Search Results (209)

Efficient plastic waste end-of-life management is a serious worldwide environmental issue motivated by growing waste production and negative effects of wrongful disposal. This study presents a comparative overview of plastic waste management regimes within the European Union (EU), the United States of America (USA), and Romania, ranked with circular economy goals. By using the United States Environmental Protection Agency (US EPA) Waste Reduction Model (WARM), version 16, the study provides a quantified score to greenhouse gas (GHG) emissions within three large options of management: recycling, energy recovery through combustion, and landfilling. The model setup utilizes region-specific information on legislation, base technology, and recycling efficiency. The outcomes show that recycling always entails net GHG emissions reductions, i.e., −4.49 kg CO_2e/capita/year for EU plastic waste and −20 kg CO_2e/capita/year for USA plastic waste. Combustion and landfilling have positive net emissions from 1.76 to 14.24 kg CO_2e/capita/year. Economic indicators derived from the model also show significant variation: salaries for PET management amounted to USD 2.87 billion in the EU and USD 377 million in the USA, and tax collection was USD 506 million and USD 2.01 billion, respectively. The conclusions highlight the wider environmental and socioeconomic benefits of recycling and reinforce its status as a cornerstone of circular-economy sustainable plastic waste management and a strategic element of national development agendas, with special reference to Romania’s national agenda. Full article

Despite the well-documented health risks of noise pollution, its impact remains overlooked mainly in life cycle assessment (LCA). This study introduces a methodological innovation by integrating both traffic and construction noise into the LCA framework for concrete construction, providing a more holistic and realistic evaluation of environmental and health impacts. By combining building information modeling (BIM) with LCA, the method automates material quantification and assesses both environmental and noise-related health burdens. A key advancement is the inclusion of health-based indicators, such as annoyance and sleep disturbance, quantified through disability-adjusted life years (DALYs). Two scenarios are examined: (1) a comparative analysis of concrete versus timber flooring and (2) end-of-life options (reuse vs. landfill). The results reveal that concrete has up to 7.4 times greater environmental impact than timber, except in land use. When noise is included, its contribution ranges from 7–33% in low-density regions (Darwin) and 62–92% in high-density areas (NSW), underscoring the critical role of local context. Traffic noise emerged as the dominant source, while equipment-related noise was minimal (0.3–1.5% of total DALYs). Timber slightly reduced annoyance but showed similar sleep disturbance levels. Material reuse reduced midpoint environmental impacts by 67–99.78%. Sensitivity analysis confirmed that mitigation measures like double glazing can cut noise-related impacts by 2–10% in low-density settings and 31–45% in high-density settings, validating the robustness of this framework. Overall, this study establishes a foundation for integrating noise into LCA, supporting sustainable material choices, environmentally responsible construction, and health-centered policymaking, particularly in noise-sensitive urban development. 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

The increasing volume of global waste presents a critical environmental and societal challenge, demanding innovative solutions to support sustainable practices such as recycling. Advances in Computer Vision (CV) have enabled automated waste recognition systems that guide users in correctly sorting their waste, with state-of-the-art architectures achieving high accuracy. More recently, attention has shifted toward lightweight and efficient models suitable for mobile and edge deployment. These systems process data from integrated camera sensors in Internet of Things (IoT) devices, operating in real time to classify waste at the point of disposal, whether embedded in smart bins, mobile applications, or assistive tools for household use. In this work, we extend our previous research by improving both dataset diversity and model efficiency. We introduce an expanded dataset that includes an organic waste class and more heterogeneous images, and evaluate a range of quantized CNN models to reduce inference time and resource usage. Additionally, we explore ensemble strategies using aggregation functions to boost classification performance, and validate selected models on real embedded hardware and under simulated lighting variations. Our results support the development of robust, real-time recycling assistants for resource-constrained devices. We also propose architectural deployment scenarios for smart containers, and cloud-assisted solutions. By improving waste sorting accuracy, these systems can help reduce landfill use, support citizen engagement through real-time feedback, increase material recovery, support data-informed environmental decision making, and ease operational challenges for recycling facilities caused by misclassified materials. Ultimately, this contributes to circular economy objectives and advances the broader field of environmental intelligence. Full article

Textile recycling approaches require input material streams of defined purity. Establishing sorting facilities and defining viable sorting fractions for efficient subsequent recycling necessitates knowledge on the composition and material content of the textiles to be processed. Subsequently, this information is crucial for the implementation of a sustainable circular economy for textiles. This study presents the results of a comprehensive waste textile sampling and characterisation along with data on the quantities and composition of waste textiles in Vienna in 2022. The data reveals that only 28% of the 19,975 t of waste textiles generated end up in separate collection, of which a significant amount goes to the international market. However, the results regarding the fibre composition show that textiles from mixed municipal solid waste and separate collection are very similar. Cotton fibres accounted for approx. half of the fibre mass from non-complex textiles, with 9328 t overall (6776 t in the mixed municipal solid waste and 2522 t in separate collection). A further analysis regarding fibre blends found that a total of 6275 t of single-fibre materials and 5132 t of two-fibre materials were present. This reveals great potential for using this waste stream in fibre-to-fibre recycling processes. Collecting accurate data on this waste stream enables sorters and recyclers to tailor their processes to the expected input material. By increasing the amount of recycled materials, the share of incinerated or landfilled textiles will decrease, which in turn will have a positive impact on the environment. However, further research in textile identification and material separation as well as regulations to keep these materials in a sustainable closed loop are required. Full article

Food waste is a significant global issue with substantial environmental, economic, and social implications. This exploratory study aimed to evaluate the impact of an educational composting program on reducing food waste generation and promoting proper waste sorting practices within multi-family housing units in San Marcos, Texas. A comprehensive methodology was employed, encompassing pre- and post-intervention waste audits, educational interventions, weekly organic waste collection, and quantitative data analyses. Nine multi-family complexes, spanning student housing, conventional family units, low-income residences, and senior living facilities, were targeted through strategic recruitment efforts and incentivization. The treatment group, consisting of 43 participants, received ongoing education throughout the eight-week implementation period, facilitated through informational resources, feedback mechanisms, and door-to-door organic waste collection. Conversely, the control group did not partake in the educational component. Statistical analyses, including descriptive statistics and paired t-tests, facilitated comparisons across various dimensions, such as housing types, treatment versus control groups, and pre- versus post-intervention periods. The findings revealed significant reductions in organic waste and compostable materials within the treatment group’s weekly landfill trash, underscoring the effectiveness of the educational program. Furthermore, insights into contamination patterns and housing-specific waste characteristics were garnered, informing targeted intervention strategies and policy recommendations for optimizing multi-family composting initiatives. Full article

Monitoring the amount of waste in open landfill sites in developing countries is important from the perspective of building a sustainable society and protecting the environment. Some landfill sites provide information on the amount of waste in reports and news articles; however, in many cases, the survey methods, timing, and accuracy are uncertain, and there are many sites for which this information is not available. In this context, monitoring the amount of waste using satellite data is extremely useful from the perspective of uniformity, objectivity, low cost, safety, wide coverage area, and simultaneity. In this study, we developed a method for calculating the relative volume of waste at 15 landfill sites in six developing countries using time-series digital surface model (DSM) data from the satellite optical sensor, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), which has accumulated more than 20 years of observational data. Unnecessary variations between images were reduced by bias correction based on a reference area around the site. In addition, by utilizing various reported values, we introduced a method for converting relative volume to absolute volume and converting volume to weight, enabling a direct comparison with reported values. We also evaluated our method compared with the existing method for calculating changes in waste volume based on TanDEM-X DEM Change Map (DCM) products. The findings of this study demonstrated the efficacy of the employed method in capturing changes, such as increases and stagnation, in the amount of waste deposited. The method was found to be relatively consistent with reported values and those obtained using the DCM, though a decrease in accuracy was observed due to the depositional environment and the absence of data. The results of this study are expected to be used in the future for technology that combines an optical sensor and synthetic aperture radar (SAR) to monitor the amount of waste. Full article

Approximately 2.5 billion tons of waste are generated annually worldwide, with food waste constituting a significant portion: 88 million tons in the European Union (EU) alone. Food waste has severe societal, economic, and environmental consequences, contributing 15–16% of greenhouse gas (GHG) emissions from the food supply chain. In response, many countries, including EU member states, the United States of America (USA), and China, have introduced policies mandating food waste sorting. These regulations are informed by scientific research on waste prevention, environmental impact assessments, and cost–benefit analyses of waste reduction strategies. For example, studies on organic waste treatment technologies, economic incentives for waste sorting, and the effectiveness of landfill bans have influenced the development of the EU Waste Framework Directive (2008/98/EC), China’s National Waste Classification Policy (2017), and the USA Food Recovery Act (2015). As waste management continues to evolve, understanding the economic, technological, and policy dimensions of food waste sorting remains crucial for achieving sustainable development and circular economy goals globally. This study systematically reviews the international literature on food waste sorting, analyzing sorting behaviors and identifying theoretical frameworks that explain these behaviors. Using the PSALSAR systematic review methodology, 67 relevant studies from diverse geographic regions were analyzed. The findings highlight the critical influence of external factors in shaping sorting behaviors, such as financial incentives and infrastructure, alongside internal drivers, such as environmental awareness and social norms. While external measures often yield immediate compliance, internal motivation fosters long-term behavioral changes. Moreover, significant regional and cultural variations in food waste sorting practices were identified. The Theory of Planned Behavior (TPB) emerged as a dominant framework in the study of waste sorting behaviors, often complemented by other models such as Social Cognitive Theory (SCT). Policy recommendations emphasize the need for tailored interventions that address regional and demographic differences, community-driven educational initiatives, and the integration of innovative waste sorting technologies. Future research should focus on assessing the economic and psychological impacts of waste sorting policies across different socio-cultural contexts and exploring innovative strategies to enhance global public participation in food waste management. Full article

The rapid increase in construction and demolition waste (C&DW) has emerged as a significant environmental challenge, particularly due to the hazardous substances embodied within the fine residues destined into landfills. The disposal of C&DW in landfills has been widely recognized as a source of leachate, containing toxic contaminants, which pose significant environmental risks. A controlled column leaching experiment was conducted using samples with varying proportions of C&DW, gypsum, and organic content to assess their impact on leachate chemistry. The results indicate that higher C&DW content leads to increased concentrations of heavy metals, such as Pb, Hg, As, Cr, Ni, Cu, Zn, and Co, as well as other metals like Al and Fe, with peak contamination occurring within the first 13–15 weeks. Gypsum presence exacerbates heavy metal solubility by reducing pH, increasing sulfate levels, and promoting metal-sulfate complex formation. Despite remaining within regulatory thresholds, the cumulative concentration of toxic metals over time highlights potential environmental risks, particularly in landfill settings. This study underscores the need for improved C&DW management practices, enhanced waste segregation, and sustainable alternatives to gypsum to mitigate long-term ecological impacts. These findings contribute to a deeper understanding of C&DW leachate dynamics and inform policy recommendations for sustainable waste management in the construction sector. Full article

The occurrence of illegal waste activities is a worldwide problem, due to improper actions and inadequate services across many territories. Geographical Information Systems (GISs) software plays a crucial role in optimizing waste management and determining the shortest route paths for waste transportation. This work focuses on the development of a GIS-based workflow for the detection of Illegal Abandoned Waste Sites (IAWSs) and waste management planning. The integration of remote/ground sensing activities, geospatial data, and models within a GIS framework is a useful practice for conducting cost analysis and supporting the development of efficient waste management plans. Firstly, available satellite images are employed in a baseline assessment, combining ancillary and remote sensing data. As a result of satellite monitoring, a ground-piloted survey is carried out by checking the potential-IAWSs density map retrieved from the satellite pre-recognition phase. Hence, a total of 171 ground points are geo-localized and spatialized, according to qualitative on-site products and 2.5D volume analysis. Consequently, distances from illegal dumping sites to proper disposal plants are calculated, achieving the shortest route paths as geospatial information. From these data, a Functional Unit (FU) of 1 ton of mixed waste plus 381.6 kg of inert material is determined, a fundamental stage for comparing different cost analysis processes in similar contexts. By using a GIS-based workflow, a cost analysis assessment is provided, aiming to support principal activities such as waste transportation and disposal to the proper plant (e.g., landfill or incineration). In conclusion, spatial data analysis results are fundamental in managing illegal abandoned waste sites, helping to establish a cost analysis assessment. Full article

Methane is a powerful greenhouse gas and short-lived climate pollutant generated in landfills. In this work, five first-order decay models were implemented to estimate the methane emissions from a landfill near Oaxaca city. The five models were the simple first-order decay model, the modified first-order decay model, the multiphase model, the LandGem model, and the Intergovernmental Panel on Climate Change (IPCC) model. An autoregressive integrated moving average (ARIMA) model was built to predict waste generation, and a gravimetric method was used to estimate the volume of stored waste. The ARIMA model correctly predicted the generation of municipal solid waste, calculating 108,202 tons of solid waste in the landfill for the year 2022. In terms of the models and considering the experimental data measured in 2020, the simple model and the simple modified model were more accurate, with 3.50 × 10⁶ m³ (relative error = 1.0) and 3.76 × 10⁶ m³ of methane (relative error = 6.3), respectively. The multiphase model calculated a value of 3.09 × 10⁶ m³ of methane (relative error = 12.6), the LandGEM model calculated a value of 4.97 × 10⁶ m³ (40.7), and the IPCC model calculated a value of 3.19 × 10⁶ m³ (relative error = 9.7). The LandGEM model was improved when the standard values proposed by the Environmental Protection Agency (EPA) were considered. According to the simple model and the simple modified model, by 2050, the landfill will emit 1.22 × 10⁶ m³ and 1.37 × 10⁶ m³, demonstrating that important methane emissions will be released in the decades to come. This information is important for the implementation of methane mitigation strategies, to which Mexico has committed in the Global Methane Initiative. Full article

The quantity of construction demolition waste (CDW) has been increasing due to the demolition of many old buildings throughout the world. So far, all the statistics indicate that there is a very large generation of CDW, which increases annually. The increasing amount CDW in landfills will cause a scarcity of landfill space and will also increase pollution and cost due to transportation. Recycled brick aggregate concrete (RBAC) incorporating polystyrene (EPS) aggregate beads has emerged as an alternative lightweight material with numerous obvious sustainable benefits, suitable for a future circular economy. The goal of this paper is to assess the feasibility of obtaining lightweight aggregate concrete of structural grade with recycled brick aggregate (RBA) as a coarse aggregate and the incorporation of polystyrene beads in a certain percentage by conducting an experimental study on the dry and apparent density, compressive strength, split-tensile strength and elasticity modulus. In addition, the effects of the w/c ratio and cement content on these properties were studied to provide useful information for the performance optimization of this concrete with RBA and polystyrene (EPS) beads. The properties were investigated for two cement contents, 400 and 360 kg/m³, and two ratios between water and cement, 0.43 and 0.39, respectively. The RBAC mixtures containing EPS beads in 15%, 25% and 35% replacement percentages were evaluated through a comprehensive test program based on the European standards. The results showed that, in general, the use of polystyrene (EPS) beads decreased the mechanical properties of the recycled brick aggregate concrete; however, the outcome indicates the potential for producing lightweight concrete of different grades, including structural classes. It was found that the developed lightweight concrete presents a uniform distribution of the polystyrene granules in the hardened volume of concrete. Also, it was found that the recycled brick aggregate with a 16 mm maximum size did not negatively influence the uniform distribution of the EPS beads, avoiding concentrations of beads. With the increase in the percentage of EPS beads, the properties of the recycled brick aggregate concrete were found to be less sensitive to the water-to-cement ratio. Full article

Solid waste management in Jordan is still following a linear model, where more than 90% of solid waste, including organic waste, is collected and disposed into landfills. Such practices are not sustainable and may lead to adverse public health and environmental impacts. Therefore, there is a pressing need to look for alternative organic waste management by adopting circular economy principles through which the adverse impacts are minimized and the benefits from the resources are maximized. The main objective of this study is to select the appropriate treatment technology for organic solid waste management in Jordan. To achieve this objective, an analytical hierarchy process was used as a decision making tool. A hierarchy model that consists of four levels was employed with 3 main criteria and 10 sub-criteria to assess 4 alternatives of organic waste treatment. Based on the experts’ opinions and the pairwise comparison, the AHP model results showed that the environmental and public health criterion is the most important. On the other hand, the most sustainable treatment option of the organic waste treatment is composting with a weight of 0.373, followed by landfilling with a weight of 0.203. Anaerobic digestion ranked third as an alternative, with a weight of 0.201, while the least-preferred treatment technology was found to be the mechanical biological treatment, with a weight of 0.193. Sensitivity analysis based on varying the main criteria weights under different scenarios showed the robustness of the AHP model, where composting continued to be the first ranked under most of the considered scenarios. Since the national solid waste management strategy is currently subject to review, the findings of the current study provide a valuable information for the decision makers in Jordan to update their strategic plans and move towards a circular economy option. Full article

Waste is a complex challenge that requires collaboration between multiple stakeholders to achieve a circular economy. In this context, there is a growing demand for digital solutions that integrate physical and digital infrastructure to create digital waste governance systems. Analog management, without accurate data, is becoming increasingly unfeasible in light of the UN Sustainable Development Goals. Tools such as online geographic information systems (WebGIS) allow the collection and integration of large volumes of physical and human data and the establishment of a digital governance structure that brings together different technologies, tools and methods in the same environment. This article aims to present the State of the Art on the topics of zero-waste cities, WebGIS, and disruptive innovation. The article starts from the hypothesis that only a process of disruptive and systemic innovation in the value chain and urban solid waste management (MSWMS), supported by the principle of zero-waste cities, circular economy and webGIS, can effectively help to solve this problem. The research uses an exploratory literature review on the concepts of zero-waste cities, systemic innovation and webGIS applied to waste management, linking them to the theoretical framework of sustainability as a science and to Brazilian public policies, such as the National Solid Waste Policy (Law 12.305/2010), the National Circular Economy Policy (Law 1.874/2022) and the National Digital Government Strategy of Brazil 2024–2027 (ENGD). As a result, scientific publications on zero-waste cities increased from 2018 to 2023 and several countries have adopted zero-waste guidelines in waste management policies. WebGIS, remote sensing, geoprocessing and different technologies are increasingly being incorporated into waste management, generating significant impacts on the diversion of resources from landfills, mitigating climate change, and generating and/or adding value to the useful life of waste and garbage resources, in addition to the optimization and efficiency of collection operators and citizen engagement in public policies. Disruptive innovation has proven to be a concrete process to enable the transition from obsolete sociotechnical systems (such as the linear economy), where sustainable finance and environmental entities play a fundamental role in orchestrating and coordinating the convergence of private, public and civil society actors towards this new sustainable development paradigm. The case study proved to be fruitful in proposing and encouraging the adoption of such methods and principles in municipal waste management, allowing us to outline a first conception of a digital government structure and digitalization of public services for zero-waste cities, as well as pointing out the difficulties of implementing and transforming these systems. This digital governance structure demonstrates the possibility of being replicable and scalable to other cities around the world, which can materialize an important tool for the implementation, articulation and development of a long-term sustainable development paradigm, based on the vision of the circular economy and zero-waste cities. Full article

Plastic pollution is one of the biggest current global threats to the environment given that petroleum-based plastic is recalcitrant and can stay in the environment for decades, even centuries, depending on the specific plastic type. Since less than 10% of all plastic made is recycled, and the other solutions (such as incineration or landfill storage) are pollutant methods, new, environmentally friendly solutions are needed. In this regard, the latest biotechnological discovery on this topic is the capability of insect larvae to use plastic polymers as carbon feedstock. This present review describes the most relevant information on the insect larvae capable of degrading plastic, mainly Galleria mellonella (Fabricius, 1798), Tenebrio molitor (Linnaeus, 1758), and Zophobas atratus (Fabricius, 1776), and also adds new information about other less commonly studied “plastivore” insects such as termites. This review covers the literature from the very first work describing plastic degradation by larvae published in 2014 all the way to the very latest research available (till June 2024), focusing on the identification of a wide variety of plastic-degrading microorganisms isolated from larvae guts and on the understanding of the potential molecular mechanisms present for degradation to take place. It also describes the latest discoveries, which include the identification of novel enzymes from waxworm saliva. Full article