Search Results (3,467)

Increasing freshwater scarcity has intensified the need for energy-efficient and sustainable desalination technologies, making solar-assisted Direct Contact Membrane Distillation (DCMD) an attractive solution due to its low-temperature operation, high salt rejection, and compatibility with renewable energy. The PRISMA 2020 framework was used to systematically review and analyze the literature published on Scopus during the period 1974–2026 from a bibliometric and critical technical perspective. The study combines bibliometric analysis with critical analysis of technological development to investigate the development of solar-assisted DCMD and its use for sustainable production of freshwater, which was not incorporated in previous reviews. The analysis identifies rapid research momentum since 2017, with China, the USA, Saudi Arabia, Australia and Turkey being major contributors, and shows how the research focus has shifted to include the use of membrane materials, integration with renewable energy, fouling prevention, temperature polarization and energy efficiency. Significant advances have been made, yet commercialization is severely hampered by wetting of membranes, thermal losses, and low numbers of pilot-scale validations and inadequate standardized testing of performance. The review highlights the major research gaps and future directions, such as the development of advanced membrane materials and advanced hybrid renewable energy systems, the use of artificial intelligence (AI) for process optimization, conducting a comprehensive techno-economic and life-cycle assessment, and pilot-scale demonstration over a long duration. The results offer a comprehensive plan for the further development of solar-assisted DCMD for reliable and sustainable water production. Full article

As a major beef cattle producing country, China’s beef industry is expanding and undergoing structural transformation. A systematic assessment of the spatiotemporal evolution and driving factors of its water footprint is of great significance for the green and sustainable development of the beef cattle industry, and also provides a reference for understanding the current status of beef cattle water footprint, formulating environmental policies, and supporting the sustainable development of other livestock and poultry species. Based on the life cycle assessment (LCA) method, quantified the green, blue, and grey water footprints of China’s beef cattle industry “from cradle to farm gate” across 31 provinces from 2002 to 2022, covering three farming scales (small-scale, medium-scale, and large-scale) classified according to the proportion of beef cattle slaughter numbers (1–49 head, 50–500 head, and >500 head), and encompassing four stages: feed crop cultivation, beef cattle farming, manure leaching, and transportation and processing, covering three farming scales (small-scale, medium-scale, and large-scale) classified according to the proportion of beef cattle slaughter numbers (1–49 head, 50–500 head, and >500 head), and encompassing four stages: feed crop cultivation, beef cattle farming, manure leaching, and transportation and processing. Furthermore, kernel density estimation and standard deviational ellipse methods were employed to reveal the spatiotemporal evolution characteristics, and a Spatial Durbin Model (SDM) was constructed to identify the driving factors. The findings indicate that the total water footprint of China’s beef cattle industry first decreased and then increased, reaching 918.70 km³ in 2022. The grey water footprint accounted for an average of 90.85% annually, and the manure leaching stage contributed the largest share (averaging 62.24% annually), suggesting that this stage warrants priority attention from the perspective of this indicator. Large-scale farming exhibited the lowest water footprint per unit of beef (averaging 29.39 m³/kg), while small-scale farming had the highest (54.65 m³/kg). The spatial pattern showed a trend of “high in the west and low in the east, rising in the west and declining in the east.” The spatial model results revealed that the water footprint per unit of beef exhibited significant spatial agglomeration and spatial spillover effects. Full article

The construction industry accounts for a substantial share of global greenhouse gas emissions, underscoring the need to explore sustainable building technologies. Bamboo is a rapidly growing renewable resource used in various building contexts, including structural and non-structural purposes, with properties equivalent to those of other conventional building materials. The objective of this research was to compare the environmental life cycle assessment impact of bio-based bamboo floor construction with that of conventional concrete floors using a cradle-to-grave and EoL of 60 years for both materials. Comparing the data extracted from the analysis of a square metre of floor system using bio-based construction materials, the LCIA, using the database Simapro 9.5, revealed that bio-based alternatives generally have lower environmental impacts compared to conventional materials. The study establishes that whereas the global warming potential carbon (GWPC) per square metre of concrete floor recorded a mid-point result of 160 kg CO₂-eq, that for bamboo was 12 kg CO₂-eq, with bamboo exhibiting additional carbon sequestration during the growth period. The mid-point result for the acidification potential was 0.68 kg SO₂-eq and 0.12 kg SO₂-eq for concrete and bamboo, respectively, with bamboo showing an 82% improvement over concrete. Again, the eutrophication potential revealed that bamboo showed a 78% improvement over concrete. When analysed within the context of rapidly urbanising regions like Ghana, these LCIA findings provide a strong empirical justification for substituting traditional grey building materials with bio-based structural composites. Concrete and steel remain highly exposed to supply chain energy premiums, given the high energy demands during the clinker and steel production phases. Transitioning urban building models to structurally engineered bamboo could successfully mitigate localised urban heat retention and lower municipal scope 3 emissions. Full article

The increasing adoption of electric vehicles (EVs) is expected to generate a substantial number of retired lithium-ion batteries, creating both environmental challenges and opportunities for second-life energy storage applications. However, the performance variability of retired batteries makes the identification of suitable candidates for repurposing a significant challenge. This study proposes a Battery Stability Index (BSI) framework for evaluating the suitability of second-life EV batteries for stationary energy storage applications supporting EV charging infrastructures. Battery cycling data from Nissan Leaf and Mitsubishi i-MiEV battery packs were analyzed using degradation rate, energy efficiency retention, operational stability, and energy throughput indicators. In addition, EV charging demand data were utilized to assess charging session support capability as a practical deployment-oriented performance metric. The proposed BSI integrates stability, degradation, and throughput characteristics into a unified assessment framework for battery ranking and suitability evaluation. The results demonstrate significant performance differences between the evaluated battery families. Nissan Leaf batteries exhibited lower capacity degradation rates (0.0086) than Mitsubishi i-MiEV batteries (0.0170), maintained higher energy efficiency retention (91.4% versus 79.0%), and achieved substantially greater energy throughput (21,911 Wh versus 6230 Wh). Furthermore, Nissan Leaf batteries supported up to 1.16 EV charging sessions, whereas Mitsubishi i-MiEV batteries supported fewer than 0.34 sessions. Consequently, Nissan Leaf batteries achieved the highest BSI values, with Leaf-1 and Leaf-2 obtaining scores of 0.658 and 0.638, respectively. The findings demonstrate that battery suitability cannot be reliably determined using a single health indicator. The proposed BSI framework provides a comprehensive and practical approach for identifying suitable second-life batteries, supporting battery repurposing decisions, sustainable energy storage deployment, and the integration of second-life batteries within EV charging ecosystems. Full article

Power modules (PMs) from waste electrical and electronic equipment (WEEE) represent an underexploited source of strategic secondary raw materials. However, due to their high level of integration and heterogeneity, PMs remain difficult to recycle, resulting in low recovery rates for several materials. This study analyzes the material composition of different PM types to identify key challenges and opportunities related to their end-of-life management. A step-by-step comprehensive parametric inventory model of PM recycling is developed from data collection, literature review and a corresponding dataset from the Ecoinvent database. Parametric inventory models are used to carry out environmental impact assessment of PM recycling according to material selection and different recycling process options. The models are made simple to use for PM designers such that it can be useful to guide and support design decision-making to maximize material recovery rates and minimize recycling-related environmental impacts. Implemented during the design phase, the models support the development of more sustainable PMs. Models are also made simple for recycling practitioners to access important data regarding PM material compositions. Full article

The transition towards a circular economy of agri-food wastes requires innovative strategies for transforming them into value-added products. This study evaluates the environmental and economic sustainability of a laboratory-scale process that converts 100 g of pomegranate waste, experimentally processed and defined as functional unit (FU), into a cosmetic emulsion. Primary data were collected from laboratory activities carried out in an Italian university, including material and reagent consumption, equipment operating times and energy use. A cradle-to-gate Life Cycle Assessment was performed in SimaPro according to ISO 14040 and 14044 using the Environmental Footprint 3.1 method, while Life Cycle Costing was developed in Microsoft Excel using the same system boundaries. The process valorized the three main pomegranate fractions (arils, mesocarp and exocarp) to obtain a cosmetic emulsion. The exocarp treatment was identified as the main impactful phase. The overall climate change impact reached 328 g CO₂ eq/FU, while fossil resource use amounted to 5.3 MJ/FU. The total production cost was estimated at 189 €/FU, mainly due to labor, reagents, enzymes and equipment costs. Although laboratory-scale operation results in relatively high impacts and costs, the study identifies the main hotspots and provides a baseline for future process optimization and industrial scale-up. Full article

Educational buildings account for approximately 17% of the building sector’s energy consumption, making them critical for zero-emission building (ZEB) strategies. With students spending over 50% of their time indoors, life-cycle carbon assessments and targeted retrofitting are essential for realizing UN sustainability goals on campuses. This study develops a comprehensive life-cycle carbon assessment framework using a Calibrated Building Energy Simulation to simultaneously evaluate embodied and operational carbon emissions in campus facilities. This research evaluates two distinct university buildings for analysis: a historical 1970 educational building in Cosenza, Italy (Mediterranean climate) and a modern 2009 building in Ankara, Türkiye (semi-arid/continental climate). To minimize the total carbon footprint, seven distinct retrofitting scenarios are systematically simulated and compared: adding photovoltaic (PV) panels, integrating solar films on windows, applying internal and external insulations, implementing green wall applications, applying psychological-adaptive HVAC control and decreasing the heating set-point temperature. Results indicate that psychological-adaptive HVAC control is the most effective, achieving approximately 19.3% operational carbon savings across both cases with a low embodied carbon penalty. Conversely, the green wall application was the least effective, with a carbon payback period of 53.55 years. Ultimately, this study provides actionable engineering pathways for transforming campus buildings into net-zero emission educational facilities. Full article

The transition toward a circular economy in the mining sector has increased the need for sustainable strategies capable of recovering value from tailings generated during mining activities and supporting the safe closure of tailings dams. The present study evaluates the environmental performance of reverse mining as a circular economy strategy by comparing two iron ore tailings valorization pathways: mineral reprocessing for iron recovery and reuse as aggregates in cementitious composites. A Life Cycle Assessment (LCA), conducted in accordance with ISO 14040 and ISO 14044 standards, was applied using OpenLCA software and primary operational data collected from a full-scale tailings dam decommissioning project in Minas Gerais, Brazil. Environmental impacts were assessed in ten impact categories using the ReCiPe Midpoint methodology, with emphasis on Global Warming Potential (GWP). Reverse-mined tailings presented a GWP of 1.91 kg CO₂ eq/t, substantially lower than conventionally mined iron ore (6.80 kg CO₂ eq/t) and comparable to natural sand (1.88 kg CO₂ eq/t). Mineral reprocessing reduced the GWP associated with iron ore production by approximately 50%, while the reuse of tailings as construction aggregates proved environmentally competitive under suitable transport conditions. These findings demonstrate that reverse mining can support sustainable tailings dam closure by reducing environmental impacts, recovering secondary resources, and advancing circular economy practices in the mining sector through a practical decision-support framework based on primary industrial data. Full article

Background: Fresh-cut apples are highly susceptible to quality deterioration due to enzymatic browning and oxidative degradation of bioactive compounds. This study investigated the effects of conventional polyethylene packaging (PE, Pack 1) and two innovative biodegradable packaging materials (Pack 2 and Pack 3) on the stability of bioactive compounds in fresh-cut Golden Delicious apples during refrigerated storage. Individual phenolic compounds ((+)-catechin, caffeic acid, (−)-epicatechin, p-coumaric acid, rutin, and quercetin) were quantified by HPLC-PDA, while spectrophotometric assays were used to determine total phenolic content (TPC), total flavonoid content (TFC), and antioxidant capacity (ABTS and DPPH). The environmental performance of the packaging materials was assessed through Life Cycle Assessment (LCA) using SimaPro v.9.5.5. Results: Polyphenol stability was significantly influenced by packaging and storage time (p < 0.001). Compared with fresh-cut apples at t0, Pack 2 promoted a 17.4% increase in total phenolic content after 21 days, whereas Pack 1 and Pack 3 showed reductions of 31.0% and 37.6%, respectively. HPLC analysis revealed compound-specific responses, with rutin and quercetin being markedly better preserved in Pack 3 after 21 days (17.65 and 1.93 mg/100 g, respectively) than in Pack 1 (0.67 and 0.19 mg/100 g, respectively). Two-way ANOVA confirmed significant effects of storage time, packaging, and their interaction on TPC, TFC, ABTS activity, and all individual phenolic compounds (p < 0.001), whereas DPPH activity was not significantly affected (p > 0.05). Pearson correlation (TPC–ABTS, r = 0.6885, p < 0.001) and principal component analysis indicated that antioxidant capacity was more closely associated with the qualitative phenolic profile than with total phenolic concentration alone. LCA highlighted environmental trade-offs among the packaging systems: Pack 1 showed lower impacts in several categories, Pack 2 displayed an intermediate environmental profile, whereas Pack 3 reduced dependence on fossil resources but exhibited higher land- and water-use impacts together with limitations related to end-of-life management. Conclusion: Packaging materials significantly affected the preservation of phenolic compounds and antioxidant activity in fresh-cut apples while exhibiting distinct environmental profiles. The results demonstrate that no packaging system simultaneously maximized product quality and environmental sustainability, highlighting the importance of integrating analytical performance with life-cycle assessment when developing innovative food packaging solutions. Full article

Environmental sustainability of natural and synthetic fibers used in textiles and composites depends on their impacts throughout production, use, and end-of-life (EoL) stages. Natural fibers are renewable and biodegradable but may require substantial water and agricultural inputs, whereas synthetic fibers contribute to fossil resource depletion, microplastic pollution, and persistent waste generation. Natural fibers are often regarded as more sustainable alternatives to synthetic fiber; however, evidence from a life cycle assessment (LCA) reveals a more nuanced reality. As demand for fiber-based materials increases across textile and composite applications, a deeper understanding of the environmental implications of both natural and synthetic options becomes essential. This review compares these fiber categories from a life cycle perspective, examining carbon footprint, energy demands, resource consumption, and EoL pathways. Natural fibers such as cotton, flax, jute, hemp, sisal, banana, coir, and emerging plant-based alternatives offer advantages including biodegradability and carbon sequestration during cultivation. Nevertheless, agricultural practices and subsequent industrial processing require substantial land, water, and chemical inputs. Synthetic fibers, predominantly derived from fossil resources, provide a long service life and consistent performance but are associated with high greenhouse gas (GHG) emissions, dependence on non-renewable feedstocks, microplastic pollution, and broader environmental impacts. By presenting a comprehensive life cycle-based comparison, this review identifies the conditions under which each fiber type may offer environmental benefits, supporting informed material selection for sustainable development. Full article

Forage conservation is a strategic component of Mediterranean livestock systems, where seasonal drought, irregular rainfall, and high summer temperatures limit the availability of fresh forage. In these environments, hay and haylage are widely used as preservation strategies, yet their environmental performance remains insufficiently quantified under semi-arid conditions. It is hypothesized that the higher material and energy inputs required for haylage could be compensated for by the combined effects of biomass preservation efficiency and forage productivity, resulting in comparable or lower impacts per unit of conserved forage under Mediterranean farm conditions. To test this hypothesis, a life cycle assessment was conducted to compare hay and haylage production in a forage farm located in Sicily, Italy, considering the 2024–2025 season. The analysis adopted a cradle-to-farm-gate system boundary, and two complementary impact assessment methods, namely the CML-IA baseline method and the ReCiPe 2016 method, were applied. Environmental burdens were calculated per hectare of cultivated land and per ton of dry matter produced to capture both land-based and product-based performance. The choice of functional unit strongly influenced the interpretation of the environmental impact results. Per hectare, hay and haylage displayed comparable overall burdens, with haylage showing higher impacts in impact categories linked to plastic use and wrapping operations. Per ton of dry matter, however, haylage showed consistently lower impacts, attributed to greater biomass recovery and higher dry matter output, reflecting the combined effect of forage composition, crop productivity, and conservation efficiency. Hay systems showed greater burdens per unit of product under the evaluated farm conditions due to prolonged drying periods, repeated field operations, and higher biomass losses during harvesting and storage. The results suggest that, within the specific Mediterranean farm context analyzed, the combined effects of biomass preservation efficiency and crop productivity were important factors influencing environmental performance when impacts were expressed on an output basis. This case study contributes to current knowledge by identifying biomass recovery, rather than input minimization alone, as a key driver of sustainable forage conservation. Full article

Fuel cells (FCs) are critical for decarbonizing the transport industry, with Life Cycle Assessment (LCA) serving as the standard evaluation framework. However, existing literature exhibits severe methodological heterogeneities and divergent system boundaries that introduce deep epistemic uncertainties. This review conducts a systematic analysis to critically harmonize FC environmental performance across the road, aviation, and maritime sectors. Quantitative synthesis reveals global warming potential (GWP) as the dominant metric. For light-duty vehicles, GWP drops to around 30 gCO₂eq/km, matching battery-electric configurations exclusively under deeply decarbonized grids. Manufacturing FC stacks and advanced storage imposes a severe upfront carbon debt, particularly prominent in heavy-duty freight (60–130 tCO₂eq). In aviation, 80–90% in-flight GWP reductions trigger massive burden-shifting, transferring 60–70% of lifecycle damages to ground-based infrastructure. Maritime FCs shrink GWP to 0.06–0.60 kgCO₂eq/kWh, strictly contingent on upstream hydrogen production. Crucially, despite long-term GWP advantages, FC pathways face systematic penalties in acidification, eutrophication, and ecotoxicity, heavily driven by platinum-group catalysts and fluoropolymer membranes. By isolating software-driven biases and database discrepancies, this work delivers an actionable methodological roadmap, establishing a policy-aligned baseline for future FC transportation sustainability frameworks. Full article

The transportation sector is a major contributor to global greenhouse gas emissions, driving the need for low-carbon energy solutions. Hydrogen is increasingly recognised as a promising option for decarbonising heavy-duty and long-distance transport; however, hydrogen storage systems contribute significant environmental burdens through material production, manufacturing and end-of-life challenges. This study presents a comparative life cycle assessment of a conventional Type IV composite pressure vessel and a novel additively manufactured, internally reinforced titanium alloy pressure vessel concept for heavy-duty vehicle applications. The two pressure vessel designs were compared within the same available packaging volume on a heavy-duty vehicle. A cradle-to-grave system boundary was applied, covering production, manufacturing, transport, use and end-of-life stages. The environmental assessment was limited to cumulative energy demand and CO₂ emissions, which were used as the metrics for comparing the two hydrogen storage systems. Across the entire life cycle, the Type IV pressure vessel exhibited approximately 16% lower energy demand and CO₂ emissions that the titanium alloy pressure vessel. The use phase dominated both energy demand and environmental impacts, contributing more than 75% of the total life cycle impacts for both pressure vessel designs due to the high energy demand for hydrogen production. For the manufacturing phase, when normalised per kilogram of pressure vessel, the Type IV vessel produced 21.9 kgCO₂eq/kg, compared with 80 kgCO₂eq/kg for the titanium alloy vessel. Material production dominated the cradle-to-gate impact of the titanium alloy pressure vessel, primarily because of the energy-intensive primary production of titanium. Although the use of recycled titanium was also assessed, it reduced the manufacturing stage impacts by only 9%, and the overall impacts remained higher than those of the composite alternative. Full article

Municipal solid waste (MSW) incineration with energy recovery is embedded in national decarbonization strategies but emits fossil CO₂ from plastic-derived combustion, challenging the long-term sustainability of waste-to-energy systems. Carbon capture and utilization (CCU) offers a potential mitigation route, yet assessments rarely link technology economics, environmental performance, and the carbon-pricing instruments that would finance deployment. This study develops a break-even carbon-pricing framework integrating life-cycle CO₂ emissions (LCCO₂) and discounted annualized life-cycle cost (LCC; capital-recovery-factor annualization at a 4% real discount rate) for two CCU routes—methanation and methanol synthesis—applied to a 300 t/day Japanese incineration facility (84,000 t/y) under 2024 and 2050 energy-system conditions, thereby quantifying the environmental and the economic dimensions of sustainable CCU deployment in the waste sector. Two complementary indicators are distinguished: an incremental break-even carbon price, the price at which adding CCU to the existing waste-to-energy facility becomes economically neutral, and a plant-level cash balance price. Under the product-system boundary and photovoltaic-electrolysis hydrogen, both routes show lower life-cycle emissions than the baseline in both years; the magnitude—and, for methanation in 2024, the sign—of the net climate benefit depends on the downstream-use accounting boundary. The incremental break-even price for methanol falls from 20.3 × 10⁴ JPY/t-CO₂ (≈1293 USD/t-CO₂) in 2024 to 1.90 × 10⁴ JPY/t-CO₂ (≈122 USD/t-CO₂) in 2050, while that for methanation falls from 32.2 × 10⁴ JPY/t-CO₂ to 0.75 × 10⁴ JPY/t-CO₂ (≈48 USD/t-CO₂)—about half the 2023 EU ETS average price—and approaches zero at approximately a one-third capital subsidy. This collapse is driven largely by the assumed hydrogen-price decline (100 → 20 JPY/Nm³); hydrogen-supply policy, rather than carbon pricing alone, therefore appears to be the dominant lever for making CCU at MSW incineration a viable contribution to sustainable, carbon-neutral waste management. Sensitivity analyses covering the discount rate (2–8%), plant scale (300–900 t/day), methane leakage, product-market absorption, and hydrogen delivered price premiums support the robustness of this sequencing conclusion. Full article

Phosphogypsum (PG), a gypsum-rich by-product of wet-process phosphoric acid production, is increasingly considered for land application because it can supply calcium and sulfur and alleviate constraints such as sodicity, subsoil acidity, and vegetation establishment limitations. However, PG may also contain residual acidity, soluble salts, fluoride, heavy metals, and naturally occurring radionuclides, creating multiple exposure pathways. This critical review distinguishes direct PG evidence from gypsum or sulfate analogue evidence, life cycle assessment/material flow analysis evidence, and risk control studies. It evaluates PG land application according to receiving soil conditions, diagnosed constraints, exposure pathways, and environmental safety boundaries. The strongest evidence supports use in diagnosed sodic and saline–sodic soils, whereas applications in Al-toxic acid subsoils, flooded paddy systems, contaminated or degraded soils, and non-food vegetated systems require conditional assessment. PG should therefore be treated as a context-specific management option rather than an unrestricted disposal route. By linking waste valorization with soil demand, source quality, exposure control, and long-term monitoring, the proposed framework contributes to sustainability by integrating circular resource use with soil health, water protection, food/feed safety, and risk-informed governance, while helping to prevent the transfer of environmental burdens across ecosystems or generations. Full article