Search Results (138)

Background: School lunch programs play a crucial role in shaping the nutritional status and academic performance of children, making them a cornerstone of public health initiatives worldwide. Objective: To elucidate emerging trends and propose a comprehensive framework for free school lunch as a nutrition policy through a combined bibliometric approach and critical review. Methods: A bibliometric analysis was performed to identify key thematic areas, influential research, and knowledge gaps from global literature databases, followed by a critical review synthesizing insights on nutritional adequacy, socio-cultural considerations, policy effectiveness, and innovative practices in free school meal programs. Results: The analysis revealed an increasing focus on sustainability, food waste management, and integration of nutrition education within school curricula, alongside notable disparities in implementation and accessibility, particularly in low-income regions. Conclusions: We propose a future-oriented framework emphasizing stakeholder collaboration, culturally adaptive meal designs, and utilization of technology for personalized nutrition strategies, contributing to the optimization of school lunch programs and advancement of sustainable development goals, particularly Zero Hunger and Quality Education. Full article

The increasing complexity in hospital waste management requires innovative solutions that integrate sustainability and regulatory compliance. This study proposes an AI-based decision tool to support the circular management of healthcare waste. The approach combines two key elements: (i) the systematic qualitative analysis of international, European, and national regulations, scientific literature, and best practices aimed at identifying strategic actions; (ii) the prioritization of these actions through machine learning, using a Random Forest classifier. We identified 55 actions, grouped into 13 thematic areas, and used them as input variables to assess their impact on regulatory compliance. The variable importance analysis allowed us to classify actions according to their strategic relevance, guiding the structure of the tool and its user interface. Validation, conducted on four simulated case studies, demonstrated the system’s ability to improve compliance monitoring, operational efficiency, and the implementation of circular economy and Zero-Waste strategies. The proposed model represents a scalable and evidence-based solution capable of supporting the ecological transition of healthcare facilities in line with EU directives and the Sustainable Development Goals. Full article

In the digital era, online search patterns provide a practical way to track changes in the public interest in sustainability. This study analyzes monthly Google Trends data in the United States (January 2019–December 2024) for five keywords: two institutional (“ESG”, “carbon neutral”), and three consumer-oriented (“eco friendly”, “zero waste”, and “plastic free”). Drawing on agenda-setting theory and the diffusion-of-innovations framework, we test the directional links between institutional and consumer attention. The methods include Granger causality tests, impulse response functions, and cross-correlation analysis. The findings reveal a consistent lead–lag structure in which institutional terms precede consumer-oriented searches, but the timing and persistence of influence vary across concepts. A broad discourse such as ESG produces slower, yet more sustained, effects, whereas action-oriented concepts like carbon neutrality generate quicker but shorter-lived responses. Seasonal analysis also shows recurring peaks in consumer interest around events such as Earth Day and Plastic-Free July, underscoring the cyclical nature of attention to sustainability. By integrating communication theory with multi-year digital trace data, this study provides evidence of how institutional messaging diffuses into consumer behavior, while highlighting the roles of timing and message framing. The results contribute to sustainability communication research and offer practical insights for policymakers, NGOs, and marketers relevant to aligning campaigns with evolving public attention. Full article

The escalating climate crisis and unsustainable waste management practices necessitate integrated approaches that simultaneously address energy security and environmental degradation. Hydrogen, with its high energy density and zero-carbon combustion, is a key vector for decarbonization; however, conventional production methods are fossil-dependent and carbon-intensive. This systematic review explores biowaste-to-hydrogen (WtH) technologies as dual-purpose solutions, converting organic waste to clean hydrogen while reducing greenhouse gas emissions and landfill reliance. A comprehensive analysis of different conversion pathways, including thermochemical (gasification, pyrolysis, hydrothermal, and partial oxidation (POX)), biochemical (dark fermentation, photofermentation, and sequential fermentation), and electrochemical methods (MECs), is presented, assessing their hydrogen yields, feedstock compatibilities, environmental impacts, and technological readiness. Systematic literature review methods were employed using databases, such as Scopus and Web of Science, with strict inclusion criteria focused on recent peer-reviewed studies. This review highlights hydrothermal gasification and dark fermentation as particularly promising for wet biowaste streams, like food waste. Comparative environmental analyses reveal that bio-based hydrogen pathways offer significantly lower greenhouse gas emissions, energy use, and pollutant outputs than conventional methods. Future research directions emphasize process integration, catalyst development, and lifecycle assessment. The findings aim to inform technology selection, policymaking, and strategic investment in circular, low-carbon hydrogen production. Full article

This paper investigates the cultural, spiritual, and ecological use and value of fish by-products in the material practices of Alaska Native (Indigenous Peoples are the descendants of the populations who inhabited a geographical region at the time of colonisation and who retain some or all of their own social, economic, cultural, and political institutions. In this paper, I use the terms “Indigenous” and “Native” interchangeably. In some countries, one of these terms may be favoured over the other.) and Greenlandic Inuit women. It aims to uncover how fish remnants—skins, bones, bladders, vertebrae, and otoliths—were transformed through tanning, dyeing, and sewing into garments, containers, tools, oils, glues, and adornments, reflecting sustainable systems of knowledge production rooted in Arctic Indigenous lifeways. Drawing on interdisciplinary methods combining Indigenist research, ethnographic records, and sustainability studies, the research contextualises these practices within broader environmental, spiritual, and social frameworks. The findings demonstrate that fish-based technologies were not merely utilitarian but also carried symbolic meanings, linking wearers to ancestral spirits, animal kin, and the marine environment. These traditions persisted even after European contact and the introduction of glass trade beads, reflecting continuity and cultural adaptability. The paper contributes to academic discourse on Indigenous innovation and environmental humanities by offering a culturally grounded model of zero-waste practice and reciprocal ecology. It argues that such ancestral technologies are directly relevant to contemporary sustainability debates in fashion and material design. By documenting these underexamined histories, the study provides valuable insight into Indigenous resilience and offers a critical framework for integrating Indigenous knowledge systems into current sustainability practices. Full article

This study proposes an integrated framework for sustainable tropical agriculture by combining biochemical waste valorization with spatial carbon footprint estimation in ‘Phulae’ pineapple production. Peel and eye residues from fresh-cut processing were enzymatically converted into rare sugar, achieving average conversion efficiencies of 35.28% for peel and 37.51% for eyes, with a benefit–cost ratio of 1.56 and an estimated unit cost of USD 0.17 per gram. A complementary zero-waste pathway produced functional gummy products using vinegar fermented from pineapple eye waste, with the preferred formulation scoring a mean of 4.32 out of 5 on a sensory scale with 158 untrained panelists. For spatial carbon modeling, the Bare Land Referenced Algorithm (BRAH) and Otsu thresholding were applied to multi-temporal Sentinel-2 and THEOS imagery to estimate plantation age, which strongly correlated with field-measured emissions (r = 0.996). This enabled scalable mapping of plot-level greenhouse gas emissions, yielding an average footprint of 0.2304 kg CO₂ eq. per kilogram of fresh pineapple at the plantation gate. Together, these innovations form a replicable model that aligns tropical fruit supply chains with circular economy goals and carbon-related trade standards. The framework supports waste traceability, resource efficiency, and climate accountability using accessible, data-driven tools suitable for smallholder contexts. By demonstrating practical value addition and spatially explicit carbon monitoring, this study shows how integrated circular and geospatial strategies can advance sustainability and market competitiveness for the ‘Phulae’ pineapple industry and similar perennial crop systems. Full article

Abrasive waterjet technology is a promising sustainable and green technology for cutting underground structures. Abrasive waterjet usage in demolition promotes sustainable and green construction practices by reduction of noise, dust, secondary waste, and disturbances to the surrounding infrastructure. In this study, a numerical framework based on a coupled Smoothed Particle Hydrodynamics (SPH)–Finite Element Method (FEM) algorithm incorporating the Riedel–Hiermaier–Thoma (RHT) constitutive model is proposed to investigate the damage mechanism of concrete subjected to abrasive waterjet. Numerical simulation results show a stratified damage observation in the concrete, consisting of a crushing zone (plastic damage), crack formation zone (plastic and brittle damage), and crack propagation zone (brittle damage). Furthermore, concrete undergoes plastic failure when the shear stress on an element exceeds 5 MPa. Brittle failure due to tensile stress occurs only when both the maximum principal stress (σ₁) and the minimum principal stress (σ₃) are greater than zero at the same time. The damage degree ($\chi$) of the concrete is observed to increase with jet diameter, concentration of abrasive particles, and velocity of jet. A series of orthogonal tests are performed to analyze the influence of velocity of jet, concentration of abrasive particles, and jet diameter on the damage degree and impact depth (h). The parametric numerical studies indicates that jet diameter has the most significant influence on damage degree, followed by abrasive concentration and jet velocity, respectively, whereas the primary determinant of impact depth is the abrasive concentration followed by jet velocity and jet diameter. Based on the parametric analysis, two optimized abrasive waterjet configurations are proposed: one tailored for rock fragmentation in tunnel boring machine (TBM) operations; and another for cutting reinforced concrete piles in shield tunneling applications. These configurations aim to enhance the efficiency and sustainability of excavation and tunneling processes through improved material removal performance and reduced mechanical wear. Full article

The construction industry’s escalating environmental footprint, coupled with the underutilization of construction waste streams, necessitates innovative approaches to sustainable material design. This study investigates the dual functionality of recycled clay brick powder (RCBP) as both a supplementary cementitious material (SCM) and an alkali–silica reaction (ASR) inhibitor in hybrid mortar systems incorporating recycled glass (RG) and recycled clay brick (RCB) aggregates. Leveraging the pozzolanic activity of RCBP’s residual aluminosilicate phases, the research quantifies its influence on mortar durability and mechanical performance under varying substitution scenarios. Experimental findings reveal a nonlinear relationship between RCBP dosage and mortar properties. A 30% cement replacement with RCBP yields a 28-day activity index of 96.95%, confirming significant pozzolanic contributions. Critically, RCBP substitution ≥20% effectively mitigates ASRs induced by RG aggregates, with optimal suppression observed at 25% replacement. This threshold aligns with microstructural analyses showing RCBP’s Al³⁺ ions preferentially reacting with alkali hydroxides to form non-expansive gels, reducing pore solution pH and silica dissolution rates. Mechanical characterization reveals trade-offs between workability and strength development. Increasing RCBP substitution decreases mortar consistency and fluidity, which is more pronounced in RG-RCBS blends due to glass aggregates’ smooth texture. Compressively, both SS-RCBS and RG-RCBS mortars exhibit strength reduction with higher RCBP content, yet all specimens show accelerated compressive strength gain relative to flexural strength over curing time. Notably, 28-day water absorption increases with RCBP substitution, correlating with microstructural porosity modifications. These findings position recycled construction wastes and glass as valuable resources in circular economy frameworks, offering municipalities a pathway to meet recycled content mandates without sacrificing structural integrity. The study underscores the importance of waste synergy in advancing sustainable mortar technology, with implications for net-zero building practices and industrial waste valorization. Full article

Maize (Zea mays) is one of the most cultivated crops in South Africa, serving as a staple food, stock feed, and a key element in several industrial applications. It contributes significantly to the growth of the South African agricultural economy. The cultivation of maize generates a large amount of agricultural waste, mainly in the form of maize stover (MS), which encapsulates leaves, stalks, cobs, and husks. Approximately 5.15 metric tons (Mt) yr⁻¹ of MS are generated in South Africa. This corresponds to an energy potential of 94 PJ. There is immense potential to surpass the annual yield of MS by 126% up to about 11.66 Mt yr⁻¹ through practices such as zero tillage and improved agricultural production systems. MS may pose a serious threat to the environment if not managed in a sustainable and eco-friendly manner. Valorization of MS into biogas presents an excellent opportunity to effectively control biomass waste while contributing to renewable energy production and mitigating dependence on depleting fossil fuels. However, MS continues to be overlooked as a sustainable bioenergy resource due to its lignocellulosic structure. This study explores the potential of converting MS into biogas for heat and power generation, addressing both energy needs and waste management in South Africa. The purpose is to provide knowledge that will inform researchers, innovators, industrialists, policy makers, investors, and other key stakeholders interested in renewable energy systems. Collaborative efforts among multiple stakeholders are vital to leverage biogas as a technology to promote socio-economic development in South Africa. Full article

This study focuses on the shift to a circular economy (CE) in the textile, apparel, and fashion (TAF) sectors, which generate tons of waste annually. Thus, embracing CE practices is essential for contributing to UN Sustainable Development Goals. This study employs a mixed-methods approach, integrating PRISMA for systematic literature selection, BERTopic modeling and AI-driven SDG mapping, and case study analysis to explore emerging CE themes, implemented circular practices, and systemic barriers. Machine-learning-based SDG mapping reveals strong linkages to SDG 9 and SDG 12, emphasizing technological advancements, industrial collaborations, and circular business models. Moderately explored SDGs, namely, SDG 8, SDG 6, and SDG 7, highlight research on labor conditions, water conservation, and clean energy integration. Reviewing 655 peer-reviewed papers, the BERTopic modeling extracted six key themes, including sustainable recycling, circular business models, and consumer engagement, whereas case studies highlighted regulatory frameworks, stakeholder collaboration, and financial incentives as critical enablers. The findings advance institutional theory by demonstrating how certifications, material standards, and regulations drive CE adoption, reinforcing SDG 12 and SDG 16. The natural resource-based view is extended by showing that technological resources alone are insufficiently aligned with SDG 9. Using the Antecedents–Decisions–Outcomes framework, this study presents a structured, AI-driven roadmap for scaling CE in the TAF industry, addressing systemic barriers, and supporting global sustainability goals, highlighting how multistakeholder collaboration, digital traceability, and inclusive governance can improve the impact of CE. The results recommend that CE strategies should be aligned with net-zero targets, carbon credit systems, and block-chain-based supply chains. Full article

This study aims to address the challenge of backfill compaction in the confined spaces of municipal utility tunnel trenches and to develop an environmentally friendly, zero-cement-based backfill material. The research focuses on the excavation slag soil from a utility tunnel project in Handan. An alkali-activated industrial-solid-waste-excavated slag-soil-based controllable low-strength material (CLSM) was developed, using NaOH as the activator, a slag–fly ash composite system as the binder, and steel slag-excavated slag as the fine aggregate. The effects of the water-to-solid ratio (0.40–0.45) and the binder-to-sand ratio (0.20–0.40) on CLSM fluidity were studied to determine optimal values for these parameters. Additionally, the influence of excavated soil content (45–65%), slag content (30–70%), and NaOH content (1–5%) on fluidity (flowability and bleeding rate) and mechanical properties (3-day, 7-day, and 28-day unconfined compressive strength (UCS)) was investigated. The results showed that when the water-to-solid ratio is 0.445 and the binder-to-sand ratio is 0.30, the material meets both experimental and practical requirements. CLSM fluidity was mainly influenced by the excavated soil and slag contents, while NaOH content had minimal effect. The unconfined compressive strength at different curing ages was negatively correlated with the excavated soil content, while it was positively correlated with slag and NaOH content. Based on these findings, the preparation of “zero-cement” CLSM using industrial solid waste and excavation slag is feasible. For trench backfill projects, a mix of 50–60% excavated soil, 40–60% slag, and 3–5% NaOH is recommended for optimal engineering performance. CLSM is a new type of green backfill material that uses excavated soil and industrial solid waste to prepare alkali-activated materials. It can effectively increase the amount of excavated soil and alleviate energy consumption. This is conducive to the reuse of resources, environmental protection, and sustainable development. Full article

This paper provides a conceptual analysis of pollution control in the hospitality industry, focusing on pollution generated by hotel operations. Hotels produce significant waste, emissions, and wastewater, impacting environmental and public health. We propose a framework distinguishing between flow and stock pollutants to highlight how both immediate emissions and long-term pollutant accumulation inform pollution management strategies. Using a conceptual framework, with an optimal dynamic model for pollution control, we illustrate the trade-offs hotels face in optimizing pollution control. Practical methods, from regulatory compliance to voluntary sustainability initiatives and economic incentives, are explored to support effective pollution mitigation. While achieving zero emissions is often impractical, an optimal pollution level allows hotels to balance environmental responsibility with economic feasibility, contributing to sustainable tourism and aligning with the values of eco-conscious consumers. Full article

Since 2003, Kamikatsu in Japan has established a sustainable zero-waste practice that has achieved a recycling rate exceeding 80%. By exploring how the community has shaped itself around the zero-waste concept, this paper aims to enhance our understanding of zero waste in practice from a universal design perspective. Interviews and photo documentation were used to gather data. The zero-waste concept was not driven by technical solutions. Instead, the results highlight what initiatives contributed to the design of the zero-waste concept. Key themes presented include fostering a lifestyle shift, changing norms, creating co-located experiences, establishing an incentive system, and developing self-awareness routines. The paper also addresses the challenges and opportunities from a universal design perspective when applying zero waste, emphasizing the importance of designing for diverse needs while promoting long-term environmental sustainability. This research contributes to the understanding of zero waste practices, combining the ecological dimension with the social dimension of sustainable development. Full article

Achieving net-zero carbon emissions, this study introduces a sustainable pathway for reducing strontium sulfate (SrSO₄) and celestite ore to strontium sulfide (SrS) using biofuels (biomethane, bioethanol) derived from agro-industrial waste and green hydrogen. Traditional SrSO₄ reduction methods, which rely on fossil-derived reductants like coal and operate at energy-intensive temperatures (1100–1200 °C), generate significant greenhouse gases and toxic byproducts, highlighting the need for eco-friendly alternatives. Experimental results demonstrate that bioethanol outperformed other reductants, achieving 97% conversion of synthetic SrSO₄ at 950 °C within 24 min and 74% conversion of natural celestite ore over 6 h. Remarkably, this bioethanol-driven process matches the energy efficiency of the conventional black ash method while enabling carbon neutrality through renewable feedstock utilization, reducing CO₂ emissions by 30–50%. By valorizing agro-industrial waste streams, this strategy advances circular economy principles and aligns with Mexico’s national agenda for sustainable industrial practices, including its commitment to decarbonizing heavy industries. This study contributes to sustainable development goals and offers a scalable solution for decarbonizing strontium compound production in the chemical industry. Full article

This paper shows a case study on a novel community-based sustainability planning framework that balances environmental, social, cultural dimensions for a high-density urban setting. The case study presents a community-driven “Four-Zero” sustainability model—zero energy, zero water, zero food, and zero waste—as a foundation for environmental sustainability practices implemented in a high-density estate in Hong Kong, alongside community-led ecological and heritage initiatives that reinforce place-based resilience. Through integrated activities, such as community farming, aquaponics, organic waste composting, biodiversity monitoring, and heritage mapping, the residents co-produced knowledge and activated novel bottom–up planning schemes and fostered social cohesion while advancing environmental objectives. Notably, the discovery of rare species and historic Dairy Farm remnants catalyzed a community-led planning proposal for an eco-heritage park that stimulated policy dialogues on conservation. These collective efforts illustrate how circular resource systems and cultural and ecological conservation can be balanced with urban development needs in compact, high-density communities. This case offers policy insights for rethinking urban sustainability planning in dense city contexts, contributing to global discourses on urban political ecology by examining socio–nature entanglements in contested urban spaces, to environmental justice by foregrounding community agency in shaping ecological futures, and to commoning practices through shared stewardship of urban resources. Full article