Search Results (2,788)

To quantitatively assess the environmental impact of producing a typical bamboo-based fiber composite material—bamboo scrimber (BS)—and to explore pathways for low-carbon optimization, this study adopts the Life Cycle Assessment (LCA) method with a focus on carbon footprint analysis. Using the actual production process of an enterprise as a case study, field data were collected and analyzed for bamboo scrimber with a nominal thickness of 1.5 cm. The results show that the carbon footprint of 1 m² of this product is 3.11 kg CO₂-eq, with the manufacturing stage contributing the highest emissions at 1.45 kg CO₂-eq. The primary source of carbon emissions is steam consumption, mainly occurring during the carbonization and drying of bamboo bundles. Therefore, optimizing these stages is crucial for reducing the overall carbon footprint of the product. This study provides a scientific basis for the sustainable development of bamboo-based fiber composite materials and offers practical recommendations for improving their environmental performance in production. Full article

Geothermal energy has been recognized as a promising renewable resource for sustainable power generation; however, the efficiency of conventional geothermal power plants has remained relatively low, and high investment costs have limited their competitiveness with other renewable technologies. In this context, the present study introduced an innovative geothermal electricity generation system aimed at enhancing energy efficiency, cost-effectiveness, and sustainability. Unlike traditional configurations, the system raised the geothermal source temperature passively by employing advanced heat transfer mechanisms, eliminating the need for additional energy input. Comprehensive energy, exergy, and exergoeconomic analyses were carried out, revealing a net power output of 43,210 kW and an energy efficiency of 30.03%, notably surpassing the conventional Kalina cycle’s typical 10.30–19.48% range. The system’s annual electricity generation was 11,138.53 MWh, with an initial investment of USD 3.04 million and a short payback period of 3.20 years. A comparative assessment confirmed its superior thermoeconomic performance. In addition to its technoeconomic advantages, the environmental performance of the proposed configuration was quantified. A streamlined life cycle assessment (LCA) was performed with a functional unit of 1 MWh of net electricity. The proposed system exhibited a carbon footprint of 20–60 kg CO₂ eq MWh⁻¹ (baseline: 45 kg CO₂ eq MWh⁻¹), corresponding to annual emissions of 0.22–0.67 kt CO₂ eq for the simulated output of 11,138.53 MWh. Compared with coal- and gas-fired plants of the same capacity, avoided emissions of approximately 8.6 kt and 5.0 kt CO₂ eq per year were achieved. The water footprint was determined as ≈0.10 m³ MWh⁻¹ (≈1114 m³ yr⁻¹), which was substantially lower than the values reported for fossil technologies. These findings confirmed that the proposed system offered a sustainable alternative to conventional geothermal and fossil-based electricity generation. Multi-objective optimization using NSGA-II was carried out to maximize energy and exergy efficiencies while minimizing total cost. Key parameters such as turbine inlet temperature (459–460 K) and ammonia concentration were tuned for performance stability. A sensitivity analysis identified the heat exchanger, the first condenser (Condenser 1), and two separators (Separator 1, Separator 2) as influential on both performance and cost. The exergoeconomic results indicated Separator 1, Separator 2, and the turbine as primary locations of exergy destruction. With an LCOE of 0.026 USD/kWh, the system emerged as a cost-effective and scalable solution for sustainable geothermal power production without auxiliary energy demand. Full article

Rapid population growth and accelerating urbanization are intensifying the demand for construction materials, particularly concrete, which is predominantly produced with Portland cement and natural aggregates. This reliance imposes substantial environmental burdens through resource depletion and greenhouse gas emissions. Within the framework of sustainable construction, recycled aggregates and industrial by-products such as fly ash, slags, crushed glass, and other secondary raw materials have emerged as viable substitutes in concrete production. At the same time, three-dimensional concrete printing (3DCP) offers opportunities to optimize material use and minimize waste, yet it requires tailored mix designs with controlled rheological and mechanical performance. This review synthesizes current knowledge on the use of recycled construction and demolition waste, industrial by-products, and geopolymers in concrete mixtures for 3D printing applications. Particular attention is given to pozzolanic activity, particle size effects, mechanical strength, rheology, thermal conductivity, and fire resistance of recycled-based composites. The environmental assessment is considered through life-cycle analysis (LCA), emphasizing carbon footprint reduction strategies enabled by recycled constituents and low-clinker formulations. The analysis demonstrates that recycled-based 3D printable concretes can maintain or enhance structural performance while mix-level (cradle-to-gate, A1–A3) LCAs of printable mixes report CO₂ reductions typically in the range of ~20–50% depending on clinker substitution and recycled constituents—with up to ~48% for fine recycled aggregates when accompanied by cement reduction and up to ~62% for mixes with recycled concrete powder, subject to preserved printability. This work highlights both opportunities and challenges, outlining pathways for advancing durable, energy-efficient, and environmentally responsible 3D-printed construction materials. Full article

The growing volume of decommissioned wind turbine blades (WTBs) poses substantial challenges for end-of-life (EoL) material management, particularly within the composite repurposing and recycling strategies. This study investigates the repurposing of EoL WTB segments in a full-scale demonstrator for a photovoltaic (PV) floating platform. The design process is supported by a calibrated numerical model replicating the structure’s behaviour under representative operating conditions. The prototype reached Technology Readiness Level 6 (TRL 6) through laboratory-scale wave basin testing, under irregular wave conditions with heights up to 0.22 m. Structural assessment validates deformation limits and identifies critical zones using composite failure criteria. A comparison between two configurations underscores the importance of load continuity and effective load distribution. Additionally, a life cycle assessment (LCA) evaluates environmental impact of the repurposed solution. Results indicate that the demonstrator’s footprint is comparable to those of conventional PV-floating installations reported in the literature. Furthermore, overall sustainability can be significantly enhanced by reducing transport distances associated with repurposed components. The findings support the structural feasibility and environmental value of second-life applications for composite WTB segments, offering a circular and scalable pathway for their integration into aquatic infrastructures. Full article

Building envelopes play a pivotal role in influencing building energy consumption. Among its components, the roof, as a critical element, directly absorbs solar radiation and serves as a primary medium for external heat exchange. Its thermal performance significantly impacts the overall energy consumption of buildings. This study focuses on cool roofs as the research subject to investigate their thermal performance and its effects on building energy consumption. Drawing on the principles of life cycle assessment (LCA), a novel concept of environmental payback period is introduced. By comparing cool roofs with photovoltaic roofs, this research employs energy consumption simulation and life cycle assessment to evaluate their performance across three dimensions: economic, energy, and environmental impacts. A comprehensive 3-E (Economic, Energy, Environmental) static payback period theoretical framework based on LCA is established. Within this framework, the concepts of economic static payback period, energy static payback period, and environmental static payback period are explicitly defined, and corresponding calculation formulas are provided. A case study in Nanjing is conducted to validate the proposed framework. The results indicate that the economic payback periods for cool roofs and photovoltaic roofs are 1.75 years and 10.90 years, respectively; the energy payback periods are 13.6 years and 43.7 years, respectively; and the environmental payback periods are 2.2 years and 7.6 years, respectively. In terms of energy savings, photovoltaic roofs outperform cool roofs significantly, with an annual energy saving of 139 kWh/m² for photovoltaic roofs compared to 6.5 kWh/m² for cool roofs. However, cool roofs demonstrate clear advantages in the comparison of payback periods. Full article

Heating and cooling (H&C) account for nearly half of the EU’s energy consumption, with significant potential for decarbonization through renewable energy sources (RES) integrated in district heating and cooling (DHC) systems. This study evaluates the environmental and social impacts of RES-powered DHC solutions implemented in three European small-scale demo sites (Bucharest, Luleå, Córdoba) under the Horizon 2020 WEDISTRICT project. Using the Life Cycle Assessment (LCA) and Social Life Cycle Assessment (S-LCA) methodologies, the research compares baseline fossil-based energy scenarios with post-implementation renewable scenarios. Results reveal substantial greenhouse gas emission reductions (up to 67%) and positive environmental trade-offs, though increased mineral and metal resource use and site-specific impacts on water and land use highlight important sustainability challenges. Social assessments demonstrate improvements in gender parity, local employment, and occupational safety, yet reveal persistent issues in wage equity, union representation, and inclusion of vulnerable populations. The findings emphasize that while renewable DHC systems offer significant climate benefits, social sustainability requires tailored local strategies and robust governance to avoid exacerbating inequalities. This integrated environmental-social perspective underscores the need for holistic policies that balance technical innovation with equitable social outcomes to ensure truly sustainable energy transitions. Full article

Progressive climate change and the increasing concentration of carbon dioxide in the atmosphere represent one of the most serious challenges facing modern energy systems. At the same time, the global overproduction of plastics, particularly polyethylene terephthalate (PET), places a significant burden on the natural environment and waste management infrastructure. Electrochemical reactors offer a promising solution by enabling the simultaneous conversion of CO₂ and EG into valuable products such as carbon monoxide and glycolic acid, using electricity derived from renewable energy sources. Carbon monoxide can be further processed into high-energy synthetic fuels, such as propanol, while glycolic acid holds substantial importance in the pharmaceutical and plastics industries. An economic analysis was conducted to estimate the capital expenditures required for an electrochemical reactor and to assess the investment’s profitability based on the net present value (NPV) indicator. In addition, a Life Cycle Assessment (LCA) was carried out to evaluate the environmental impact of the proposed technology, with particular attention to its carbon footprint. The results indicate that the profitability of the system strongly depends on the market price and purity of glycolic acid, as well as on access to low-cost renewable electricity. The LCA confirms a significantly lower carbon footprint compared to conventional CO production, though further technological advancements are required for industrial deployment. Full article

Bioplastics are gaining attention as eco-friendly alternatives to conventional plastics, with Polybutylene Adipate Terephthalate (PBAT) emerging as a promising biodegradable substitute for polyethylene (PE) in food packaging. Commercial PBAT is often blended with other plastics or bio-based fillers to improve mechanical properties and reduce costs, though these additives can influence its environmental footprint. Therefore, this study quantifies the environmental impacts of producing PBAT resin blends reinforced with common inorganic fillers and compares end-of-life (EoL) performance against PE. While prior studies have largely assessed virgin PBAT or PBAT/Polylactic Acid (PLA) systems, systematic LCA of commercial-style PBAT blends with inorganic fillers and screening LCA level for comparisons of composting vs. landfill remain limited. The contributions of this study are to: (i) map gate-to-gate environmental hotspots for PBAT-blend conversion, (ii) provide a screening gate-to-grave comparison of PBAT composting vs. PE landfill using ReCiPe 2016 and IPCC GWP100 methods, and (iii) discuss theoretical implications for material substitution in the context of EoL strategies. The results indicated that producing 1 kg of PBAT blend generated a single score impact of 921 mPt with Human Health and Resource categories contributing similarly, and a GWP of 8.64 kg CO₂-eq, dominated by mixing and drying processes. EoL screening showed PBAT composting offered clear advantages over landfilling PE, yielding −53.9 mPt and 11.35 kg CO₂-eq savings, effectively offsetting production emissions. In contrast, landfilling PE resulted in 288.8 mPt and 2.2 kg CO₂-eq emissions. Sensitivity analysis further demonstrated that a 30% reduction in electricity use could decrease impacts by up to 10%, underscoring the importance of energy efficiency improvements and renewable energy adoption for sustainable PBAT development. Full article

To understand how landscapes have changed in Yanqing District, Beijing, during its urban development over the past 15 years, we referred to the Landscape Character Assessment (LCA) theory, selecting altitude, slope, roughness, forest type, land cover, and forest vegetation cover as characteristic factors, identified nine types of landscape character types (LCTs) from 2005 to 2020 through unsupervised clustering. Then, we applied multi-model interpreters, including the Optimal Parameter-Based Geographical Detector (OPGD) and SHapley Additive exPlanations (SHAP), to analyze how social and natural factors impact the spatiotemporal changes of these LCTs. The results indicate that over the past 15 years, the landscape character of Yanqing District has undergone significant changes, with more frequent changes occurring in the “piedmont” areas where mountains meet plains. Slope and precipitation are the main factors affecting the intensity of LCT changes. In contrast, the transformation of different landscape characters is affected by factors such as altitude, slope, precipitation, and distance to artificial surfaces. This study reveals the dynamic changes in landscape character and their driving mechanisms, helping to develop more targeted strategies for landscape management in Yanqing District to promote sustainable regional development. Full article

Fluoride-containing wastewater poses a significant environmental challenge, especially in the mineral processing sector. This study applies a life cycle assessment (LCA) to evaluate an electrocoagulation-based treatment process, integrating biogas-derived CO₂ for pH regulation and cogeneration of electricity, using the Egalitarian perspective, which is the most precautionary that takes into account the longest time frame and impact types that are not yet fully established but for which some indication is available. The LCA considered five subsystems: electrocoagulation, pH adjustment, sedimentation, pumping, and sludge transport, across three operational scenarios. Scenario 1 (S1) employed hydrochloric acid for pH control, Scenario 2 (S2) used biogas exclusively for pH regulation, and Scenario 3 (S3) combined biogas-based pH adjustment with power generation. Results showed an environmental impact ranking of S3 < S1 < S2, with S3 reducing overall impacts from 12.5 Pt to 6.4 Pt compared to S1. The electrocoagulation unit was the dominant contributor to environmental burdens; however, in S3, the pH adjustment subsystem delivered a net environmental benefit through surplus electricity generation. Additionally, sludge reuse as a raw material for brick production, implemented in all scenarios, further mitigated impacts. Human health emerged as the most affected endpoint, driven mainly by toxicity (carcinogenic and non-carcinogenic), climate change potential, marine ecotoxicity, and particulate matter formation. These findings highlight the benefits of integrating biogas utilization and sludge valorization into industrial wastewater management strategies. Full article

Per- and polyfluoroalkyl substances (PFASs) represent one of the most challenging classes of persistent organic pollutants, and adsorption is currently one of the most widely deployed method for their removal from water. However, the long-term sustainability of adsorption-based treatment depends on how adsorbents are regenerated, managed after exhaustion, and integrated into broader environmental and regulatory frameworks. This review synthesises recent advances in regeneration strategies for PFAS-saturated adsorbents, including thermal, solvent-based, chemical, hybrid, and emerging methods, and provides a targeted analysis of policy and regulatory frameworks governing PFAS management in water. Evidence from the literature is critically assessed with attention to regeneration efficiencies, adsorbent stability, secondary waste generation, and long-term reuse potential. Life cycle assessment (LCA) studies are also examined to evaluate the environmental and cost implications of different management options. The analysis highlights that while solvent and chemical regeneration achieve high short-term recovery, thermal processes offer partial destructive potential, and electrochemical methods are emerging as promising but unproven alternatives. Persistent challenges include incomplete PFAS desorption, performance decline over multiple cycles, energy intensity, and secondary waste burdens. Advancing sustainable PFAS treatment requires integrated evaluation frameworks linking technical performance with environmental impact and cost, supported by policy drivers that incentivize regeneration and safe end-of-life management. Full article

The construction sector accounts for one-third of Europe’s total greenhouse gas (GHG) emissions, offering significant potential for emission reduction. Emission reduction can be achieved by substituting conventional building materials with wood- or bio-based alternatives; the difference in GHG emissions is referred to as the substitution potential (SP). In this study, a literature review was conducted to identify studies in which SPs had been determined. The calculation methods used for these SPs were then analysed in detail. The analysis considered the general conditions, outcomes, and scaling effects, revealing that differing initial conditions lead to inconsistent results. Therefore, transparent allocation of SPs and comparable product life cycle assessments (LCAs) based on functional equivalence are essential. To reliably extrapolate the benefits of wood use to the entire construction sector, scaling effects must be justified by consistent functional equivalence. For policy relevance, it is crucial that SPs are determined using the standardised rules and that the building level, as the actual place of material use, is not overlooked. This is particularly important when scaling up the effects of increased wood use to the landscape level. Only with these measures SPs at the product level can provide reliable results in a broader context. Additionally, the studies reviewed indicate that changes in forest management have not yet been considered. Full article

This study evaluates glass and carbon fibre-reinforced concrete in terms of performance, durability, environmental impact, and a novel enzymatic self-healing method. An experimental program was conducted on seven concrete mixes, including a plain control and mixes with varying dosages of glass and carbon fibres. Glass and carbon fibres were incorporated at identical dosages of 0.12%, 0.22%, and 0.43% fibre volume fraction ($V_f)$ to enable direct comparison of their performance. The experimental investigation involved a comprehensive characterization of the concrete mixes. Fresh properties were evaluated via slump tests, while hardened properties were determined through compressive and split tensile strength testing. Durability was subsequently assessed by measuring the rate of water absorption, bulk density, and moisture content. Following this material characterization, a cradle-to-gate Life Cycle Assessment (LCA) was conducted to quantify the embodied carbon and energy. Finally, an evaluation of a novel Carbonic Anhydrase (CA)-based self-healing treatment on pre-cracked, optimised fibre-reinforced specimens was conducted. The findings highlight key performance trade-offs associated with fibre reinforcement. Although both fibre types reduced compressive strength, they markedly improved split tensile strength for glass fibres by up to 70% and carbon fibres by up to 35%. Durability responses diverged: glass fibres increased water absorption, while carbon fibres reduced water absorption at low doses, indicating reduced permeability. LCA showed a significant rise in environmental impact, particularly for carbon fibres, which increased embodied energy by up to 141%. The CA enzymatic solution enhanced crack closure in fibre-reinforced specimens, achieving up to 30% healing in carbon fibre composites. These findings suggest that fibre-reinforced enzymatic self-healing concrete offers potential for targeted high-durability applications but requires careful life-cycle optimisation. Full article

This paper addresses the underrepresentation of traffic activity in Life Cycle Assessment (LCA) practice despite its critical influence on the energy and environmental footprint of both electrified and conventional vehicles. To bridge this gap, the paper proposes a new framework that enhances the integration of traffic dynamics into fleet LCAs while maintaining computational simplicity. The approach combines Macroscopic Fundamental Diagrams (MFDs), which estimate network-level traffic performance, with an average-speed-based emissions model to evaluate on-road energy use and emissions performance of traffic. This quantification is further extended by applying life cycle inventory emission factors to account for upstream and downstream impacts, including energy production, vehicle manufacturing, and end-of-life treatment. The framework is demonstrated through a case study involving urban traffic networks in Zurich and Thessaloniki. Results illustrate the method’s capacity to evaluate multiple vehicles within realistic flow scenarios and adaptability to variable traffic conditions, offering a practical and scalable tool for improved energy and environmental assessment of road transport fleets. Full article

Global waste generation is a ubiquitous challenge, driving a paradigm shift towards viewing waste as a valuable resource for a circular economy across diverse sectors. While innovative waste-to-resource pathways are crucial, rigorous Life Cycle Assessment (LCA) is essential to ensure the pathways are an important part of current practices. However, LCA application to waste valorization varies, leading to incomparable results due to differing methodological choices. This paper examines three key nuances in waste-as-resource LCAs: the zero-burden assumption, the biogenic carbon neutrality assumption, and the benchmark assumption for emissions avoidance. Using a waste gasification to hydrogen case study, we demonstrate how these methodological decisions impact LCA outcomes. Our findings reveal that waste composition significantly influences the results and highlight challenges associated with biogenic carbon accounting under various system boundary assumptions. Emissions avoidance accounting requires multi-functional unit perspectives and robust benchmark selection. This paper clarifies these accounting approaches, empirically illustrates their influence, and discusses broad implications for accurate sustainability assessment, emphasizing the critical role of transparent LCA choices for effective policy and investment in circular economy solutions. Full article