ABSTRACT. Ethical conduct in research, whether concerning COIs, IRB review, or peer review quality and integrity, is critical in ensuring scientific advancement. Since guidelines -especially for COIs- are not uniformly defined across Journals and Institutions, this interactive workshop could assist both senior and young researchers in taking into account and integrating all applicable ethical considerations at all stages of publishing.

Themes that will be discussed include: - Overview of peer review - Conflicts of Interest (COIs) - Ethical consederations (approval/exemption, consent, incentives etc.) - Examples of unethical behaviors in research and publishing - Examples of requirements of IRB review - Types of publishing - Predatory Journals

ABSTRACT. We live in a materials world. Everything we use is made from materials extracted from the planet. Yet, our current way of making and using most materials follows a linear model: take, make, and dispose. This unsustainable approach is pushing the planet’s limits. If our production and consumption behaviours remain unchanged, we would need 2.75 worlds to meet our demands. But we only have one. To secure a sustainable future, we must transition to a circular materials world, where we minimise the extraction of raw materials and maximise the reuse, remanufacturing, and recycling of existing materials. Achieving this transformation requires innovations in mindsets, technologies, business models, and systems. The Transforming the Foundation Industries Research and Innovation Hub (TransFIRe) was a UK governmental initiative to support the Cement, Ceramics, Chemicals, Glass, Metals and Paper industries in the UK on the journey to net zero 2050 and addressed some the challenges covering technical, economic and social issues within these fundamental industries for our modern society. This presentation will share some of the key outcomes from the 3.5 years programme.

ABSTRACT. In the transition towards a circular economy and more sustainable business practices, industrial symbiosis (IS) has emerged as a promising strategy to enhance resource efficiency, reduce waste, and generate economic and environmental benefits. Despite its well-documented advantages, IS adoption remains fragmented and inconsistent across industries and regions, raising critical questions about the drivers and barriers that influence its implementation. Energy-based IS, particularly bioenergy production like biogas, exemplifies the complexities of IS adoption. Thus, this study seeks to examine the interplay between drivers and barriers and their effect on adoption and implementation of biogas-based IS on five industrial symbioses, where additional challenges such as competition with fossil fuels and fragmented supply chains add further complexity. The results show that economic incentives drive industrial biogas symbioses, social factors, especially collaboration and networking, are crucial enablers. A higher number of social barriers, compared to environmental ones, underscores that trust, cooperative competence, and stable relationships are not peripheral but essential. This research contributes to a more comprehensive understanding of biogas IS adoption, offering insights for business managers, policymakers, and sustainability practitioners seeking to advance IS as a scalable strategy for circular economy transitions.

ABSTRACT. The growing global demand for renewable energy sources has positioned photovoltaic (PV) systems as a key player in the transition towards a sustainable energy future. In recent years, researchers have begun to explore the integration of circular economy (CE) principles into PV systems, addressing issues such as the recycling of PV waste, the recovery of critical materials, and the economic viability of these processes. By combining bibliometric and content analysis, we identify leading journals, countries, institutions, authors, articles, and critical research areas in PV systems. The database chosen for the collection of articles was Scopus since it is a trusted, source-neutral abstract and citation database curated by independent subject matter experts who are recognized leaders in their fields. Using significant PV terms to search in topic, an initial dataset for this work consisted of 193 302 publications. From this total of publications, 5.41% of the papers are review articles (the remaining 94.59% are articles), with a total of 322 340 authors and 38 765 institutions. Over the last few decades, there has been a rapid increase in publications related to PV systems, reflecting their growing importance in the global energy transition. The first record dates to 1959 and in 2000 there was a "take-off", with an almost exponential increase. The last year (2024) has the highest number of publications, suggesting PV research is at its most active phase ever. The literature predominantly concentrates on more technical aspects of PV systems, ranging from materials until technologies and conversion efficiencies. This notion is supported by the analysis of keywords (both author and index keywords) and the most influential papers in terms of citations. Through that, it is possible to observe an evolution in PV research — starting with fundamental efficiency limits and dye-sensitized cells in the 90s, transitioning through organic and nanomaterial-based approaches in the 2000s, and finally culminating in the perovskite revolution of the 2010s. There has also been an increase in the number of open access articles published and in country and continent collaboration. In the context of PV systems research, this increase brings important advantages, including the access to cutting-edge PV research without paywalls and the acceleration of global efforts in achieving sustainable and renewable energy goals. This can be very relevant in many developing nations, which have high solar potential but lack the resources for extensive research. To understand the trends of CE and environmental sustainability, OpenAlex concepts were used. Concepts are abstract ideas that works are about and are hierarchical. Each work is tagged with multiple concepts, based on the title, abstract, and the title of its host venue. Thus, relevant concepts for this analysis were categorized into four distinct streams: Economics & Policy (9692 papers); Energy & Renewable Resources (3489 papers); Environmental Management & Policy (5632 papers) and Environmental Science & Sustainability (2446 papers). Over the years, there has been an increasing interest in these topics, particularly in Economics & Policy. Although the articles of interest only constitute 12% of the initial dataset, the growing trends mark an important shift toward sustainability-driven research in PV, highlighting the field’s increasing commitment to environment sustainability and CE principles. For example, the number of papers in PV research that explore recycling themes has had an exponential rise after 2020, suggesting a boom in research interest in CE applied to PV systems.

ABSTRACT. This study examines the management and recycling of Construction and Demolition Waste (CDW) at a construction site in Greece, using Material Flow Analysis (MFA) to assess waste generation, handling, and recovery. The construction sector, a major contributor to global waste, plays a vital role in transitioning to a circular economy through efficient waste management. The study integrates data from a local recycling center, mapping material flows before and after processing, and classifies waste based on type, processing method, and compliance with European and national regulations. Sankey diagrams are used to visualize waste distribution and identify inefficiencies in waste segregation and recovery practices. The study also evaluates the environmental impact of current practices and offers recommendations for improving resource use and recycling efforts. Findings highlight critical areas where waste reduction and material recovery can be optimized, supporting more sustainable construction practices. By linking MFA with circular economy principles, the study provides actionable insights for advancing waste management strategies and promoting resource efficiency in the construction industry, contributing to the decarbonization of the built environment.

ABSTRACT. Waste Electrical and Electronic Equipment (WEEE) has become the fastest growing stream of waste in the world. In 2022 alone, approximately 62 million tonnes of WEEE were produced worldwide, with only 22.3% formally collected and recycled. Effective recovery of Electrical and Electronic Equipment (EEE) is critical to avoid CO2 emissions; it has been reported that, for every tonne of WEEE recovered, 1.44 tonnes of CO2 emissions could be avoided. The abundance of critical raw materials in EEE also makes the recovery of these materials from WEEE key to mitigate supply chain risks and to reduce reliance on emission-intensive mining and extractive industries.

Transitioning to the Circular Economy for EEE is therefore critical for enabling economic, environmental and societal sustainability. However, to better inform industry and policy decision-making on Circular Economy, there is a need for better understanding about the current sources, pathways and sinks of EEE across its lifecycle. Previous studies have mapped flows of WEEE at the national level, while other studies have also applied Material Flow Analysis (MFA) to investigate historical trends in the consumption of critical metals in household EEE, domestic and export flows of specific EEE products, for instance computers, and to evaluate WEEE management systems in different geographical contexts. Nonetheless these studies do not show in detail the specific pathways of EEE and they do not show how these flows vary for different EEE product categories (e.g. small domestic appliance, large domestic appliance, IT and telecoms) or source type (e.g. household or commercial). As such, there is limited understanding about which product categories or sources generate the most waste and pollution. This is hindering effective policy and industry decision-making on Circular Economy.

To address this research problem, this study maps the material flows of EEE throughout their life cycle from point-of-sales to end-of-life. London is selected as a case study for this analysis, with the aim of generating scientific knowledge and data on the UK WEEE system. A detailed static MFA is conducted for all household and non-household EEE, classified according to the 14 UK WEEE categories, used and discarded in all London boroughs in 2022, the year for which the latest publicly available waste data is available.

Following the UNU E-waste Statistical Framework methodology, the study followed the flows of EEE place on the market in London, through their use-phase as stocks both in households and in the commercial and public sector, considering potential reuse, repair and remanufacturing resulting in a second use, and up to collection at their end-of-life (formal collection, WEEE in residual waste, WEEE treated as scrap metal). Data was collected from various sources including: the UK Environment Agency, WasteDataFlow (a web-based system for municipal waste data reporting by UK local authorities to government), the UK Office of National Statistics, the UNU E-waste statistics, privately collected data from the project’s partners. The methodology and data were validated through engagement with experts and stakeholders across the EEE value chain, both by conducting structured individual interviews and in a workshop with over 40 industry stakeholders.

There are several notable findings. First, the significant proportion of WEEE ending up in informal collection routes highlights that current formal collection infrastructure is insufficient and that scrap metal recycling is a diverting a significant amount of WEEE from being recovered. Second, the large volume of WEEE entering residual waste suggests that awareness about proper WEEE disposal is low and should be urgently addressed. In addition, it is clear that recycling is the favoured end-of-life option, despite it being lower in the waste hierarchy than alternative Circular Economy strategies, such as reuse and remanufacture. This discrepancy between guidelines and industry practice needs further attention.

This study contributes to both research and practice. By defining and quantifying the flows of EEE in London, including the pathways to reuse, repair, remanufacturing, formal collection (either to recycling, landfill, incineration or export) and leakages, the study generates new data on Circular Economy for EEE in the UK, which can inform future research and policy. Additionally, by establishing a methodology that can be replicated in other geographical contexts, the insights and approach used in this study can be applied to other regions to obtain a country-wide picture of the UK EEE system.

ABSTRACT. The EU-funded iCOSHELLs project, started in September 2024, has created a few Soil Health Living Labs across Europe to promote innovative soil recovery methods. Among that, three Italian sites have a common approach based on the transformation of residual biomasses, of local interest, into an amendment produced by an enhanced approach (high temperature pre-treatment). In the first case, the experimental site based on the valorisation of source separated food waste allows evaluating a scenario in a predominantly rural context, involving a small city (Oppeano). Like the other two sites, this case faced with a common problem, the sudden unavailability of a pilot/demonstrative scale Hydro Thermal Charbonisation (HTC) reactor able to produce an adequate amount of hydro-char for in-filed tests; indeed, after the winning of the EU project, the unique reactor suitable for preparing by a viable way the needed char was dismantled. That opened to an alternative solution: bio-char production through pyrolysis. The second site is at the Parco del Mincio (Lombardy region) aimed to the creation of a 'circular ecology' through the excess allochthonous biomass present in the area. Originally the process to be used was HTC but the strategy suffered the same problem of the first case; thus, also here the approach was converted into bio-char production. In a third case, the zootechnical waste management is creating soil challenges in regions with intensive zootechnical activity. This is a typical issue in the Italian alpine region. A solution for a decentralised valorisation alternative to HTC was confirmed to be pyrolysis. The change of approach simplified the activities: biochar can be mixed directly with compost to regulate some parameters, through a way that cannot be sufficient in case of HTC as in this case co-composting seems to be only solution, delaying the lasting of the preparation of the amendement.

ABSTRACT. In the Horizon Europe COP-PILOT project, iLINK New Technologies leads two complementary use cases under Cluster 3a: AgriTech Transformation and Sustainability Initiative, targeting systemic inefficiencies in agri-food logistics, monitoring, and data management. Implemented at the facilities of Barba Stathis in Central Macedonia—covering farm-to-processing-to-market operations—the pilot leverages decentralised digital technologies to enhance sustainability, traceability, and logistics performance in fresh produce value chains. The first use case introduces a blockchain-based infrastructure to ensure secure, tamper-proof, and GDPR-compliant data exchange across stakeholders. This enables transparent traceability of agricultural operations, from crop conditions to delivery metrics. This architecture eliminates data silos and provides a trusted digital backbone for regulatory compliance and sustainability certification. Blockchain is orchestrated through a multi-cloud architecture and integrated with AgroApps' field data (IoT, satellite, UAV) and the Agricultural University of Athens’ autonomous ground robot for crop interventions. The second use case provides an AI-driven Just-In-Time (JIT) logistics engine, which dynamically optimizes delivery schedules and transport routes for perishable crops based on real-time telemetry, produce readiness, and downstream demand. By integrating GNSS tracking, weather data, and product freshness constraints, the system reduces post-harvest spoilage and CO₂ emissions, while enhancing responsiveness and time-to-market for leafy vegetables like spinach. The solution suite includes: • Wearable plant sensors for antinutrient and stress detection, • Edge AI for real-time spraying and input application via autonomous robots, and • A unified FMIS platform for harmonised agronomic decision support. • Automated Spraying Robots (AUA) Early results and expected KPIS include a 20–30% reduction in spoilage, up to a 25% decrease in emissions per delivery unit, and blockchain-secured traceability for over 90% of audit processes. These outcomes reflect a holistic transition from reactive, fragmented agri-logistics to predictive, orchestrated, and transparent supply chains, demonstrating how smart technologies support circular economy and EU Green Deal objectives.

ABSTRACT. Hubs for Circularity (H4Cs) play a crucial role in the transition to a circular economy by enabling resource, energy, and service exchanges among industries. The Horizon Europe IS2H4C project aims to demonstrate 17 symbiotic interactions across four European hubs, targeting significant reductions in raw material use, energy consumption, and carbon emissions. A key challenge in optimizing H4Cs lies in managing complex decision-making processes at strategic, tactical, and operational levels, accounting for multiple stakeholders, diverse resource flows, and uncertainty in market conditions. This study focuses on the development of decision-support tools leveraging operations research, data analytics, and machine learning to optimize hub operations, particularly in resource flow management and energy systems. Specifically, a sequential optimization approach under uncertainty is employed for resource flow optimization, comparing a forecast-based reoptimization method and a deep Q-learning model. Preliminary results indicate that while the latter method provides superior operating policies, the former remains advantageous for larger hubs due to computational constraints. In energy management, an extended optimization model for district heating systems is adapted to H4C networks, integrating hydrogen-based energy flows in a two-stage stochastic programming framework. Initial findings suggest significant efficiency gains, guiding further model refinements. The development of such advanced optimization tools is vital for ensuring the economic, environmental, and social sustainability of H4Cs. Next steps of this work will focus on real-world validation and expanding the framework to incorporate additional ecosystem elements.

ABSTRACT. Background: Hubs for Circularity (H4C) drive a paradigm shift both in terms of material sourcing and the organisation of interconnected production networks, aiming toward climate neutrality, circular economy, and net-zero competitive industries. H4C has its roots in the practices of industrial symbiosis, replacing production inputs with the waste generated by other production processes. Compared to traditional industrial symbiosis, H4C operates on a broader scale in terms of geographical scope and stakeholder composition. H4C aims to increase the sharing of resources (e.g., energy, materials, and water), data, services, technology, and infrastructure via joint development and implementation activities at a regional scale. Resource streams span larger geographic areas, ensuring sufficient secondary feedstock supply while maintaining economic and environmental sustainability. Moreover, H4C involves collaborations among diverse stakeholders beyond industrial zones, including actors in surrounding ecosystems, government, and society. In this regard, H4C plays an important role in sharing knowledge, skills, experiences, and expertise.

Challenges: However, it is a non-trivial task to realise the ambitious vision of H4C. The complex multi-actor interactions, dynamic resource and information flows across large geographic areas, hinder the design and management of H4C. Specifically, the involvement of diverse stakeholders creates coordination challenges, including misaligned costs and incentives, and power imbalances, affecting collaboration and trust. Also, material and energy flows are highly dynamic, influenced by market fluctuations, technological advancements, supply chain disruptions, and geographical constraints. This further leads to the uncertainty in resource availability and demand. Policy interventions add another layer of complexity, as regulatory fragmentation, unintended consequences, the availability of government incentives, and stakeholder adaptation strategies make it difficult to predict the long-term impacts of interventions.

Agent-Based Modelling: These challenges underscore the need for advanced simulation and modelling approaches that can capture emergent behaviours, simulate decentralised decision-making, and test policy intervention scenarios. H4C can be complex systems that involve diverse stakeholders, dynamic resource flows, and evolving policies. Traditional modelling approaches, such as linear optimisation and system dynamics, provide valuable insights but have methodological limitations in capturing the decentralised, adaptive, and multi-agent nature of H4C. In this regard, Agent-Based Modelling (ABM) serves as a powerful tool to address these gaps and provide a more realistic and flexible approach to system analysis.

Research Gap: Currently, a conceptual framework for applying ABM in H4C is still missing. There is a lack of understanding of what basic modelling elements need to be considered in this new research niche. How these elements interconnect to form a coherent modeling framework that enables a comprehensive analysis of H4C remains unclear. Therefore, this research aims to bridge this gap by proposing a conceptual framework for applying ABM in H4C.

Framework: The framework is developed based on the prior work on applying ABM and other digital tools to Industrial Symbiosis (Fraccascia et al., 2019; Yazan et al., 2022). It begins with key modelling elements, including target and scope, sociological theory, network structure, and operational data. Next, the overall processes of establishing Industrial Symbiosis are presented as an iterative cycle with options for continuation and discontinuation after post-assessment. These processes represent the target phenomena in the context of Industrial-Urban symbiosis. Beyond providers and receivers in urban and industrial areas, the main actors also include facilitators and policymakers, who influence the performance of H4C. Finally, common scenarios are proposed in a matrix with (1) top-down and bottom-up as a vertical axis standing for coordination manners, and (2) operational and strategic as a horizontal axis representing decision-making levels. Overall, this framework lays a theoretical foundation for simulating H4C from an agent-based perspective.

ABSTRACT. Global warming, one of the most critical challenges of humanity, mainly results from greenhouse gas emissions through human and industrial activities. According to IPCC, a 1.5 ℃ increase in surface temperature compared to pre-industrial levels poses the risk of irreversible damage. To mitigate this risk, IPCC proposes a scientific plan covering rapid reduction in emissions, technological advancements and systemic policy changes [1]. Carbon Capture, Utilization, and Storage (CCUS) is one of the mitigation strategies, especially applicable to reduce CO2 emissions of process industries. Although there are numerous implemented, ongoing and planned Carbon Capture and Storage (CCS) investments; Carbon Capture and Utilization (CCU) is lagging behind due to the high investment and operational costs, limited market demand for CO2-derived products, and lack of an actionable policy framework. According to a detailed market study conducted by The Global CO2 Initiative, CCU has the potential to reduce the CO2 emissions by 10% by 2030 [2]. Therefore, greater attention should be given to the development and deployment of economically viable and emission-negative CCU technologies. From circularity perspective, CCU is a key pillar of the Circular Carbon Economy aiming to capture CO2 emissions from industrial processes to be used as secondary input in various supply chains and to be converted into valuable circular products. Contrary to permanent CO2 sequestration, CCU reuses/recycles waste CO2 into CO2-derived products such as fuels, chemicals, and building materials, as well as enhances biological processes such as algae production and greenhouses. This aligns with the concept of industrial symbiosis (IS) where the waste or by-product of a process can be used as a substitute resource for another process [3] and offers a new IS category: i.e., carbon-based IS. This study aims to investigate the current picture and trends in the development of CCU-based circularity solutions and carbon-based IS, categorizing three main components: (i) the potential sourcing industries of CO2 for CCU, (ii) available technologies for CCU, and (iii) potential industries which can use the captured CO2.

The Systematic Literature Review (SLR) methodology is applied using the Web of Science Database. The research is conducted in two level of depth, first with the following search string: TS=("CO2 utili*ation" OR "carbon utili*ation" OR "carbon dioxide utili*ation" OR "carbon dioxide valori*ation" OR "carbon valori*ation" OR "co2 valori*ation") AND PY=(2000-2025). With the limitation of timeframe of 2000-2025, English language and document type of Articles and Review articles; the search yielded 5,406 publications. Second, additional filtration of AND TS=("Industrial Symbiosis" OR "Circular*") is applied and search yielded 175 publications.

The keyword co-occurrence analysis is conducted using VOSviewer software, based two search algorithms mentioned above. A thesaurus file is created to merge the keywords with the same meanings. Keywords not contributing to the analysis (“efficient”, “temperature”, “pressure”) are omitted. Figure 2 shows two network visualization maps developed. The left one shows broader perspective in CCU technologies whereas the right shows their connection with circularity and IS. A more in depth analysis on technology trends, CO2 provider and user industries will be assessed in circular economy perspective and will be presented in Alexandroupolis, Greece.

References [1] IPCC (2023) Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. [2] The Global CO2 Initiative by the University of Michigan (2016), Global Roadmap for Implementing CO2 Utilization. [3] Chertow, M. R. (2000). Industrial symbiosis: Literature and taxonomy. Annual Review of Energy and the Environment, 25(1), 313–337. [4] IEA (2019) Putting CO2 to Use: Creating value from emissions.

ABSTRACT. Hubs for Circularity (H4C) facilitate resource efficiency and sustainable development by developing inter-organizational collaborations in terms of urban-rural-industrial symbiosis of resources and by-product sharing in the context of local region. Frequent communication and knowledge sharing is very important for trust-building, which is a crucial requisite for industrial symbiosis relationship and mutual benefits building for organizations involved in H4C. This study employs Social Network Analysis (SNA) to examine knowledge-sharing and resource-flow bipartite networks within H4C across four regions (Basque, Turkiye, Netherlands, and Germany). By applying clustering analysis, centrality measures, network density evaluations, and core-periphery classifications, we examine structural characteristics of the networks, their inter-dependencies and knowledge diffusion patterns.

We analyze two interlinked networks: (1) an organizational network representing knowledge exchange and communication dynamics, and (2) the resource network reflecting resource flow exchanges. Centrality measures, including degree, closeness, betweenness, eigenvector, and eccentricity, highlight key organizational actors facilitating knowledge transfer and resource utilization. Network density analysis reveals that organizational interactions are more interconnected than resource exchanges, suggesting stronger knowledge-sharing. Core-periphery analysis indicates that most resource exchanges occur within the core network, while organizational communications extend beyond the core, integrating peripheral actors.

Findings suggest that H4C exhibit distinct symbiotic structures, with German and Turkish hubs displaying centralized, industry-led networks, while the Dutch and Basque hubs demonstrate more collaborative structures involving community and research institutions. The results provide policy and managerial implications for policymakers and industrial stakeholders aiming to facilitate effective inter-organizational collaboration, increase H4C network resilience, expand H4C networks, and enhance resource-sharing mechanisms within industrial ecosystems.

ABSTRACT. Background: Hubs for Circularity (H4C) are self-sustaining industrial ecosystems that close energy, resource, and data loops (A.SPIRE, 2021). They integrate Industrial Symbiosis (IS), where industries exchange resources, waste, and by-products to improve efficiency. H4C connects stakeholders, technologies, and infrastructures to enhance resource exchange and societal well-being. DigitalH4C supports H4C development by providing a digital collaboration platform that enables resource monitoring, supply-demand matchmaking, secure data sharing, and decision support. Among its key technologies, digital twins enable the visualisation and assessment of synergies within the H4C context.

Research niche: Digital Twins (DTs) are digital representations of physical environments that integrate diverse data sources and analytical methods to support decision-making. Unlike static 2D or 3D models, DTs function as dynamic, continuously evolving systems that reflect past, present, and future states (Ferré-Bigorra et al., 2022). In the context of H4C, IS networks depend on resource exchanges between industries, and they interact with surrounding urban and rural ecosystems. These exchanges involve complex interactions, shaped by resource flows between involved stakeholders and socio-economic factors influencing those flows. This requires a systematic evaluation. A DT-based approach allows for performance assessment and monitoring of these synergies, enabling stakeholders to make informed decisions on resource flows based on specified Performance Indicators (PIs). Such PIs include waste reduction, byproduct valorisation, and resource recovery efficiency, which help evaluate how effectively resources are repurposed within the IS network. However, to ensure reliable decision-making, PIs must be carefully quantified and tailored before their integration into the DT.

Challenges: It remains unclear how DT can be applied in the IS context, both in terms of its objective and the selection of PIs that measure synergies effectively. Besides, there is a lack of DT models that incorporate IS streams, making it challenging for practitioners to define a placement of DT in an IS network and prioritise which PIs should be integrated into the DT model. We identify the key challenges in quantifying the PIs of an IS-based DT as follows:

• Multi-stakeholder collaboration: H4C involves diverse stakeholders with different priorities in evaluating synergies, making it challenging to define common PIs and ensure effective decision-making. Quantifying PIs must be adaptable and multi-criteria-based to address varying stakeholder needs and priorities. • Multi-dimensional indicators: IS span economic, environmental, functional, and operational dimensions, requiring SMART (specific, measurable, achievable, relevant, and time-bound) indicators that are both standardised and adaptable. Some indicators lack clear definitions and universal calculation methods, making consistency and comparability across industries challenging. • Mapping indicator relationships and dependencies: Drawing the relationships and dependencies between multi-dimensional indicators is complex, as changes in one dimension (e.g., economic) can have cascading effects on others (e.g., environmental).

Objectives: This research aims to (1) explore the applications of DTs throughout the lifecycle of an IS network and (2) define and quantify the PIs necessary for assessing and monitoring synergies within the H4C context. The proposed indicators tackle the aforementioned challenges and offer a flexible and integrated framework that make up a solidified DT.

We employ a top-down approach, beginning with the selection of IS-based PIs through literature review and stakeholder analysis. This is followed by data collection from an existing case study in H4C in the Netherlands, where parameters are extracted for further analysis. The PI framework comprises a set of features and data analytics that support the assessment and monitoring of IS networks. This research provides a foundational knowledge base that (1) advances the integration of digital twin technology into the IS field, (2) facilitates complex dynamics of stakeholder interaction within H4C, and (3) guides the future demonstration and evaluation of an IS-based digital twin. We view this research as a preliminary step towards developing an IS-oriented digital twin component for H4C, recognising that PI quantification is a critical step in DT development. Ultimately, this research contributes to the transition from IS to H4C via providing a digital decision-support tool for practitioners.

ABSTRACT. The European Union (EU) is at the forefront of global environmental policy, addressing critical issues such as climate change, resource depletion, and pollution. An important component of its strategy is Industrial Symbiosis (IS), which aligns with the EU's circular economy strategy. The 8th Environmental Action Programme (EAP), guiding policy until 2030, envisions a toxic-free and climate-neutral Union by 2050. The EU's Circular Economy Action Plan emphasises circularity, while the Clean Industrial Deal (CID) supports clean-tech competitiveness and industrial decarbonisation.

The EU promotes Industrial Symbiosis through projects funded by the Horizon Programme, aiming to raise awareness and achieve environmental and economic benefits. However, challenges like data collection and exchange still need to be addressed. To overcome these obstacles, the EU fosters policies conducive to IS. The Horizon Programme supports these efforts with projects designed to integrate IS into technosystems and foster decarbonization in energy-intensive industries.

The innovative Hubs4Circularity (H4C) exemplify Industrial and Urban symbiosis implementations by engaging diverse stakeholders to optimise resource use and reduce waste through advanced technologies. By embracing Industrial Symbiosis, the EU advances towards a zero-carbon, circular economy, enhancing regional growth, resilience, and job creation.

ABSTRACT. Industrial Symbiosis (IS) presents a transformative opportunity for industries to shift toward more sustainable practices by enhancing resource efficiency, reducing waste and lowering environmental impacts. This approach hinges on the shared use of resources, such as energy, water, and raw materials, between industries that may otherwise operate in silos. By fostering the exchange of resources among industries, IS can help to optimize waste management, reduce costs and contribute to the broader transition to a Circular Economy. However, while the potential benefits of IS are widely acknowledged, its widespread implementation faces a range of multifaceted barriers. These barriers are explored in depth through stakeholder engagements conducted within the INSET project, which offers critical insights into the complex landscape of IS adoption. The INSET project (Industrial Symbiosis Capacity Building for Enterprises and Related Sectors through a Disruptive, Digital, and Pragmatic Training and Awareness Approach) is an Erasmus+ funded initiative designed to address these barriers through an innovative and comprehensive training approach. The project targets a diverse range of stakeholders—enterprises, governmental bodies, and academia—by combining digital tools, disruptive methodologies and hands-on, pragmatic training. This approach seeks to increase awareness, build capacity and equip enterprises with the knowledge and skills needed to implement IS strategies effectively. By utilizing a forward-thinking, cross-disciplinary approach, the INSET project aims to catalyze the shift toward industrial symbiosis in a variety of sectors and industries, fostering a more sustainable, resource-efficient and economically resilient industrial ecosystem. Despite the growing recognition of the importance of IS, several challenges continue to impede its implementation. The findings of the INSET project highlight the need for tailored strategies to address the specific challenges faced by different stakeholder groups. For instance, governmental bodies and regulatory agencies need to collaborate more effectively with businesses and support organizations to create clearer, more consistent policies that encourage IS adoption. This might include offering incentives, streamlining regulatory processes, and creating frameworks that promote resource sharing across industries. Additionally, businesses require targeted support in the form of training and capacity-building programs that address both the technical and organizational aspects of IS. By building awareness and providing enterprises with the skills and tools necessary to implement IS, training programs can help bridge the knowledge gap and reduce the barriers to adoption. Another key finding of the INSET project is the importance of fostering collaboration between various stakeholders involved in the IS process. Collaboration is essential for the successful design and implementation of IS systems, as it enables businesses to share knowledge, resources, and expertise. Our study underscores the need for businesses to develop stronger networks with other actors in the industrial ecosystem—ranging from suppliers and customers to regulatory agencies and academic institutions. By collaborating more effectively, these actors can create synergies that drive the development of innovative IS solutions. This approach will also help build trust and encourage a culture of cooperation, which is essential for the successful realization of IS practices. Two capacities emerge as particularly crucial in advancing IS: the ability to design IS systems that facilitate collaboration and resource exchange, and the ability to manage IS implementation effectively. Designing IS systems involves understanding the technical, economic, and organizational requirements of different industries and identifying opportunities for resource exchanges that create value for all participants. This requires a comprehensive understanding of the industrial ecosystem and the ability to align different actors' interests and goals. Managing IS implementation involves coordinating activities across multiple stakeholders, establishing regulatory frameworks that support resource sharing, and ensuring that IS initiatives are monitored and evaluated to track progress and identify areas for improvement. In conclusion, while the barriers to Industrial Symbiosis are significant, they are not insurmountable. The findings from the INSET project provide valuable insights into the critical areas requiring targeted intervention. By addressing the skills and technology gaps, alleviating economic constraints, and streamlining regulatory processes, stakeholders can pave the way for successful IS implementation. Furthermore, by fostering collaboration and equipping stakeholders with the necessary knowledge and skills through innovative training and awareness initiatives, the full potential of IS can be unlocked. This will not only lead to a more sustainable industrial ecosystem but also contribute to the broader goals of resource efficiency, environmental sustainability, and economic resilience. Through these collective efforts, IS can become a central pillar in the transition to a circular economy and a more sustainable industrial future.

ABSTRACT. The present work reviews the lessons learnt from four (4) applied research projects, run at different Technology Readiness Levels (TRLs) and geographic areas in Europe, aiming at showcasing how wastes from one sector of economy could be transformed to custom made solutions for another, under the perspective of Industrial Symbiosis (IS).

ABSTRACT. Faced with growing environmental pressure and resource scarcity, sustainability has become essential for the continuity of global companies (Bansal & DesJardine, 2014). The Circular Economy, by challenging the traditional “take-make-discard” model (MacArthur, 2013), focuses on reuse and remanufacturing, aiming for resource efficiency and waste reduction (Awan & Sroufe, 2022). Effective implementation depends on stakeholder involvement and the internalization of externalities, such as carbon pricing, to encourage sustainable practices (Figge et al., 2022; Tapaninaho & Heikkinen, 2022). Sectors ranging from oil to hydrogen are adopting circular models to improve efficiency and reduce environmental impacts (Hina et al., 2023). Projects in this area aim to promote circular business models, such as circular economy hubs that facilitate industrial symbiosis, resource sharing and the use of digital platforms to optimize the flow of these resources (Pieroni et al., 2019). This research assesses the sustainability of four hubs, located in Turkey, Spain, the Netherlands, and Germany, including their facilities, partners, focus industries and surrounding ecosystems. In addition, this research suggests refined business models to reduce risks and optimize costs, with the aim of creating a framework for the development of sustainable and financially robust circular centers (Giacomarra et al., 2020). As mentioned above, this project aims to assess the sustainability of circular economy hubs, focusing on quantifying environmental, social, and economic externalities, developing a new Circular Business Model impact assessment methodology. As a first step, a literature review and sector impact analyses were carried out to identify possible externalities. The second step of this methodology consisted of holding a workshop with stakeholders to identify the most relevant externalities. During the workshop, stakeholders assessed the relevance of the externalities using a digital platform, which allowed data to be collected in real time and anonymously. Externalities were classified into three main dimensions (environmental, social, and economic) and into positive and negative impacts. The assessment was made on a scale of 0 to 5 to facilitate subsequent analysis. Finally, to validate the externalities collected, KPMG Portugal carried out technical visits to all the hubs. The externalities addressed are shown in Table 1. Regarding the results obtained at the stakeholder workshop, 38 people took part, including representatives from the hubs in Spain (13), Turkey (4), Germany (3), the Netherlands (2), and 16 project members. In the environmental pillar, reducing GHGs and pollution (4.6 points) were the top priorities, followed by circularity and renewable energy. Land management was considered less urgent. In the social pillar, employment (4.1 points) and health and safety and training and education (3.9 points) were the most valued externalities, while diversity and inclusion received a lower score. In the economic pillar, innovation (4.5 points) was identified as the most relevant positive externality, while concern about the costs of decommissioning infrastructure (3.7 points) also stood out. These results reflect the stakeholders' emphasis on reducing emissions, creating jobs and innovation, with a view to long-term sustainability.

Table 1. Externalities analysed in the stakeholder workshop Externality Dimension Environmental Social Economic Externality Impact Positive Renewable Energy & Efficiency GHG & Pollution Reduction Land Management Circularity & Recycling Employment Impact on Communities Human Rights DE&I Health & Safety Training & Education Innovation Economic Development Wages & Payments Infrastructure & Materials Negative GHG Emissions Pollution Land Use & Ecosystem’s Degradation Waste Raw Material & Resources Usage Occupational Hazards & Risks Exploitation Dismantling costs

Adding these 22 externalities to traditional economic and financial models, it is possible to develop an impact assessment model to measure the mitigation of negative externalities and the enhancement of the positive ones, with the aim of creating a model that contributes to a more innovative and better circular business model. It is concluded that the approach adopted can be replicated for the assessment and prioritization of externalities in other contexts, providing a useful model for integrating stakeholder perceptions and contributing to the development of sustainable practices in circular economies.

ABSTRACT. Industrial symbiosis (IS) represents a powerful strategy for advancing circular economy practices by fostering collaboration between industries to exchange resources, materials, energy, and knowledge. However, its successful implementation is often hindered by gaps in technical expertise, institutional capacity, and stakeholder engagement. In this context, training and capacity building play a pivotal role in accelerating the adoption and scalability of industrial symbiosis across sectors and regions. Through specialized training programs spanning areas related to IS, training programs equip practitioners, industrial stakeholders, policymakers, and local authorities with the necessary skills and competencies to design, implement, and manage symbiotic networks. This work assesses the real case of a research and technology organization (RTO) that, among other aims, trains people within topics such as circular economy, sustainability, decarbonization, and bioenergy among others, to understand how learning contributes to the implementation of IS-based projects. Figure 1 shows the training courses that focus on areas related to IS or have specific modules on IS, that enabled to develop this study.

Figure 1 – Flowchart of the system boundaries for the LCA studies. Many of these courses integrate group projects that simulate circularity challenges, requiring participants from diverse backgrounds to co-develop innovative solutions. This collaborative learning model not only mirrors real-world dynamics but also builds lasting professional networks that support circular implementation efforts, while fostering cross-disciplinary thinking. Course participants consistently highlight the importance of networking opportunities and collaborative exercises. By integrating real-world case studies, hands-on tools, and interactive learning formats, the assessed training programs enhance practical understanding and promote the replication of successful industrial symbiosis models. As such, training is not merely a knowledge transfer activity, it is a strategic instrument for building the human capital, institutional trust, and systems thinking required to embed industrial symbiosis within regional and national circular economy strategies. These features support the participants to apply these techniques in real-world problems, being in an improved position to champion circular projects within their organizations. Thus, these awareness building moments not only support mindset changing, as also trigger the development of practical skills. Moreover, training serves as a catalyst for stakeholder engagement, unlocking new opportunities for cross-sectoral collaboration and innovation. One of the main outputs of this study was to understand on how structured training initiatives offered by RTOs can make a significant impact in supporting the systemic uptake of industrial symbiosis, contributing to a more resource-efficient, resilient, and low-carbon industrial future. Our experience demonstrates that targeted training not only raises awareness of the technical and economic benefits of IS but also fosters the development of a shared language and collaborative mindset among diverse actors.

Key words: industrial symbiosis, sustainability, training, synergy, collaboration

Acknowledgements: This work is funded by national funds through the FCT – Fundação para a Ciência e a Tecnologia, I.P. and, when eligible, by COMPETE 2020 FEDER funds, under the Scientific Employment Stimulus - Individual Call (CEEC Individual) - 2021.03036.CEECIND/CP1680/CT0003(https://doi.org/10.54499/2021.03036.CEECIND/CP1680/CT0003).

ABSTRACT. This study presents an integrated modelling framework combining agent-based modelling (ABM), net present value (NPV) analysis, and life cycle assessment (LCA) data to analyze the impact of different policy scenarios on end-of-life (EoL) wind turbine blade (WTB) management decision. Findings show that while policy incentives improve financial outcomes for recyclers and manufacturers and contribute to initial CO2eq. emission reductions, maintaining long-term impact requires sustained policy support and adaptability to market dynamics. Additionally, we discuss that the adoption of circular business models (CBMs) such as solvolysis and pyrolysis is influenced not only by their sustainability performance but also by value chain factors, including operator preferences, market competition, and demand.

ABSTRACT. The environmental impacts of computing infrastructure in higher education are often overlooked, despite its increasing role in scientific research. This study evaluates the energy and resource efficiency of computing hardware and software at the University of Manchester’s Faculty of Science and Engineering (FSE), with the goal of informing sustainability guidelines aligned with the university’s Net Zero commitments.

Using life cycle assessment (LCA), hardware usage audits, and software energy profiling, the environmental performance of three computing setups—desktop computers with screens (DTCs), laptops (LTs), and high-performance computing systems (HPCs)—was quantified. DTCs and LTs were assessed based on representative usage, while HPCs were analysed through Herwig, a particle physics simulation software. The assessment, conducted in SimaPro using the EcoInvent v3.10 database and ReCiPe 1.1 method, considered 18 environmental impact categories.

Preliminary findings show that, per unit, HPCs have the highest impact across all categories, contributing 6.8 tonnes of CO₂ eq. over five years, mainly from electricity use. At the faculty level (with ~4,300 DTCs, 4,600 LTs, and 660 HPCs), the total global warming impact over five years is 26.5 kt CO₂ eq. HPCs dominate six major impact categories, while DTCs lead in others. Extending the replacement cycle from five to nine years significantly reduces environmental impacts, with up to 41% reduction in marine eutrophication.

The results highlight the need for policies supporting energy-efficient use, especially for HPCs, and suggest that adjusting hardware replacement cycles is a cost-effective way to reduce emissions. Future work will refine infrastructure modelling and explore the impact of adopting more efficient computing technologies.

ABSTRACT. The Russian military aggression in Ukraine has severely impacted global food security, particularly in relation to Sustainable Development Goal 2 (SDG 2), which targets hunger eradication and sustainable agriculture. Ukraine, a key global exporter of wheat, corn, and rapeseed to 67 countries, has experienced major disruptions in agricultural output and exports. War-related damage led to approximately USD 2.25 billion in losses for rural households with devastating long-lasting implications. The study employs Fuzzy logic to rank countries according to SDG 2 indicators—malnutrition, food insecurity, and agricultural productivity—revealing critical vulnerability in Sub-Saharan Africa and other Least Developed Countries. Using Arena simulation software, the research models scenarios for Ukraine's key crops to develop proper strategies for optimizing production under uncertainty. This integrated, data-driven approach emphasizes the need for resilient food, energy, and environmental systems policies. The findings highlight the broader global implications of regional conflicts and the importance of targeted investments and technological planning in rebuilding more resilient Ukraine’s agricultural sector at the same time addressing global food security.

ABSTRACT. The development of blue carbon fisheries, particularly in mariculture, has emerged as a key pathway for transitioning to a low-carbon economy. This approach plays a vital role in addressing global climate challenges while promoting the green development of the marine economy. This paper examines the data on mariculture shellfish and algae of seven coastal cities in Shandong province from 2016 to 2021 to assess the economic value of blue carbon fisheries’ carbon sinks and analyze their spatial and temporal evolution by constructing the economic value model of fishery carbon sinks. The impacts of blue carbon fisheries on non-blue carbon fisheries, as well as upstream and downstream industry chain effects, are explored through horizontal and vertical spillovers using the improved Feder model and the Cobb-Douglas production function. The findings reveal that the economic value of blue carbon fisheries’ carbon sinks in most coastal areas of Shandong province shows a fluctuating upward trend. The development of blue carbon fisheries has significantly boosted the economic growth of marine fisheries. In terms of horizontal spillovers, the positive effects of blue carbon fisheries on non-blue carbon fisheries have strengthened over time. Additionally, blue carbon fisheries have promoted upstream and downstream sectors of the industry chain, exhibiting notable technological spillovers. These conclusions highlight the potential of blue carbon fisheries in driving the green development of the coastal fisheries economy.

ABSTRACT. In line with the goals of sustainable development, this study evaluates the environmental performance of four tourism hotels owned by Doğuş Hospitality and Retail—D-Resort Göcek, D Maris Bay, D-Resort Ayvalık, and Argos in Cappadocia—through a comparative analysis of their carbon and water footprints. Using internationally recognized methodologies (ISO 14064-1, ISO 14046, and GHG Protocol), the research provides a detailed account of Scope 1, 2, and 3 carbon emissions as well as direct water consumption. Carbon calculations are supported by verified emission factors from sources such as IPCC and DEFRA, while water footprints are disaggregated into blue, green, and grey water components. The results, normalized by metrics such as per room, per bed, and per night, highlight significant operational differences in terms of environmental efficiency and offer valuable insights for circular economy strategies in the hospitality industry.

ABSTRACT. One of the major concern countries and economies for the transition to a low-carbon and sustainable economy, is the requirement for an approach that is both environmentally regenerative and socially just. The Circular Economy (CE) and Just Transition (JT) are two intricately beneficial and interrelated frameworks that, when integrated, can facilitate a sustainable transformation that minimizes social and economic inequalities. While the Circular Economy focuses on resource efficiency, waste reduction, and closed-loop production systems, the Just Transition ensures that affected workers and communities are not left behind in the shift toward sustainability. However, the interplay between these two frameworks remains underexplored in academic and policy discourse. This paper critically examines the synergies and challenges in aligning Circular Economy principles with Just Transition objectives. Additionally, it examines policy and legal frameworks that can align Circular Economy principles with Just Transition objectives. Through an analysis of policy frameworks, industry case studies, and labor market transformations, it explores how circular strategies—such as resource recovery, remanufacturing, and industrial symbiosis—can drive job creation, economic resilience, and social equity in transitioning sectors such as mining, energy, and manufacturing. This paper highlights key governance and regulatory challenges, including labor market disruptions, policy misalignment, and skills gaps, that must be addressed to ensure a just and inclusive transition. By positioning the Circular Economy as a catalyst for the Just Transition, this paper provides a foundation for policymakers, industry leaders, and scholars to develop integrated strategies that promote both environmental sustainability and economic justice.

ABSTRACT. The study investigates the dynamic relationship between Gross Domestic Product (GDP), renewable energy consumption (REC), and carbon dioxide (CO₂) emissions in Greece, using time series data from 1990 to 2023. It examines both long-term and short-term causality between these variables using methodologies such as ARDL. The results indicate long-term causal relationships from GDP and REC to CO₂ emissions, which aligns with the Environmental Kuznets Curve (EKC) hypothesis. Additionally, there is long-term causality from GDP to REC. The study highlights that an increase in the use of renewable energy sources leads to a long-term reduction in CO₂ emissions. Conversely, no short-term causality was found between the variables. The analysis also includes diagnostic tests to ensure the stability and reliability of the results, as well as cumulative dynamic multipliers to analyze the relationship between the variables in a dynamic model. Overall, the study emphasizes the importance of renewable energy sources for the long-term reduction of CO₂ emissions without hindering economic growth in Greece, thus achieving a balance between economic development and environmental sustainability.

ABSTRACT. iLINK New Technologies implements the ENVISION pilot within the Horizon Europe CHAMELEON project, which aims to operationalise sustainable environmental management by deploying reconfigurable UAVs and AI-on-demand bundles. ENVISION focuses on high-resolution surveillance and analysis of forests and agricultural areas using multispectral UAV imaging and geospatial analytics, validated through CHAMELEON’s Drone Innovation Platform (DIP). The DJI Mavic 3M has been used for the collection of imagery in RGB, Red, Green, Near Infrared (NIR), and Red Edge bands, enabling fine-grained vegetation analysis at ground sampling distances (GSD) as low as 1.5–2.7 cm/pixel. In the context of the ENVISION pilot, autonomous flights over four geographically diverse test sites (Parnitha and Seih Sou forests, Stylida agricultural zone in Greece, and Lommedalen forest in Norway) have been conducted. The imagery was processed and aligned using WebODM, corrected for radiometric consistency, and exported in orthorectified formats. Three core AI bundles were validated: • BC1 – Vegetation Monitoring and Census: Provides tree species identification, canopy segmentation, and population mapping via computer vision and NDVI/NGRDI/VARI indices. • BC3 – Continuity of Vegetation: Assesses vegetative density and fragmentation, enabling fire risk profiling through continuity mapping and NDVI-based gradient metrics. • BC7 – Health Status of Vegetation: Detects stress indicators such as bark beetle activity, fungal growth, drought stress, and wildlife browsing by integrating spectral analysis and vegetation health thresholds. The DIP platform outputs include NDVI/NDMI/VARI index maps, 3D vegetation models, tree crown detection layers, and structured GeoJSON/SHP datasets. Visual insights such as canopy density maps, fire-prone zone identification, and crop health anomalies were extracted using computer vision algorithms. These are critical for early warning, precision agriculture, and post-disturbance forest planning. From a sustainability perspective, ENVISION exemplifies how AI-powered UAV surveillance can enhance Circular Economy practices by optimizing water usage, biodiversity conservation, and resource allocation across managed natural ecosystems.

ABSTRACT. Over the past few decades, the advocacy for the circular bioeconomy has risen as an essential cornerstone for fostering sustainability within society (Feng et al., 2023). The biobased economy aims to convert renewable biological resources and wastes into value-added products such as bio-based products and bioenergy. This approach is related to the sustainable development goals (SDGs), especially with the SDG2, SDG6, SDG11, SDG13, and SDG14. Freshwater macrophytes are essential primary producers in freshwater environments, providing habitats for periphyton, invertebrates, and vertebrates which also play critical role in biogeochemical processes, including the production of organic carbon (Poveda, 2022). Additionally, they facilitate the mobilization of nitrogen and phosphorus, absorbing surplus nutrients from the water and averting significant environmental issues like eutrophication (Poveda, 2022). However, some species can be highly invasive, posing significant ecological challenges. Thus, the management strategies should be implemented to control macrophyte overgrowth as well as maintain water quality in the ecosystem (Lizasoain et al., 2016). Since the production of biomethane requires significant amounts of organic materials (Maes and Van Passel, 2019), the aquatic biomass presents an appealing third-generation substrate for anaerobic digesters due to its non-competitive nature with agricultural land designated for food and feed production (Bauer et al., 2018). It was aimed to assess the viability of aquatic biomass in biomethane production. In this context, four different macrophyte species (Scirpus, Phyragmites, Ceratophyllum, Potamogeton), which are quite abundant in our freshwater resources, were harvested from Sapanca Lake (Türkiye), and biomethane potentials were assessed using the Automatic Methane Potential Test System (AMPTS) II (Bioprocess Control, Sweden, Lund) as described in Ozbayram et al. (2017). Standard inoculum was obtained from an anaerobic digester of full-scale wastewater treatment plant (Istanbul, Türkiye). The reactors were operated for 35 days at 37°C with an inoculum/substrate ratio of 2 based on volatile solids (VS). Each reactor configuration was run in triplicates. The biomethane yields of four different macrophytes were calculated on the basis of VS content of each substrate and depicted in Figure 1. The digesters operated with Phragmites exhibited the highest methane yield, calculated as 238 mLN CH4gVS-1. Subsequently, lower biomethane yields were observed for the submerged macrophytes Ceratophyllum (165 mLN CH4gVS-1) and Potamogeton (193 mLN CH4gVS-1) and the methane production was almost completed within the first 10 days of the operation period.

ABSTRACT. This study investigates the dynamic relationship between economic growth, CO₂ emissions, and climate resilience within the framework of circular economy and sustainability, using Greece and Turkey as case studies. These two geographically and economically interconnected countries provide a unique comparative perspective due to their shared environmental challenges and distinct policy trajectories in addressing climate change. The research examines the influence of energy consumption, environmental taxation, renewable energy adoption, and trade openness on environmental degradation, proxied by CO₂ emissions and ecological footprint. Employing a time-series econometric approach with structural breaks and cointegration techniques, the study accounts for asymmetric effects and policy shifts over the past two decades. Preliminary findings suggest that while economic growth contributes to environmental stress, the implementation of circular economy practices—particularly in waste reduction and energy efficiency—moderates this effect. Environmental taxes and renewable energy policies are found to be more impactful in Greece, whereas Turkey exhibits a stronger dependency on trade and industrial growth, often at the expense of environmental quality. The results highlight the importance of coordinated regional strategies and offer policy recommendations for integrating circular economy principles into national climate action plans. This research contributes to the broader discourse on sustainable development and the green transition in Southeastern Europe.

ABSTRACT. In response to growing environmental concerns and the imperative to conserve natural resources, the wastewater management sector is transitioning toward circular economy models that emphasize resource recovery. A notable advancement in this field is the Anaerobic Membrane Bioreactor (AnMBR), a technology that integrates anaerobic digestion with membrane filtration to simultaneously achieve wastewater treatment and bioenergy production.

AnMBRs offer a viable alternative to conventional aerobic activated sludge processes, primarily due to their lower energy demands, absence of aeration requirements, and minimal excess sludge generation. The system utilizes an anaerobic reactor for the microbial degradation of organic matter, resulting in the production of biogas, while membrane units ensure the separation of solids and pathogens, yielding a high-quality effluent. This effluent retains essential nutrients such as nitrogen and phosphorus, enabling reuse in agricultural applications or microalgae cultivation. The small volume of stabilized sludge can also be valorized through biochar production or soil amendment.

This study investigates a pilot-scale AnMBR system incorporating an Expanded Granular Sludge Bed (EGSB) reactor and ultrafiltration membranes treating municipal wastewater. System performance was evaluated under two hydraulic retention times (48 h and 24 h) at mesophilic temperatures (38°C to 20°C). High chemical oxygen demand (COD) removal effluents (ranging from 94.2% to 97.9%) were maintained across all conditions, indicating robust system stability.

While AnMBRs entail higher capital costs, particularly for membrane units and automation infrastructure, operational expenditures are dominated by labor, monitoring, and electricity. Despite these costs, energy recovery through methane-rich biogas enables energy-neutral or even energy-positive operation. In the context of a circular economy, AnMBRs represent a sustainable and economically viable solution for municipal wastewater treatment, supporting both energy self-sufficiency and nutrient recovery.

ABSTRACT. The transition to a circular economy (CE) in the olive oil sector is gaining momentum, driven by strategies aimed at reducing waste and valorizing by-products. While substantial attention has been paid to environmental and multi-dimensional CE indicators, the economic dimension remains significantly underexplored. This study addresses this gap by assessing the economic efficiency of circular practices in olive oil mills, with a focus on a pilot case study in Greece. The research has two main objectives: first, to evaluate the degree of circularity using a tailored set of indicators that reflect the unique processes of olive oil production; second, to assess the economic viability of these practices through a Cost-Benefit Analysis (CBA). The indicators used consider factors such as resource efficiency, waste reduction, energy use, and by-product valorization, while the economic analysis accounts for both tangible and intangible costs and benefits. The study draws on an extensive literature review to design an appropriate methodological framework for application in the agri-food sector. Findings from this pilot are intended to inform a replicable assessment model applicable to a broader range of olive oil mills. By integrating environmental and economic perspectives, the research supports evidence-based decision-making and promotes sustainable practices within the sector.

ABSTRACT. Clean technologies have become increasingly popular, with diverse stakeholders from governments, to operators, to the research community and consumers looking into new sustainable energy options. Biomass has the potential to be a cost-effective and sustainable energy source among renewable resources [1], gasification being among the most popular waste-to-energy (WtE) methods, as a green thermochemical technology [2]. WtE techniques convert residues (for instance forestry and agricultural wastes) into energy, that may be used to gradually replace fossil-derived fuels. Thus, gasification supports biomass as a more viable renewable baseload energy source, promoting a low-carbon economy and contributing to decarbonization [3, 4]. A very useful tool to avail the environmental performance of these solutions is the life cycle assessment (LCA) approach, that also enables to shows areas for improvement to maximize the environmental advantages of the system [5-7]. This work addresses the environmental analysis of electricity production (1 MJ) from gasified bagasse and compares it with combustion, estimating the environmental impact of the two processes. The environmental analysis focuses on the valorization stage, disregarding the bagasse cultivation, extraction, transport and pretreatment stages. The ReCiPe 2016 Midpoint (H) method was applied to calculate the results of different impact categories, such as resource depletion, acidification, and climate change [8]. Additionally, the study also investigates the environmental performance of the gasification process with the integration of solar energy with conventional gasification systems. As main outcomes, it could be seen that, when compared to combustion, gasification generally shows a better environmental performance, especially regarding the potential for global warming and resource efficiency. Nevertheless, certain impact areas, such as particulate matter generation and soil acidification, suggest that further optimization is necessary to mitigate the environmental impact. Using solar energy in the gasification process is such an improvement aspect, showing notable reductions in environmental impacts for several categories, as greenhouse gas potential, particulate matter formation, acidification, and freshwater eutrophication, compared to fossil-based gasification. These results suggest that solar energy significantly reduces the environmental footprint of bagasse gasification. As a general overview, from a life cycle perspective, gasification offers environmental advantages over combustion, particularly in terms of greenhouse gas emissions and energy efficiency. However, technology complexity, cost, and operational challenges must be considered when selecting the most appropriate pathway. In contexts where cleaner energy production is prioritized and investments in advanced technologies are viable, bagasse gasification stands out as a more sustainable solution, especially when solar-driven systems are applied.

Key words: biomass gasification, electricity production, bagasse, LCA, solar energy

Acknowledgements: This work is funded by national funds through the FCT – Fundação para a Ciência e a Tecnologia, I.P. and, when eligible, by COMPETE 2020 FEDER funds, under the Scientific Employment Stimulus - Individual Call (CEEC Individual) - 2021.03036.CEECIND/CP1680/CT0003 (https://doi.org/10.54499/2021.03036.CEECIND/CP1680/CT0003), and under the project with grant number 2022.08625 (https://doi.org/10.54499/2022.08625.PTDC). References 1. Pelkmans, L. and A.C.G. Berndes, The role of bioenergy in the energy transition, and implications on the global use of biomass, in IEA Bioenergy Task 45. 2024, IEA Bioenergy. 2. Monteiro, E., A. Ramos, and A. Rouboa, Fundamental designs of gasification plants for combined heat and power. Renewable and Sustainable Energy Reviews, 2024. 196: p. 114305. 3. Helf, A., et al., Carbon-negative hydrogen from biomass using gas switching integrated gasification: Techno-economic assessment. Energy Conversion and Management, 2022. 270: p. 116248. 4. Pleshivtseva, Y., et al., Comparative analysis of global trends in low carbon hydrogen production towards the decarbonization pathway. International Journal of Hydrogen Energy, 2023. 48(83): p. 32191-32240. 5. Zang, G., et al., Life cycle assessment of power-generation systems based on biomass integrated gasification combined cycles. Renewable Energy, 2020. 149: p. 336-346. 6. Loução, P.O., J.P. Ribau, and A.F. Ferreira, Life cycle and decision analysis of electricity production from biomass – Portugal case study. Renewable and Sustainable Energy Reviews, 2019. 108: p. 452-480. 7. Ramos, A., et al., Environmental and socio-economic assessment of cork waste gasification: Life cycle and cost analysis. Journal of Cleaner Production, 2020. 249: p. 119316. 8. Huijbregts, M.A., et al., ReCiPe2016: a harmonised life cycle impact assessment method at midpoint and endpoint level. The international journal of life cycle assessment, 2017. 22: p. 138-147.

ABSTRACT. The theory of the circular economy (CE) has now arisen as a strategic approach toward mitigating the aforementioned issues by promoting longevity, reuse, recycling, and regeneration through the lifecycle of infrastructures. In the context of this approach, CE initiatives hold the potential to make transport systems more efficient and sustainable by enabling better utilization of resources, reducing the environmental impact, and upgrading the lifespan of resources. However, the success and evaluation of these initiatives depend heavily on the ability to identify, decode, and respond to complex supply chain and operation data. This research discusses the key role of supply chain analytics (SCA) in supporting and monitoring circular economy initiatives in the transport infrastructure industry as well as the effect of those initiatives on corporate performance. The study develops a conceptual framework describing the interrelationship between the principles of the circular economy, supply chain analytics tools, and corporate performance metrics in the given context of the transport infrastructure sector. The framework integrates insights from industry reports, academic sources, and empirical case studies and applies this data to give a holistic overview of the ways in which data-driven approaches can optimize both sustainability and competitive success in the operations in the infrastructure space. Finally, this research adds to the body of knowledge by incorporating circular economy thinking into supply chain analytics in the highly critical and capital-intensive industry of transport infrastructure development. It provides a strategic framework demonstrating how organizations can use analytics to not just optimize physical systems but also drive sustainable value creation, ensure regulatory compliance, and create leadership in sustainability efforts. The findings offer actionable suggestions to infrastructure developers, governments and government agencies, as well as private investors who want to align corporate performance goals with sustainable development goals and circular economy goals.

ABSTRACT. This study empirically investigates the dynamic relationships in spatial and time domains between economic, demographic, and trade-related factors and ecological footprint per capita (EFconsPC) in G-7 countries. To do so, we adopt the novel spatiotemporal artificial intelligent regression models, specifically the Geographically Neural Network Weighted Regression (GNNWR) model, introduced by Yin et al. (2024). This innovative method integrates a spatiotemporal weighting framework with neural network architectures. The GNNWR results suggest that GDP per capita negatively affects ecological footprints, suggesting that higher economic development leads to lower environmental pressure. Population and renewable energy consumption exhibit a positive relationship with EFconsPC, highlighting the effect of economic expansion and energy use on environmental outcomes. Additionally, globalization appears to increase carbon emissions, while having a weaker influence on the ecological footprint. In contrast, economic complexity and trade openness show negative effects in EFconsPC. These results provide valuable insights for policymakers and governments striving to balance economic growth with environmental responsibility.

ABSTRACT. The transition towards a circular economy (CE) in the built environment requires robust tools and methods to evaluate and manage building stocks, material flows, and renovation strategies across scales. While most existing building stocks were not designed with CE principles in mind, recent advances in data collection, modeling, and classification methodologies have enabled new approaches to align construction and demolition practices with sustainability goals. Among these, the use of archetypes has emerged as a unifying framework, facilitating the aggregation of information on material intensity, energy use, spatial distribution, and structural vulnerability, with the aim of enabling scalable and transferable assessments of environmental and economic performance. Several recent studies have demonstrated the potential of archetype-based methodologies to support CE strategies and inform policy and planning decisions. For instance, Rajaratnam et al. [1] conducted a systematic review of GIS and remote sensing techniques for building stock mining, analyzing over 50 studies across multiple countries. Their work highlighted the relevance of geo-referenced data in the estimation of end-of-life (EOL) scenarios for buildings and the strategic location of recycling infrastructure, especially in urban contexts. The study emphasized the need for standardized data collection and integration across disciplines to effectively support CE applications through urban mining strategies and building material recovery pathways. Plank et al. [2] introduced a novel economy-wide material flow database covering 14 key building stock materials such as concrete, steel, timber, and glass, across 177 countries from 1900 to 2016. Although it focuses exclusively on primary materials, its structured and long-term historical data can support the design of circular economy strategies at the national level by helping policymakers identify material-intensive sectors, assess dependency on raw materials, and plan future transitions toward increased resource efficiency and material circularity. In a complementary effort, Marinova et al. [3] developed a global construction material stock model for residential buildings using a bottom-up approach. Building upon these foundations, the European Project Green RenoV8, LIFE23-CET, Project ID 101167626 [4] proposes a harmonized approach to building stock classification, aiming to define up to 30 building archetypes per pilot country and region, with an integrated focus on energy efficiency, seismic resilience, and environmental performance. The project involves five pilot countries: Italy, Greece, Slovenia, Austria, and Belgium, which provide diverse climatic, regulatory, and construction contexts. Each country will develop national and regional archetype frameworks tailored to its building stock characteristics and renovation priorities. These archetypes will include detailed data on geometric and constructive features, energy uses (heating, cooling, domestic hot water, ventilation, lighting), and non-renewable primary energy indicators, under EPBD (Energy Performance of Buildings Directive) guidelines. To ensure methodological robustness, Green RenoV8 will leverage existing databases and knowledge platforms such as the MODERATE project, the European Building Observatory, TABULA, and the EPISCOPE project. These sources provide valuable typologies and empirical data on building stock composition, age, energy performance, and renovation dynamics across Europe. Additionally, the definition of archetypes will benefit from the multidisciplinary knowledge of project partners in both the civil and energy engineering domains, drawing on national practices, regulatory standards, and field data. This will allow for a more realistic characterization of buildings and enable the identification of technically and economically viable renovation strategies that address both seismic and energy-related vulnerabilities. This work offers a comprehensive methodological framework for defining and using archetypes in the context of CE, including a critical assessment of assumptions, identification of data gaps, and guidance for replicability in non-pilot countries. This work contributes directly to several key topics, including circular materials and product flows, integrated waste management, green accounting, regional circular economy, and smart buildings and cities. By aligning archetype-based modeling with CE principles and integrating it into a broader strategy for sustainable renovation and construction, Green RenoV8 sets the stage for an operational transition toward regenerative, resilient, and zero-waste built environments in Europe and beyond.

References 1. Rajaratnam, D., Stewart, R. A., Liu, T., & Vieira, A. S. (2023). Building stock mining for a circular economy: A systematic review on application of GIS and remote sensing. Resources, Conservation & Recycling Advances, 18, 200144. https://doi.org/10.1016/j.rcradv.2023.200144 2. Plank, B., Streeck, J., Virág, D., Krausmann, F., Haberl, H., & Wiedenhofer, D. (2022). Compilation of an economy-wide material flow database for 14 stock-building materials in 177 countries from 1900 to 2016. MethodsX, 9, 101654. https://doi.org/10.1016/j.mex.2022.101654 3. Marinova, S., Deetman, S., van der Voet, E., & Daioglou, V. (2020). Global construction materials database and stock analysis of residential buildings between 1970–2050. Journal of Cleaner Production, 247, 119146. https://doi.org/10.1016/j.jclepro.2019.119146 4. Green RenoV8 (LIFE23-CET-GreenRenoV8, Project ID: 101167626).

ABSTRACT. The aim of this research is to investigate the role of alternative assets as potential safe havens or hedging instruments, especially during times of financial and economic crises. Specifically, the research will examine the dynamic interconnectedness among diverse global asset. Through a comprehensive analysis of various alternative asset indices, this study seeks to provide insights into their effectiveness in offering protection or diversification for investors amid market volatility.

ABSTRACT. The transition toward a circular economy (CE) is an imperative strategy for advancing global sustainability goals, particularly in resource-intensive industries such as aviation. Airports, as key nodes in international supply chains, have a unique opportunity to integrate circular principles into their operations, waste management, and energy systems. This study conducts a comparative assessment of CE practices in European (EU) and United States (U.S.) airports, evaluating their performance in areas such as emissions reduction, energy efficiency, water conservation, and waste management. Through a systematic review of sustainability reports, industry case studies, and empirical data, this research develops a standardized evaluation framework based on the 9Rs principles (Reduce, Reuse, Recycle, Recover, Refuse, Rethink, Repair, Regenerate, Redesign). The study maps circular economy strategies implemented in selected EU and U.S. airports, benchmarking them against key performance indicators (KPIs) related to waste reduction, resource recovery, sustainable energy adoption, and closed-loop systems. A mixed-methods approach was applied to quantify and compare circular economy adoption across airports. The study first conducted a systematic content analysis of airport sustainability reports, focusing on key material issues: ● Emissions (GHG monitoring, reduction targets, carbon footprint tracking) ● Energy (renewable energy adoption, efficiency measures, SAF integration) ● Water (reuse, recycling, wastewater treatment, regulatory compliance) ● Waste (sorting, recovery, recycling rates, landfill diversion) Quantitative indicators were normalized per passenger and per operational area to ensure comparability across airports of different sizes. A weighted scoring model was developed to evaluate CE performance, assigning scores to each 9Rs principle based on airport implementation levels. Data was further analyzed through benchmarking techniques, comparing EU and U.S. airports against industry standards (ACI Airport Carbon Accreditation, GRI, ICAO sustainability frameworks, and FAA environmental regulations). A statistical analysis was conducted to identify regional trends, key gaps, and best-performing airports. The analysis provides comparative insights into CE adoption across regions, identifying leading airports, regional policy influences, and strategic gaps. The study also examines the role of certification frameworks in promoting transparency and regulatory alignment for sustainable airport operations. Based on the findings, this research offers strategic recommendations for airport operators, policymakers, and stakeholders to accelerate the transition toward circular and resource-efficient supply chains in aviation. By synthesizing insights from European and U.S. perspectives, this study contributes to a global understanding of circular economy integration in airport operations, emphasizing the transformative role of sustainability frameworks. The results aim to guide future investments, policy decisions, and industry collaborations toward achieving circularity in the aviation sector.

ABSTRACT. The importance of adopting a circular economy is becoming increasingly apparent, as non-renewable resources are depleted and natural resource prices become more volatile. The circular business model (CBM) is based on minimizing the waste of resources by applying the principles of reuse, recycling, and regeneration, maintaining materials and products in use for as long as possible. In contrast to traditional linear models, circular economy business models promote sustainability by enhancing resource efficiency, minimizing waste, and reducing environmental impacts while generating economic benefits. Sustainable business models (CBM) adopt a more comprehensive approach, encompassing environmental, social, and economic dimensions. A sustainable circular business model utilizes innovation to generate, deliver and retain value within closed material loops, enhancing resource efficiency, minimizing waste, and achieving long-term economic, social, and environmental gains through collaborative and systemic strategies. The transition to sustainable business models requires organizations to integrate sustainability not only into their operational and business strategies but also into their human resource management and organizational culture. Organizational culture significantly influences corporate sustainability efforts. Companies must cultivate a sustainability-oriented culture to successfully integrate environmental and social responsibilities. Despite extensive sustainability policies, effectiveness is often limited by cultural norms prioritizing short-term financial gains. Achieving corporate sustainability requires a fundamental cultural transformation aligning organizational values, leadership, and employee engagement with sustainability principles. This transition depends on the unique cultural characteristics of each organization and requires leadership commitment, employee training, and the integration of sustainable practices into daily operations. The increasingly challenging organizational environment underscores the importance of ethical corporate practices. Organizational culture influences ethical behavior, supporting responsible business decisions, improved performance, and stakeholder engagement. A robust corporate code of ethics fosters a diverse, inclusive workplace, empowering employees to contribute their perspectives. Sustainable Human Resource Management (SHRM) emphasizes human, social, and environmental outcomes, ensuring organizational sustainability through employee well-being, social responsibility, and minimized environmental impacts. Sustainability in HRM encompasses responsibility-oriented, efficiency and innovation-oriented, and substance-oriented dimensions. Several measures to assess sustainable human resource management practices are already in use within organizations, including climate, well-being and work-life balance surveys, workforce planning to forecast future skills requirements, and assessments of the organization’s carbon footprint. However, a sustainable human resource management approach requires the systematic integration of these measures into a comprehensive human resource management strategy. This study explores the linkage between circular business models and sustainable corporate culture, emphasizing the crucial roles of corporate ethics and sustainable HRM. It highlights how adopting circular economy practices requires not only technological and operational changes but also significant cultural transformation within organizations. Successfully embedding sustainability involves aligning ethical standards, organizational culture, and human resource practices to foster employee engagement and commitment. Moreover, it requires clear communication of sustainability objectives, ongoing training, and monitoring of sustainable practices. This research provides managers and industry experts with valuable insights and practical guidance to effectively navigate cultural transformations and integrate sustainable practices into their organizational strategies.

ABSTRACT. Metal-organic frameworks (MOFs) have emerged as highly promising materials for wastewater remediation due to their permanent porous structures, extensive surface area, and precisely arranged structures composed of interconnected metallic nodes and organic ligands. Given the large amount of MOF materials synthesized, there has been an increasing interest in the use of MOFs in circular economy applications related to the protection of the environment and agriculture. Current research is increasingly focused on expanding the practical applications of water-stable MOFs,based on ecologically friendly metal ions and organic ligands, by combining them with other types of sorbents, such as bamboo Biochar, Clay, and alginates, to create MOF composites (MOFCs) with high stability and capability to sorb a wide range of pollutants. MOFCs derived from these materials have been employed in wastewater treatment and show potential for additional uses, including as sophisticated fertilizers. Moreover, developing affordable and efficient sphericalMOF composite beads that can be easily separated from water is important since this will facilitate their use in advanced filters employed in wastewater treatment.