative approach of this manuscript. The methodology consisted of a case study with an analysis of the legislation, official data research and evaluation of goals, and socio-spatial distribution. The separate collection rate grew from 0.69% in 2006 to 2.85% in 2024, but this volume represents less than 10% of the target originally projected for the period. A socio-spatial inequality was found as well as a lack of dedicated collection for the organic fraction. It can be concluded that progress is incremental, but limited by structural barriers and urban inequities. Results indicate for São Paulo and for other large cities, mainly in low and middle-income countries, recycling success cannot depend on legislation as it is also correlated with demographic factors, such as educational level, and to the need of targeted policies for a progressive increase in source-separated recycling. Full article

In most developing countries, the composition of municipal solid waste (MSW) arriving at final disposal sites (FDSs) differs from that at the source due to informal segregation of potentially recyclable waste (PRW) during its management, as well as because FDSs typically receive MSW from multiple municipalities. After exhaustively reviewing methods and studies of MSW characterization at their source, in collection trucks, and at FDSs, a lack of standardized methods for in situ characterization was identified, so this work proposes an innovative methodology to characterize MSW in situ at FDSs through the integration of geographic information systems to delimit the FDS or the selected cell(s) and the application of systematic sampling based on the NMX-AA-132-SCFI-2016 standard. To validate its applicability, MSW was sampled and characterized during the 2023 and 2024 dry (DS) and rainy seasons (RS) at a waste integral center in Tenango del Valle, Estado de México. The average compositions of organic waste were 15.3 ± 0.8% and 10.6 ± 0.1%; for PRW, they were 59.3 ± 5.4% and 50.5 ± 4.0%; and for the residual fraction, they were 25.4 ± 4.6% and 39.0 ± 4.1% in DS and RS, respectively; however, significant differences between seasonal or annual means could not be determined due to the limited sample size. The high percentages of PRW determined in situ are attributed to mixed household collection and show the potential to be recovered. The use of the proposed methodology enables representative in situ characterization of MSW after disposal with a lower level of significance, and it can be useful for decision-making regarding sustainable waste management projects. Full article

Decarbonising municipal solid waste (MSW) is a defining algorithmic challenge for smart cities: waste-to-energy (WtE), composting and material-recovery investments must be committed years ahead under deep uncertainty about household source-separation uptake and the governing policy instruments (landfill taxes, carbon prices, compost subsidies). We present a two-stage stochastic mixed-integer linear programming (MILP) framework, applied to the Attica region of Greece (Athens; 5122 t/day MSW) and calibrated to confirmed 2024 weighbridge data. The contribution is an integration strategy rather than a new technique: endogenous WtE capacity sizing (Special Ordered Sets of Type 2 (SOS2) piecewise-linear cost, economies-of-scale exponent 0.85), the bilinear capacity–build coupling linearised exactly by McCormick envelopes (one factor being binary), and Pigouvian shadow-price recovery of the optimal policy instruments are combined in a single-shot, gap-bounded MILP and embedded in a 10,000-run Latin-hypercube Monte Carlo layer over 12 parameters with Spearman sensitivity indices. The individual components are established; their joint formulation is, to our knowledge, new. The pipeline solves 10,415 MILP instances. Three results are policy-relevant: investment is robust to rollout uncertainty (VSS ≈ €0; EVPI ≈ €5.4 M, 0.15%); the carbon price alone explains ~80% of cost variance (ρ = +0.891); and, under the model’s calibration, the implied Pigouvian-optimal landfill tax (€1100–3300/t) indicates a binding landfill cap is needed to secure diversion. The framework transfers to any metropolitan MSW system facing decarbonisation and circular-economy mandates. Full article

Household food waste remains a huge challenge for solid waste management in municipalities worldwide, especially in the Global South. Existing studies that measure food waste (FW) in cities are scarce, have limited geographic scope, and have limited timeframes. In that direction, the current investigation provides data on the FW composition of nine regions of the municipality of Rio de Janeiro (Brazil), based on a three-year sampling across 155 neighborhoods. Waste samples were collected from 2021 to 2023. In total, about 24,038 kg (fresh weight) was analyzed. Results showed that FW accounts for an average of 47.7 ± 1.9% of household waste in the study period. The FW composition in the city of Rio de Janeiro ranged from 60.3–76.5% for fruits, vegetables, and salads, 15.0–25.1% for fine aggregate (small-sized food residues < 2.54 cm, like rice, beans, grains, and fragmented food particles), and 3.2–5.8% for proteins (discarded animal-based protein foods like chicken and meat). The chi-square goodness-of-fit test was applied to evaluate whether the FW composition in each of the nine regions differed from the mean FW composition of the Rio de Janeiro municipality. The findings revealed statistically significant differences (p-value < 0.05) in the average FW fractions in specific regions and years compared with the city’s average composition. Thus, one of the key takeaways of this investigation was that the percentages of discharged food waste fractions vary over time and across locations, even within the same municipality. The present research took a first step toward understanding the food waste problem in Rio de Janeiro (Brazil) and underscores the importance of monitoring food waste data to guide the development of locally specific strategies for sustainable urban food systems, including waste prevention, recycling, and food recovery. Full article

Peri-urban regions around Southeast Asian megacities connect agriculture, markets, food-service facilities, households, and municipal waste systems, yet comparable data for individual waste streams are often unavailable. This study presents a screening framework for selecting the first organic waste streams and node types to measure in Tangerang Raya, Indonesia, before treatment performance data are available. The framework complements, rather than replaces, city scale circularity monitoring, life cycle assessment, and technology selection tools. Public and institutional data were screened by evidence class and temporal and spatial compatibility. The core Peri-Urban Organic Waste Circularity Readiness Index (PU-OCRI) evaluates five intrinsic criteria: feedstock concentration, source separation readiness, treatment pre-screening compatibility, institutional readiness, and the safety/quality gate. Scores represent collective author judgments linked to a criterion level evidence trail; they have not been independently rated by local stakeholders or empirically calibrated. Korea linked support is assessed separately and cannot affect the index. Available evidence included 3248.1 t of large chili production in Kabupaten Tangerang in 2024, 798,406 t yr⁻¹ of reported potential municipal-waste generation in Kota Tangerang in 2024, and a planning-based estimate that 52.89% of non-residential waste in Kota Tangerang Selatan was biogenic organic material. Under equal weights, market-linked organics scored 76/100 and garden and landscape organics 72; production-side residues and household food waste each scored 56, and mixed residual waste scored 32. In 100,000 weight only simulations, market linked organics ranked first in 65.9% of runs and garden and landscape organics in 31.2%. When each score was allowed to vary by one point and sampled together with the weights, the corresponding first-rank frequencies were 50.7% and 40.7%. These results define a provisional paired audit hypothesis, not evidence of superior circular-economy performance. A required 8–12-week comparison of market/food-service and garden/landscape nodes will apply predefined criteria for mass stability, contamination, safety, treatment feasibility, cost, and operator and stakeholder participation before scores are updated or any treatment or scale-up decision is made. Korea-linked cooperation is limited to digital logging, training, QA/QC, and pilot-operation protocols. Data provenance is explicit: the 798,406 t yr⁻¹ value is the issuing agency’s population × per-capita estimate, whereas 52.89% is an author calculated category sum (kitchen + garden + wood) used only as a screening proxy, not as a direct stream level measurement or the plan’s official aggregate organic fraction. Full article

This study develops a mobile-supported system that municipalities can use in their irregular waste collection services within the scope of smart cities. Irregular waste refers to waste that individuals or organizations produce non-periodically, which arises unexpectedly or in an unusual manner. Unlike small-volume household waste collected at routine times, irregular waste is generally large-volume waste such as construction rubble, vegetable oil, mineral oil, and garden waste. In the irregular waste collection system developed in this study, waste locations are marked on the map of an application running on mobile devices, and notifications are sent to the municipality. The Google Distance Matrix API was used for processing and visualizing the notification locations on the map. Daily or 4 h planning is carried out using this data. In this study, a genetic algorithm and a differential evolution algorithm were used for vehicle routing and vehicle type optimization. To compare the efficiency of both methods, four different scenarios were designed with different numbers of waste locations and different types and amounts of waste, and the successes of the methods were compared. Differential evolution is found to be on average 0.8% better. Optimizations performed with actual road distances were found to be 8.0% more successful than optimizations performed with Euclidean distances. Full article

Municipal solid waste management (MSWM) systems in Latin America are constrained by limited access to high-resolution operational data, compelling local authorities to depend on aggregated national statistics that are inadequate for behaviorally informed intervention design. This limitation is particularly evident in the State of Mexico, which generates about 16,187 tons of waste every day but only recycles only 11%. In this context, this study introduces a diagnostic data science framework to identify behaviorally grounded citizen segments and their defining attributes, supporting evidence-based decision-making in MSWM. Primary survey data from 560 households across three municipalities were used, and a three-stage analytical pipeline was implemented to account for contextual heterogeneity. First, k-means clustering was applied to identify behavioral segments. Second, random forest classifiers were used to validate cluster coherence and quantify feature importance. Third, the Apriori algorithm was used to extract association rules that capture recurrent material-mixing behaviors. The results revealed municipality-specific segmentation structures (Tequixquiac: K = 6; Tlalpujahua: K = 3; Xalatlaco: K = 2), with material-specific disposal behaviors emerging as stronger segmentation drivers. Random forest classifiers validated cluster coherence with 100% accuracy, confirming that segments represent behaviorally distinct archetypes. The proposed framework converts raw behavioral data into actionable municipal visions. This approach focuses on finding diagnostic patterns instead of making predictions by utilizing machine-learning-driven MSWM research. Full article

Kuwait faces mounting challenges in municipal solid waste (MSW) management alongside continued dependence on fossil-fuel-based electricity generation. Per capita waste generation in Kuwait is approximately 1.7 kg/person/day, exceeding the global average of 0.74 kg/person/day, indicating substantial potential for resource recovery and energy conversion. This study evaluates public perceptions of waste-to-energy (WtE) in Kuwait’s residential sector and estimates the potential electricity that could be generated from household waste. A structured online household survey (n = 470) was administered to assess socio-demographic characteristics and key perception constructs, including awareness, perceived risks, perceived benefits, and overall attitudes toward WtE. In parallel, a quantitative estimation was undertaken using literature-based parameters for monthly per capita waste generation and electricity consumption to derive household-level waste quantities, corresponding energy potential, and generated-to-consumed energy ratios. Survey findings indicate generally favourable attitudes toward WtE and recognition of its potential to reduce landfill dependence and contribute to electricity supply, although respondents showed stronger support for locating WtE facilities away from residential neighbourhoods. Perceived risks—particularly related to health and environmental impacts—remained salient, while perceived benefits associated with waste reduction and local economic value were also acknowledged. The technical assessment indicates that higher waste generation increases theoretical energy recovery potential; however, high residential electricity demand reduces the relative contribution of WtE, with a generated-to-consumed energy ratio of approximately 2, compared with a global benchmark ratio of 4.1. This study highlights the need for targeted public engagement, improved source segregation, and more detailed Kuwait-specific technical and economic evaluations to support evidence-based WtE policy and investment decisions. Full article

This study evaluates the performance of six feature selection methods (BORUTA, LASSO, RFE, XGBoost, FSM, and SEV) and five predictive modelling techniques (ANN, MARS, RST, SRT, and SVM) for the spatial estimation of municipal waste accumulation rates across 79 districts in the Slovak Republic. Using a 2022 cross-sectional dataset comprising 45 socio-economic and demographic variables, the study focuses on spatial prediction for unseen districts rather than temporal forecasting. Feature selection results indicate that BORUTA, RFE, and XGBoost consistently identify key predictors, notably the share of three-person households, the density of transport and warehousing companies, and average monthly wages. Model robustness was ensured through repeated random sub-sampling (30 iterations, 70/30 split) and validated using the Friedman test with Nemenyi post hoc comparisons (α = 0.05). The highest accuracy was achieved by MARS and ANN models coupled with SEV selection (MAE ≈ 28–30 kg/(person·year), MAPE ≈ 6%, R² > 0.88), and by SVM with XGBoost (MAE ≈ 30 kg/(person·year), R² ≈ 0.90). Reducing the predictor set from ten to five resulted in only minor performance degradation (MAPE increase < 1 pp), confirming the effectiveness of dimensionality reduction. The proposed approach enables accurate, computationally efficient waste generation estimation, thereby supporting regional planning and evidence-based policy development. In a broader context, the findings contribute to the implementation of the European Green Deal and circular economy objectives by providing tools for spatially targeted waste management strategies, directly aligned with United Nations Sustainable Development Goal 11 (Sustainable Cities and Communities) and Goal 12 (Responsible Consumption and Production). Full article

Backyard activities (BAs) constitute a traditional rural food production strategy, although their sustainability-related outcomes remain underexplored in rural contexts. Our objective is to analyze how BAs in rural communities in the municipality of Guasave, Sinaloa, Mexico, represent a local strategy for producing healthy food through sustainable practices, focusing on the relationship between production processes and indicators associated with waste management, water use, and environmental impact. A stratified sampling approach was employed, and a structured survey was administered to 387 households practicing BAs in the region. Instrument consistency was verified using the Kuder–Richardson coefficient. Results show that BAs are relevant in the region: 89.15% of respondents have a family garden and 67.96% raise animals for domestic consumption, supporting an additional income. Chi-square tests revealed statistically significant correlations (p < 0.05) among the study variables, ranging from moderate to strong, with backyard animal husbandry practices standing out in relation to nutritional and health management in animal production, reaffirming that these are not isolated events but complementary activities. These findings indicate that BAs involve interconnected systems rather than isolated activities, reflecting an integrated household-level system with potential implications for resource management and environmental sustainability in rural contexts. Full article

Illegal solid waste dumping is a key urban sustainability challenge due to increased urbanisation and human consumption, but its prevalence and impacts across a socially differentiated gradient are seldom considered. We used street and off-street road surveys to examine the extent of illegal solid waste dumping across an income gradient in two medium-sized towns of Makhanda and Knysna in South Africa. We enumerated all dumpsites encountered in low- and high-income areas, recorded their GPS coordinates, and visually estimated size and composition using a standardised typology. We encountered 215 illegal solid waste dumpsites unevenly distributed by town (155 in Makhanda and 60 in Knysna) and income status, with the majority located in low-income areas compared to high-income areas. Most illegal solid waste dumpsites in low-income areas were small and located along roadsides and vacant plots. In both towns, illegal solid waste dumpsites were dominated by household and garden waste. The findings suggest that social differentiation matters in illegal solid waste dumping and should be factored into service provision strategies for ensuring environmental justice. We recommend that (i) municipalities should consider income heterogeneity in designing effective and equitable waste management plans, (ii) the national government should consider additional human and financial support to municipalities for efficient and equitable residential waste management, (iii) waste recycling at source (within households) should be mainstreamed in waste management strategies, and (iv) cleanup campaigns should be considered as a short-term solution to manage existing illegal solid waste dumpsites. Full article