ABSTRACT. Solid waste management (SWM) is a global challenge directly correlated to urbanization, population growth, consumption patterns, and environmental sustainability. The term “solid waste” includes various streams, namely: i) mining, ii) construction and demolition, iii) manufacturing, iv) energy related, v) agricultural / animal husbandry, vi) municipal solid waste (MSW), that include household, commercial, institutional, vii) sludges from wastewater treatment, viii) hazardous waste (that do not belong to the above categories). While progress in SWM is evident, the path is not clear due to the large variance among the situations per country / continent. Current sustainability efforts dominate only in the developed parts of the world. For example, Europe relies on recycling, incineration and landfilling to treat MSW, the USA relies mostly on landfilling (due to low land cost) and China relies mostly on incineration to recover energy. A holistic approach—combining technology, policy, equity, and behavioral shifts—is essential to steer toward sustainability. The key to success is decoupling economic growth and prosperity from solid waste generation, which so far looks impossible. The question is not whether we are on the correct path, but whether we are moving fast enough to redefine waste as a resource to recovery energy and secondary materials.

ABSTRACT. Industrial Symbiosis is increasingly recognized as a practical solution for reducing waste, minimizing resource depletion and lowering greenhouse gas emissions. By connecting diverse industries through resource-sharing networks, businesses can significantly improve their operational efficiency while contributing to broader environmental objectives. Case studies like Kalundborg Symbiosis in Denmark showcase the potential of Industrial Symbiosis to facilitate cleaner production processes, reduce operational costs and promote circular strategies for long-term sustainability. The adoption of Industrial Symbiosis, however, is not without challenges. One major barrier is the considerable upfront investment required to establish the necessary infrastructure for resource exchange systems. Additionally, technical feasibility constraints, including the compatibility of waste streams and logistical challenges, often limit the scalability of Industrial Symbiosis initiatives. Non-technical barriers such as limited awareness, insufficient stakeholder engagement and a lack of knowledge-sharing platforms further complicate efforts to expand Industrial Symbiosis practices. Furthermore, regulatory frameworks in some regions fail to provide adequate incentives for industries to embrace symbiotic partnerships, underscoring the need for policy reforms that support cross-sector collaboration. To overcome these barriers, the LIAISE COST Action was established to create a platform for collaboration, research and innovation in Industrial Symbiosis. The initiative was born out of the need to address existing obstacles such as fragmented knowledge, limited cross-sector cooperation and the lack of clear policy frameworks that hinder the adoption of Industrial Symbiosis practices. By bringing together experts from diverse fields, LIAISE actively works to develop strategies, share insights and create solutions that drive sustainable industrial transformation. The LIAISE COST Action is dedicated to advancing sustainable industrial practices through the promotion and application of Industrial Symbiosis as a transformational tool. By connecting industries through resource-sharing networks, LIAISE aims to support the transition towards a Circular Economy and contribute to achieving climate neutrality. The LIAISE COST Action’s research coordination objectives focus on producing and continuously updating state-of-the-art knowledge in Industrial Symbiosis and its subareas. This involves addressing technical, regulatory, governance, financial, and training drivers and barriers to support wider implementation. To enhance the integration of Industrial Symbiosis processes, LIAISE coordinates and consolidates research outcomes by leveraging ICT tools and databases on by-products and waste. These efforts aim to define optimized holistic approaches that improve Industrial Symbiosis performance and promote its use in industries across Europe and beyond. By synthesizing and improving existing knowledge from regional, national, and European contexts, LIAISE develops coherent strategies that support Industrial Symbiosis implementation. Moreover, LIAISE establishes a collaborative platform that enables knowledge exchange by providing access to training materials, peer-to-peer contacts, reports, and documentation. Furthermore, LIAISE serves as a stakeholder platform to identify barriers, needs and requirements from various sectors through a bottom-up approach, engaging industries, academia, and policymakers. By raising awareness of the negative consequences of the linear economy, LIAISE encourages policy adoption and promotes Industrial Symbiosis practices. LIAISE has established four working groups to organize its activities effectively. WG1 focuses on Industrial Symbiosis technical synergies, improving resource-sharing practices to enhance sustainable development. WG2 concentrates on developing frameworks that support Industrial Symbiosis business models and financial mechanisms. WG3 is dedicated to raising awareness, acceptance, and engagement with Industrial Symbiosis through training, supporting tools, and governance frameworks. WG4 ensures impactful dissemination and outreach efforts to maximize the Action’s impact during and beyond its four-year duration. LIAISE has established four working groups to organize its activities effectively. WG1 focuses on Industrial Symbiosis technical synergies, improving resource-sharing practices to enhance sustainable development. WG2 concentrates on developing frameworks that support Industrial Symbiosis business models and financial mechanisms. WG3 is dedicated to raising awareness, acceptance, and engagement with Industrial Symbiosis through training, supporting tools, and governance frameworks. WG4 ensures impactful dissemination and outreach efforts to maximize the Action’s impact during and beyond its four-year duration. Through collaboration among researchers, policymakers and industry stakeholders, LIAISE facilitates knowledge exchange, best practice sharing and innovative solutions that enhance the implementation of Industrial Symbiosis across Europe. This paper explores the potential of Industrial Symbiosis as a transformative strategy for addressing industrial challenges and mitigating climate change. Drawing on insights from the LIAISE COST Action, the study highlights how Industrial Symbiosis fosters resource efficiency, promotes Circular Economy practices and reduces environmental impacts by enabling the exchange of resources such as energy, water, and raw materials across industries.

ABSTRACT. Hubs for Circularity (H4C) are expected to play a critical role in sustainable regional development across Europe. These H4C, implemented based on the industrial symbiosis concept, represent encouraging opportunities not only for companies located in industrial zones with heavy carbon emissions but also for the surrounding rural and/or urban ecosystems to achieve resource/energy savings, decarbonization, and reduced health impacts.

Within this framework, “From Industrial Symbiosis to Hubs for Circularity (IS2H4C)” project (https://is2h4c-project.eu/) aims to scale up circular technologies such as carbon capture and utilization, electrolysis for hydrogen production, e-fuels production, etc. from technology readiness levels (TRL) 3-6 to TRL 7-9 to facilitate implementation of industrial symbioses in the establishment of near-commercial-scale H4C. The project aims to develop four first-of-a-kind H4C in the Netherlands, Germany, Türkiye, and Basque (Figure 1) country via deployment and demonstration of these scaled up technologies and integration of existing and new infrastructure connecting industrial zones (dominated by process industry) with the surrounding urban/rural ecosystems.

A key objective of the IS2H4C is to ensure the resilience and sustainability of H4C by taking into account the interconnected dimensions of planet, people, and profit. To support broader adoption, the project seeks to facilitate market penetration of H4C by introducing novel financial schemes and social innovation approaches. In fact, aligned with the European Commission’s Green Deal and Circular Economy Action Plan, H4C are expected to be exemplary for sustainable business development where green investments from both public and private financial institutions will play a facilitator role to tackle with high investment and operational costs of circular technologies enabling industrial symbioses.

Central to the project is the development of a digital collaboration platform that enables effective information-sharing and smart decision-support among stakeholders. Additionally, IS2H4C aims to establish a standardized top-down H4C design methodology that can serve as a replicable model for regional development beyond project’s own life cycle. Finally, the project is committed to maximizing the wider uptake and long-term impact of its results, ensuring their relevance and application both during and beyond the project’s execution.

This study aims to reflect on the first 16 months of the IS2H4C project, summarize up-to-date achievements, findings from project deliverables and milestones, challenges faced during the project execution, and sheds a light to the remainder 33 months of the project. The study shares lessons learned from all work packages (WPs): technological advancements (WP2), implemented field work in hubs (both technology and infrastructure, WP6), results of drivers-barriers-enablers analyses for implementation of H4C and outcomes of stakeholder interviews (WP3), a summary of initial hub optimization models based on descriptive, predictive, and prescriptive analytics and decision-support tools developed by project partners for effective operations of the hubs (WP4), potential innovative circular business models and financial strategies to support these business models (WP5) and the alpha version of the digital collaboration platform, i.e., DigitalH4C, which facilitates cyber-safe management of physical H4C (WP7).

ABSTRACT. Smart agriculture leverages AI, machine learning, IoT, and robotics to transform traditional farming, addressing challenges like population growth, labor shortages, and environmental sustainability. This study explores how autonomous machinery - such as tractors, drones, robotic harvesters, and swarm robotics - is reshaping modern agriculture by enhancing efficiency, precision, and resilience. This study is a Case Study where Precision Drone Spraying and Bonsai Robotics’ Orchard Systems are used in a common innovative establishment. A Cost-Benefit Analysis on these agricultural automation technologies was performed. The innovative establishment was found in the region of Heraklion Crete, where drones for precision spraying in vineyards are used alongside the performance of robotic automation for practices like olive tree pruning. Results demonstrates that agricultural automation technologies offer substantial economic, operational, and environmental benefits. While high initial capital investments may pose financial barriers, the long-term cost savings, increased productivity, and sustainability advantages significantly outweigh these costs.

ABSTRACT. The concept of double materiality has emerged in the European regulatory context with the European Sustainability Reporting Standards (ESRS) developed under the Corporate Sustainability Reporting Directive (CSRD). Double materiality reflects a double perspective on the relevance of sustainability, On one side, it considers how environmental, social, and governance (ESG) factors impact the financial performance and the position of the company (financial materiality). On the other side, it captures the impacts that the company itself has on the environment and society (impact materiality) (EFRAG, 2023). According to the global reporting initiative (GRI), this approach marks a paradigm shift in corporate reporting, positioning the organizations not only as economic agents but also as societal actors with wide-ranging responsibilities, while in the past, the materiality assessment was done only with one perspective, the impact one (Global Reporting Iniciative, 2022).

ABSTRACT. At the regional level, the goals and activities of innovation ecosystems are typically aligned with both national and regional innovation strategies such as the Smart Specialisation Strategy promoted by the European Union since 2015 (European Parliament Resolution 2015/2278(INI); Rissola and Sörvik, 2018). Local innovation ecosystems, where innovation hubs operate, are inherently complex and dynamic. They serve as environments that foster the development and diffusion of innovation. Hoffecker (2019) defines innovation ecosystems as “place-based communities of interacting actors engaged in producing innovation and supporting processes of innovation, along with the infrastructure, resources, and enabling environment that allow them to create, adopt, and spread more effective ways of doing things”. Their collaborative nature enables stakeholders to create value that no single organization can achieve on its own (Granstrand and Holgersson, 2020). Within this context, the present study focuses on a circular hub functioning as an innovation system that delivers targeted services to accelerate innovation, supporting the development of competencies among ecosystem actors and building a robust scientific knowledge base for sustainable innovations. This research is grounded in innovation management and Open Innovation (OI) (Chesbrough, 2003). It is based on related theoretical perspectives, including innovation ecosystems (Adner and Kapoor, 2010), which emphasise the interdependencies among actors that co-create value; collaborative innovation (Heil and Bornemann, 2018), which highlights the importance of partnerships in the innovation process; and innovation hubs as spaces that facilitate collaborative R&D, innovation, and knowledge creation (Doloreux et al., 2023). Circular hubs, as a type of innovation hub, can be conceptualized as both physical spaces that enable innovation (Jiménez and Zheng, 2021) and virtual environments that support distributed collaboration, data flows, and knowledge exchange. Their core function is to foster innovation and co-creation among diverse stakeholders within the regional innovation ecosystem. The concept of OI (Brunswicker and Vanhaverbeke, 2015; Chesbrough and Vanhaverbeke, 2018) offers a broader theoretical lens for understanding collaborative R&D and knowledge flows within these hubs. OI refers to the strategic use of external sources of innovation to complement and enhance a company’s internal capabilities. It involves the deliberate inflow and outflow of data (resources and waste) and knowledge to accelerate internal innovation processes and expand markets for external innovations (Chesbrough, 2003). A key tenet of OI is its focus on value creation and value capture, particularly the generation of innovation-based value for customers (Chesbrough, 2003). This aligns with the role of circular hubs in creating shared value for multiple stakeholders. Innovation hubs embedded within local ecosystems (Remneland and Styhre, 2022) typically bring together multiple actors around a shared thematic focus, such as the circular economy. From a practical perspective, Siebert et al. (2019) describe innovation hubs as a combination of physical and digital workspaces and tools that facilitate interaction among community members for learning and innovation. Specifically, digital innovation hubs support companies in exploring and adopting digital technologies to enhance efficiency, improve product quality, and boost overall competitiveness (Kalpaka et al., 2020). Therefore, our study aims to explore the role of circular hubs within regional innovation ecosystems and understand how they can support sustainable transitions through innovation and co-creation. Specifically, it seeks to address the following research questions: What is the need for a circular hub in a particular region? What is the hub's vision, and who benefits from its value? What unique value does the hub provide? Who are the key players and strategic partners? How are operations structured to foster innovation and co-creation within regional innovation ecosystems? This study adopts a qualitative, multi-stage case study research design (Eisenhardt, 1989). The case study method allows for an in-depth exploration of a specific phenomenon and is particularly effective for investigating new or unique phenomena (Yin, 2005). Case selection was guided by the principles of maximising learning (Stake, 1995) and ensuring access to relevant information (Perry, 1998). In line with Viitanen (2016), this research focused on three case hubs from the Interreg-Europe Project Cheers4EU: Chemelot Hub (Netherlands), PARVIC Hub (Czech Republic), and Skive Hub (Denmark). These hubs were studied concurrently to capture the complexity and contextual variability of circular innovation ecosystems. The research was carried out by a transdisciplinary research team covering areas such as management, industrial engineering and management, law, chemical engineering, natural sciences, and civil engineering. This diverse expertise contributed to more robust data interpretation and enhanced the reliability of the findings. The primary data collection method consisted of workshops involving various stakeholder groups, designed to uncover their needs, expectations, and visions for hub operations. Semi-structured interviews were conducted with key stakeholders to complement the workshops and deepen the insights. Additionally, a desk study was performed, drawing on publicly available information and project documentation. The collected data were analysed using thematic analysis and categorisation techniques to identify key themes and patterns across cases. To ensure the validity and consistency of interpretations, triangulation (Denzin, 1973) was applied by involving multiple researchers in the analysis process. This study expects to generate actionable insights into best practices for the design, implementation, management, and facilitation of circular hubs. Expected outcomes include a deeper understanding of effective organizational structures, collaboration mechanisms, and business models that foster innovation and co-creation, while also offering practical guidance for policymakers, businesses, and other stakeholders seeking to establish, develop, or enhance circular hubs. Ultimately, it contributes to improved resource use efficiency, regional development, resilience, economic sustainability, and decoupling of natural resource use from wellbeing (UNEP, 2011).

ABSTRACT. The wind industry is committed to achieving full turbine recyclability, aligning with the EU's Circular Economy Action Plan and Green Deal, by pledging to fully recycle and recover decommissioned wind turbine blades (WTBs). This paper introduces a Stackelberg game model to analyze the relationship between the government, a wind turbine owner/operator, a manufacturer, and a recycler within a circular business context. The study evaluates the effectiveness of subsidy policies in promoting the eco-design of WTBs to enhance recyclability while preserving their mechanical properties. The findings indicate that substantial upfront investments by society are necessary to achieve full recyclability. However, these investments are justified, as the societal benefits—both economic and environmental—far outweigh the costs, particularly when recycling methods like microwave pyrolysis, which result in positive net greenhouse gas emissions, are employed.

ABSTRACT. Economic transformations from industrial to service-based economies resulted in the closure of industries in several European counties and brownfields containing soil contaminated with hydrocarbons, polyaromatic hydrocarbons and heavy metals leaching to soil and groundwater. Therefore, these sites were made unsuitable for agriculture and pose health threats to citizens living close by. This study investigates the operational and environmental costs of contaminated soil bioremediation with biopile technology. This treatment technology involved piling contaminated soil and stimulating aerobic autochthonous microbial activity through aeration and the addition of amendments (compost) and encapsulated nutrients (apple waste-alginate carriers).. Operational inputs were collected, to calculate environmental impacts with Life Cycle Assessment (LCA) and subsequently convert them to environmental costs, and combined with operational costs to bioremediate soil. The functional unit was 1 kg of polluted or bioremediated soil. The results (Figure 1) showed that bioremediation eliminated toxicity impacts at the expense of other environmental impacts. While initial soil pollution concerned mainly ecotoxicity impact subcategories, bioremediation affected all impact categories due to the employment of consumables. Operational costs were 0.047 €/kg soil and environmental costs were 0.002 €/kg soil (Table 1). The main contributors of operational costs and environmental costs were the purchase of sand and gravel, and Fine particulate matter formation impact, respectively. This study shows that soil bioremediation with biopile treatment was effective in eliminating initial toxicity impacts calculated with LCA. This is crucial when soil pollution needs to be handled and eliminated. However, bioremediation resulted in increasing other environmental impact values (for a short period) and dominated cost calculation.

ABSTRACT. This study introduces eventCO₂, a digital tool designed to calculate and visualize the carbon footprint of events by evaluating emissions from activities such as transportation, energy use, catering, procurement, and waste. Built on the GHG Protocol and ISO 14064-1 standards, eventCO₂ provides real-time calculations and interactive engagement with participants to raise environmental awareness and promote sustainability The tool supports event organizers in identifying major emission sources, planning reduction strategies, and moving toward carbon-neutral event management.

ABSTRACT. The transition to a circular economy in the steel and cement industries requires optimizing supply chain decision-making to overcome barriers and achieve large-scale implementation. Steel slag carbonation presents a promising solution, sequestering up to 75% of CO₂ while transforming industrial residues into valuable raw materials for cement production. This process not only reduces carbon emissions but also enhances resource efficiency by partially replacing clinker, the most carbon-intensive component of cement. However, challenges such as slow reaction kinetics, high processing costs, and supply chain inefficiencies hinder widespread adoption.

This study develops a system dynamics-based framework to address key barriers to industrial implementation. The model incorporates multiple decision variables, including production costs, carbon sequestration efficiency, economic feasibility, pricing, and regulatory compliance. By simulating intervention scenarios, the framework identifies optimal strategies to maximize CO₂ capture, reduce waste, and enhance economic sustainability. Preliminary results suggest that carbonated slag can replace up to 30% of cementitious materials while achieving sequestration rates of 536 kg CO₂ per tonne of slag under optimized conditions.

Furthermore, the study introduces a market-driven system dynamics approach to analyze supply-demand interactions, optimal pricing, and policy interventions. Unlike traditional economic models, this approach integrates material availability, consumer behavior, and regulatory incentives to support commercial adoption. Through scenario analysis, it provides insights for industry stakeholders and policymakers to optimize pricing strategies, assess policy impacts, and drive sustainable industrial transformation.

By demonstrating the environmental and economic benefits of steel slag carbonation, this research advances circular supply chain management and highlights the role of system dynamics in supporting low-carbon industrial solutions. Future work will refine the model with real-world data and adaptive policy frameworks, further promoting the transition to circular, low-carbon economies.

ABSTRACT. The transition to a circular economy in the energy sector requires optimizing supply chain decision-making to facilitate the large-scale adoption of alternative fuels. Synthetic natural gas (SNG), produced by combining CO₂ captured from industrial emissions with hydrogen from water electrolysis, presents a promising renewable energy solution. This process not only reduces greenhouse gas emissions but also enables industrial symbiosis, where CO₂ emissions from one sector become valuable inputs for another. Integrating SNG production into circular supply chains enhances resource efficiency, minimizes waste, and reduces dependence on fossil-based methane.

This study develops a system dynamics-based framework to assess the substitution of natural gas with SNG in the Basque Country, leveraging CO₂ reuse from energy-intensive industries. The model incorporates key factors such as CO₂ capture efficiency, economic feasibility, supply chain logistics, and regulatory compliance. By simulating policy and investment scenarios, it provides insights into optimizing industrial symbiosis, reducing emissions, and accelerating SNG adoption. The study follows a demand-driven approach, analyzing how pricing strategies, supply availability, and regulatory incentives influence market penetration, particularly in transport and industrial applications.

The regulatory landscape in Spain and the EU supports renewable fuel adoption, with policies such as the Plan Territorial Sectorial de Energías Renovables de Euskadi, Real Decreto-ley 18/2022, and the REPowerEU program promoting industrial decarbonization. The CO₂ methanation process, known as the Sabatier reaction, operates optimally at 300–400°C and 1–10 bar to maximize methane yield and stability. Understanding the trade-offs associated with SNG production, including increased water and electricity demand, is essential for evaluating its long-term sustainability.

By providing a quantitative decision-support tool, this research advances circular supply chain management and supports the transition to low-carbon energy systems. Future work will refine the model with real-time market data and evolving regulatory frameworks to enhance its industrial applicability.

ABSTRACT. The shift to a circular economy (CE) is increasingly seen as important for addressing the complex challenges of population growth, climate change, and the need to boost production in food, feed, fiber, and bioenergy amidst depleting natural resources. Due to their sheer size and complexity, supply chains are viewed as major sources of resource waste and, as such, systems in need of attention and great potential in the quest for a more responsible management of limited resources. In this context, we present a general, empirically relevant, integrated multi-market framework that illustrates the supply chain transition to a more circular system and enables the development of technical, environmental, and economic metrics of circularity. Additionally, we discuss the economic issues that arise during this transition and the policy options to support a successful shift towards more circular supply chains.

ABSTRACT. The transition towards a Circular Economy (CE) for electrical and electronic equipment (EEE) in the UK is crucial due to increasing volumes of electronic waste (e-waste) and resource depletion. This study provides a comprehensive systems analysis of the WEEE sector, identifying key barriers and enablers for the CE transition in the EEE sector in the UK, while also exploring tensions between circular strategies across EU WEEE categories. A multi-method approach is employed, including a PRISMA-guided systematic literature review of 112 sources coded using MAXQDA, expert interviews with industry stakeholders, and a Group Model Building (GMB) workshop to validate findings and inform a causal loop diagram (CLD).

Key barriers identified include informal e-waste handling, limited infrastructure for e-waste recovery, environmental and health risks from improper e-waste management, lack of consumer knowledge and awareness, limited availability and traceability of e-waste data, and environmental and health risks from improper e-waste management. Enablers include strengthening governmental policies and regulations, promoting eco-design practices for product longevity, advancing sustainable technologies, encouraging collaboration, increasing consumer knowledge and awareness, and improving collection infrastructure. The study also highlights tensions between CE strategies, particularly reuse versus recycling, and repair versus reduce. These tensions vary by product category: reuse is more viable for IT and telecommunication equipment, while repair and reduce are less feasible for small household equipment. For large household equipment, energy efficiency and material value influence end-of-life decisions.

By combining systems thinking with stakeholder perspectives, this research identifies leverage points for systemic change and offers actionable insights for policymakers and industry to support a more circular EEE sector in the UK.

ABSTRACT. This study evaluates the carbon footprint associated with the production of Sultana grapes procured by Voicevale from over 100 vineyards in Manisa, Turkey. Utilizing agriCO₂, a data collection and carbon accounting tool developed by 3pmetrics specifically for agricultural products, the analysis was conducted in alignment with the GHG Protocol methodologies. Field-level data on energy use, agricultural inputs, and logistics were collected and analyzed. As a result, the cradle-to-farm-gate carbon intensity was calculated as 0.249 kgCO₂e per kg of grapes. This field-based approach offers actionable insights for sustainable sourcing practices and transparent environmental reporting in the agri-food supply chain.

ABSTRACT. The Circular Economy (CE) provides a transformative framework for restructuring agri-food supply chains from linear models toward regenerative, closed-loop systems. Given the sector’s intensive resource use and environmental impact, the integration of CE principles—such as resource efficiency, waste valorization, and regenerative design—is essential [1]. Applications include repurposing organic residues and leveraging digital tools for traceability and resource monitoring [2,3], which help reduce losses and improve system efficiency. However, achieving circularity in agri-food systems requires more than isolated interventions; it demands system-wide coordination and strategic redesign across supply chain stages [4]. To address this complexity, decision-making frameworks are needed to help stakeholders prioritize and implement CE strategies [5]. Tools like Quality Function Deployment (QFD) can translate CE goals into actionable supply chain decisions, supporting long-term sustainability, resilience, and innovation in agri-food systems [6]. In this study, the basic structure of the House of Quality (HoQ) from the QFD methodology is adapted to serve as a decision-making framework for integrating CE principles into agri-food supply chains. To enhance accessibility and reflect real-world expert judgment, the model incorporates linguistic variables through the 2-Tuple Linguistic Model [7] -2TL-HoQ-, supported by Linguistic Hierarchies (LH). This approach allows decision-makers to express their evaluations using linguistic terms of varying granularity, depending on their expertise, thereby fostering a more intuitive, human-centered assessment environment. To validate the framework, five domain experts contributed assessments, each representing a specialized area: sustainability, circular economy, sustainable agriculture, supply chain management, and agri-food systems. Drawing from academic and grey literature, the model identifies eight core CE principles as Customer Needs (CNs), including goals related to waste elimination, regenerative resource use, ecosystem health, energy efficiency, resource circularity, and responsible biomass allocation. These are then linked to six key Design Requirements (DRs) corresponding to critical stages in the agri-food supply chain: material and resource management, production processes, logistics and distribution, packaging and storage, digitalization and traceability, and stakeholder-driven business model innovation. The resulting framework offers a structured, yet flexible tool to support strategic decision-making under CE priorities in agricultural contexts. The following figure (also showing the detected CNs and DRs) presents an example of the second expert’s assessment—representing the supply chain domain—for the relationship matrix within the HoQ. Based on individual assessments provided by five experts, the final prioritization of the DRs was obtained through an aggregation process. Subsequently, a sensitivity analysis was conducted to examine how variations in CE priorities influence the resulting rankings. The findings of this study, based on expert assessments and scenario-based sensitivity analysis, highlight the strategic centrality of Digitalization and Traceability (DR5) in advancing circular agri-food supply chains. Its robust performance across diverse contexts reflects both its systemic importance and alignment with emerging policy trends such as the EU Digital Product Passport and broader digitalization in agriculture. In contrast, other DRs demonstrated scenario-dependent variation: DR2 and DR1 showed consistent relevance in process- and input-focused scenarios, while DR6 gained prominence under collaborative and systemic transition contexts. DR3 and DR4 remained lower in priority, suggesting that without integration into broader strategies—such as reverse logistics or consumer engagement—they offer limited leverage for CE transformation. These findings offer multiple academic implications. First, they validate the robust prioritization of DR5 as a foundational requirement for circular transition in agriculture [4]. Second, they reveal the adaptive relevance of certain DRs (e.g., DR1, DR6), which gain or lose importance depending on the CE objective emphasized. Third, the application of scenario-based weighting within the QFD framework provides a nuanced understanding of how diverse CE visions influence strategic priorities across the supply chain. This not only supports more tailored decision-making but also enhances the explanatory power of QFD as a methodological tool for structuring complex sustainability trade-offs. Ultimately, this approach demonstrates the value of integrated, expert-informed, and flexible design frameworks in supporting the strategic transformation of agri-food systems under CE paradigms.

ABSTRACT. The hospitality sector, particularly small and medium-sized enterprises (SMEs), plays a crucial role in addressing global environmental challenges such as climate change, resource depletion, and waste generation. This research focuses on the adoption of circular economy (CE) practices in SMEs within the hospitality sector of Limburg, the Netherlands. The region, known for its thriving tourism and culinary heritage, presents unique opportunities for implementing sustainable business models that prioritize resource optimization, material circularity, and waste reduction. Using a mixed-methods approach, this study combines quantitative data from surveys distributed to hospitality SMEs with qualitative insights from in-depth interviews and case studies. The survey assesses current awareness, attitudes, and practices regarding CE, as well as the barriers faced by SMEs in adopting these principles. Key obstacles identified include financial limitations, knowledge gaps, and the lack of technological resources. Interviews with key stakeholders provide deeper insights into the challenges and opportunities for integrating CE practices, while case studies of successful implementations highlight best practices and success factors. Preliminary findings reveal that while awareness of CE concepts is growing, there is significant variation in the level of adoption across businesses. Resource optimization, waste reduction, and digital integration are among the most promising areas for improvement. However, many SMEs require additional support in the form of policy incentives, access to funding, and tailored training programs to fully embrace circular practices. The study also explores the role of regional governments and industry associations in creating an enabling environment for CE adoption. This research contributes a framework specifically designed to integrate CE principles into the daily operations of hospitality SMEs, addressing their unique challenges and leveraging their potential for sustainable growth. Additionally, it evaluates the environmental and economic benefits of CE implementation, demonstrating how these practices can reduce waste, lower costs, and enhance business competitiveness. Recommendations for local policymakers and industry leaders include targeted financial incentives, improved access to digital tools, and collaborative initiatives to foster a circular economy mindset. By focusing on Limburg's hospitality sector, this study provides region-specific insights that are relevant to both industry practitioners and policymakers. The findings aim to promote sustainability and resilience within the hospitality industry while offering a replicable model for other regions and sectors seeking to transition towards circular economy practices.

ABSTRACT. Traditional linear systems based on extraction and disposal no longer support sustainable development. Circular Business Models (CBMs) offer an alternative by closing resource loops, reducing input dependency, and recovering value from waste. While these models are expanding in industrial sectors, their use in agriculture remains limited. The objective of this study is to identify Circular Business Models in the literature and explore which ones are more suitable for the agro-industry sector. The study builds on the OECD (2023) CBM typology and aims to connect academic literature with sector-specific needs. Although CBMs have been increasingly studied, limited research has assessed their relevance to the operational and policy challenges of agro-industrial systems. This gap in the literature highlights the need for a sector-focused synthesis of models, applications, and implementation barriers. The Circular Business Models defined by the OECD are: i) Circular Inputs, involving the substitution of virgin or polluting inputs with renewable, recycled, or bio-based materials; ii) Product Use Extension, focusing on extending the life of products through repair, refurbishment, resale, and reuse; iii) Sharing Models, aimed at increasing the utilization of underused assets by allowing multiple users access to the same resource; iv) Product-as-a-Service (PaaS), which provides users with the functionality of a product without transferring ownership; v) Resource Recovery, involving the reclamation of useful materials, nutrients, or energy from waste streams; vi) Circular Design, emphasizing the creation of durable, modular, easy to repair, and recyclable products. A literature review was conducted using the Scopus and Web of Science databases to identify the main characteristics and applications of CBMs in general and in the agro-industry sector in particular. After defining the six CBMs, their application in the agro-industry was explored, as summarized in Table 1.

This study makes several contributions to the understanding and application of Circular Business Models in the agro-industry sector. First, it comprehensively reviews existing CBMs in the literature, offering a structured synthesis of their core principles, strategies, and implementation frameworks. Second, it evaluates the suitability of different CBMs for the agro-industry by considering sector-specific challenges. Third, it identifies the most effective CBMs for enhancing circularity in agro-industry value chains, contributing to both theoretical knowledge and practical applications. Finally, it provides a foundation for policymakers, businesses, and researchers to design and implement circular strategies that promote sustainability and resilience in agro-industrial systems.

ABSTRACT. The “Sorbent based processes for highly efficient and compact CO2 capture technologies” – SHEETS research and demonstration project funded by the Clean Energy Transition Partnership-2023 (CETP-2023 HORIZON EUROPE program) has recently started in March 2025 with a duration of 36 months. Coordinator of the project is SINTEF (Norway) leading a consortium of 2 Research Organisations (CNRS and CRES) , 4 Large Enterprises (Munters, Saint-Gobain, TotalEnergies and KANFA), a municipal enterprise (BIR) and a non-profit organization (Axel’ One) from 4 countries (Norway, France, Sweden and Greece) with a total budget of 2,532,276.03 € funded by 66% through the CETP program. The SHEETS project deals with the development of cheap and scalable sheet-shaped sorbent modules for CO2 capture processes. This involves subsequent development steps starting from 1) preparation and testing of structured sorbents to 2) adsorption process cycle design and process optimization to 3) design and construction of two proof-of-concept demonstrators to validate the technology at TRL5, and finally 4) sustainability assessment through TEA, LCA and an assessment of social impact, to maximize societal impact. The overall objective of the SHEETS project is to develop cheap and scalable sheet-shaped sorbent modules for CO2 capture processes having optimal volumetric sorption capacities and fast sorption kinetics giving CO2 purities above 95% and capture rates above 90% using sorption/desorption cycle times below 2 minutes for end-of-pipe/post-combustion contexts to assure a reasonable footprint of the process. The main aim of the project is to optimize the production and performance of sheet-shaped sorbents for a limited number of selected sorbents for CO2. Only sorbents with proven high water/steam stability will be examined. The sheet shaped sorbents will be evaluated for post-combustion CC and for DAC/low CO2 concentrations. The SHEETS project will develop production processes for sheet-shaped adsorbents of various natures, the choices being based on CO2 adsorption capacity, CO2/N2 selectivity, chemical stability of sorbent and (tentative) price of multi-tonne amounts of sorbent. Since both post-combustion CO2 capture and direct air CO2 capture/low CO2 concentrations are targeted in the project, both sorbents that can capture significant amounts of CO2 at 400 ppm CO2 concentration (DAC condition) will be tested, in the range of 4 to 20 vol% CO2 (post-combustion). Since the ease of sorbent regeneration is one of the major contributions to the process energy requirement, a sorbent suitable for DAC may not be the best suited for post-combustion use. The sheet-shaped adsorbents developed will be up-scaled to pilot capacities to demonstrate the relevance in terms of properties, reproducibility, quality control and costs for industrial applications. For both pilots (post-combustion and DAC/low CO2 concentrations), the structured sorbent modules will be integrated into systems to provide the correct flow, temperature, steam properties, and if in rotor format, the rotation rate. Two pilots will be designed, installed and tested for technology verification. The first one will be hosted by Munters, which will build and host the post-combustion pilot, operates labs for designing, building and testing/verification of prototypes for various air treatment applications. The pilot may be based €)on a Munters dehumidification air treatment system, but with components and configuration adapted in accordance with the findings from earlier WPs. The second pilot for DAC/low CO2 concentrations will also be designed and built by SINTEF and Saint-Gobain, and this will be tested by Saint-Gobain for both DAC and an industrial source with low CO2 concentration (1-3%) at one of their ceramic plants. This will be a one column VTSA pilot using the same type of sorbent modules as the post-combustion pilot. These two pilots constitute demonstration of the SHEETS project at TRL 5. Successful development in the project will contribute to minimizing or avoiding adverse impact on human health and the environment since solid sorbent-based processes are believed to have less emissions to the atmosphere and less waste issues than state-of-art amine scrubbing-based technologies. In SHEETS, robust life cycle assessment (LCA) and techno-economic analysis (TEA) will be performed that fully address the environmental, social, and economic implications that might impact industry adoption of the proposed technology. Finally, the project will contribute to accelerating to the clean energy transition with a significant reduction of CO2 emissions by 2030 and to the climate neutrality by 2050.

Acknowledgments This research is supported by the CETP 2023 programme under the grant agreement No. CETP-2023-00028, SHEETS project. This output reflects only the authors' view, and the European Union cannot be held responsible for any use that may be made of the information contained therein.

ABSTRACT. Within the context of the Horizon Europe-funded Sustainable Circular Economy Transition: from Industrial Symbiosis to Hubs for Circularity (IS2H4C) project, the Almelo-Twente Hub for Circularity (H4C), located in the Netherlands, presents a promising case study for the cultivation and evaluation of industrial symbiosis synergies. At first, it is examined how the implementation of a green hydrogen system (production-storage-distribution) facilitates the decarbonization related to the heating requirements of five buildings in the village of Aadorp, and the operation of the local crematorium, by replacing natural gas as the main fuel. Next, the contribution of the electrolysis-produced oxygen in narrowing resource loops and further avoiding carbon emissions is also quantified.

ABSTRACT. The integration of waste into the production of construction materials may show significant environmental benefits within the entire construction industry, particularly when evaluated with Life Cycle Assessment (LCA). This approach aligns sustainable development goals by addressing critical environmental concerns associated with traditional construction materials and aims to reduce greenhouse gas emissions, conserve natural resources, and divert waste from landfills. This study evaluated the production of a light clay brick (henceforth called brick) and a 30 MPa concrete block (henceforth called block) using waste limestone and waste from cement production, respectively, with LCA. The LCA was limited to the global warming category and considered a cradle-to-grave approach for both waste-derived products. The environmental impact assessment occurred with ReCiPe 2016 Midpoint model (H). The results showed that the block resulted in global warming benefits of approximately 45%, while the brick resulted in a global warming burden of approximately 17% when compared with reference products (Figure 1). For both products, the production of Portland cement (a main input material) was the dominant contributor (78% and 87% for the brick and block, respectively), whilst transportation of input materials also contributed between 7-10%. To conclude, replacing input materials in the production of construction materials does not necessarily result in global warming benefits because replacing materials may not be the dominant contributor to global warming impact. Lastly, this study focused on global warming; but it is also important to calculate other environmental impacts, because the latter may not have Portland cement as their main contributor.

ABSTRACT. In the construction sector, the circular economy concept serves as an economic model that considers the construction of buildings and their infrastructure to keep resources, products, and components at their highest possible technical, financial, and environmental qualities. Aiming to promote the adoption of circular economy practices, the European project CO2NSTRUCT (Horizon Europe, 2022–2026) incorporates consumer behavior toward the circular economy and climate change mitigation into future plans. In order to accomplish this goal, approx. 4500 participants in nine European countries participated in a consumer behavior survey that examined their opinions and views regarding circular economy practices in the building sector. The participants were questioned about their attitudes and motivational factors towards performing residential renovations, which correspond to the repair (R4) and refurbishment (R5) circular practices. The participants were questioned about the frequency of residence renovation by renovation category (light, medium, in-depth). Regarding light renovation, the most common answer is "every 2-5 years"; the most common responses for medium and in-depth renovations are "every 5-10 years" and "never", respectively. Moreover, participants were asked to select the factors motivating them to renovate their residences. In the overall sample, the most critical factors were "improve life quality" and "reduce energy costs". Other important factors for participants were the "improved thermal comfort" and the "improved energy efficiency". On the other hand, "change living settings" and "CO2 emission reduction" were considered as less important factors for respondents. A set of tests was performed to examine the existence of statistically significant differences between the nine countries. The results of the tests indicate that there are statistically significant differences in all variables under examination on a significant level of a = 0,01, apart from the variable "Factors motivating residence renovation: Environmental benefits".

ABSTRACT. The Sustainable Development Goals (SDGs) were prepared by the United Nations in 2015 as a universal call to action to end poverty, protect the planet, and ensure peace and prosperity for all people by 2030. This effort entails reevaluating conventional architecture education to include sustainability literacy, eco-friendly construction techniques, and novel pedagogical approaches to enhance students' comprehension of sustainable design. This study demonstrates the curriculum practice of a graduate program developed by the newly established Faculty of Architecture at Hacettepe University, supporting the improvement of the quality of education and training through technical, dynamic, and sustainable methodologies. The Faculty of Architecture also seeks to deliver an architectural education focused on fostering the understanding of constructing comfortable, healthy, and disaster-resistant edifices through the efficient utilization of the natural environment and careful consideration of energy, water, and material usage. Since being guided by this sensitivity, the faculty is preparing to launch a “Sustainable Architecture Master’s Program” to address the contemporary needs of Turkey's architectural community. The curriculum is built around global approaches to the topic of sustainability and the SDGs. Following the assessment on the impacts of these goals on the creation history of a graduate education curriculum in architecture, it is possible to provide the connection between the theoretical framework and practical attempts by preparing the courses that align with the SDGs for a sustainable built environment. Accordingly, a road map is also determined to improve this program, which will be developed with the opinions of external consultants, in line with students’ opinions. At last, a graduate program in ‘sustainable architecture’ was prepared to provide the integration of environmental sustainability within architecture curricula, which makes it a pioneer in revealing the contribution of graduate education to the intervention criteria concerning ecological design and green architecture in Türkiye.

ABSTRACT. This article presents the evolution of an international collaboration begun in late 2023 from a video-meeting, followed by an exchange of letters between pupils of two Primary classrooms in Italy and Latvia, to become in 2025 an international project on environmental sustainability in the Erasmus+ frame, characterized by a cooperation that involves education levels wider than usual. The collaboration is taking advantage on the flexibility and verticality of the environmental sustainability as a topic suitable for discussions at all ages. Presently the network involves representatives of 7 universities and 5 schools in three European countries (Italy, Latvia, Romania) but the seed event was a video-call organized to allow the pupils of a classroom of the primary level (3rd grade) of the Collegio Arcivescovile in Trento (Italy) and of the Babite School near Riga (Latvia) to meet together in December 2023 (using English as common language). There, an idea was presented: writing an Italian-Latvia book by pen-pals. The book was presented in May 2024 to the two embassies receiving their patronage. The contents were not strictly related to the environmental sustainability but they were seed of a new idea based on it: find a project that could enlarge the contacts among pupils and open to collaboration with higher levels of education. The contacts already available allowed to focus on a tool to be adapted to the case study: the Erasmus+ Blended Intensive Programmes (BIP), in progess since 2025. Even if BIP is a typical project for universities, some aspects of environmental sustainability can be considered a meeting point between students and pupils of a wider age spectrum. The plastic issue is a recurrent topic and will cross the BIP by another international project. Pupils will contribute to the project by questions and observations from their direct experience. A replication is expected.

ABSTRACT. The fashion industry faces several environmental challenges by following the linear economy model due to the high rates of production and consumption dictated by fast fashion, resulting in the overproduction of products and their high disposal rates in a short period. This linear textile system puts pressure on resources, leaves many economic opportunities untapped, and has adverse effects on the environment.

To address environmental impacts, Europe adopted the Waste Framework Directive in 2018 (851/2018/EU), which, among other things, mandates Member States to adopt separate collection for textile waste by 2025 as part of the circular economy. In March 2024, the European Parliament adopted the proposal to revise the aforementioned Waste Framework Directive, according to which EU countries are required to establish extended producer responsibility (EPR) schemes for the separate collection of textile products within the framework of the European Strategy for Sustainable and Circular Textiles (Textiles Strategy) and the Circular Economy Action Plan (CEAP). Consequently, analyzing and understanding the disposal practices of textile products currently applied by citizens is essential. The aim of this study is to investigate the disposal practices of textile waste with a case study of Greece.

A questionnaire survey was conducted as part of a diploma thesis, which included questions about the frequency of clothing purchases, clothing expenditures, their knowledge and preferences regarding fast and slow fashion, as well as the importance they place on the composition of clothing materials, with a total of 250 respondents. It is noteworthy that in the combinations of multiple responses, the respondents mostly chose correct waste disposal methods. Overall, the findings highlight some statistically significant correlations between age, the amount of money they spent on clothing, the frequency of purchases, the knowledge of the concepts of fast and slow fashion and which of these they prefer for their purchases, awareness of the materials their clothes are made of, and their discomfort with the presence of recycled materials in their clothes. These findings provide information about consumer behavior patterns and environmental awareness and consciousness.

ABSTRACT. Packaging plays a crucial role in extending the food shelf-life, enhancing its preservation, maintaining and increasing its safety, and minimizing food waste. Given the concerns over pollution of land and water ecosystems, which mainly comes from plastic packaging, the demand for sustainable, innovative, and intelligent solutions is growing. Our solution combines the traditional knowledge of beeswax wrap with R strategies of circular economy, and technology. The combined use of natural materials, such as beeswax with embedded propolis, cotton fabric, marc, pine resin, and olive oil, makes the product unique in the field of eco-friendly food packaging, for fresh and perishable food, such as vegetables, fruits, cheeses, and also individual meals, snacks, pastries, bread, legumes, and pasta.

ABSTRACT. The changing dynamics of the global aviation industry have escalated the call for transparency, ethical operations, and sustainable practices in airport contexts. Faced with increasing public pressure and regulatory expectations, airports must not only reduce their environmental footprint but also make their operations socially acceptable and ethically justifiable. However, the question of corporate ethical stigma, wherein a corporation seems to be acting against the societal ethical standards, remains a gap area of study related to airport governance and sustainability. The present research aims at bridging this gap by developing a systematic framework liable for detecting, analyzing, and measuring ethical stigma as it arises in airport corporate policy and practices as well as in firm-stakeholder interface contexts. The key aim of this paper is the development of a structured framework for the measurement of corporate ethical stigma in the aviation sector and its unique contributions toward sustainability, innovation, and strategic flexibility. It aims at emphasizing the causation of deficiencies or failures in ethical governance toward a decline in trust perception by stakeholders and affecting corporate image as well as hampering long-run sustainable progress. This study also points toward the strategic relevance of simultaneously dealing with both the business context as well as the innovation-related elements in addressing ethical stigma and corporate flexibility.

ABSTRACT. The Digital Product Passport (DPP) can play a key role in driving the dual green and digital transition. This paper presents the results of an online survey conducted in Italy to explore consumer perceptions related to the DPP, with a particular focus on the theme of altruism. This questionnaire received 549 responses. To this end, it is possible to highlight that a very clear result emerges. For this purpose, participants were asked to choose between three purchasing options: i) P1: Jeans priced at 50 €; ii) P2: Jeans with a Digital Product Passport (DPP) priced at 55 € and iii) P3: Jeans with DPP plus a 3 € donation to families in need. The social challenge of overcoming selfishness is reflected in the findings of this study: 91% of interviews chose the more expensive jeans featuring the DPP, and 58% also expressed willingness to make a donation. No significant gender differences were observed; however, individuals with an annual income above 40,000 € showed a greater inclination toward charitable giving. Notably, all age groups (except those aged 18–30) showed a clear preference for the option that included a donation, highlighting a generational gap in altruistic behavior linked to sustainability.

ABSTRACT. The Digital Product Passport (DPP) functions as a digital identification tool that compiles comprehensive information about a product’s composition, production processes, lifecycle, sustainability credentials, and ownership history. The present study investigates the implementation and potential of the DPP as a strategic tool to align business perspectives in its design, thereby facilitating the adaptation of corporate models in the shift toward more sustainable and integrated production systems. o address this, nine criteria were selected, and the insights of 10 experts were sought to identify the key factors that make the Digital Product Passport (DPP) crucial for competitiveness. The key findings from the analysis show that the most important criterion for DPP data inclusion is reuse, repair, and recycling, with a value of 0.592, reflecting the strong focus on circular economy and end-of-life management. Similarly, the importance of Made in Italy is becoming increasingly evident (0.462).

ABSTRACT. Renewable Energy Communities (RECs) represent an innovative model of social organization and technological advancement within the modern energy sector. This work proposes a social topic on the role of concern and information. The sample analysed comprises 423 participants. The results indicate a moderate overall concern about climate change, with an average score of 4.0, and a moderate level of self-reported information, averaging 3.3. The results reveal that initial willingness to participate in an energy community (prior to any explanation) averages 3.15 (Pre-Definition, PBD). However, once participants are provided with a clear definition and explanation of how RECs work, the average willingness significantly increases to 4.0 (Post-Definition, PAD). The results therefore show that it is essential to involve citizens in the social transition, making them an integral part of the change. To this end, targeted information campaigns, new educational models and the involvement of all stakeholders are needed.

ABSTRACT. Southern and Eastern European countries suffer more from energy poverty than other parts of Europe. Although winter climates in Southern Europe are milder, these regions experience more serious difficulties in meeting basic energy needs (Bollino & Botti, 2017). This study investigates the phenomenon of energy poverty in Greece and Italy, employing descriptive statistical and comparative analysis between the countries and within their NUTS 1 regions. The research investigates three consensual energy poverty indicators from the EU-SILC database, examining the incidence of i) having arrears on utility bills, ii) living in dwellings with deteriorated characteristics, and iii) being unable to keep home adequately warm.

ABSTRACT. In the advent of digital transformation, smart cities are deploying advanced technologies with the intention to global-brand their urban environments by accenting the transformation of infrastructure and service delivery. Within this dynamic framework, digital marketing has become a pivotal mechanism for promoting sustainable urban growth, attracting investment, boosting tourism, and enhancing the overall quality of life for city residents. It plays a crucial role not only in shaping a modern city image but also in fostering innovation, civic pride, and a long-term vision for urban sustainability.

ABSTRACT. The rapid industrialization driven by modern societal demands has led to significant environmental pollution, particularly through the discharge of harmful substances like toxic metal ions, dyes, antibiotics, and various industrial wastes into water bodies. Metal-Organic Frameworks (MOFs) are crystalline materials composed of metal nodes and organic ligands, offering high surface areas, permanent porosity, and tunable structures. Their chemical and thermal stability also makes them suitable for environmental applications, particularly in wastewater remediation. One of the main challenges in using MOFs is their stability in aqueous environments, which is essential for practical water treatment. Studies have shown that using Zr⁴⁺ ions enhance the hydrolytic stability of MOFs by strengthening the metal-ligand bonds. As environmental sustainability becomes a priority, there is growing interest in utilizing MOFs in circular economy applications, including protection of the environment and agriculture. Recent research focuses on combining MOFs with natural, low-cost sorbents including Biochar (symbolized as BC), Clays, and various organic polymers to form MOF composites (MOFCs) with superior sorption capability and appropriate size, mechanical strength and shape that will allow their use in practical applications. We shall discuss the scale up synthesis of a series of Zr4+ MOFs based on different dicarboxylate ligands including [Zr6O4(OH)4(BDC)6] (H2BDC = terephthalic acid, UiO-66), [Zr6O4(OH)4(NH2-BDC)6] (NH2-H2BDC = 2-aminoterephthalic acid, UiO-66-NH2) and [Zr6O4(OH)4(Fu)6] (H2Fu = fumaric acid, ZrFu). In addition, the corresponding MOFCs with Cyprus bamboo BC, Clay (bentonite) and Calcium Alginate were also synthesized, including UiO-66/BC(10%), UiO-66/Clay(10%), UiO-66/Ca-Alginate, UiO-66-NH2/BC(10%), UiO-66-NH2/Clay(10%), UiO-66-NH2/Ca-Alginate, ZrFu/BC(10%), ZrFu/Clay(10%) and ZrFu/Ca-Alginate. The characterization of these MOFs and MOFCs with various techniques, including single crystal X-ray diffraction analysis, PXRD study, IR and ¹H NMR spectroscopy, porosimetry and thermal analysis will also be discussed. Their sorption capacities for organic pollutants (pharmaceuticals and pesticides) were also evaluated using UV-Vis spectroscopy.

ABSTRACT. This paper presents a dynamic Stackelberg game model to assess the interactions among key stakeholders in wind turbine blade (WTB) circularity. Results show that performance-based incentives and dynamic subsidies effectively align private strategies with circular economy goals. The findings offer actionable insights for designing economically viable and environmentally sustainable WTB end-of-life (EoL) management systems.

ABSTRACT. Climate change mitigation refers to actions reducing greenhouse gas emissions and preventing anthropogenic climate change. The Circular Economy (CE) concept is an increasingly important mitigation approach, aiming to minimise energy and resource waste. CE is a production and consumption model involving practices such as reusing, repairing, refurbishing, and recycling existing materials and products to keep materials within the economy as long as possible. The importance of the CE is underlined by the adoption of a specific European Commission (EC) action plan on this topic. The construction sector is a major contributor to CO2 emissions and one of the sectors where CE principles can be applied. To proceed with the appropriate measures to implement CE practices in the construction sector, it is important to examine the views and perceptions of the key stakeholders in the sector. In this context, a quantitative survey was conducted, targeting stakeholders from the research, academic, industrial, policy and construction sectors. The research was initiated with a literature review, based on which a questionnaire was developed. The questionnaire was then distributed to key stakeholders, who were requested to weigh the importance of various CE construction product specifications/requirements, as well as different barriers to adopting and drivers for enhancing CE practices. The stakeholders' survey was carried out in several European countries. This study focuses on the results from the survey conducted in Greece, undertaken from October 2024 to April 2025. The survey in Greece was distributed to stakeholders through an online and a paper-printed questionnaire. The results of the survey identified stakeholders' perceptions of the financial, environmental, social, and policy aspects of CE in the construction sector. The study aims to provide recommendations to enhance the implementation of CE practices to achieve climate change mitigation.

ABSTRACT. Municipalities play a crucial role in advancing urban waste management policies aligned with European Union directives, which set ambitious targets for recycling and landfill reduction by 2025 and 2035, respectively. This study focuses on the city of Paris, one of Europe’s largest and most densely populated capitals, which faces significant waste management challenges due to its high population density, daily visitor influx, and the complexity of its urban structure. In light of the 2024 Olympic Games, Paris adopted a zero single-use plastic waste strategy, offering a unique opportunity to investigate the enabling factors and bottlenecks involved in implementing ambitious waste reduction policies. Using a qualitative case study approach and the Gioia methodology, the research draws on archival material, onsite observations, and ten in-depth interviews with key stakeholders, including public officials and consultants. Findings reveal that strong political leadership, dedicated resources, and effective communication strategies are critical enablers, while producer lobbying and fragmented governance emerge as major obstacles. The Paris case demonstrates that large cities can effectively implement waste reduction strategies in complex environments when supported by coherent policies and stakeholder engagement. This case provides a replicable framework for cities worldwide aiming to scale up waste reduction efforts, especially in the context of major public events.

ABSTRACT. The present study is motivated by the increasing ecological impact resulting from the energy consumption of the internet and in particular from the large number of websites. Building on the theoretical and empirical research of this analysis, it is argued that practices of sustainable web design, which include the reduction of data volume, the optimization and compression of website elements as well as ecological hosting, can not only reduce the ecological footprint, but also improve the technical performance and user experience of websites. Against this background, a mixed-methods research approach was developed on the basis of a literature analysis, which includes both expert interviews and a discrete choice experiment. With the help of qualitative research, the main practices of sustainable web design as well as communication measures with which the sustainable design of websites can be disclosed to users are first recorded. Based on the results of a literature analysis and expert interviews, five attributes can be deduced for the design of this study’s choice cards. Table 1 summarizes the attributes and their respective levels. The default level for each attribute is marked in bold face.

Table 1. Research Design - Attributes and Labels Attribute Level 1 Level 2 Sustainability Label Present Not present Hosting Location Green Hosting Standard Hosting Information Page on Sustainability Endeavors Present Not present Loading Speed Fast Slow Design Sophisticated Minimalistic

The collected sample for the study was 63.6 % female, 31.1 years on average, with a monthly net income of 2,400.76 € on average. Table 2 summarizes the results of the regressions carried to evaluate the choice experiment using the R package Apollo. Model I is the model determining in how far the attributes impact the general perception of the company. Model II considers the attributes regarding their impact on the perceived product or service quality. Finally, Model III addresses the effect that the attributes have on the participants’ purchase intention.

Table 2. Results Choice Experiment – Multinomial Logit Estimation Model I Model II Model III Sustainability Label 1.0689*** 0.8125*** -1.0821*** (0.1566) (0.1183) (0.1651) Hosting Location 0.8901*** 0.7291*** 0.9425*** (0.1367) (0.1202) (0.1242) Information Page on Sustainability Endeavors 0.6144*** 0.5110*** 0.7560*** (0.1297) (0.1196) (0.1197) Loading Speed 0.9127*** 1.1586*** 1.3134*** (0.1338) (0.1510) (0.1419) Design 0.0307 -0.1735 -0.2537* (0.1358) (0.1305) (0.1318) Constant -0.4841* -0.6139** -1.0821*** (0.2466) (0.2193) (0.1651) N 856 856 856 AIC 1,428.57 1,550.78 1,571.3

First of all, it can be stated that sustainable web design is a practice within web design and web development that has yet to establish itself in the consciousness of the broad mass of companies, web designers and end users. The results of the three multi-nominal Logit models show a significant impact of the communication of sustainable web design practices on the perception and decisions of website visitors. A fast loading time of websites turns out to be particularly decisive. Although this cannot be disclosed through a direct communication measure, it is actively perceived by users when visiting the website and can be achieved through the use of sustainable practices. The results show that websites with fast loading times significantly increase the likelihood that users will perceive the company or brand and the quality of the products or services offered more positively. The probability of a purchase also increases. In addition, the results show that communication measures of sustainable web design practices in the form of sustainability seals, the disclosure of hosting using green electricity and the provision of transparent information about corresponding sustainability efforts also have a positive impact on users. The use and implementation of appropriate measures on websites significantly increase the probability of a positive perception, quality assessment and purchase decision on the user side and is with positive effects on circular economies.

ABSTRACT. This paper discusses the integration of sustainability into fashion product development using systemic and morphological methods. The research examines key stages of the product life cycle, including material sourcing, sustainable design strategies, construction techniques, technological choices, and packaging. Through morphological mapping, a structured model is created to explore various design alternatives for sustainable garment production. Core principles such as longevity, modularity, zero-waste construction, and emotional durability are aligned with appropriate material, construction, and technology solutions. The study concludes that even small design and construction decisions can significantly improve a garment’s sustainability profile. Morphological analysis provides a framework for integrating creative thinking and environmental responsibility from the concept stage. By using this approach, the fashion industry can take tangible steps toward circularity and ethical transformation.

ABSTRACT. This study explores hydrogen’s integration within circular economy principles, emphasizing its role in industrial symbiosis and sustainable energy systems. It discusses advancements in hydrogen production, storage, and applications across sectors while addressing challenges such as economic feasibility, technological barriers, and policy gaps. The study highlights opportunities for hydrogen to enable resource efficiency and emissions reduction in industrial hubs, contributing to a resilient and sustainable energy future.

ABSTRACT. Additive manufacturing (AM) is becoming a cornerstone technology while offering a range of sustainability advantages; however, there is a critical need for a comprehensive understanding of the environmental impacts (Ford & Despeisse, 2016; Paris et al., 2016; Torres-Carrillo et al., 2020). AM holds a significant role in the transition to a circular economy framework and promising for Industry 4.0, and it can reduce resource utilisation, lighten product structures, drive down environmental impact, and extend product lifespans through increased capability to repair specific and complex components (Colorado et al., 2020; Tavares et al., 2020; Gouveia et al., 2022; Korner et al., 2020; Santiago-Herrera et al., 2023). Since one of the significant advantages of MAM is its ability to significantly reduce material waste compared to traditional manufacturing techniques, particularly for intricate geometries where conventional methods produce substantial waste (Arrizubieta et al., 2020). Recycling and reusing unfused powder as feedstock for future productions in MAM can mitigate its material usage and environmental impacts (Ma et al., 2017). This study addresses the gap by conducting an in-depth analysis in the production processes by assessing Carbon Footprint with considering its powder and ingot production. A holistic approach followed in this study includes a detailed examination of 23 production units. Energy consumption, waste generation, and water consumption were used in material and energy flow studies, offering a comprehensive view of the system's environmental impact. Where the data was collected from three specific manufacturing facilities: ingot production was done with a vacuum induction furnace at TÜBİTAK Marmara Research Centre, while powder production was carried out with an atomisation machine at the production facility; additive manufacturing and its finishing processes were done by utilising Selective Laser Melting (SLM) and Electron Beam Melting (EBM) methods at the Additive Manufacturing Technologies Application and Research Centre (EKTAM) primarily for prototyping purposes. In addition to the production units, auxiliary units with the potential to generate carbon emissions have been evaluated. The analysis of the carbon footprint for different AM processes (EBM, SLM, and SLM 2) reveals variations in their overall emissions. For producing 1kg of a product, the Electron Beam Melting (EBM ) method results in a carbon footprint of approximately 120.06 kg CO2 equivalent, while the SLM (Selective Laser Melting) method generates around 232.33 kg CO2 equivalent. The SLM 2 machine has the highest carbon footprint among the three, with an emission value of 383.90 kg CO2 equivalent. These differences indicate that each method has distinct energy demands and emission drivers, which can be further analyzed by examining their respective processes in detail. The application of an energy-based 'Carbon Footprint' approach is used to identify carbon-intensive processes and explore opportunities for emissions reduction within the system.

This approach supports transitioning towards more sustainable production and contributes to the detailed discussions on environmental sustainability in MAM. With evaluating various methods found in the literature our study discusses adaptable strategies for the examined system for integrating circular economy principles. Our work highlights the carbon dioxide equivalent emissions from production and auxiliary units. However, the MAM machines are the most significant contributor to emissions. The analysis suggests that optimizing MAM machine operations could significantly reduce emissions. This study highlights the need for continued research and development efforts focused on reducing the environmental footprint and increasing circularity of MAM processes.

ABSTRACT. The Nordic countries are widely recognized for their strong performance in sustainability metrics, consistently ranking among the global leaders in environmental policy, innovation, and green infrastructure. Given this context, it is reasonable to hypothesize that such leadership would extend to the implementation and visibility of Circular Economy (CE) practices across the region. However, while national-level indicators and policy frameworks suggest a high degree of alignment with circular principles, there remains limited understanding of how these commitments are reflected at the organizational level, particularly in how companies engaged in the CE articulate and communicate their identity in the public digital domain. This study investigates the thematic landscape and social visibility of CE-oriented companies in the Nordic region by leveraging data mined from LinkedIn company profiles. Using the platform’s public organizational metadata, a dataset of publicly available company data of over 1,000 companies associated with the term “circular economy” was collected and analyzed, filtered by geolocation settings to include Nordic countries. Key attributes such as staff size, industry classification, follower count, headquarters location, and self-declared specialties and descriptions were included to extract patterns at the organizational, geographic, and thematic levels. Results reveal that the sector predominantly comprises micro- and small-sized enterprises, with micro firms (1–10 staff) comprising over half of the dataset. Nevertheless, larger firms attract a disproportionately higher share of social visibility. Geospatial mapping using geocoded headquarters data indicates dense urban clustering in key innovation hubs. Notably, thematic emphasis varies by company size: micro and small firms highlight innovation and environmental values, while larger enterprises emphasize operational keywords like packaging, service, and technology. To further explore cross-sectoral language dynamics, a bipartite network graph was constructed connecting the top 10 most common industries to frequently used keywords. This network analysis revealed both shared and sector-specific vocabulary.

ABSTRACT. Water scarcity is a wide-Europe problem. IPCC’s Assessment Report 6 concluded that GHG forcing has increased the differences in precipitation amounts between wet and dry seasons causing mismatch in water balances, in areas usually humid and cold, such as Central Europe and the Nordic Countries, affecting the quality and supply of water. Europe consumes an average of around 243 000 hm3 of water annually, to meet consumption needs. On the other hand, Zerowasteurope estimates the EU countries produce around 114 M Tons/Year of Municipal Biowaste, while the production of sewage sludges is estimated around 10 M Tons; regarding Biowaste from food Industries, the total amount includes very different sources that account for huge amounts of biowaste. I.e. only the European Brewing activity produces more than 7 billion Tons of solid waste, of which approximately six billion are Bagasse (BSG). Päijät-Häme (FI), amounts around 80K tons of biowaste (17K tons of BSG), are used for biogas production. To promote a circular economy, the aim is to reduce carbon-based energy and shift to production and storage of carbon in plastic. In particular, waste valorization is required to increase the BSG value and the environmental performance of the brewing process. Business opportunities are expected in sectors such as food and health care. In this regard, the conventional system used in the water supply and sewage treatment should be transferred to a more sustainable system. For this reason, companies are required to map their entire business value chain. Therefore, to collect the data this study uses the qualitative research method for which the data is collected by organizing workshop with different company representatives and experts in this field in the Päijät-Häme region in Finland.

ABSTRACT. Photosynthetic microorganisms have emerged as an environmentally friendly and sustainable resources due to the accumulation of valuable biomolecules in their photosynthetic biomass, their ability to assimilate nutrients and to contribute to carbon sequestration. CO₂ capture through photosynthetic microorganisms, such as microalgae and cyanobacteria, is a long-term and environmentally friendly approach, as both capture carbon dioxide from the atmosphere, while producing valuable biomass that can be utilized for energy and biomolecules recovery. Microalgae and cyanobacteria have been identified as a viable resource to produce high value-added bioproducts, such as lipids, including polyunsaturated fatty acids, carbohydrates, proteins, carotenoids, etc. Cyanobacteria and microalgae can thrive in diverse environments, including wastewater streams. Compared to other photosynthetic organisms, like plants, microalgae exhibit 20 times higher photosynthetic efficiency, produce more biomass and possess the ability to produce biofuels. Moreover, they do not require agricultural land or raw materials for human consumption for their cultivation. In this research work, indigenous photosynthetic microorganisms were isolated from various aquatic ecosystems to assess their biotechnological potential regarding the content of valuable biomolecules in their biomass. A photosynthetic cyanobacterial Cyanobium gracile strain was isolated and cultivated under controlled light and temperature conditions. To examine its biomass content in a photobioreactor, this photosynthetic cyanobacterium was cultivated in a 2 L photobioreactor, which was operated at 25°C under 4800 lumen. Its content in carbohydrates, proteins and chlorophyll was assessed under semi-continuous growth conditions in the photobioreactor. The protein content was determined to be 440 mg/g dw, while chlorophyll a and chlorophyll b concentrations were equal to 1.72 mg/g DW and 1.21 mg/g dw respectively. Moreover, carbohydrates were identified to be 13.8% of the dry weight of the cells. The estimated content of these biomolecules highlighted the importance of uncovering the biotechnological potential of the unexplored cyanobacterial diversity within the context of the bioeconomy.