Search Results (495)

Background: this research presents an integrated approach to enhancing the sustainability of plastic bag supply chains in Indonesia by addressing critical issues related to ineffective post-consumer waste management and low recycling rates. The objective of this study is to develop a combined framework of material flow analysis (MFA) and sustainable supply chain planning to improve demand forecasting and inflow management across the plastic bag lifecycle. Method: the research adopts a quantitative method using the XGBoost algorithm for forecasting and is supported by a polymer-based MFA framework that maps material flows from production to end-of-life stages. Result: the findings indicate that while production processes achieve high efficiency with a yield of 89%, more than 60% of plastic bag waste remains unmanaged after use. Moreover, scenario analysis demonstrates that single interventions are insufficient to achieve circularity targets, whereas integrated strategies (e.g., reducing export volumes, enhancing waste collection, and improving recycling performance) are more effective in increasing recycling rates beyond 35%. Additionally, the study reveals that increasing domestic recycling capacity and minimizing dependency on exports can significantly reduce environmental leakage and strengthen local waste management systems. Conclusions: the study’s novelty lies in demonstrating how machine learning and material flow data can be synergized to inform circular supply chain decisions and regulatory planning. Full article

Background: Gold mining is a critical part of the industry of Central Asia, contributing significantly to regional economic growth. However, gold production management faces numerous challenges, including adopting innovative technologies such as AI, using improved logistical equipment, resolving supply chain inefficiencies and disruptions, and incorporating modernized waste management and advancements in gold bar processing technologies. This study explores how advanced technologies and improved logistical processes can enhance efficiency and sustainability. Method: This paper examines gold production processes in Kyrgyzstan, a gold-producing country in Central Asia. The case study approach combines qualitative interviews with industry stakeholders and a system dynamics (SD) simulation model to compare current operations with a technology-based scenario. Results: The simulation model shows improved outcomes when innovative technologies are applied to ore processing, waste refinement, and gold bar production. The results also indicate an approximate twenty-five percent reduction in transport time, a thirty percent decrease in equipment downtime, a thirty percent reduction in emissions, and a fifteen percent increase in gold extraction when using artificial intelligence, smart logistics, and regional smelting. Conclusions: The study concludes with recommendations to modernize equipment, localize processing, and invest in digital logistics to support sustainable mining and improve operational performance in Kyrgyzstan’s gold sector. Full article

Due to increasing environmental concerns and the constant development of the bottling industry, research into the environmental impact of beverage packaging processes is crucial. The aim of this article is to determine the environmental impact, in selected aspects, of automated beverage bottling and packaging processes using life cycle analysis (LCA). The analysis covers key process stages, such as filling, packaging and internal transport, in the context of raw material consumption, but also energy and waste generation. This work focuses primarily on the impact of changing the raw material used for bottle and shrink film production on the environmental impact of the studied technical facility within the adopted system boundaries and on analyzing scenarios for the management of these post-consumer materials. This research has shown that the stage associated with the greatest negative environmental impact is the shrinking of the film around the bottles. Furthermore, it has been demonstrated that recycling plastic film and bottle waste is a more environmentally friendly solution than landfill disposal. The analysis shows that using recycled materials in the tested production line allows for the reduction of harmful emissions and a reduction in the overall environmental footprint of the tested system. Full article

Sewage sludge, characterized by its high organic matter and nutrient content, as well as the presence of microbial pathogens and other contaminants, requires proper management due to its significant generation rate. The table olive sector, which is highly significant in Spain as a global leader in production and export, generates various waste streams such the Organic Solid By-Products from Table Olive Processing (OSBTOP), which are mainly derived from the olive pit after the pitting process. The main aim of this study was to enhance the methane production performance of sewage sludge through co-digestion with OSBTOP as a co-substrate. Batch assays demonstrated that employing OSBTOP as a co-substrate increased methane content by 35–41% across all tested mixtures. While the highest methane yield was produced at a 40:60 (sludge:OSBTOP) ratio, a 60:40 mixture proved to be a more advantageous option for scale-up and practical application. This is attributed to factors such as the higher availability of sludge and its inherent buffering capacity, which counteracts the accumulation of volatile fatty acids and promotes process stability, thereby contributing to the study’s objective of significantly enhancing methane production from sewage sludge through co-digestion. In semi-continuous operation, methane yields in the co-digestion scenario exceeded those of mixed sludge digestion, showing a yield of 180 versus 120 LCH₄⁻¹ · kgVS_added⁻¹, representing a 50% improvement. This study highlights the potential of anaerobic digestion as a strategy for valorizing OSBTOP, a by-product with no prior studies, while demonstrating that its co-digestion with sewage sludge enhances methane generation, offering a sustainable approach to organic waste treatment. Full article

Italy strives to meet its renewable energy targets for 2030 and 2050, with photovoltaic (PV) technology playing a central role. However, the push for increased solar adoption, spurred by past incentive schemes such as “Conto Energia” and “Superbonus 110%”, raises long-term challenges related to PV waste management. In this study, we present a multi-scale approach to forecast End-of-Life (EoL) PV waste across Italy’s 20 regions, aiming to support national circular economy strategies. Historical installation data (2008–2024) were collected and combined with socio-economic and energy-related indicators to train a Backpropagation Neural Network (BPNN) for regional PV capacity forecasting up to 2050. Each model was optimised and validated using R² and RMSE metrics. The projections indicate that current trends fall short of meeting Italy’s decarbonisation targets. Subsequently, by applying a Weibull reliability function under two distinct scenarios (Early-loss and Regular-loss), we estimated the annual and regional distribution of PV panels reaching their EoL. This analysis provides spatially explicit insights into future PV waste flows, essential for planning regional recycling infrastructures and ensuring sustainable energy transitions. Full article

This paper proposes a ladder carbon trading-based low-carbon economic dispatch model for integrated energy systems (IESs), incorporating flexible load optimization and hybrid energy storage systems consisting of battery and thermal energy storage. First, a ladder-type carbon trading mechanism is introduced, in which the carbon trading cost increases progressively with emission levels, thereby providing stronger incentives for emission reduction. Second, flexible loads are categorized and modeled as shiftable, transferable, and reducible types, each with distinct operational constraints and compensation mechanisms. Third, both battery and thermal energy storage systems are considered to improve system flexibility by storing excess energy and supplying it when needed. Finally, a unified optimization framework is developed to coordinate the dispatch of renewable generation, gas turbines, waste heat recovery units, and multi-energy storage devices while integrating flexible load flexibility. The objective is to minimize the total system cost, which includes energy procurement, carbon trading expenditures, and demand response compensation. Three comparative case studies are conducted to evaluate system performance under different operational configurations: the proposed comprehensive model, a carbon trading-only approach, and a conventional baseline scenario. Results demonstrate that the proposed framework effectively balances economic and environmental objectives through coordinated demand-side management, hybrid storage utilization, and the ladder-type carbon trading market mechanism. It reshapes the system load profile via peak shaving and valley filling, improves renewable energy integration, and enhances overall system efficiency. Full article

This paper presents an integrated Smart City platform that combines digital twin technology, advanced machine learning, and a private blockchain network to enhance data-driven decision making and operational efficiency in both public enterprises and small and medium-sized enterprises (SMEs). The proposed cloud-based business intelligence model automates Extract, Transform, Load (ETL) processes, enables real-time analytics, and secures data integrity and transparency through blockchain-enabled audit trails. By implementing the proposed solution, Smart City and public service providers can significantly improve operational efficiency, including a 15% reduction in costs and a 12% decrease in fuel consumption for waste management, as well as increased citizen engagement and transparency in Smart City governance. The digital twin component facilitated scenario simulations and proactive resource management, while the participatory governance module empowered citizens through transparent, immutable records of proposals and voting. This study also discusses technical, organizational, and regulatory challenges, such as data integration, scalability, and privacy compliance. The results indicate that the proposed approach offers a scalable and sustainable model for Smart City transformation, fostering citizen trust, regulatory compliance, and measurable environmental and social benefits. Full article

EU accession countries, including the Republic of Serbia, are under growing pressure to align their plastic waste management systems with EU environmental directives. Despite this, significant challenges remain, including inadequate infrastructure, a limited recycling capacity, and weak enforcement mechanisms. This study employs life cycle assessment (LCA) to evaluate the environmental impacts of polyethylene terephthalate (PET) packaging waste in Serbia, focusing on three end-of-life scenarios (EoL): landfilling, recycling, and incineration. Using GaBi Professional v6.0 software and the ReCiPe 2016 methodology, the results indicate that mismanaged PET waste contributes notably to terrestrial ecotoxicity (3.69 kg 1.4-DB eq.) and human toxicity (non-cancer) (2.36 kg 1.4-DB eq.). In 2023, 14,967.8 tons of PET were collected by authorized operators; however, unreported quantities likely end up in landfills or the natural environment. Beyond the quantified LCA results, this study highlights microplastic pollution as an emerging environmental concern. It advocates for the development of Serbia-specific characterization factors (CFs) for PET microplastics, incorporating localized fate, exposure, and effect data. Tailored CFs would enhance the precision of impact assessments for Serbian terrestrial ecosystems, contributing to more effective, evidence-based environmental policies. These insights are crucial for supporting Serbia’s transition to sustainable waste management and for meeting EU environmental standards. Full article

Urban growth has intensified the generation of solid waste, particularly in densely populated and vulnerable neighborhoods, leading to environmental degradation and public health risks. This study presents a multidisciplinary methodology to estimate the mass of macroplastic litter mobilized from urban surfaces into nearby watercourses during storm events. Focusing on the Villa Páez neighborhood in Cordoba, Argentina—a data-scarce and flood-prone urban basin—the approach integrates socio-environmental surveys, field observations, Google Street View analysis, and hydrologic modeling using EPA SWMM 5.2. Macroplastic accumulation on streets was estimated based on observed waste density, and its transport under varying garbage collection intervals and rainfall intensities was simulated using a conceptual pollutant model. Results indicate that plastic mobilization increases substantially with storm intensity and accumulation duration, with the majority of macroplastic mass transported during high-return-period rainfall events. The study highlights the need for frequent waste collection, improved monitoring in vulnerable urban areas, and scenario-based modeling tools to support more effective waste and stormwater management. Full article

Food waste management is a major global issue, and alternative protein sources like insect farming offer a sustainable solution. This study investigated the environmental impacts of black soldier fly larvae (BSFL) production using a Life Cycle Assessment (LCA), evaluating its role in both protein production and food waste treatment. The assessment considered three functional units: FU₁ (1 kg of dried larvae), FU₂ (per kg of protein), and FU₃ (treatment of 1 ton of food waste). The results indicate that larvae rearing is the largest contributor to emissions in FU₁ (46% of 18.51 kg CO₂ eq). In FU₂, BSFL protein shows a higher climate impact (49.41 kg CO₂ eq) than fishmeal or soybean meal but requires significantly less land. FU₃ demonstrates that BSFL-based composting can achieve net negative emissions (~−24.8 kg CO₂ eq), outperforming conventional waste treatment. An optimized scenario (Scenario A) shows marked improvements across all units compared to a Business-as-Usual case, including a 79% reduction in FU₁ emissions and a 577% increase in FU₃ carbon savings. These findings underline the environmental advantages of BSFL systems, especially in Singapore, and support their potential as sustainable alternatives for protein production and food waste management. Full article

To ensure the green, safe, and efficient extraction of mineral resources and promote sustainability, the stability of mined-out areas has become a critical factor affecting safe production and ecological restoration in underground metal mines. The instability of underground goafs poses a significant threat to mine safety, especially when irregular excavation patterns interact with high ground stress, exacerbating instability risks. Most existing studies lack a systematic and multidisciplinary integrated framework for comprehensive evaluation and management. This paper proposes a trinity research system of “assessment–optimization–governance”, integrating theoretical analysis, three-dimensional fluid–solid coupling numerical simulation, and a filling sequence optimization method based on genetic algorithms. An analysis of data measured from 243 pillars and 49 goafs indicates that approximately 20–30% of the pillars have a factor of safety (FoS) below 1.0, signaling immediate instability risks; additionally, 58% do not meet the threshold for long-term stability (FoS ≥ 1.5). Statistical and spatial analyses highlight that pillar width-to-height ratio (W/H) and cross-sectional area significantly influence stability; when W/H exceeds 1.5, FoS typically surpasses 2.0. Numerical simulations reveal pore water pressures of 1.4–1.8 MPa in deeper goafs, substantially reducing effective stress and accelerating plastic zone expansion. Stability classification categorizes the 49 goafs into 7 “poor”, 37 “moderate”, and 5 “good” zones. A genetic algorithm-optimized filling sequence prioritizes high-risk area remediation, reducing maximum principal stress by 60.96% and pore pressure by 28.6%. Cemented waste rock filling applied in high-risk areas, complemented by general waste rock filling in moderate-risk areas, significantly enhances overall stability. This integrated method provides a scientific foundation for stability assessment and dynamic remediation planning under complex hydrogeological conditions, offering a risk-informed and scenario-specific application of existing tools that improves engineering applicability. Full article

Coastal regions of Ecuador, particularly Esmeraldas and Manabí, face significant challenges related to energy access, waste management, and sustainable agricultural development. This study evaluates the renewable energy potential of cocoa waste biomass generated by smallholder farms in these provinces. A total of 20 cocoa farms, either certified or in the process of certification under the Rainforest Alliance standard, were surveyed to quantify the volume of agricultural and agro-industrial residues. Residual biomass generation ranged from 50 to 6500 tons per year, depending on farm size, planting density, and management practices. Spatial analysis revealed that Esmeraldas holds the highest concentration of cocoa waste biomass, with some farms reaching a gross energy potential of up to 89.07 TJ/year. Using thermochemical conversion scenarios, effective energy potential was estimated, and 75% of the farms exceeded the viability threshold of 100 MWh/year. The results confirm the feasibility of cocoa biomass as a renewable energy source, mainly when managed collectively at the community level. Incorporating this waste into decentralized energy systems supports circular economy models, enhances energy self-sufficiency, and aligns with sustainable supply chain goals promoted by certification schemes. This study contributes to national efforts in energy diversification and provides a replicable model for integrating renewable energy into rural agricultural systems. Full article

Circular economy in the context of municipal organic waste management has boosted the emergence of novel composting scenarios, such as community composting and decentralized urban composting in small installations, which favors localized management and valorization of organic waste streams. However, there is little information about the agronomic use of the composts obtained from these new organic waste management systems as an alternative for inorganic fertilization in crop production. In this work, municipal solid waste-derived composts from two decentralized composting scenarios (CM1 and CM2 from community composting, and CM3 and CM4 from decentralized urban small-scale composting plants) were applied and mixed in the top layer of a calcareous clayey-loam soil to assess their effects as alternative substitutes for conventional soil inorganic fertilization (IN) during two successive cultivation cycles of lettuce (Lactuca sativa L.) grown in pots with the amended soils. These treatments were also compared with an organic waste (goat–rabbit manure, E) and a control treatment without fertilization (B). The effects of the fertilizing treatments on the crop yield and quality, as well as on the properties of the soil considered were studied. In general, the application of the different composts did not produce negative effects on lettuce yield and quality. The compost-derived fertilization showed similar lettuce yields compared to the inorganic and manure-derived fertilizations (IN and E, respectively), and higher yields than the soil without amendment (B), with increases in the initial yield values of B, for the first cycle from 34.2% for CM1 to 53.8% for CM3, and from 20.3% for CM3 to 92.4% for CM1 in the second cycle. Furthermore, the organically amended soils showed a better crop development, obtaining higher values than the control treatment in the parameters studied. In addition, the incorporation of the organic treatments improved the soil characteristics, leading to 1.3 and 1.2 times higher organic matter contents in the soils with CM2 and in the soils with CM1, CM3, and E, respectively, compared to the control soil without fertilizing treatment (B), and 2.0 and 1.8 times greater organic matter contents, respectively, compared to soil with inorganic fertilization (IN). Therefore, the use of municipal solid waste-derived composts from these new organic waste management systems, such as the decentralized composting scenarios studied (community composting and urban decentralized small-scale composting plants), is presented, not only as a sustainable valorization method, but also as an alternative for the use of inorganic fertilizers in lettuce cultivation, while enhancing soil properties, contributing to increasing the circularity of agriculture. Full article

The European Union views biogas production from landfills as a crucial element in achieving decarbonization goals by 2050. Biogas is primarily composed of methane (CH₄) and carbon dioxide (CO₂), produced through the anaerobic digestion of various residual materials. This study aimed to investigate CH₄ and CO₂ concentrations from municipal solid waste in biogas capture wells in a landfill in Romania between 2023 and 2024. A peak in CH₄ concentrations occurred in the fall of 2024 (P4 well), while the highest CO₂ content was recorded in the summer of 2023 (P3 well). The Aermod View software platform (version 11.2.0) was employed to model the dispersion of pollutants in the surrounding air. A worst-case scenario was applied to estimate the highest ground-level pollutant concentrations. The highest recorded CH₄ concentration was 90.1 mg/m³, while CO₂ reached 249 mg/m³ within the landfill. The highest CH₄ concentrations were found in the southern part of the site, less than 1 km from the landfill, while CO₂ was highest in the northern area. In conclusion, municipal solid waste landfills behave like unpredictable bioreactors, and without proper management and oversight, they can pose significant risks. An integrated system that combines prevention, reuse, and correct disposal is critical to minimizing these negative effects. Full article

The dramatic increase in domestic and industrial waste over recent centuries has significantly polluted water bodies, threatening aquatic life and human activities such as drinking, recreation, and commerce. Understanding pollutant dispersion is essential for designing effective waste management systems, employing both experimental and computational techniques. Among Computational Fluid Dynamics (CFD) techniques, the Lattice Boltzmann Method (LBM) has emerged as a novel approach based on a discretized Boltzmann equation. The versatility and parallelization capability of this method makes it particularly attractive for fluid dynamics simulations using high-performance computing. Motivated by its successful application across various scientific disciplines, this study explores the potential of LBM to model pollutant mixing and dilution from outfalls into surface water bodies, focusing specifically on vertical dense jets in crossflow (JICF), a key scenario for the diffusion of brine from desalination plants. A full-LBM scheme is employed to model both the hydrodynamics and the transport of the saline concentration field, and Large Eddy Simulations (LES) are employed in the framework of LBM to reduce computational costs typically associated with turbulence modeling, together with a recursive regularization procedure for the collision operator to achieve greater stability. Several key aspects of vertical dense JICF are considered. The simulations successfully capture general flow characteristics corresponding to jets with varying crossflow parameter $u_{r}F$ and most of the typical vortical structures associated with JICF. Relevant quantities such as the terminal rise height, the impact distance, the dilution at the terminal rise height, and the dilution at the impact point are compared with experimental results and semi-empirical relations. The results show a systematic underestimation of these quantities, but the key trends are successfully captured, highlighting LBM’s promise as a tool for simulating wastewater dispersion in aquatic environments. Full article