Search Results (2,429)

Refractories are advanced ceramics essential for high-temperature operations in the steel, glass, cement, and power sectors. In response to growing sustainability requirements, life cycle assessment (LCA) is increasingly applied to quantify and mitigate their environmental impacts. However, current refractory-related LCA research remains limited by the scarcity of comprehensive inventories and the lack of systematic evaluation of uncertainties affecting results and ecodesign strategies. This study addresses these gaps by presenting the first published LCAs of tabular alumina, white fused alumina, and fused cast high-alumina block production, thereby expanding the environmental knowledge base across alumina products. The analysis shows that uncertainties in characterization models can significantly influence impact-category prioritization, underscoring the need for robust interpretation frameworks. Differences in category criticality across methodological levels and LCIA methods are examined, highlighting the suitability of the Product Environmental Footprint (PEF) approach for refractory applications due to its explicit consideration of model uncertainty and comprehensive coverage of impact categories. Results indicate that alumina products significantly contribute to climate change, fossil resource depletion, particulate matter formation, acidification, freshwater eutrophication, and non-cancer human toxicity. Energy supply constitutes the main environmental hotspot, both through its direct consumption and its indirect contribution during raw material preparation. Red mud disposal is also a major contributor to impacts associated with calcined alumina production. Based on these insights, improvement strategies are proposed, demonstrating the value of LCA as an ecodesign tool. Scenario analysis for fused cast high-alumina block further quantifies the potential for impact reduction under varying operational conditions. Full article

Hospitals generating waste daily need to identify efficient, cost-effective, and sustainable alternatives to conventional disposal methods. Therefore, we formulated a mathematical model to evaluate emerging healthcare waste treatment (HCW) methods by developing a multiple-criteria framework. The framework enables an evidence-based evaluation that supports better HCW management-related decisions in resource-limited settings. Results found that ozone is the optimal method for hospitals with a waste profile mostly made up of infectious and pathological wastes. Methods such as promession, for stricter environmental priorities, and superheated steam, for better performance on all evaluation criteria, may be preferred if hospital priorities shift. Full article

This study addresses a research gap in integrated environmental and spatial assessments of municipal solid waste (MSW) systems in rapidly growing secondary cities in Central Asia. Using a mixed-method approach that combines field audits, GIS-based spatial analysis, environmental monitoring, and greenhouse gas modeling, the study evaluates waste composition, infrastructure coverage, and ecological risks in Shymkent, Kazakhstan. The results reveal uneven distribution of legal waste containers, a 5–7% annual increase in illegal dumping sites, and dust (TSP) concentrations exceeding WHO thresholds near active disposal zones. Spatial hotspot mapping identifies critical pressure areas in peripheral districts, while morphological audits show a rising share of plastics and construction debris. The findings support district-specific policy interventions, infrastructure modernization, and behavior-driven recycling incentives. The proposed methodology provides a replicable framework for sustainable MSW governance in urban contexts. These results contribute to evidence-based municipal waste governance and regional sustainability planning. Full article

The management of invasive alien species (IAS) generates large amounts of plant waste biomass that is commonly disposed of by burning or destruction, leading to environmental and economic drawbacks. At the same time, the production of synthetic dyes and pigments used in printing and graphic applications remains a significant source of pollution. In this context, the valorization of IAS biomass as a source of natural colorants represents a sustainable alternative aligned with circular economy principles. Here, biocompounds and natural dyes were extracted from four invasive or non-native plant species—Arundo donax, Phytolacca americana, Tradescantia fluminensis, and Eucalyptus globulus—using five solid–liquid extraction methods: infusion, infusion with heat, thermal agitation, Soxhlet extraction, and ultrasonic-assisted extraction. Extraction efficiency and color preservation were comparatively evaluated. Although Soxhlet extraction provided the highest extraction yield (up to 30.5%), infusion with heat proved to be the most suitable method for preserving color integrity and minimizing oxidation. Liquid dyes obtained by the selected extraction method were converted into solid pigments through a lake pigment precipitation process using aluminum potassium sulfate and sodium bicarbonate. The resulting pigments were characterized in terms of chemical composition, particle size, and chromatic properties, and subsequently formulated into oil-based inks using linseed oil as binder. Scanning electron microscopy revealed pigment particle sizes ranging from approximately 2.1 to 8.3 µm, depending on the plant source, and confirmed adequate ink penetration and distribution on commercial printmaking paper. The obtained pigments exhibited color tones ranging from yellow to brown and grey, mainly associated with the phenolic and tannin content of the original biomass. Printing tests demonstrated the suitability of the developed inks for manual printmaking techniques, highlighting the potential of IAS-derived pigments as sustainable alternatives for artistic and printing applications. Full article

The environmental concerns associated with the excessive use and improper disposal of plastic waste have led to increased interest in chemical recycling methods such as pyrolysis. In this study, waste plastic pyrolysis oil (WPPO) was evaluated as a potential feedstock to produce high-quality feedstock for lubricant base oils through hydroprocessing. WPPO was obtained via the thermal degradation of waste plastic at 400 °C under a nitrogen atmosphere using a 2 t/day pyrolysis reactor. The physicochemical properties of WPPO were analyzed, including the sulfur, chlorine, and metal contents. A series of Pt-supported catalysts based on different acidic supports (SAPO-11, SAPO-34, and Zeolite Y100) was prepared using an incipient wetness impregnation method and characterized by BET, XRD, and TPD techniques. The hydroprocessing reactions were conducted under varying temperature and pressure conditions to evaluate conversion and optimize product selectivity. The catalysts exhibited different surface areas, pore structures, and acidity profiles, which directly impacted their hydroprocessing performance. The results demonstrate that Pt/Y-100 exhibited the best upgrading performance among the tested catalysts, achieving an olefin-to-paraffin conversion of over 88.65% with a dominant paraffinic hydrocarbon distribution in the C15–C25 range under optimal conditions (300 °C and 40 bar). The results demonstrate that the conversion of olefins to paraffins in WPPO can be effectively controlled by tuning the reaction conditions and catalyst. Full article

(1) Background: The safety of antioxidants (AOs) in disposable biodegradable tableware products remains insufficiently understood. (2) Methods: The migration of 20 AOs from 39 disposable biodegradable tableware under multiple usage conditions was investigated by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry. Their potential exposure risks were evaluated using three risk assessment frameworks (EU, FDA, and Monte Carlo simulation). (3) Results: Ten AOs were detected in 95% ethanol, with Irganox 1010 showing the highest migration (0.29 ± 0.62 mg/kg). Starch-based products exhibited a greater variety and higher migration of AOs compared to PLA-based and fiber-based products. Food simulant type, temperature, and time exerted a more significant effect on AO migration than microwave and ultraviolet treatments. An analysis method for six typical AOs in soybean oil using freezing degreasing was established, which demonstrated good recoveries (77.6–110.3%) and relative standard deviations (1.7–14.7%). Four AOs were detected in soybean oil, with Irganox 1010 showing the highest migration (603.7 × 10⁻³ mg/kg). Utilizing high-percentile conservative exposure scenarios derived from Monte Carlo simulation, Irganox 1010 may pose a health risk to humans under high-dose exposure in soybean oil. (4) Conclusions: This study provides a basis for the safety evaluation of AOs in disposable biodegradable tableware. Full article

Over the past few decades, the extensive use of plastics has led to significant environmental challenges due to their limited biodegradability and long-term persistence. Consequently, biodegradable materials have attracted considerable attention as sustainable alternative solutions to mitigate these environmental concerns. Also, the use and disposal of these materials present some sustainability challenges. Biopolymers have some advantages over standard polymers, such as biodegradability, non-toxicity and environmental sustainability, and they can be used in various industries. Taking into account the fact that the biopolymers are produced by living organisms and microorganisms, they are considered as the natural materials that can be composted. This review paper explores the increased demand for biopolymers and summarizes their benefits along with application. Overall, the focus is on the composting process as the promising sustainable technology for recovery of biodegradable waste as well as for biopolymers. Also, some biopolymers and their degradation in different conditions are presented, and the biodegradation test methods for these materials are mentioned in accordance with relevant international standards. This review aims to provide a comprehensive overview of current developments and future development directions for the biopolymer field. Full article

Objectives: This study aimed to characterize the age-related trends of caries experience among preschool children in Shenzhen, China. Methods: This cross-sectional study recruited 3- to 5-year-old preschool children in Shenzhen via a multistage random sampling method in 2024. Two calibrated examiners conducted oral examinations in kindergartens using disposable dental mirrors with LED illumination and ball-ended Community Periodontal Index probes. Caries experience was recorded using the dmft index, as recommended by the World Health Organization. Results: This study invited 4015 children from 27 selected kindergartens, and 3534 children (1886 boys, 53%) completed the survey. The response rate was 88%. The prevalence of caries experience was 31% at age 3, 49% at age 4, and 58% at age 5, representing a 27% higher prevalence in 5-year-olds than in 3-year-olds. The mean dmft scores (±SD) were 1.2 ± 2.5 for 3-year-olds, 2.2 ± 3.2 for 4-year-olds, and 2.8 ± 3.5 for 5-year-olds, indicating a 1.6 affected teeth higher mean dmft in 5-year-olds than in 3-year-olds. The upper central incisors were the most affected teeth (23%) in 3-year-olds and remained the most susceptible across all age groups, while the prevalence of caries in lower molars increased progressively from 7% at age 3 to 24% at age 5. Conclusions: Dental caries prevalence and severity among preschool children in Shenzhen increase significantly with age. These findings highlight the need for targeted preventive strategies focusing on high-risk teeth, including the upper central incisors and lower molars, to address the rising burden of early childhood caries in this population. Full article

Coastal ecosystems of the tropical Atlantic and the Mexican Caribbean have experienced recurrent massive influxes of pelagic brown macroalgae, Sargassum natans and Sargassum fluitans, generating severe environmental, social, and economic impacts. While the accumulation of this biomass poses a significant waste management challenge, it also represents an underexploited renewable resource aligned with circular economy and sustainability principles. This study investigated the valorisation of Sargassum spp. through comprehensive physicochemical characterisation and multiple value-added applications. The biomass collected in Tulum, Quintana Roo, Mexico, was analysed to determine its chemical composition, including lignin, holocellulose, α-cellulose, ash, and moisture content, using standardised methods of the Technical Association of the Pulp and Paper Industry (TAPPI). For mechanical testing, methods from the American Society for Testing and Materials (ASTM) were used. The biomass was subjected to controlled pretreatment and thermochemical conversion processes. Evaluated valorisation pathways included: (1) taxonomic identification and physicochemical characterisation, (2) polymer composites, (3) reinforcement in construction materials such as unfired clay bricks, and (4) biochar and activated carbon production for contaminant adsorption. The results demonstrated that Sargassum spp. biomass can be transformed from an environmental nuisance into a multifunctional, high-value biomaterial, providing scalable solutions that mitigate waste disposal challenges and contribute to climate and resource sustainability. Full article

Multilayer plastic packaging waste (MPPW) represents a major challenge for waste management due to its widespread use in single-use applications and its complex, heterogeneous structure. Variations in polymer composition, layer thickness and number of layers significantly hinder conventional recycling processes, leading most MPPW to be disposed of through landfilling or incineration. This study presents the development and optimization of a dissolution–precipitation process using toluene to recover polyethylene (PE) from MPPW. The proposed method successfully produced PE with less than 5 wt% polypropylene (PP), meeting common recycling quality requirements. Design of experiments (DoEs) combined with response surface methodology (RSM) was applied to evaluate the influence of key operating parameters, including temperature, dissolution time, solvent to waste ratio and agitation speed, to identify optimal processing conditions. The results demonstrated that temperature had the most significant influence on both dissolution yield and polymer purity. Optimal conditions of 100 °C, 30 min, 400 rpm, and a solvent-to-waste ratio of 15 mL/g resulted in a total recovery yield of 39.1% with a polymer composition of 97.7 wt% PE and 2.3 wt% PP. Owing to the use of established and scalable unit operations, the process shows strong potential for industrial-scale implementation without requiring complex or specialized infrastructure. Full article

Against the backdrop of China’s booming edible fungi industry, shortages and price hikes of traditional cultivation substrates have emerged as critical bottlenecks. Meanwhile, the disposal of a large amount of ginger straw produced during the ginger cultivation process is also a major challenge. To address these issues, this study explored ginger straw as an alternative substrate for Pleurotus geesteranus and Hericium erinaceus, focusing on the optimization of substrate formulas and their effects on the nutritional quality of the fungi. Superior strains were first screened, after which the addition ratios of ginger straw (10–40%) were optimized. Commercial characteristics, nutritional components, and safety indicators of the fruiting bodies were determined, and a comprehensive quality evaluation was conducted using the membership function method. Results indicated that excellent strains of both fungi were selected: the optimal ginger straw addition ratio was 15–30% for P. geesteranus and 15% for H. erinaceus. Compared with the conventional cottonseed hull substrate, the optimized formulas significantly increased the biological efficiency (BE) by 9.08–27.1% for P. geesteranus and 9.16% for H. erinaceus. They also improved the contents of key nutrients (e.g., proteins and amino acids), enhanced total antioxidant capacity, and optimized the composition of flavor-contributing amino acids. This study offers a novel approach for the efficient utilization of ginger straw, provides technical and theoretical support for the low-cost and high-quality cultivation of edible fungi, and contributes positively to the development of ecological circular agriculture. Full article

Using disposable screen-printed electrodes faces major challenges when attempting to monitor a continuous process, especially in systems where there is pronounced adsorption, fouling, degradation, or in cases of irreversible electrochemical reactions. Methylene Blue (MB) exhibits some therapeutic properties and is commonly used as a redox reporter in DNA sensors, but is also considered a toxic pollutant in aquatic systems. MB demonstrates strong adsorption to carbon materials, which prevents its electroanalytical determination in multiple measurements with a single electrode. Our work details direct electrochemical determination of MB with only the native carbon screen-printed working electrode as sensing material and optimization of the analytical method. In batch mode, we significantly improved sensitivity and interelectrode reproducibility by introducing a prepolarization step, but successive measurements in lower concentrations were not feasible due to strong adsorption. A fully customizable, modular flow cell was 3D printed to allow in operando replacement of the planar screen-printed three-electrode system after measurement during continuous flow. As confirmed by mechanical properties testing, the rigid polyacrylate upper section of the flow cell provides structural stability, combined with a flexible TPU lower section which enables effortless sensor hot swapping and effective sealing during flow. With an optimized hot swapping flow detection method, MB was detected via square wave voltammetry with a sensitivity of 65.59 µA/µM and a calculated LOD of 7.75 nM, which outperforms similar systems from the literature. We envisage this approach can be integrated into low-cost continuous environmental monitoring systems or in-line quality control, especially in flow chemistry synthesis. Full article

Background/Objectives: Improper medication use, premature treatment discontinuation, and inadequate disposal contribute to irrational drug consumption and environmental contamination. Although pharmaceutical take-back programs have expanded globally, real-world evidence on household medication accumulation in academic and community settings remains limited. This study aimed to describe longitudinal patterns of medication collection during an eleven-year university-based take-back campaign, with detailed pharmacological characterization available for selected post-pandemic years. Methods: Real-world data were analyzed from a sustainable medication take-back campaign conducted annually at the University of Colima between 2015 and 2025. Expired or unused medications were voluntarily returned by students and community members. Total collected weight was recorded for all years, while detailed classification by dosage form, Anatomical Therapeutic Chemical (ATC) group, and Mexican regulatory fraction (Fractions II, IV, V, and VI) was performed for years with complete records (2023–2025). All materials were disposed of through an authorized hazardous-waste company in compliance with NOM-052-SEMARNAT-2005. Descriptive analyses were performed using SPSS version 29.0. Results: Approximately 3.9 tons of pharmaceutical products were collected over eleven years, reflecting persistent household accumulation of unused or expired medicines. In the years with detailed analysis, oral solid dosage forms predominated. In 2025, ATC groups M, A, and C were most frequently returned, consistent with medications used for chronic conditions. Therapeutic composition varied annually, with NSAIDs/analgesics predominating in 2023–2024 and antibiotics in 2025. Across analyzed years, 5–7% of collected items corresponded to non-medication products. Conclusions: This long-term campaign provides valuable real-world evidence on medication non-use and disposal, highlighting ongoing challenges in rational medicine use, treatment continuity, and environmentally responsible pharmaceutical waste management. Full article

The modern development of the energy and metallurgy industries is accompanied by the increasing use of coal in the form of fuel and raw material. However, at the same time, urgent issues are arising concerning assessments of its radiological and environmental safety. Coal and ashes accumulate natural radionuclides (such as thorium, uranium, and potassium-40), and toxic and rare earth elements (REEs) that are capable of migrating into the environment during the processes of production, burning and ash disposal. Special attention has recently been paid to rare earth elements that are of economic value as critical metals for sophisticated technologies, but these can pose environmental risks. Their presence in coal is becoming an increasingly relevant issue for cross-disciplinary research, at the intersection of geochemistry, radioecology and the sustainable use of natural resources. Moreover, issues regarding the radiological safety of coal deposits and their derivative products are especially crucial for Kazakhstan, Russia, China and other countries with developed coal production industries. Studies demonstrate that ash and slag of thermal power plants can comprise increased concentrations of natural radionuclides that can accumulate in soil, water and the environment. Therefore, the study of rare earth, toxic and radioactive element contents in coal using nuclear analytical methods is of high practical and environmental significance, especially in terms of assessing radiation load on the environment, designing control measures and ash disposal, and the prospect of the selective extraction of REEs from the coals. Full article

Potassium mining activities result in the discharge of highly saline wastewaters, creating severe environmental impacts in water and soil. This study evaluates the environmental performance of a novel pilot system developed in the framework of the LIFE Brine-Mining project. The system comprises membrane, precipitation and thermal technologies, recovering high-purity water and five valuable resources from it: magnesium hydroxide, calcium carbonate, calcium sulfate, sodium chloride, and potassium chloride. A cradle-to-grave Life Cycle Assessment (LCA) was performed following the standards ISO14040 and EN15804 and using 1 m³ of potassium wastewater as functional unit. The LCA results indicated that the novel system environmental impact is mainly affected by the use of chemicals (20.63 × 10⁰ kg/FU) during its operation and energy consumption (1.39 × 10¹ kWh/FU). The chemical use dominates areas like the Abiotic Depletion, and the Eutrophication Potential, and the Water Depletion Potential. The novel pilot system was compared with another novel configuration that treated a brine from coal mining activities and with a conventional method of potassium brine management, which is the disposal in underground old mines. The potassium brine treatment system exhibited lower environmental impact than the coal mine brine system, and outperformed compared to the conventional disposal method. Full article