Search Results (615)

The transition of adsorbent materials from laboratory synthesis to industrial application requires a rigorous assessment of their durability under high concentrations. This study evaluates composite alginate hydrogels incorporating mill scale-derived magnetite (Fe₃O₄), activated carbon, and L-ascorbic acid (Fe₃O₄/AC/VitC alginate hydrogels) for the detoxification of highly concentrated chromium effluents. We investigated the operational limits of these hydrogel bubbles through three distinct scenarios: (1) Single-Batch Adsorption–Regeneration Cycling in Fresh Cr(VI) Solutions, (2) Sequential Reuse of Single-Batch Hydrogel Bubbles in the Same Effluent for Complete Cr(VI) Removal, and (3) the Multi-Batch Treatment Capacity Test for highly concentrated Cr(VI) loads. The composite demonstrated exceptional robustness, maintaining >80% removal efficiency over five cycles for 100 mg/L Cr(VI) without chemical treatment. For higher loads (150–400 mg/L), a simple regeneration protocol effectively restored performance, reducing Cr(VI) levels to below stringent discharge limits (<0.25 mg/L). Furthermore, in “worst-case” scenarios involving synthetic solutions (2500 mg/L) and real electroplating wastewater (~2000 mg/L), a multi-batch approach achieved complete abatement within 8–9 cycles. Notably, the treatment simultaneously neutralized the effluent pH from ~1.0 to 7.0, confirming the potential of this waste-derived material as a resilient, multi-functional solution for complex industrial wastewater management. Beyond performance, a techno-economic analysis was conducted to evaluate the economic feasibility of industrial-scale production. The results indicate that by utilizing industrial-grade reagents and waste-derived precursors, the production cost of the dry adsorbent can be estimated at ~45 EUR/kg. These findings confirm the potential of this material as a cost-effective, multi-functional solution for SMEs struggling with high operational costs and stringent environmental regulations. Full article

Under high-Mach-number flight conditions, the combustion chambers of hypersonic vehicles encounter extreme thermal environments marked by unilateral heating, high-heat-flux density, and supercritical pressure. Traditional hydrocarbon fuel cooling often suffers from insufficient heat sinks, high-temperature cracking and coking blockages, making it difficult to meet long-endurance thermal protection requirements. Liquid metal, due to its extremely high thermal conductivity, wide liquid phase temperature range, low Prandtl number and electromagnetic pump driving capability, has become a key technology for breaking through the bottleneck of high-heat-flux thermal protection. Apart from the magnitude of heat flux, the heat-transfer time scale (such as the characteristic thermal response time of the wall and the fluid) is also crucial. During hypersonic flight, transient thermal loads can change within milliseconds, requiring rapid thermal response. Liquid metals, due to their high thermal diffusivity, have a shorter thermal diffusion time compared to hydrocarbon fuels. This review employs a systematic literature review of approaches using gallium-indium-tin alloy, GaInSn, focusing on three core directions: the flow and heat-transfer characteristics of liquid metals, the optimization of cooling micro-channels, and the application of thermal protection systems. It summarizes the research progress at home and abroad, compares and analyzes the performance differences and applicable scenarios of typical liquid-metal working fluids, and summarizes the advantages and disadvantages of existing models, structural designs, and system schemes. The research shows that liquid metals can significantly alleviate thermal stratification and eliminate coking, and deep, narrow, tree-shaped, and biomimetic micro-channels can effectively enhance heat transfer. The liquid-metal-fuel dual-channel waste heat recovery and thermoelectric power generation system has demonstrated engineering application potential. Currently, the field still faces key challenges, such as unclear heat-transfer mechanisms under extreme conditions, the lack of general heat-transfer correlation formulas, insufficient compatibility with high-temperature materials, poor miniaturization and vibration resistance of electromagnetic pumps, and low system integration. In the future, efforts should be focused on developing multi-field coupled heat-transfer models under extreme thermal environments using engineered micro-channel structures, corrosion-resistant materials, and lightweight electromagnetic pumps, promoting the research and development of integrated thermal protection, heating and power generation systems, and providing support for the development of advanced thermal management systems for hypersonic aircraft and aviation engines. Full article

The global use of millions of small rodents annually in medical research creates a need for environmental enrichment that is both practical and sustainable. This study investigated the use of banana pseudostem, an agricultural residue, as a potential material for a laboratory-scale rodent enrichment prototype. A life cycle assessment (LCA) and life cycle costing (LCC) were conducted under a cradle-to-grave system boundary that included production, facility use, sterilization, freezer storage, transport, and infectious waste management. The prototype had a global warming potential (GWP) of 28.40 kg CO₂ eq per functional unit. The results showed that the production phase was the dominant contributor to the environmental impacts and costs. Heat pressing was identified as the main hotspot resulting from high electricity demand, while labor was the main cost contributor, as the manual production process at the laboratory scale was time-consuming. The scenario analysis revealed that modifying the press machine to press two pieces simultaneously reduced GWP by 37.54% and total life cycle cost by 29.11%. Full substitution of grid electricity with photovoltaic electricity for heat pressing reduced GWP by about 67.47%. Extending the replacement interval from 3 to 7 days showed the largest GWP reduction of 56.35%, although this option requires confirmation of animal welfare, hygiene, and structural durability. Although banana pseudostem is a renewable agricultural residue, the environmental impacts and costs of the prototype were mainly due to energy-intensive processing at the laboratory scale rather than the raw material. Further improvement in production efficiency and electricity sourcing is required to reduce impacts and increase the feasibility of the banana pseudostem enrichment prototype. Full article

Globally, Australia is ranked the fourth-top producer of e-waste. While Australian states and territories are increasingly recognising the e-waste problem and developing policies and regulations that deal with e-waste, huge amounts of e-waste still go undocumented. Currently, regional councils are concerned with the existing recycling practices owing to the escalating quantities of e-waste generated yearly. This paper examines the e-waste management practices of Victorian and Queensland regional councils, compares the current practices in managing e-waste, identifies the problems and challenges, and recommends innovative approaches to address e-waste collection and recycling practices in Australia. This study was conducted in regional Victoria and Queensland councils. A qualitative research method employing semi-structured interviews is adopted in this study. The study interviewed 49 employees of Victorian and Queensland regional councils. The findings of the study identified a number of areas that needs improvement in the management of e-waste such as: (a) lack of education and awareness about e-waste for the residents in the communities, (b) absence of knowledge about e-waste recycling (c) poor attitude towards e-waste recycling, (d) lack of sufficient funding; (e) limited number of e-waste recyclers to engage, (f) lack of specific policies and legislation on e-waste management (g) inability of the current National Television Computer Recycling Scheme (NTCRS) and mobile muster national product stewardship initiatives and schemes to cover all categories of e-waste. These results suggest that e-waste management practices in Victorian and Queensland Regional Councils need improvement. The findings of this study show that there are more similarities and fewer differences in how the Victorian and Queensland regional councils manage their e-waste. This study provides numerous practical and workable suggestions for addressing the e-waste management practices of regional councils in Australia. From a real-world scenario, this study will be useful to regional councils, environmentalists, and policymakers in identifying areas of improvement in e-waste management practices and developing impactful solutions. Full article

Plastic packaging is indispensable in modern food and beverage supply chains. However, its production and end-of-life management require substantial primary energy inputs. Improving the energy efficiency of packaging systems is therefore a key objective of circular economy strategies. This study applies Life Cycle Assessment (LCA) to evaluate the cumulative energy demand (CED) of a beverage packaging system comprising polyethylene terephthalate (PET) bottles, recycled polyethylene terephthalate (rPET) bottles, high-density polyethylene (HDPE) caps, and polypropylene (PP) labels under two end-of-life scenarios: recycling and landfilling. The assessment was performed using Polish production and waste-management conditions (2022–2024). A functional unit of 100,000 complete 1 L beverage packages was adopted, and the life cycle inventory combined primary industrial data with background datasets from the ecoinvent database. Recycling scenarios were modelled using a substitution-based allocation (system expansion) approach. The results indicate that non-renewable energy accounted for approximately 88–97% of the total cumulative energy demand of the analysed packaging components. Among the investigated materials, PP labels exhibited the highest component-specific cumulative energy demand, whereas rPET bottles showed the lowest values, corresponding to an approximately 13% lower energy demand than conventional PET bottles under the adopted modelling assumptions. Recycling consistently outperformed landfilling by reducing cumulative primary energy demand across all analysed impact categories, with the greatest energy-saving potential observed for PP labels. Negative CED values obtained for selected recycling scenarios represent avoided primary energy resulting from virgin material substitution rather than physically negative energy consumption. The findings demonstrate that component-level LCA provides a robust basis for identifying energy hotspots within plastic packaging systems and supports evidence-based decisions regarding eco-design, material selection, and recycling strategies. Although the absolute CED values are specific to Polish production and recycling conditions, the overall results confirm that material recycling is a more energy-efficient end-of-life strategy than landfilling and contributes to the development of more sustainable circular packaging systems. Full article

Bio-based origin, biodegradability, and compostability represent distinct concepts, and promising laboratory results do not always translate biopolymer-based food packaging into industrial implementation. This review adopts a value-chain perspective to critically assess the transition of biopolymer-based food packaging from renewable feedstocks to commercial products and end-of-life management. It evaluates key stages of the entire value chain, including polymer production, processing technologies, economic feasibility, regulatory requirements, environmental performance, and waste-management strategies. Major barriers to commercialization include feedstock and material variability, production and purification costs, processing limitations, performance gaps, certification challenges, and insufficient recycling or composting infrastructure. Evidence from techno-economic and life cycle assessments indicate that successful implementation depends on integrated production systems, process optimization, co-product valorization, and realistic end-of-life scenarios. Advancing biopolymer packaging therefore requires coordinated development across the entire value chain rather than isolated improvements in polymer design. Full article

The deep decarbonization of high-emission chemical industries requires green hydrogen–ammonia parks that directly integrate volatile renewable energy with continuous synthesis processes. However, high-resolution, physically consistent operational datasets covering the multi-stage evolution from grid-connected economic dispatch to off-grid resilient islanded operation remain scarce. This paper presents a comprehensive, multi-scenario operational dataset for a green-power, directly connected hydrogen–ammonia chemical park in Jilin, Northern China. Derived from 24 typical meteorological scenarios, the dataset covers grid-connected mode with five daily ammonia production targets (72–36 tons/day) and off-grid mode with dynamic yield maximization under a 195 MWh battery energy storage system. Hourly records are provided for renewable generation, electrolyzer and synthesis unit power consumption, grid exchange, battery state-of-charge, and waste heat recovery. All operational states are strictly validated against physical constraints—equipment load limits, energy conservation laws, thermodynamic recovery bounds, and state-of-charge limits—ensuring engineering feasibility. The dataset is publicly available in CSV format and serves as a benchmark for capacity planning, energy management system development, and flexible production strategy validation. Full article

Municipal solid waste (MSW) management remains a major sustainability challenge in developing and emerging regions, where open dumping, uncontrolled disposal, limited recovery, and incomplete infrastructure are still widespread. This study applies life cycle assessment (LCA) to evaluate five configurations of the MSW management system in Jujuy, Argentina, from a disposal-oriented baseline toward progressively integrated and recovery-oriented scenarios. The functional unit was the annual amount of MSW managed in the province (139,757.5 t yr⁻¹), and the assessment was performed using SimaPro 9.3, Ecoinvent 3, and ReCiPe 2016 at midpoint and endpoint levels. Relative to the baseline, expanded integrated management reduced Climate Change impacts by about 45–46% and potential Human Health damage by about 70–71%. The initial transition scenario produced a substantial reduction in the ReCiPe Human Health endpoint despite an almost unchanged Climate Change result, showing the value of a multi-impact interpretation. The complete midpoint profile also revealed category-specific trade-offs. Overall, the results highlight the importance of replacing uncontrolled disposal, increasing separate collection and recovery, and optimizing logistics. The small difference between composting and anaerobic digestion refers specifically to the low organic diversion rate modeled and should not be generalized to higher-diversion systems. Full article

Life cycle assessment (LCA) studies of polypropylene (PP) processing commonly rely on generic secondary databases, while primary industrial inventories for plastic conversion processes remain scarce. This study addresses this gap by quantifying the cradle-to-gate carbon footprint of polypropylene processing using anonymised primary industrial data collected in 2024 from four European polypropylene processing facilities. Unlike previous studies relying mainly on generic secondary inventories, the proposed approach combines primary industrial data with sensitivity and scenario analyses to identify practical priorities for emission reduction. The baseline carbon footprint was estimated at 1.44 tCO₂e per tonne of finished product, with material production and energy-intensive processing identified as the major emission hotspots. One-Factor-at-a-Time (OFAT) sensitivity analysis showed that polypropylene type, process efficiency, renewable electricity use, and process waste management were the most influential parameters, whereas water consumption and additive use had only a minor effect on overall emissions. Scenario analysis indicated that combining recycled polypropylene, improved process efficiency and renewable electricity reduced emissions by 45.8%, while reducing process waste and fully recycling production residues achieved a 42.2% reduction compared with the baseline. By integrating primary industrial inventory data with sensitivity and scenario analyses, this study provides a more representative assessment of real industrial polypropylene processing conditions than approaches based solely on generic databases and identifies practical priorities for industrial carbon mitigation. Full article

Mining operations generate continuous sensor data across heterogeneous repositories with no unified access layer. Existing integration platforms either require centralizing data into new infrastructure or demand extensive pipeline reconfiguration when sources change. We present a metadata-driven execution model in which integration behavior is resolved at runtime from executable metadata rather than encoded in static workflows, preserving existing infrastructure while enabling unified access across heterogeneous repositories. An Asset Cataloging registry stores executable specifications, including connector identifiers, connection parameters, and routing rules, which select and invoke the appropriate connector at runtime without workflow coding or redeployment. Evaluation on large-scale real mining sensor datasets spanning heterogeneous formats (JSON, CSV, Parquet) and repositories (Kafka, MongoDB, external REST APIs) confirmed zero message loss and bit-exact binary reconstruction across all scenarios under at-least-once delivery with idempotent writes. Connector dispatch overhead fell below the 1 ms measurement resolution, confirming that integration latency is dominated by storage I/O rather than orchestration cost. Following evaluation, four pilot sites deployed the platform in production, spanning from active underground operations to post-mining waste management, under the EU Horizon Europe MINE.IO project, demonstrating viability at industrial scale. Full article

End-of-life thermoset composite coatings removed from fuel storage infrastructure represent a difficult waste stream because they combine a cross-linked polymer matrix, glass fibre reinforcement, functional layers and possible contamination from long-term contact with petroleum products. This study presents a preliminary assessment of an epoxy-glass laminate removed from the internal surface of a large vertical diesel fuel storage tank. The work combined a simplified numerical analysis of the technical role of the coating with thermogravimetric analysis and microscopic examination of solid residues after thermal conversion. The numerical results confirmed that the coating had a real reinforcing function, reducing the maximum equivalent stress in the corroded steel shell from 228.80 MPa to 191.85 MPa. TG/DTG analysis showed that the main mass loss of the laminate occurred below 500–600 °C, while the residual mass depended strongly on the process atmosphere. The highest residue was obtained after pyrolysis (28.75%), followed by CO₂-assisted conversion (26.17%) and combustion (20.87%). Microscopic observations showed that pyrolysis favoured morphological preservation of the fibrous/mineral fraction, but the glass fibres remained partly associated with carbonised epoxy resin and graphite-containing particles. Combustion removed the organic fraction more completely, but the remaining fibres showed signs of degradation. The results indicate that pyrolysis should be treated as a promising preliminary pretreatment route when morphological preservation of the fibrous/mineral fraction is prioritised, although the retained mechanical performance and phase composition of the fibres were not assessed. The study should be regarded as a thermogravimetric and microscopic screening of a real post-service epoxy-glass coating, supporting preliminary selection of end-of-life management pathways rather than a complete recycling or environmental assessment. By linking the thermal behaviour of a real post-service composite coating with feasible end-of-life pathways, the study contributes to sustainable waste management by supporting more informed decisions on material preservation, energy recovery, industrial co-processing and avoidance of landfilling for difficult thermoset composite wastes. Full article

Undergraduate Water Quality Engineering courses rely on verification experiments lacking real engineering scenarios, limiting undergraduate participants’ comprehensive problem-solving skills. To remedy this issue, this study constructs an inquiry-oriented experiment using carbon-coated nano-calcium carbonate (C@CaCO₃) to enhance biological nitrification for digested wastewater with low alkalinity and high ammonia. It involves wastewater characterization, sequencing batch reactor (SBR) operation, quantification of chemical oxygen demand (COD), ammonium nitrogen (NH₄⁺-N) removal, mechanism discussion on alkalinity slow release and microbial carrier role of C@CaCO₃, and high-throughput analysis of microbial communities. Experimental results show that C@CaCO₃ increases NH₄⁺-N removal by 94.5 ± 4.8% in low-alkalinity water, while COD removal improves from 5.7 ± 3.0% to 29.5 ± 5.2%. These findings demonstrate that C@CaCO₃ effectively mitigates alkalinity limitation, facilitates microbial attachment, and promotes functional microbe enrichment, offering a practical solution for sustainable nitrogen management in nutrient-rich waste streams. Pedagogically, the case links water-quality monitoring, reactor control, and solid-waste resource recovery, enabling undergraduate participants to trace the full engineering workflow problem identification through quantitative design, operation, and mechanistic interpretation. Post-laboratory surveys and performance assessments indicate significant gains in experimental competence, data-analysis skills, and engineering judgment. By embedding a real-world, low-alkalinity wastewater challenge within the curriculum, the module advances sustainable water-resource management education and provides a replicable model for reforming laboratory teaching in Water Quality Engineering and related environmental-engineering courses. Full article

Phosphate rock is a finite resource whose extraction in sedimentary deposits generates substantial volumes of waste rock. This study develops a panel-scale 3D geological modeling workflow for operational material accounting in a multilayer sedimentary phosphate deposit. Phosphate layers were modeled using a hanging wall–footwall approach and evaluated against independent well data. Bone Phosphate of Lime (BPL) grades were estimated from borehole-layer composite assay values using nearest neighbor, inverse distance weighting, and ordinary kriging. Domain-wise external validation showed that ordinary kriging provided the most consistent agreement with withheld observations in most mineable layers. Each mineable layer was treated as an independent estimation domain, with one composite BPL value retained per drillhole and per mineable layer. The validated block models were regularized to the mine plan and aggregated into operational strips, enabling strip-scale material accounting and mineability filtering under operation-specific technical criteria. To limit disclosure of confidential operational quantities, panel-scale resource, recoverable resource, and residual ore results are presented in relative rather than absolute terms. The results show that most modeled phosphate-bearing material satisfies the applied criteria and is classified as recoverable, whereas residual phosphate-bearing material excluded by the operational criteria remains concentrated in a limited subset of layers. The terms ‘resource,’ ‘recoverable resource,’ and ‘residual ore’ are used throughout in an operational material-accounting sense only and are not intended in the sense of any international mineral reporting code. Strip-based stripping ratio maps further reveal spatial variability in waste-to-ore and waste-to-grade relationships. The resulting workflow provides a quantitative spatial basis for future scenario-based assessment of waste management and selective dumping alternatives in sedimentary phosphate mining. Full article

Small-scale anaerobic digestion offers a decentralized pathway for organic waste recovery; however, its performance is often evaluated through fragmented modules that do not ensure formal traceability between design, operation, sustainability assessment, and decision-making. This study proposes an integrated five-stage methodological framework—diagnosis, design, operational control, economic-environmental assessment, and decision-making validation with feedback—whose ACT (Acceptance–Control–Traceability) decision block applies three sequential filters: data-quality control ($C_{data}\ge 0.90$), multivariable operational stability ($SR\ge 0.75$), and comprehensive sustainability verification ($\mathsf{\Omega }$: $GE{I}_{net}>0$, $NPV>0$, $\varphi <1$, and $\beta \ge 0.10$). A phased bibliographic mapping of 48 references confirmed the modular structure of the state of the art:60.4% address operation/optimization and 39.6% address economic-environmental evaluation, whereas only 2.1% incorporate a formal decision closure. The framework was inductively derived from two Peruvian case studies: Chillón, as a structural-predictive reference, and Huaycán, focused on active pH–EC control through stoichiometric NaHCO∗3 dosing. It was then prospectively evaluated on an independent 200-L co-digestion prototype in Lurín. The Lurín reactor delivered a mean biogas production of 96.9 L,d⁻¹, a methane fraction of 54.2%, and a specific methane yield of 177.4 L,CH∗4,kgVS⁻¹; nevertheless, the ACT decision yielded $SR=0.33$, classifying the system as not validated (Type A failure) due to ionic drift and thermal variability. Although the co-product scenario showed conditionally positive economic ($NPV>0$) and environmental ($GEI\ast net=38.2$ kgCO₂eq/a) indicators, $\mathsf{\Omega }$ could not be evaluated because Stage 1 territorial inputs ($E\ast dem$, $P\ast energy$) were undefined. By rejecting a system that a fragmented modular assessment would have classified as viable, the framework demonstrates the practical value of enforcing operational-stability verification before any sustainability claim and prescribes targeted feedback to Stage 3 for ionic and thermal management. Full article

The rapid growth of express packaging waste (EPW) is creating increasing challenges for urban waste management and high-quality resource recovery, while reliable automated sorting remains difficult because of heterogeneous materials, deformable packaging, random stacking, and frequent partial occlusion. This study develops a system-oriented RGB-D sensing framework to improve the reliability of EPW sorting in conveyor-belt recycling operations. A synchronized and spatially registered RGB-D paired dataset, MEPWaste, was constructed containing 4528 paired samples (9056 RGB/depth images) from 10 representative categories of inner and outer packaging under multiple levels of stacking and occlusion. Based on this dataset, a multimodal detection framework was designed to improve feature reliability within each modality, reinforce spatial consistency between modalities, and enhance detection stability in densely stacked scenes with fragmented visible evidence. The proposed framework achieved 89.1% ${mAP}_{50}$ and 69.3% ${mAP}_{50:95}$, exceeding the RGB-only model by 5.3 and 5.8 percentage points, respectively, and the RGB-D baseline by 2.7 and 3.4 percentage points, with recall reaching 85.1%. A closed-loop sensing–inference–execution pipeline integrating synchronized RGB-D acquisition, real-time detection, robotic grasping, and PLC-based control was further implemented to examine engineering feasibility. Overall, the study provides a practical technical pathway for improving EPW sorting reliability and supporting intelligent resource recovery in waste management systems, with potential applicability to green campus management scenarios characterized by high-frequency parcel consumption and concentrated packaging waste generation. Full article