Circular Economy Goals Research Articles

Tracking Secondary Raw Material Operational Framework—DataOps Case Study

The ceramic and glass industries, integral to the EU Emissions Trading System (EU ETS), face significant challenges in achieving decarbonization despite advancements in energy efficiency. The circular economy offers a promising pathway, emphasizing the reuse and recycling of waste materials into secondary raw materials (SRMs) to reduce resource consumption and emissions. This study investigates a standardized waste supply chain framework, developed collaboratively with stakeholders, tailored for the ceramic sector. The Waste Resource Platform (WRP) integrates Industry 4.0 paradigms, utilizing a modular, layered architecture and a process-centric design. The framework includes experimental tests and co-creation methodologies to refine a digital marketplace that connects stakeholders, facilitates SRM exchange, and fosters industrial symbiosis. The WRP demonstrates the potential for SRMs to replace virgin materials, reducing environmental impacts and production costs. It enhances supply chain transparency through digital traceability, promotes predictive material sourcing, and streamlines logistics via algorithmic optimization. Challenges such as regulatory gaps and quality standards are addressed through standardized processes, open data governance, and innovative algorithms. The WRP project advances circular economy goals in the ceramic sector, promoting waste reuse, industrial symbiosis, and supply chain resilience. Its standardized, open-access platform offers a scalable model for other industries, fostering sustainable practices and resource efficiency while addressing global climate targets.

Promoting Sustainability in the Recycling of End-of-Life Photovoltaic Panels and Li-Ion Batteries Through LIBS-Assisted Waste Sorting

To promote sustainability and reduce the ecological footprint of recycling processes, this study develops an analytical tool for fast and accurate identification of components in photovoltaic panels (PVs) and Li-Ion battery waste, optimizing material recovery and minimizing resource wastage. The laser-induced breakdown spectroscopy (LIBS) technique was selected and employed to identify fluoropolymers in photovoltaic back sheets and to determine the thickness of layers containing fluorine. LIBS was also used for Li-Ion batteries to reveal the elemental composition of anode, cathode, and separator materials. The analysis not only revealed all the elements contained in the electrodes but also, in the case of cathode materials, allowed distinguishing a single-component cathode (cathode A containing LiCoO2) from multi-component materials (cathode B containing a mixture of LiMn2O4 and LiNi0.5Mn1.5O4). The results of LIBS analysis were verified using SEM-EDS analysis and XRD examination. Additionally, an indirect method for identifying fluoropolymers (polytetrafluoroethylene (PTFE) or poly(vinylidene fluoride) (PVDF)) employed to prepare dispersions of cathode materials was proposed according to the differences in wettability of both polymers. By enabling efficient material identification and separation, this study advances sustainable recycling practices, supporting circular economy goals in the renewable energy sector.

The Role of Ionic Liquids in Textile Processes: A Comprehensive Review.

Thanks to their unique physicochemical properties, ionic liquids (ILs) have moved from niche academic interest to critical components in various industrial applications. The textile industry, facing significant environmental and economic pressures, has begun to explore ILs as sustainable alternatives to traditional solvents and chemicals. This review summarizes research on the use of ILs in various textile processes, including dyeing, finishing, and fiber recycling, where their high thermal stability, tunable solubility, and low volatility are exploited to reduce resource consumption and environmental impact. The discussion also extends to the integration of ILs in textile waste recycling, highlighting innovative approaches to fiber dissolution and regeneration aimed at circular economy goals. Despite these advances, challenges such as high production costs and scalability remain barriers to the widespread adoption of ILs in the textile sector. Addressing these barriers through continued research and development is essential to fully realize the potential of ILs for sustainable transformation in textiles.

Mapping of Circular Construction Ecosystems’ Characteristics: Interconnections, Relationships, and Synchronization of Stakeholders at the Micro, Meso, and Macro Scales

The application of circular strategies in the architecture, engineering, construction, and operations (AECO) sector has been extensively researched, demonstrating the significance of technical approaches. However, research also focuses on the organizational challenges that arise within circular networks. Recent studies emphasize the importance of collective action in fostering cooperation across the value chain to achieve circular economy (CE) goals. Nevertheless, a considerable amount of research, including EU policies, tends to concentrate on “end-of-pipe” solutions, while failing to adequately address the socio-ecological challenges inherent in the transition to a CE. This study aims to explore collective activities and work in circular construction ecosystems at the macro, meso, and micro scales, identifying their interconnections. The findings of the literature review indicate that a successful transition to a CE requires a deeper commitment from stakeholders, which is influenced by the structure and relationships within the ecosystem. The increasing complexity of these ecosystems necessitates a redefinition of stakeholder roles and competencies, emphasizing a collective perception of value. Given the lack of tools and research on collaboration, we propose developing a map of circular construction ecosystems to improve the visualization and understanding of their dynamics.

Sustainable Additive Manufacturing: An Overview on Life Cycle Impacts and Cost Efficiency of Laser Powder Bed Fusion

This overview study investigates integrating advanced manufacturing technologies, specifically metal additive manufacturing (AM) and laser powder bed fusion (LPBF) processes, within Industry 4.0 and Industry 5.0 frameworks, to enhance sustainability and efficiency in industrial production and prototyping. The manufacturing sector, a significant contributor to global greenhouse gas emissions and resource consumption, is increasingly adopting technologies that reduce environmental impact while maintaining economic growth. Selective laser melting (SLM), as the subsection LPBF technologies, is highlighted for its capability to produce high-performance, lightweight, and complex components with minimal material waste, thus aligning with circular economy goals for metal alloys. Life cycle assessment (LCA) and life cycle costing (LCC) analyses are essential methods for evaluating the sustainability of any new technology. Sustainable technologies could support the concepts of the factory of the future (FoF), fulfilling the requirements of digital transformation and digital twins. This overview study reveals that implementing AM—specifically SLM—has the potential to reduce the environmental impact of manufacturing. It underscores the ability of these technologies to promote sustainable and efficient manufacturing practices, thereby accelerating the shift from Industry 4.0 to Industry 5.0.

Proposed guidelines to implement flexible-plastic circular economy business models in Colombia

[Introduction]: The lack of feasible circular economy models for recycling single-use plastics poses a significant challenge to sustainable waste management. Single-use plastics, particularly flexible types, contribute to environmental pollution and require effective recycling strategies. [Objective]: This study aimed to analyze global recycling models for single-use plastics under key parameters: type of pollutant, impacts on sustainability, value generation, stakeholders involved, and level of technology. [Methodology]: A global review of 21 circular economy models focused on single-use flexible plastics was conducted, evaluating their feasibility and effectiveness. Six models were identified as the most relevant based on the selected criteria. [Results]: The findings indicate that improving eco-efficiency requires the integration of physical and chemical recycling processes to achieve cost reductions. Additionally, maintaining a constant flow of recyclable materials is essential, emphasizing the critical role of material collection and classification cooperatives. In Colombia, the collection and classification of plastic materials emerged as a pivotal element for the long-term sustainability of recycling models. [Conclusions]: The study highlights the necessity of combining technological and logistical efforts to enhance recycling processes. Strengthening material recovery systems and cooperative efforts is crucial for advancing circular economy goals in the context of single-use plastics.

AI-Driven Process Design for Closed-Loop Manufacturing

This study investigates the potential of artificial intelligence (AI) in enhancing closed-loop manufacturing (CLM) systems, which emphasize sustainability through recycling, reuse, and optimized resource utilization. CLM faces significant challenges in minimizing waste, improving operational efficiency, and optimizing resource usage. Although AI holds promise in addressing these challenges, its application in CLM systems, especially in dynamic decision-making and resource optimization, requires further exploration. This research aims to explore how AI technologies can improve material flows, reduce waste, and enhance decision-making to achieve both sustainability and operational efficiency in manufacturing systems. To understand the impact of AI on CLM, the study conducted a comprehensive review of case studies and literature across various industries. It focused on AI techniques, such as machine learning (ML) and reinforcement learning (RL), and their roles in optimizing resource usage, refining recycling processes, and improving production schedules. Statistical methods, including regression and sensitivity analysis, were employed to evaluate the effectiveness of AI-driven models in enhancing closed-loop manufacturing performance. The review revealed promising results, highlighting AI's ability to optimize resource consumption and waste management strategies across diverse manufacturing environments. The study’s findings demonstrated significant improvements in resource efficiency, waste reduction, and cost savings across multiple industries. AI-driven models optimized material consumption, resulting in reductions of up to 12% in raw material use. Additionally, AI-enhanced recycling and waste management strategies led to a 25% increase in material recovery, while operational costs were reduced by up to 15%. AI models also displayed a strong ability to adapt to fluctuations in demand and production conditions, ensuring sustained operational efficiency even amid dynamic market changes. These outcomes highlight AI’s transformative potential in achieving sustainable manufacturing practices and advancing circular economy goals.

Circular Water and Wastewater Management in State College, Pennsylvania

In recent years, great attention has been paid to activities aimed at implementing a circular economy (CE) in the management of water resources around the world. One of the possibilities for the practical implementation of CE, based on the sustainable management of primary and secondary resources (waste), is the circular management of water and wastewater generated in urban wastewater treatment plants (WWTPs). This work presents examples of good practices in the implementation of CE in the college town of State College, Pennsylvania (United States of America). There are two WWTPs here – one belonging to Penn State University (Water Reclamation Facility) and another operated by the municipality (University Area Joint Authority). Both facilities implement CE goals through various initiatives dedicated to water, raw materials and energy recovery. The scope of these activities include using reclaimed water for irrigation of green areas, production of renewable energy, as well as recovery of biogenic components by processing sewage sludge in compost. This approach, where the university and municipality propose solutions in the environmental and social areas, is consistent with the idea of building social responsibility of units, which is a path to sustainability. Further actions to implement the CE model are expected to counteract ongoing climate change in various regions.

Goal-Framed Attitude and Sustainability Literacy in Shaping Circular Consumption Intention in Fast Fashion

Adapting the circular economy to fast fashion requires transitioning to a responsible business model that reduces overstock and promotes a pro-environmental ‘less consumption’ trend. This study, grounded in the goal-framing theory (Lindenberg & Steg, 2007) examines how goal-framed attitudes and sustainability literacy influence consumers’ circular consumption intentions. Analyzing data from 299 Prolific respondents, multiple regression results showed that goal-framed attitudes toward ‘circular economy’ and ‘reliable information,’ alongside sustainability literacy on ‘circular initiatives’ and ‘environmental awareness,’ positively impact intentions to engage in circular product purchases and practices. Clustering analysis identified three circular-minded consumer groups with differing perceptions of goal-framed attitudes, sustainability literacy, and circular consumption intentions. Fast fashion consumers prioritize reliable information on circular economy goals, intending to adopt circular practices, such as the 6Rs (Reducing, Recycling, Repairing, Redesigning, Reselling, and Renting), which reinforce circular business models in fast fashion.

Potential of Refuse Derived Fuel (RDF) in Medan City's Waste Management Strategy

Medan City faces significant waste management challenges, with increasing waste volumes and limited landfill capacity creating an urgent need for sustainable solutions. This study evaluates the potential of Refuse Derived Fuel (RDF) technology as an alternative waste management strategy. Using a qualitative descriptive approach and SWOT analysis, the research explores the strengths, weaknesses, opportunities, and threats associated with RDF implementation in Medan City. The findings highlight that RDF technology can reduce landfill waste by up to 86%, decrease carbon emissions, and create economic opportunities, such as new jobs and cost efficiencies in waste management. However, significant challenges remain, including high initial investment costs, limited infrastructure, and low public awareness of waste segregation. Government support, private sector partnerships, and community participation are identified as critical factors for successful RDF implementation. Quantitative analysis of RDF production data from the Terjun Final Disposal Site (FDS) reveals that from October 2022 to December 2023, a cumulative 146,727 kg of RDF was produced, achieving daily waste reduction of over 1 ton. This aligns with global circular economy goals by transforming waste into energy while mitigating environmental degradation. This research provides a framework for cities seeking to adopt RDF technology, emphasizing the integration of environmental, economic, and social strategies. By leveraging strengths and opportunities, Medan City can position RDF as a model for sustainable waste management and energy transition.

Environmental Evaluation of Chemical Plastic Waste Recycling: A Life Cycle Assessment Approach

Due to the high environmental burden of plastics, this study aimed to evaluate the environmental performance of chemical recycling of plastic waste through Life Cycle Assessment (LCA), focusing on pyrolysis oil production as the primary output. A pyrolysis plant in Almería, Spain, was chosen as a case study. The results indicate that the production of 1 L of pyrolysis oil from plastic waste generates about 0.032 kg CO2 eq and a water consumption of 0.031 m3, with other impact categories registering values of less than 0.1 kg/L or 0.01 m2a crop eq/L, reducing impacts in 17 out of 18 categories compared to fossil diesel. In addition, its chemical and physical properties, close to those of fossil diesel, suggest its suitability for internal combustion engines, although as a blend rather than a complete substitute. Chemical recycling also appears to be more environmentally favorable than incineration and landfilling in all 18 impact categories, achieving significant benefits, including a reduction in global warming of −3849 kg CO2 eq/ton, ionizing radiation of −22.4 kBq Co-60 eq/ton, and fossil resource consumption of −1807.5 kg oil eq/ton. These results, thus, highlight the potential dual role of chemical recycling of plastic waste, both in mitigating environmental impacts and in supporting circular economy goals by reducing demand for virgin plastics. However, although it appears to be a promising technology, challenges associated with high energy requirements, raw material variability, and scale infrastructure still need to be addressed to ensure industrial competitiveness and significant environmental benefits.

Bioaugmentation of Industrial Wastewater and Formation of Bacterial–CaCO3 Coupled System for Self-Healing Cement

This study investigates the potential of bioaugmentation with Bacillus species to enhance wastewater treatment and develop a bacterial–CaCO3 system for self-healing cement applications. Utilizing microbiologically induced calcium carbonate precipitation (MICP), this study evaluates the dual functionality of Bacillus licheniformis and B. muralis strains. For wastewater treatment, the bioaugmentation process achieved significant pollutant reductions, including a 99.52% decrease in biochemical oxygen demand (BOD5), a 92.13% reduction in chemical oxygen demand (COD), and a substantial removal of heavy metals and nutrients. This process also produced high concentrations of CaCO3 precipitate enriched with viable bacterial cells, demonstrating an eco-friendly approach to improving water quality. For self-healing cement applications, bioaugmented CaCO3 crystals were coated with nutrient and sodium silicate layers to form a bacterial–CaCO3 coupled system. This system demonstrated a 92% recovery in compressive strength after 180 days, highlighting its ability to autonomously repair microcracks in cement-based materials. The layered encapsulation strategy ensured bacterial viability and a controlled activation mechanism, offering a scalable and sustainable solution for infrastructure resilience. This dual-function approach addresses critical environmental and construction challenges by linking efficient wastewater treatment with innovative self-healing material development, contributing to global sustainability and circular economy goals.

Integrating Environmental and Socioeconomic Factors for a Sustainable Circular Economy in Thailand

This study fills a significant research gap by examining the factors influencing the circular economy in Thailand, particularly within the context of developing countries. Utilizing regression and correlation analysis, we investigate key environmental and socioeconomic variables: greenhouse gas emissions, forest area percentage, income levels among the poorest 20% of the population, access to electricity, and income inequality. The novelty of this work lies in its comprehensive integration of these dimensions to identify barriers and sustainable circular economy. Key findings reveal that higher greenhouse gas emissions correlate with increased recycling, underscoring the need for stricter emission controls and cleaner technologies. Conversely, greater forest coverage is associated with reduced recycled waste, highlighting the importance of forest conservation and sustainable land use. Economic disparities significantly impact recycling efforts, necessitating supportive policies for lower-income groups. Increased access to electricity correlates with higher waste generation, emphasizing the need for sustainable consumption practices. Although income inequality correlates with recycling rates, it is not a significant predictor, indicating the necessity for broader economic and environmental policies. This study offers novel, comprehensive recommendations for advancing Thailand’s circular economy. Strategies include implementing emission controls, enhancing forest conservation, promoting economic empowerment, encouraging sustainable consumption, and developing integrated policies. These recommendations aim to address identified challenges and support sustainable growth in alignment with circular economy goals.

Waste Reduction and VAT: A Complex Interplay

The European Union’s push for waste reduction highlights a complex interplay between sustainability and VAT rules. In this column, the author analyses the ECJ case in Y KG, which reveals how rigid VAT regulations, such as the classification of free transfers of heat as taxable deemed supplies, can discourage environmentally friendly practices, emphasizing the need for VAT frameworks that align with circular economy goals.

3D Printable One-Part Alkali-Activated Mortar Derived from Brick Masonry Wastes

The exponential growth in demand for housing has resulted in a greater focus on rapid construction methods that adhere to circular economy principles. 3D concrete printing is becoming a powerful tool to find solutions to the common challenges of affordable housing for more people, rapid construction, and the digitalization of the construction industry. However, a coherent synthesis of green and digital initiatives has not yet been achieved. For 3D printable materials, recycling of materials that have reached the end of their service life should also be enabled and supported, in line with circular economy goals that prioritize waste reduction and maximization of resource efficiency. With these objectives in mind, the current study focuses on the development of a one-part 3D printable alkali-activated mortar (3DPM) derived from brick masonry waste (BMW). BMWs were used as the main precursor and filler phase, whereas materials such as ground granulated blast furnace slag, kaolin clay, and limestone have been utilized to enhance/control the mechanical and rheological properties. To investigate the evolution of alkali-activation and the effect of anisotropy, the macromechanical properties of the developed 3DPM were investigated by compressive strength, flexural strength, split tensile, and direct tensile tests. The micromechanical properties were analyzed using X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR), thermogravimetry (TG), differential scanning calorimetry (DSC), scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDX), and computed tomography (MicroCT) tests. Overall, the results revealed the presence of anisotropy, which can be reduced by optimizing the layer height. Through this optimization, reductions in pore content and distribution, validated by MicroCT, indicated that the disadvantage of the weak interlayer bond zone in stress transfer could be diminished. Micromechanical analysis showed that the gel formation responsible for the strength was the calcium-based gel structures. Considering these findings, it is believed that the BMW-based 3DPM can be an important alternative for the digitalization of the construction industry and its transition to a circular economy.

Holistic approach to energy storage management aspects in sustainable community

Energy management is nowadays key topic for synchronic operation of renewable sources of energy and their recipients. Contemporary national electrical power grid systems more often cannot supply efficiently electrical energy and cannot receive energy produced by renewable sources. The common approach to the problem is to meet energy demands supplying from electrical grid and renewable power sources with energy storage feature. From the other side, off-grid solutions based on the co-generation biogas plants are commonly aimed on small local communities as power supply supported by renewable energy systems like photovoltaic (PV) systems, wind power plants or small water plants with energy storage to support self-consumption of electrical energy. Integration of intermittent renewable power sources, such as solar, wind and biogas plant, increases the difficulty of managing the electricity grid and maintaining the balance of electricity supply and demand, especially in small communities. The holistic approach to the energy storage management takes all above aspects and presents the concept where municipal waste is used to produce energy in biogas plant supported by PV systems and community shared electrical energy storage to provide uninterrupted power supply. The study also presents how energy storage management can be used in whole process to adjust the size and manage energy supply and demand within the community based on energy self-consumption optimization. It is also shown that by utilizing municipal waste produced by the community we can meet the goals of circular economy and sustainable development of local communities as the waste will be used in full without necessity of recycling it outside the community. The novelty of the study is the foundation for energy storage capacity and renewable energy sources size evaluation to balance energy management process without the need of on-grid power supply and with use only municipal biodegradable waste for biogas fuel supply and solar energy for energy production.

Review of the Integrated Approaches for Monitoring and Treating Parabens in Water Matrices.

Due to their antibacterial and antifungal properties, parabens are commonly used as biocides and preservatives in food, cosmetics, and pharmaceuticals. Parabens have been reported to exist in various water matrices at low concentrations, which renders the need for sample preparation before their quantification using analytical techniques. Thus, sample preparation methods such as solid-phase extraction (SPE), rotating-disk sorptive extraction (RDSE), and vortex-assisted dispersive liquid-liquid extraction (VA-DLLE) that are commonly used for parabens extraction and preconcentration have been discussed. As a result of sample preparation methods, analytical techniques now detect parabens at trace levels ranging from µg/L to ng/L. These compounds have been detected in water, air, soil, and human tissues. While the full impact of parabens on human health and ecosystems is still being debated in the scientific community, it is widely recognized that parabens can act as endocrine disruptors. Furthermore, some studies have suggested that parabens may have carcinogenic effects. The presence of parabens in the environment is primarily due to wastewater discharges, which result in widespread contamination and their concentrations increased during the COVID-19 pandemic waves. Neglecting the presence of parabens in water exposes humans to these compounds through contaminated food and drinking water. Although there are reviews that focus on the occurrence, fate, and behavior of parabens in the environment, they frequently overlook critical aspects such as removal methods, policy development, and regulatory frameworks. Addressing this gap, the effective treatment of parabens in water relies on combined approaches that address both cost and operational challenges. Membrane filtration methods, such as nanofiltration (NF) and reverse osmosis (RO), demonstrate high efficacy but are hindered by maintenance and energy costs due to extensive fouling. Innovations in anti-fouling and energy efficiency, coupled with pre-treatment methods like adsorption, help mitigate these costs and enhance scalability. Furthermore, combining adsorption with advanced oxidation processes (AOPs) or biological treatments significantly improves economic and energy efficiency. Integrating systems like O₃/UV with activated carbon, along with byproduct recovery strategies, further advances circular economy goals by minimizing waste and resource use. This review provides a thorough overview of paraben monitoring in wastewater, current treatment techniques, and the regulatory policies that govern their presence. Furthermore, it provides perspectives that are critical for future scientific investigations and shaping policies aimed at mitigating the risks of parabens in drinking water.

Advantages of Co-Pyrolysis of Sewage Sludge with Agricultural and Forestry Waste

This paper explores the advantages of the co-pyrolysis of municipal sewage sludge with agricultural and forestry biomass, emphasizing its potential for environmental and economic benefits. Co-pyrolysis with lignocellulosic biomass significantly enhances biochar quality, reduces the heavy metal content, increases porosity, and improves nutrient retention, which are essential for soil applications. The biochar produced through co-pyrolysis demonstrates enhanced stability and a lower oxygen-to-carbon (O/C) ratio, making it more suitable for long-term carbon (C) sequestration and pollutant adsorption. Additionally, co-pyrolysis generates bio-oil and syngas with improved calorific value, contributing to renewable energy recovery from sewage sludge. This synergistic process also addresses waste management challenges by reducing harmful emissions and immobilizing heavy metals, thus mitigating the environmental risks associated with sewage sludge disposal. This paper covers key sections on the properties of waste materials, improvements in biochar quality and energy products, and the environmental benefits of co-pyrolysis, such as emissions reduction and heavy metal immobilization. The paper highlights trends and challenges in co-pyrolysis technology, aiming to optimize parameters for maximizing biochar yield and energy recovery while aligning with sustainability and circular economy goals. The paper concludes with recommendations for optimizing co-pyrolysis processes and scaling applications to support sustainable waste management. Overall, co-pyrolysis represents a sustainable approach to valorizing sewage sludge, transforming it into valuable resources while supporting environmental conservation.

Modelling and evaluation of mechanical performance and environmental impacts of sustainable concretes using a multi-objective optimization based innovative interpretable artificial intelligence method

This study focuses on modelling sustainable concretes' mechanical and environmental properties with interpretable artificial intelligence-based automated rule extraction, management of waste materials, and meeting future prospects. In this context, 24 sustainable concrete series containing fly ash and recycled aggregates were produced. Compressive strength tests were performed on these specimens at 7, 28, and 90 days, and their mechanical properties were evaluated. Concrete classes (Class A, B, C, D) were determined using the compressive strength values obtained for each test day. The results of each concrete class were analyzed using a unique interpretable multi-objective rule extraction model, and the range values of the materials used were determined. The applied multi-objective rule extraction method is used for the first time in the literature, and its most important novelty is that, unlike other black-box artificial intelligence methods, it can also enable the creation of sustainable concrete recipes. After the range values of the materials used were found by automatic rule extraction, environmental impact assessments were performed. Among the impact categories, energy consumption and global warming potential were considered. The energy consumption results for Rule 4 were calculated as 814.8–1467.1 MJ, respectively, and a reduction of approximately 44.5% was observed. Similarly, global warming potentials for Rule 3 were obtained as 187.0–267.3 kg m3, respectively, with a reduction of about 30%. The limitations and future prospects of the study have been extensively investigated. The importance of adopting explainable/interpretable artificial intelligence-based approaches within the scope of sustainable development and circular economy goals to develop social infrastructure and buildings with low carbon emissions that are feasible in terms of mechanical and environmental properties is highlighted. Multi-Objective Optimization Based Innovative Interpretable Artificial Intelligence Method, used for the first time in mechanical and environmental modelling of sustainable concretes, can make significant contributions to the literature and future studies.

Durability of non-woven geotextiles produced from recycled polyethylene terephthalate (PET)

Achieving the goals of sustainable development and circular economy requires recycling and reusing plastic materials. In this research, the durability of five needle-punched non-woven geotextiles were experimentally studied. The geotextiles were made of recycled PET (rPET), virgin PET (vPET), and combinations of rPET and vPET fibers. The samples were hydrolyzed for a period of 14, 28, and 56 days and the retained tensile strength and puncture resistance of the samples were determined at the end of each interval. Moreover, this study took the benefits from the capability of differential scanning calorimetry (DSC), Fourier transforms in infrared spectroscopy (FTIR) analysis, and scanning electron microscopy (SEM) images to interpret the results acquired. Testing on as-received products, it was understood that recycling process could increase crystallinity of the fibers, increasing the fibers fragility, reducing the tensile strength and elongation capacity of rPET fibers. Moreover, considering the borderline value of 50% retained strength, a shorter service life (up to 30%) of rPET products in comparison with vPET products, due to higher degradation rates, was observed.