Search Results (10,252)

Illegal dumping is a significant environmental and public health challenge in South African townships. This study investigates the drivers of illegal dumping in Ngwelezana Township, KwaZulu-Natal, using a qualitative case study approach. Data were collected through semi-structured interviews with municipal officials, waste workers, and community stakeholders, supplemented by field observations and document analysis. Qualitative content analysis identified that dumping is driven by a misalignment between waste generation and service provision, characterized by ‘institutional incoherence’ and ‘constrained compliance.’ Specific drivers include weak enforcement capacity, inadequate municipal resources, high disposal and transport costs, and the availability of unmanaged open spaces. The findings suggest that current reactive clean-up approaches are insufficient to address the systemic nature of the problem. This study proposes a transition toward preventative, community-centred waste governance that prioritizes strategic resource allocation, infrastructure accessibility, and integrated spatial planning. By analyzing the intersection of governance, cost, and infrastructure, this research provides a framework for addressing waste mismanagement in comparable Global South contexts. Full article

The growing demand for sustainable soil management strategies has intensified interest in hydrochar (HC), a waste-derived amendment produced via hydrothermal carbonization (HTC). This review synthesizes recent advances in HC production, characterization, and agri-environmental applications within a waste-to-resource framework. It covers studies conducted mainly over the last decade, encompassing a wide range of feedstocks, including agricultural residues, sewage sludge, animal manures, and food waste. HTC is typically performed at 130–280 °C under autogenous pressure (2–15 MPa), generating HCs with low intrinsic surface area (<50 m²g⁻¹) and oxygen-containing functional groups that govern nutrient dynamics and soil interactions. Reported application rates vary broadly between 10 and 60 t ha⁻¹, with most experiments conducted under greenhouse conditions. Positive effects on soil pH, cation exchange capacity, water retention, and phosphorus availability are frequently observed. However, plant responses vary according to the type of stimulation promoted by HC, as well as its processing conditions, application rates, and the soil characteristics in which it is applied. Advanced molecular-level analyses (e.g., FT-ICR-MS, GC-MS, and ¹³C-NMR) have provided mechanistic insights into carbon stability, nutrient release, and interaction with soil organic matter. Reusing HTC process water offers an additional pathway for nutrient recovery, although concerns about phytotoxic compounds remain. Despite promising short-term results, long-term field evaluations and standardized assessment protocols are still limited. This review integrates structural, functional and agri-environmental perspectives to identify critical knowledge gaps and guide the optimized and context specific use of hydrochar in sustainable agricultural systems. At the same time, it emphasizes its role in advancing carbon sequestration and in operationalizing resource-circular strategies, thereby underscoring its broader practical and strategic relevance. Full article

Processing rosehips generates substantial solid waste that retains valuable bioactive compounds. This study evaluated the effects of different treatments on the composition, phenolic and flavonoid contents, and antioxidant capacity of powders derived from rosehip waste. Rosehips were processed into purée by cold screw pressing or boiling, yielding raw and boiled processing waste fractions (RW and BW). These fractions were then dehydrated by hot-air drying or lyophilisation to obtain RWd, RWl, BWd, and BWl. Additionally, a previous cold screw pressing step was applied to the boiled processing waste, producing BWpd and BWpl. Cold screw pressing increased phenolic and flavonoid levels and enhanced the antioxidant capacity of the resulting waste compared with traditional boiling. The lyophilised powder derived from raw processing waste exhibited the highest total phenolic content (TPC, 27.16 mg GAE/g), total flavonoid content (TFC, 20.35 mg QUE/g), and Trolox equivalent antioxidant capacity by ABTS and DPPH (TEAC-ABTS, 89.13 µmol TE/g; TEAC-DPPH, 163.99 µmol TE/g), although at higher processing costs. As hot-air drying achieved comparable levels for TPC (20.01 mg GAE/g), TFC (19.53 mg QUE/g), TEAC-ABTS (58.01 µmol TE/g), and TEAC-DPPH (150.01 µmol TE/g), it may represent a more economical alternative to lyophilisation. These findings demonstrate the potential of rosehip-processing waste as a sustainable raw material for the development of functional food ingredients. Full article

Processes for generating clean hydrogen from waste plastics through thermochemical methods such as pyrolysis and gasification are a promising solution for both waste management and clean energy initiatives. Then, this derived hydrogen powers the fuel cell, which produces electricity that can be directly fed to charge electric vehicles (EVs). Although this complex process has many challenges related to energy efficiency during the conversion processes—starting from the generation of hydrogen from thermochemical processes and hydrogen storage and followed by fueling the fuel cells and charging EV infrastructure—the simplistic conceptual modeling developed for this research demonstrates how an ecosystem of such processes can be made feasible commercially. Clean hydrogen generated using known techniques reported in the literature is promising for commercialization, but harnessing hydrogen from plastics offers additional benefits, such as reducing greenhouse gas (GHG) emissions. Overall, the feasibility of clean hydrogen using this methodology is not limited by potential cost inefficiencies, especially when savings from GHG emissions reduction are taken into account. EVs have become commercially viable thanks to high-energy-density Li-ion batteries. And therefore, research continues to optimize charging performance through the integration of renewable energy and battery storage systems. This study examines another potential of clean hydrogen: its use as a power source in grids, especially V-2-G (vehicle-to-grid) systems. Additionally, direct current (DC) power from a fuel cell powers an EV charger at DC input voltages for e-ambulances. In particular, this designed system operates on DC voltages throughout the power system, combining high-voltage direct current (HVDC) lines, renewable energy sources, DC-DC converters, DC EV chargers, and other supporting components. The literature review identified gaps in plastics production, waste management, and processes for converting them into useful energy. The presented model is a stepping stone towards a novel, innovative process for clean hydrogen production to power electric vehicle charging infrastructure for emergency response systems in healthcare, thereby improving public safety. The limitations of the study would be governed by the effective establishment of locations where waste management services are performed (for example, landfills) and adoption by local government authorities with deregulated power systems. Full article

The last few years have been marked by intense debates about the environmental agenda. Forums all over the world are discussing effective actions that can mitigate the effects of human actions on the environment. What was once destined for the imposed policy of developed countries upon emerging ones is now a global policy. Countries, nations, and the corporate world need to adopt urgent measures to make their activities less impactful before the feared tipping point is reached. In this context, hospitals (public and private) take on a fundamental role. As major consumers of water, generators of waste, and sources of high greenhouse gas emissions, hospital ecosystems must re-evaluate their processes to ensure the efficient use of water and energy resources. Although still a recent action, the Green Health concept has been disseminated globally, contributing to the achievement of the Sustainable Development Goals. The present study analyzes the current landscape of Green Health within the Brazilian context, based on a review of scholarly literature. To this end, consultations were made to publications deposited in the period from 2003 to 2025, whose information was processed and used to generate similarity visualization maps. This exploratory study sought to provide a proof of concept by defining a baseline to assess how the term ‘Green Health’ is being appropriated by researchers in Brazil. The results indicate that even though there are some actions in Brazil directed toward Green Health practices, they are modest and lack greater integration, especially regarding research on the topic. Full article

The rapid growth of electronic waste (e-waste) demands sustainable recovery solutions based on green chemistry. Conventional recycling relies on energy-intensive pyrometallurgical routes that cause emissions and material losses. This study applies Molecular Recognition Technology™ (MRT™) for selective energy-efficient recovery of base (Cu, Ni, Fe, Sn) and precious/platinum group metals (Ag, Pd, Pt) from a collector metal alloy. A hydrometallurgical process combining electrowinning, sequential acid leaching, and MRT™ separations achieved >99% metal purity with minimal waste generation. The results demonstrate MRT™ as a scalable green alternative for high-efficiency metal recovery from e-waste, supporting circular economy objectives. Full article

The Chocó Andino Biosphere Reserve in Ecuador faces growing challenges associated with food consumption and waste management in rural contexts. However, the role of educational institutions in promoting sustainable practices in these territories has been scarcely studied. This paper analyzes how rural schools contribute to circularity processes in food and waste management, shaping what we conceptualize as school trajectories toward circularity. A mixed methodology was applied in four public institutions in the Reserve. The quantitative component consisted of characterizing and measuring the weight, composition, and generation of waste, while the qualitative component was based on observations and semi-structured interviews with administrators and teachers. The results indicate that recyclable dry fraction constitutes the predominant fraction across schools, revealing an overlooked but significant potential for reuse and recycling in rural educational settings. They also reveal that sustainable practices within the schools are primarily supported by pedagogical leadership and active community participation. These practices shape environmental learning trajectories in which care and co-responsibility become integrated into everyday school life. The findings contribute empirical insights on the sociocultural determinants of circular food behavior in contexts of the Global South. Full article

This LCA study addresses the research gap concerning the comprehensive environmental implications of using paving block aggregates (PBA), derived from crushed waste concrete paving blocks (CPB), as a sustainable replacement for natural aggregates in cementitious materials. While the concrete industry faces twin challenges—high CO₂ emissions from cement and the massive ecological toll of extracting 20 Gt/year of natural aggregates—a systematic life cycle assessment of this specific waste stream was necessary, especially one that considered potential material interaction trade-offs. The study’s conclusions offer critical insight into achieving genuine sustainability. Consistently, cement production was identified as the overwhelming environmental hotspot, contributing over 90% of the global warming potential (GWP) across all scenarios. This finding indicates that even substantial changes in aggregate sourcing can only deliver limited GWP reductions unless accompanied by strategies targeting cement-related emissions. While substituting natural aggregates with PBA generally provided environmental benefits, a crucial trade-off was identified: the significantly higher dosage of superplasticizer required to maintain the workability of the PBA mixes. For mortar, the burden from the increased plasticizer became a major secondary hotspot, occasionally offsetting the gains from aggregate replacement. In these scenarios, the contribution of admixtures to the total GWP was sufficiently high to reduce or negate the environmental benefits achieved through aggregate substitution. In contrast, aggregate replacement proved more favorable in concrete than in mortar, as the concrete scenarios showed a weaker correlation between environmental impact and plasticizer use. The authors conclude that future strategies must prioritize reducing cement content and, critically, systematically consider the necessary use of admixtures to ensure that the intended environmental improvements are genuine and not counteracted by the side effects of material substitution. The quantified LCA results demonstrate that cement reduction offers the highest mitigation potential, while admixture optimization is essential to prevent secondary environmental hotspots, particularly in mortar applications. Full article

To meet the energy-saving requirements of user equipment (UE) operating in Radio Resource Control idle/inactive states (RRC_IDLE/RRC_INACTIVE) in the 3rd-Generation Partnership Project (3GPP) 5G-Advanced (5G-A) networks, the New Radio (NR) downlink paging procedure relies on periodic monitoring and frequent synchronization signal block (SSB) measurements, which wastes energy when no paging arrivals occur. Meanwhile, heterogeneous Quality of Service (QoS) constraints make it difficult for fixed-parameter Idle Discontinuous Reception and Paging Early Indication mechanisms (IDRX/PEI) to balance energy, delay, and reliability. This paper develops a UAV-assisted 5G-A paging control framework that maps services into multiple QoS classes and models QoS violation risk and system energy consumption under unified accounting, including UE monitoring/reception energy and unmanned aerial vehicle (UAV) forwarding energy. We then propose a QoS-aware risk-driven paging strategy: an offline Long Short-Term Memory (LSTM) predictor is trained to estimate the time-to-next-arrival (TTNA) of paging events and produce a bounded urgency/risk signal to initialize class-dependent thresholds, while online triggering and QoS-feedback-based threshold adaptation regulate the empirical violation rate toward target constraints under varying loads, enabling a controllable energy–delay trade-off. A simulation-based evaluation is conducted to compare the proposed method with representative baselines (Enhanced Paging Monitoring (EPM), Split Paging Occasion (SPOP), and Predicted Paging Early Indication (PPEI)) and to examine the impact of SSB overhead and UAV relaying on the energy–delay–reliability trade-offs. Full article

This study explores a solar-driven hybrid desalination approach developed for Saudi Arabian climatic conditions, combining adsorption desalination (AD) based on a silica gel/CaCl₂ composite with an ejector (EJ) and a HDH system. The proposed integration aims to enhance vapor utilization and reuse condenser heat to generate additional distillate. Two operating modes are examined, including a productivity-focused strategy that activates evaporator/condenser heat recovery (HR) when cooling is not required. Compared to raw silica gel (SG), the composite adsorbent improves adsorption cycle performance, raising the COP from about 0.38–0.43 to 0.55–0.63, and increasing SCP from roughly 130–240 W/kg to 320–675 W/kg. Without HR, the full AD–EJ–HDH system achieves SDWP of 52–100 m³/ton·day with GOR of 2.40–2.75 over the year. In HR-enabled operation, SDWP increases to 81–140 m³/ton·day and GOR rises to 2.7–2.95, reflecting stronger internal heat reuse and improved vapor management. Techno-economic results show that the solar-driven unit cost for AD–EJ–HDH decreases from winter values (2.7–2.9 $/m³) to a minimum around June (1.53 $/m³), while waste heat operation reduces the cost further to 0.49 $/m³ in June (rising to ~0.76–0.80 $/m³ in winter). With HR, the full AD–HR–EJ–HDH reaches around 1.44 $/m³ (solar, June) and 0.38–0.40 $/m³ (waste heat, summer), confirming the advantage of desalination-focused HR operation when cooling is not required. Finally, compared with SWRO, the AD–HR–EJ–HDH configuration delivers an approximately 90% lower carbon footprint on the same environmental assessment basis. The study highlights the environmental benefit of the intensified SG/CaCl₂ hybrid configuration. Full article

Electric vehicles (EVs) represent a key pathway toward reducing greenhouse gas emissions and fossil fuel dependence. Although significant advances have been achieved in energy storage technologies for EVs, a structured comparative assessment that jointly evaluates batteries, supercapacitors, and their hybridisation remains lacking. This review addresses that gap by systematically comparing lithium-ion, lead-acid, and nickel-based batteries with electrochemical double-layer capacitors (EDLCs), pseudocapacitors, and hybrid capacitors across ten performance and sustainability criteria. A literature-informed scoring framework, supplemented by sensitivity analysis under alternative weighting scenarios, is employed to rank the technologies. Particular attention is given to Hybrid Energy Storage Systems (HESS), which combine the high energy density of lithium-ion batteries with the high power density and long cycle life of supercapacitors. The review synthesises evidence that HESS can improve overall energy efficiency by up to 20% and extend battery lifetime by 30–50%, thereby reducing raw-material extraction, electronic waste, and lifecycle cost. Second-life pathways and circular-economy implications are discussed in depth. The findings demonstrate that neither batteries nor supercapacitors alone can satisfy the full spectrum of EV energy demands; instead, their integration within HESS offers the most balanced, sustainable, and economically viable solution. This work provides actionable insights for engineers, policymakers, and stakeholders engaged in next-generation sustainable mobility. Full article

Cellulose and hemicellulose, both widely present in radioactive waste, undergo combined radiolytic and hydrolytic degradation during disposal under the highly alkaline conditions imposed by the cementitious waste matrices and engineered barriers. This combined process generates water-soluble organic compounds that can complex with radionuclides, thereby potentially enhancing their migration from the waste to the biosphere. Identification of these degradation products formed by cellulosic materials is essential for assessing their complexation potential and predicting their impact on radionuclide mobility. In this work, degradation products resulting from sequential radiolytic and alkaline degradation of cellulosic tissues, realistically present in radioactive waste, were identified using multiple advanced techniques, i.e., Electrospray Ionization Time-of-Flight Mass Spectrometry, Ion Chromatography Mass Spectrometry, and Nuclear Magnetic Resonance spectroscopy. Our results confirm that isosaccharinic acid (α-ISA and β-ISA) is the major end product from cellulose degradation, while xylo-isosaccharinic acid (XISA) indicates hemicellulose degradation. Furthermore, significant concentrations of formic and lactic acid were detected, alongside minor products including glycolic, acetic, propionic, malonic, and oxalic acids, with malonic and oxalic acids appearing only after irradiation at high irradiation doses and under air (malonic) or argon (oxalic). Additional unquantified compounds, such as glutaric acid, 2-hydroxybutyric acid, and oligosaccharides, were observed as well. These findings advance our insight into the degradation of end products of cellulosic materials in radioactive waste and establish a foundation for future research on their complexation potential and impact on radionuclide mobility, especially for compounds where data are lacking. Full article

The management of invasive alien species (IAS) generates large amounts of plant waste biomass that is commonly disposed of by burning or destruction, leading to environmental and economic drawbacks. At the same time, the production of synthetic dyes and pigments used in printing and graphic applications remains a significant source of pollution. In this context, the valorization of IAS biomass as a source of natural colorants represents a sustainable alternative aligned with circular economy principles. Here, biocompounds and natural dyes were extracted from four invasive or non-native plant species—Arundo donax, Phytolacca americana, Tradescantia fluminensis, and Eucalyptus globulus—using five solid–liquid extraction methods: infusion, infusion with heat, thermal agitation, Soxhlet extraction, and ultrasonic-assisted extraction. Extraction efficiency and color preservation were comparatively evaluated. Although Soxhlet extraction provided the highest extraction yield (up to 30.5%), infusion with heat proved to be the most suitable method for preserving color integrity and minimizing oxidation. Liquid dyes obtained by the selected extraction method were converted into solid pigments through a lake pigment precipitation process using aluminum potassium sulfate and sodium bicarbonate. The resulting pigments were characterized in terms of chemical composition, particle size, and chromatic properties, and subsequently formulated into oil-based inks using linseed oil as binder. Scanning electron microscopy revealed pigment particle sizes ranging from approximately 2.1 to 8.3 µm, depending on the plant source, and confirmed adequate ink penetration and distribution on commercial printmaking paper. The obtained pigments exhibited color tones ranging from yellow to brown and grey, mainly associated with the phenolic and tannin content of the original biomass. Printing tests demonstrated the suitability of the developed inks for manual printmaking techniques, highlighting the potential of IAS-derived pigments as sustainable alternatives for artistic and printing applications. Full article

Food waste remains a critical sustainability challenge for the European Union (EU), with significant negative impacts on environmental resources, economic efficiency, and social equity. This paper presents a comprehensive analysis of food waste across EU member states during the 2020–2023 period, examining waste generation across five key sectors: households, food service (restaurants and catering), retail, food manufacturing, and primary agriculture. The study uses Eurostat statistical data, standardising measurements to kilograms per capita and absolute tonnage to enable cross-country comparisons. Particular attention is devoted to the impacts of the COVID-19 pandemic, which disproportionately affected the service and retail sectors. Beyond descriptive analysis, the research investigates potential relationships between major economic indicators (Gross Domestic Product [GDP], median income, and material deprivation) and food waste rates, employing Kruskal–Wallis statistical tests to examine sectoral and cross-national patterns. Contrary to conventional assumptions, analyses reveal no statistically significant direct correlation between economic prosperity and waste generation, suggesting that institutional design, infrastructure availability, consumer awareness, and education exert greater determinative influence than aggregate wealth. Results demonstrate that households are the largest source of food waste across the EU, accounting for approximately 50% of food waste. At the same time, sectoral variations reflect country-specific structural and regulatory factors rather than levels of economic development. The research concludes with actionable policy recommendations targeting three intervention levels: individual behaviour change (consumer education, digital tools, and purchase planning), community infrastructure (food redistribution networks and collective composting), and institutional reform (regulatory harmonisation, circular economy incentives, and extended producer responsibility). These recommendations align with EU strategic priorities, including the European Green Deal, Farm to Fork Strategy, and 2030 Circular Economy Action Plan, with the specific objective of halving food waste by 2030 to enhance both environmental sustainability and food security. Full article

The increasing emphasis on sustainability in digital printing requires quantitative methods for optimizing key performance indicators (KPIs) under technical and operational constraints. The term digital twin is used here in a methodological and analytical sense, as a simulation framework for analyzing interdependence, prediction, and multi-criteria optimization of KPIs, rather than as a direct virtual replica of a specific physical production system. This paper proposes a hybrid simulation–prediction model based on a digital twin framework for optimization of KPIs in sustainable digital printing, with particular emphasis on overall equipment effectiveness (OEE). Due to the limited availability of structured industrial data, the model is developed using a synthetically generated dataset constructed in accordance with industry-reported operating ranges and technically realistic digital printing process variables. Random Forest and XGBoost algorithms are applied to model nonlinear relationships between process parameters and KPIs, including material waste, energy consumption, machine downtime, and OEE. Based on these predictive models, a constrained multi-objective optimization procedure is performed to identify Pareto-efficient configurations that reduce material waste and energy consumption while maintaining acceptable downtime and OEE levels. The results characterize structural trade-offs among environmental and operational KPIs within a formally defined decision space. Full article