Search Results (981)

This paper presents the research outcomes of the Golden Seal project, which addresses the omnipresent issue of plastic pollution in coastal areas while enhancing their touristic value through the deployment of Internet of Things (IoT) technologies integrated into a gamified recycling framework. The developed system employs an IoT-enabled Wireless Sensor Network (WSN) to systematically collect, transmit, and analyze environmental data. A centralized, cloud-based platform supports real-time monitoring and data integration from Unmanned Aerial and Surface Vehicles (UAV and USV) equipped with sensors and high-resolution cameras. The system also introduces the Beach Cleanliness Index (BCI), a composite indicator that integrates quantitative environmental metrics with user-generated feedback to assess coastal cleanliness in real time. A key innovation of the project’s architecture is the incorporation of a Serious Game (SG), designed to foster public awareness and encourage active participation by local communities and municipal authorities in sustainable waste management practices. Pilot implementations were conducted at selected sites characterized by high tourism activity and accessibility. The results demonstrated the system’s effectiveness in detecting and classifying plastic waste in both coastal and terrestrial settings, while also validating the potential of the Golden Seal initiative to promote sustainable tourism and support marine ecosystem protection. Full article

Given the increasing volume of selectively collected bio-waste and the requirement to increase waste treatment system energy efficiency, dry anaerobic digestion (DAD) represents a more sustainable choice for the treatment of municipal organic fraction instead of conventional technologies. The current paper provides an overview of the existing knowledge on DAD of green waste or kitchen waste collected selectively. Key substrates characteristics (chemical composition, methane potential), novel reactor design and process conditions relevant to effective digestion at elevated dry matter content are considered. Of special interest is the process intensification techniques, impact of contamination and co-fermentation opportunity with other biodegradable wastes. This article also discusses energy and economic performance of DAD plants and puts their environmental burden in perspective versus other bio-waste treatment processes. The current legislation and DAD’s role in the circular economy are also considered. Selectively collected biowaste has significant energy potential and dry anaerobic digestion is an effective technology, especially in areas with limited water availability, offering both waste volume reduction and minimized energy losses. The aim of this work is to introduce the potential of this technology as a sustainable option within the context of renewable energy and modern waste management. Full article

Municipal solid waste incineration fly ash (MSWI FA) is recognized as a hazardous solid waste due to its enrichment in toxic heavy metals and high leaching potential. This review systematically summarizes the current understanding of heavy metal occurrence in MSWI FA and associated environmental risks. Solidification and stabilization methods, such as cement-based curing and chemical immobilization, are widely applied due to their cost-effectiveness and operability, though their long-term stability and recovery potential remain limited. Thermal treatment technologies, including sintering, vitrification, thermal separation, and molten salt processes, have shown excellent performance in reducing volume and enhancing the immobilization or recovery of heavy metals. However, these methods are often limited by high energy demands and operational complexity. Recently, emerging technologies such as electrodialysis, bioleaching, and electrokinetic remediation have demonstrated promising capabilities for selective metal recovery under relatively mild conditions. Nevertheless, these novel approaches remain at an early stage of development and have thus far been validated only at the laboratory or pilot scale. Overall, integrating multiple treatment technologies while advancing resource-oriented and low-carbon approaches will be essential for the sustainable management of MSWI FA. Full article

Sustainable waste management is one of the most serious global challenges today. Reusing waste materials can be an effective alternative to landfill, while recovering valuable nutrients. The purpose of this six-year field study was to investigate the potential of bottom ash from combustion of bituminous coal or biomass and municipal sewage sludge, and different doses of the waste mixtures, as a micronutrient source for plants. Yield, concentration, concentration index, uptake and simplified balance of the micronutrients (manganese, iron, molybdenum, cobalt, aluminium) in plant biomass were measured. Results showed that the wastes differently affected the parameters studied, which generally increased via treatment as follows: coal ash, biomass ash < coal or biomass ash mixtures with sewage sludge < sewage sludge. Irrespective of treatment, micronutrient recovery rate followed the following trend: Mn > Mo > Fe > Co > Al, from 0.32–25.82% for Mn to 0.04–0.28% for Al. For individual elements, recovery depended on waste. For Mn, Fe and Al, the application of ash separately or in mixtures with sludge at higher doses reduced recovery (0.04–0.78%). For Mn, Fe, Al and Mo, the application of ash–sludge mixtures at lower doses increased recovery (0.11–5.82%), with the highest recoveries when sludge was used separately (0.28–25.82%). For Co, the separate application of sewage sludge and ash–sludge mixture at the lower dose increased recovery (2.41–2.52%), with the highest Co recovery following the separate application of coal ash (2.78%). Ash, sludge and their mixtures were a valuable source of micronutrients for plants. Ash–sludge mixtures improved micronutrient uptake compared to ash used separately. Application of these wastes as fertilisers aligns with the EU Action Plan on the Circular Economy and can contribute to achieving SDGs 2 and 12. Full article

Accurate information on waste composition is essential for strategic planning in waste management and developing environmental technologies. However, detailed analyses of individual waste containers are both time- and cost-intensive, resulting in a limited number of available samples. Therefore, it is crucial to apply statistical methods that enable reliable estimation of average waste composition and its variability, while accounting for territorial differences. This study presents a statistical approach based on territorial stratification, aggregating data from individual waste container analyses to higher geographic units. The methodology was applied in a case study conducted in the Czech Republic, where 19.4 tons of mixed municipal waste (MMW) were manually analyzed in selected representative municipalities. The method considers regional heterogeneity, monitors the precision of partial estimates, and supports reliable aggregation across stratified regions. Three alternative approaches for constructing interval estimates of individual waste components are presented. Each interval estimate addresses variability from the random selection of waste containers and the selection of strata representatives at multiple levels. The proposed statistical framework is particularly suited to situations where the number of samples is small, a common scenario in waste composition analysis. The approach provides a practical tool for generating statistically sound insights under limited data conditions. The main fractions of MMW identified in the Czech Republic were as follows: paper 6.7%, plastic 7.3%, glass 3.6%, bio-waste 28.4%, metal 2.1%, and textile 3.0%. The methodology is transferable to other regions with similar waste management systems. Full article

Determining the amount of biowaste generated, separated, and recycled at source in households (BHrecycled) is crucial for assessing its potential inclusion in the total mass of waste prepared for reuse and recycling on the country level. Although the EU has introduced standardized rules for BHrecycled measurement, it is still a major challenge. This study, the first to be conducted on a large scale in Poland and the EU countries, aimed to determine the actual mass of BHrecycled (kitchen waste (B_K) per capita per year (kg/(capita·year)) and garden waste (B_G) per square meter of green area (kg/(m²·year)) in 1150 households that use an active composting unit located in more than 400 municipalities in all the voivodeships in Poland. Each municipality is characterized by individual MSW generation (MSW_G) values (the amount of waste generated per capita per year). The MSW_G values of the municipality where the household was located were used to group the data of B_K and B_G. In Poland, the average masses of B_K and B_G remained within the ranges of 81.02–107.49 kg/(capita·year) and 1.02–2.87 kg/(m²·year), respectively, across the MSW_G value. However, there was no clear statistical relationship between the MSW_G value and B_K or B_G. The average masses of B_K and B_G were ca. 97 kg/(capita·year) and ca. 2 kg/(m²·year). These results enable the determination of the total amount of BHrecycled in Poland. By incorporating these findings into waste management, strategies, monitoring, and reporting practices can be improved. Moreover, it promotes compliance with the EU recycling targets. Full article

This study presents a comprehensive analysis of the chemical composition of bottom ash samples generated during municipal waste incineration. A total of 52 samples were collected and subjected to statistical analysis for 17 elements and 2 element sums using techniques such as correlation analysis and one-way ANOVA. The results confirm a high degree of heterogeneity in the elemental content, reflecting the variability of waste streams and combustion processes. Strong correlations were identified between certain elements, including Cu-Zn, Co-Ni, and HREE-LREE, indicating common sources and similar geochemical properties. The analysis also revealed significant seasonal variability in the content of Ba and Sr, with lower average values observed during the spring season and greater variability noted during summer and winter. Although Al and HREE did not reach classical significance levels, their distributions suggest possible seasonal differentiation. These findings underscore the need for long-term monitoring and seasonal analysis of incineration bottom ash composition to optimize resource recovery processes and assess environmental risk. The integration of chemical data with operational data on waste composition and combustion parameters may contribute to a better understanding of the variability of individual elements, ultimately supporting the development of effective strategies for ash management and element recovery. Full article

As the generation of Municipal Solid Waste (MSW) has exponentially increased, this poses a challenge for waste managers, such as municipalities, to effectively control waste streams. If waste streams are not managed correctly, they negatively contribute to climate change, marine plastic pollution and human health effects. Therefore, waste streams need to be identified, categorised and valorised to ensure that the most effective waste management strategy is employed. Research suggests that a more efficient process of identifying and categorising waste at the source can achieve this. Therefore, the aim of the paper is to identify the state of research of AI-powered drones in identifying and categorising waste. This paper will conduct a systematic review and meta-analysis on the application of drone technology integrated with image sensing technology and deep learning methods for waste management. Different systems are explored, and a quantitative meta-analysis of their performance metrics (such as the F1 score) is conducted to determine the best integration of technology. Therefore, the research proposes designing and developing a hybrid deep learning model with integrated architecture (YOLO-Transformer model) that can capture Multispectral imagery data from drones for waste stream identification, categorisation and potential valorisation for waste managers in small-scale environments. Full article

The formulation of touristic policies is a time-consuming process that consists of a wide range of steps and procedures. These policies are highly dependent on the number of tourists and visitors to an area to be as effective as possible. The estimation of this number is not always easy to achieve, since there is a lack of the corresponding data (i.e., number of visitors per day). Hence, this estimation must be achieved by utilizing alternative data sources. To this end, in this paper, the authors propose a neural network architecture that is trained on waste management data to estimate the number of visitors and tourists in the highly touristic municipality of Vari-Voula-Vouliagmeni, Greece. Full article

The sustainable management of Municipal Solid Waste (MSW) relies heavily on community participation in separating it at the source and delivering it to collection systems. These practices are crucial for reducing pollution, protecting ecosystems, and maximizing resource recovery. However, in the Global South context, with conditions of socioeconomic vulnerability, community participation in the sustainable management of MSW remains limited, highlighting the need to generate context-specific interventions. MSW includes items such as household appliances, batteries, and electronic devices, which require specialized handling due to their size, hazardous components, or material complexity. This study implemented a Community-Based Social Marketing approach during the research and design phases of an intervention focused on promoting source separation and management of hard-to-manage MSW in five municipalities within the administrative region of Norte de Santander (Colombia), which borders Venezuela. Using a mixed-methods approach, we collected data from 1775 individuals (63.83% women; M _age = 33.48 years; SD = 17.25), employing social mapping, focus groups, semi-structured interviews, participant observation, and a survey questionnaire. The results show that the source separation and delivery of hard-to-manage MSW to collection systems are limited by a set of psychosocial, structural, and institutional barriers that interact with each other, affecting communities’ willingness and capacity for action. Furthermore, a prediction model of willingness to engage in separation and delivery behaviors showed a good fit (R2 = 0.83). The strongest predictors were awareness of the negative consequences of non-participation and perceived environmental benefits, with subjective norms contributing to a lesser extent. Based on these results, we designed a context-specific intervention focused on reducing these barriers and promoting community engagement in the sustainable management of hard-to-manage MSW. Full article

The aim of the article is to highlight the increasing environmental burden on aquatic ecosystems in Slovakia due to continuous pollution from municipal, industrial and agricultural sources. Laboratory analyses have shown alarming exceedance of the limit values of contaminants, with nitrate nitrogen (NO₃⁻) reaching 5.8 mg/L compared to the set limit of 2.5 mg/L and phosphorus concentrations exceeding the permissible values by a factor of five, thereby escalating the risk of eutrophication and loss of ecological stability of the aquatic ecosystem. The accumulation of heavy metals is also a problem—lead (Pb) concentrations reach up to 9.7 μg/L, which exceeds the safe limit by a factor of ten. Despite the measures implemented, such as scum barriers, there is continuous contamination of the aquatic environment, with illegal waste dumps and uncontrolled runoff of agrochemicals playing a significant role. The research results underline the critical need for a more effective environmental policy and more rigorous monitoring of toxic substances in real time. These findings highlight not only the urgency of more effective environmental policy and stricter real-time monitoring of toxic substances, but also the necessity of integrating environmental logistics into the design of sustainable solutions. Logistical approaches including the optimization of waste collection, coordination of stakeholders and creation of infrastructural conditions can significantly contribute to reducing environmental burdens and ensure the continuity of environmental management in ecologically sensitive areas. Full article

Automated waste classification is an essential step toward efficient recycling and waste management. Traditional deep learning models, such as convolutional neural networks, rely on extensive labeled datasets to achieve high accuracy. However, the annotation process is labor-intensive and time-consuming, limiting the scalability of these approaches in real-world applications. Zero-shot learning is a machine learning paradigm that enables a model to recognize and classify objects it has never seen during training by leveraging semantic relationships and external knowledge sources. In this study, we investigate the potential of zero-shot learning for waste classification using two vision-language models: OWL-ViT and OpenCLIP. These models can classify waste without direct exposure to labeled examples by leveraging textual prompts. We apply this approach to the TrashNet dataset, which consists of images of municipal solid waste organized into six distinct categories: cardboard, glass, metal, paper, plastic, and trash. Our experimental results yield an average classification accuracy of 76.30% with Open Clip ViT-L/14-336 model, demonstrating the feasibility of zero-shot learning for waste classification while highlighting challenges in prompt sensitivity and class imbalance. Despite lower accuracy than CNN- and ViT-based classification models, zero-shot learning offers scalability and adaptability by enabling the classification of novel waste categories without retraining. This study underscores the potential of zero-shot learning in automated recycling systems, paving the way for more efficient, scalable, and annotation-free waste classification methodologies. Full article

The co-disposal of municipal solid waste incineration fly ash (MSWI-FA) in cement kilns is an effective method for managing incineration by-products in China. However, the presence of heavy metals in MSWI-FA raises environmental concerns. This study analyzed the Cu, Zn, Cd, Pb, Cr, and Ni concentrations in MSWI-FA from 11 representative facilities across China and assessed the efficacy of a three-stage water washing process for Cl and heavy metal removal. The results revealed significant regional variations in heavy metal content that were strongly correlated with surface soil levels, with Zn, Pb, and Cu exhibiting the highest concentrations. Elemental correlations, such as Cu-Pb and Zn-Cd synergies and Cd-Ni antagonism, suggest common waste sources and temperature-dependent volatilization during incineration. The washing process (solid–liquid ratio = 1:10) achieved 97.1 ± 2.0% Cl removal, reducing residual Cl to 0.45 ± 0.32%, but demonstrated limited heavy metal elimination (10.28–19.38% efficiency), resulting in elevated concentrations (32.5–60.8% increase) due to 43.4 ± 9.2% mass loss. Notably, the washing effluents exceeded municipal wastewater discharge limits by up to 52-fold for Pb and 38-fold for Cd, underscoring the need for advanced effluent treatment. To mitigate environmental risks, the addition of washed MSWI-FA in cement kilns should be restricted to ≤0.5%, with Cd content prioritized in pre-disposal assessments. This study provides actionable insights for optimizing MSWI-FA co-processing while ensuring compliance with ecological safety standards. Full article

The accelerated industrialization in China has precipitated a dramatic surge in solid waste generation, causing severe land resource depletion and posing substantial environmental contamination risks. Simultaneously, the cement industry has become characterized by the intensive consumption of natural resources and high carbon emissions. This review aims to investigate the current technological advances in utilizing industrial solid waste for cement production, with a focus on promoting resource recycling, phase transformations during hydration, and environmental management. The feasibility of incorporating coal-based solid waste, metallurgical slags, tailings, industrial byproduct gypsum, and municipal solid waste incineration into active mixed material for cement is discussed. This waste is utilized by replacing conventional raw materials or serving as active mixed material due to their content of oxygenated salt minerals and oxide minerals. The results indicate that the formation of hydration products can be increased, the mechanical strength of cement can be improved, and a notable reduction in CO₂ emissions can be achieved through the appropriate selection and proportioning of mineral components in industrial solid waste. Further research is recommended to explore the synergistic effects of multi-waste combinations and to develop economically efficient pretreatment methods, with an emphasis on balancing the strength, durability, and environmental performance of cement. This study provides practical insights into the environmentally friendly and efficient recycling of industrial solid waste and supports the realization of carbon peak and carbon neutrality goals. Full article

The modern world has brought extensive socioeconomic and ecological changes. Urbanization in developing nations has significantly increased municipal solid waste, necessitating in-depth understanding of waste composition particularly in developing nations for sustainable management practices. This study aimed to classify and characterize waste while evaluating potential waste management methods. Mixed methods were used to examine landfilled waste from Soshanguve and Hatherley sites in Tshwane Metropolitan, South Africa, using techniques such as Fourier transform infrared spectroscopy, X-ray fluorescence, proximate, and ultimate analysis. Seasonal variations in waste components were analysed over two seasons. The study identified that both sites are predominantly composed of organic waste, accounting for over 42 wt.%, with moisture content of ~50 wt.%, and minimal recyclables (<5 wt.%). Seasonal variations in MSW were significant for glass (<4% increase), organic waste (<5% increase), while plastic decreased by ~7% during spring. The biodegradable waste showed high carbon (>50%) and oxygen (>40%) levels, low ash content (<18%), and calorific values of 15–19 MJ/kg. Biodegradables mainly contained oxides of calcium, silicon, iron (III), and potassium with chemical composition indicating functional groups that emphasize composting and energy recovery benefits. The research provides insights into sustainable waste management, revealing waste composition at Tshwane landfills, aiding informed decision-making for resource usage and environmental conservation. Full article