Search Results (6,239)

Military ammunition and derivative materials that have reached the end of their service life are classified as hazardous waste due to the presence of explosives, necessitating proper decommissioning. Valorization of such materials through the reuse of energetic components offers a sustainable alternative, aligning with circular economy principles. This study aims to assess the environmental impact of civilian emulsion explosives (EEs) formulated with nitrocellulose powder derived from recycled ammunition, comparing these findings to traditional EEs and EEs containing standard nitrocellulose powder. The Life Cycle Analysis (LCA) was performed using the CML Baseline v3.07 methodology combined with the Ecoinvent 3.8 database, utilizing inventory data obtained from Polish sources. The results indicate that incorporating nitrocellulose powder into conventional EEs increases the overall environmental impact by 4.5%, while utilizing recycled nitrocellulose powder reduces the impact by 4.99%. This highlights the environmental benefits of recycling energetic materials for use in civilian applications, as it not only reduces hazardous waste and reliance on virgin materials but also supports the principles of the circular economy. By closing the loop on material use, this approach promotes environmental sustainability and resource efficiency, aligning with broader goals of sustainable development. Full article

Abstract: Achieving the New World Sustainability Vision 2030 leads to enacting environmental restrictions, which aim to partially or totally reduce the negative impacts of different forms of waste and develop alternative technologies for eco-friendly and cost-effective utilization. Solid waste is a hazardous waste with many environmental and economic problems resulting from its storage and disposal. However, at the same time, these wastes contain many valuable elements. One of these solid wastes is heavy oil fly ash “HOFA” generated in power stations using heavy oil as fuel. HOFA is produced annually in massive amounts worldwide, the storage of which leads to the contamination of water resources by the contained heavy metals, resulting in many cancerogenic diseases. At the same time, these ashes contain many valuable metals in significant amounts, such as vanadium “V” and nickel “Ni” that can be extracted effectively compared to their low content and difficulty processing in their main ores. Hence, recycling these types of wastes reduces the environmental adverse effects of their storage and the harmful elements in their composition. This paper critically reviews the world resources of vanadium-bearing waste and various approaches described in the literature for recovering V, Ni, as well as other valuable metals from (HOFA) and other wastes, including pyro- and hydro-metallurgical processes or a combination. Hydro-metallurgical processes include alkaline or acidic leaching using different reagents followed by chemical precipitation, solvent extraction, and ion exchange to extract individual elements. The pyro-metallurgical processes involve the non-salt or salt roasting processes followed by acidic or alkaline leaching processes. The operational parameters and their impact on the efficiency of recovery are also discussed. The digestion mixtures of strong mineral acids used to dissolve metal ions in HOFA are also investigated. Bioleaching is a promising eco-friendly technology for recovering V and Ni through appropriate bacteria and fungi. Oxidation leaching is also a promising environmentally friendly approach and more effective. Among all these processes, the salt roasting treatment showed promising results concerning the cost, technological, and environmental effectiveness. The possibility of complex processing of HOFA has also been investigated, proposing innovative technology for completely utilizing this waste without any remaining residue. Effective zeolite for wastewater treatment has been formulated as a good alternative for conserving the available water resources. Full article

Circular economy (CE) is a model that is gaining significance in the context of sustainable development and environmental protection, focusing on minimizing waste generation and maximizing the use of available resources through recycling and extending product life cycles. The implementation of CE in various European Union countries demonstrates diverse approaches to resource management, waste production, and energy efficiency improvement. These differences primarily stem from varying strategies, national policies, levels of social awareness, and technological advancements. The article identifies the key challenges and barriers associated with CE implementation in selected countries—Poland, the Netherlands, and Romania—and highlights specific areas requiring improvement and adaptation. It emphasizes the critical role of aligning national policies with the EU guidelines, promoting ecological education, and investing in innovative technologies and solutions that support sustainable development. Additionally, it points to the need for developing appropriate waste management infrastructure and encouraging businesses and consumers to change habits and engage in pro-environmental actions. Full article

Background: Camellia oleifera Abel (C. oleifera) is widely cultivated and serves as an important source of edible oil. Yet, during oil production, pruned branches generate significant waste and contribute to environmental pollution. Objectives: In this work, we obtain a natural polysaccharide from the branches of C. oleifera and optimize its extraction using Box–Behnken design (BBD), which is a statistical method commonly used in response surface methodology. And study its properties, such as monosaccharide composition, structural features, antioxidant, and anti-inflammatory abilities. Results: BBD was employed to optimize polysaccharide extraction (solid-liquid ratio = 1:40; 90 °C; 130 min) for a higher yield. After purification, the major monosaccharides of branches of C. oleifera’s polysaccharide (CBP) were disclosed as glucose and galactose. Subsequent structural features of CBP were measured. The antioxidant and anti-inflammatory abilities were measured. The highly scavenging rates of the 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radicals, with the chelating capacity of Fe²⁺, indicate potent antioxidant activity of CBP. Conclusions: In general, CBP demonstrated significant anti-inflammatory activity with down-regulating the expression of IL-6 and IL-1β in the LPS-induced macrophage RAW264.7 model. This bioactive polysaccharide adds value to waste branches by offering a novel approach to waste recycling and the development of C. oleifera. Full article

To address the problems of virgin plastic production from fossil resources and the growing amount of plastic waste, a rapid transition to a circular economy is being pursued. The separation of mixed plastics into pure fractions is of paramount importance for promoting recycling and preventing downcycling. In this study, experimental parameters were determined for the selective bulk dissolution of polyamide 6 (PA 6) filaments (1.75 mm diameter, 1 cm length) in CaCl₂-EtOH-H₂O mixtures (CEW) at 75 °C. These parameters included the energy supply mode, dissolution time, CEW composition and CEW:PA mass ratio. Compared with energy supply by microwaves, energy supply by ultrasound improved the yield of dissolved and recovered PA 6 after 5 h from 31% to 52%. In total, the yield of PA 6 after 3 h of bulk dissolution increased from 18% to 69% when the energy supply mode was changed from microwave to ultrasound and the H₂O:EtOH molar ratio of CEW was increased from 0.40 to 1.33 while maintaining an optimal CEW:PA mass ratio of 8.5. Additionally, master plot analysis suggested that dissolution under microwave energy supply followed a contracting cylinder model, whereas dissolution under ultrasonic energy supply aligned with a 2D diffusion or third-order kinetic model. Microscopic observations suggested that, in the case of ultrasonic energy supply, oscillating bubbles on the particle surface enhanced the dissolution rate of PA 6 filaments in CEW. Full article

The production technology for stretch film is highly energy-intensive. Electrical energy is used not only to power individual components of the technological line but also to change the physical state of the raw material (granules) from solid to liquid, which is poured onto the first calender roller. The calender roller must be cooled to solidify the liquid raw material, and the low-temperature heat generated in this process has been treated so far as waste heat and dispersed into the atmosphere. A low-temperature process heat recovery line has been developed, enabling its transformation into high-temperature heat. High-temperature process heat can be utilized in the technological process for the preliminary preparation of raw material when recycled material (regranulate) with highly variable parameters is added to the base material (granules) with strict specifications. The regranulate content can be as high as 80%. The waste heat recovery system is based on two compressor heat pumps powered by eco-friendly refrigerants. This innovative solution facilitates a circular economy, reduces the carbon footprint, and aligns with the European Green Deal. Full article

Background/Objectives: Healthcare-associated infections (HAIs) and antimicrobial resistance (AMR) present significant challenges in modern healthcare, leading to increased morbidity, mortality, and healthcare costs. Examination gloves play a critical role in infection prevention by serving as a barrier to reduce the risk of cross-contamination between healthcare workers and patients. This manuscript aims to provide consensus-based guidelines for the optimal selection, use, and disposal of examination gloves in healthcare settings, addressing both infection prevention and environmental sustainability. Methods: The guidelines were developed using a multi-stage Delphi process involving healthcare experts from various disciplines. Recommendations were structured to ensure compliance with international regulations and sustainability frameworks aligned with the One Health approach and Sustainable Development Goals (SDGs). Results: Key recommendations emphasize selecting gloves based on clinical needs and compliance with EN 455 standards. Sterile gloves are recommended for surgical and invasive procedures, while non-sterile gloves are suitable for routine care involving contact with blood and other body fluids or contaminated surfaces. Proper practices include performing hand hygiene before and after glove use, avoiding glove reuse, and training healthcare providers on donning and removal techniques to minimize cross-contamination. Disposal protocols should follow local clinical waste management regulations, promoting sustainability through recyclable or biodegradable materials whenever feasible. Conclusions: These consensus-based guidelines aim to enhance infection control, improve the safety of patients and healthcare workers, and minimize environmental impact. By adhering to these evidence-based practices, grounded in European regulations, healthcare settings can establish safe and sustainable glove management systems that serve as a model for global practices. Full article

Poly(glycolic acid) (PGA) is a rapidly degradable polymer mainly used in medical applications, attributed to its relatively high cost. Reducing its price will boost its utilization in a wider range of application fields, such as gas barriers and shale gas extraction. This article presents a strategy that utilizes recycled PGA as a raw material alongside typical carbon nanomaterials, such as graphene oxide nanosheets (GO) and carbon nanotubes (CNTs), to produce low-cost, fully degradable yarns via electrospinning and twisting techniques. The results demonstrate that the tensile strength of the PGA/GO composite yarn increased to 21.36 MPa, and the elastic modulus attained a value of 259.51 MPa with a 3 wt% of GO loading. The addition of an appropriate amount of GO enhances the tensile resistance of the composite yarns to a certain extent. However, excessive application of GO and CNTs can lead to surface defects in the nanofibers, reducing their mechanical properties. Moreover, the integration of both materials could inhibit the degradation process of PGA to some extent, thereby partially addressing the issue of excessive degradation rates associated with the relatively low molecular weight of recycled PGA. Full article

The correct management of high-moisture organic waste (HMOW) is crucial to minimize its environmental impact and take advantage of its potential as a valuable resource, thus linking it to the circular economy, sustainable production and recycling. Processes such as anaerobic digestion, composting and, more recently, biodrying have been applied to support the sustainable management of HMOW. However, the latter has not yet been well characterized, so this study focuses on elucidating the behavior of microbial populations and their relationship with physical and chemical conditions during biodrying. In a greenhouse, a semi-static pile with an initial water content of 88%, composed of orange peel waste (80%), sugarcane bagasse (16.5%) and mulch (3.5%) was biodried for 50 days. Biodrying went through three stages: (1) the mesophilic stage, when different microbial populations decompose some organic matter, causing a temperature increase from 25 to 40 °C; (2) the thermophilic stage, in which the highest microbial counts were found, most of which corresponded to the highest temperatures reached and maintained between 40 and 62 °C, and, consequently, to the greatest decrease in water content (from 78 to 41%); and (3) the cooling phase, when the temperature dropped to 23–25 °C. The aeration and mainly the microbial activity were responsible for most of the water evaporation. Microbial activity in biodrying of HMOW ended on day 32, when the humidity was lower than 30% and the water activity (aw) was below 0.8. After that, moisture loss was carried out only by convection and radiation. Obtained biodried organic waste (10% water-content) could be used as an alternative fuel in many industries. Full article

The adoption of photovoltaic solar technology for renewable energy generation has been growing rapidly worldwide. In decarbonization processes, the use of photovoltaic panels has been preferred due to their reliability, safety, and efficiency. Specifically, the use of photovoltaic panels has increased significantly in Chile, as the climatic conditions are ideal for photovoltaic solar technology. The expected lifespan of a photovoltaic panel is approximately 25 years, so the amount of photovoltaic waste is projected to rise significantly in the coming decades. Consequently, interest has emerged in establishing policies and processes for recycling and recovering value from photovoltaic waste. The objective of this study is to develop a life cycle assessment (LCA) of the leaching process of photovoltaic modules using nitric acid as a leaching agent and to employ the results to analyze the projected scenario for the Antofagasta region in 2040. Through statistical analysis of currently approved photovoltaic installations, projections were made to estimate the amount of photovoltaic waste and the total value of recyclable material expected to be available in 2040, resulting in an approximate figure of 30,676,367 discarded modules. Simultaneously, a life cycle assessment of the leaching process for photovoltaic waste using nitric acid was conducted using the OpenLCA software. The analysis showed that the proposed process has a high impact on global warming potential (GWP), generating 7.07 kg of CO₂ equivalent per kilogram of photovoltaic cell waste. Finally, an environmental and economic comparative analysis was performed, comparing nitric acid with ionic liquids previously studied by the research group. Preliminary results concluded that nitric acid has a significantly lower environmental impact and production cost. Full article

With the advancement of China’s agricultural modernization and scientific and technological progress, there has been a substantial increase in corn production, resulting in significant agricultural waste of materials such as corncobs. Conventional incineration methods fail to efficiently utilize the recyclable resources present in corncobs. In this investigation, corncob biochar film (CBC) was synthesized through the pyrolysis of corncob. Single-factor and orthogonal experiments were used to determine the conditions needed to prepare biochar film with the best Cr(VI) adsorption effect. The experiments showed that at a heating rate of 5 °C/min, pyrolysis temperature of 500 °C and pyrolysis time of 120 min, the Cr(VI) removal rate of prepared biochar film reached 73.55% and the adsorption capacity was 18.39 mg/g. Meanwhile, the factors affecting the removal of Cr(VI), including pH value, initial concentration of Cr(VI) solution, dosage of adsorbent, adsorption kinetics and isothermal adsorption, were analyzed in detail. The structures of CBC before and after Cr(VI) adsorption were analyzed by SEM, FTIR, XRD, XPS, and BET. These findings demonstrate the efficacy of corncob biochar film in Cr(VI) removal. Full article

The extensive development of construction, in which cement concrete remains the key composite, enforces the need for particular environmental concerns. This applies to aspects, including ecological challenges in the cement industry and the rational use of natural construction aggregates. This review article focuses on new trends in the use of waste aggregate, with particular emphasis on concrete recycled aggregate and waste sands. The state of the art was analysed, including many years of own studies on modification of properties of waste aggregate and concrete composites made from it. It was assessed that among possible ways of quality improvement of RCA, the most promising for the macro scale seems to be carbonation, unlike biodeposition. The latter, novel and undoubtedly interesting from a scientific viewpoint, has not been studied sufficiently, and the real obstacle is the cost of its implementation in practice. Multi-recycling, the pioneering proposal of recycled concrete aggregate management, can be viewed only in the ecological context for the moment. The use of waste sands from hydroclassification combined with steel fibres is the closest to implementation for constructional purposes in engineering practice. Full article

Duckweeds, such as Lemna minor L., are invasive aquatic species that can proliferate on the surface of the nutrient solution in hydroponic systems, requiring removal operations from the cultivation tanks and disposal as waste. Several studies have demonstrated the potential use of duckweeds as an organic fertilizer. Recycling plant waste as a nutrient source for crops may be a circular approach to enhancing the sustainability of intensive horticultural production systems. Two pot experiments were carried out to evaluate the possibility of using the biomass of Lemna as a fertilizer for lettuce. The following fertilization treatments were applied: Control (no fertilization), Lemna biomass (60, 120, and 180 kg ha⁻¹ nitrogen), urea (60 kg ha⁻¹ nitrogen), and commercial organic fertilizer (60 kg ha⁻¹ nitrogen). Lettuce head diameter, fresh and dry weight, the number of leaves, and the contents of minerals, nitrates, chlorophyll and carotenoids were determined. In addition, nitrogen use efficiency was calculated. Fertilization with Lemna resulted in a significant increase in yield compared to control (+50% considering the average of the three Lemna doses) and both inorganic (+65%) and organic (+71%) fertilization treatments. No differences in yield and quality were observed between the three doses of Lemna, but the lowest one was the treatment with the best performance in terms of N productivity. These results suggest that Lemna biomass may be a proper source of nutrients for lettuce with advantages for yield and no effect on quality. Therefore, its use as an alternative to commercial fertilizers can allow farmers to profitably exploit a waste product and, at the same time, reduce the costs for fertilization, thus achieving environmental and economic benefits. Full article

In households, waste growth has become a critical global issue. This study aims to extend our understanding of promoting pro-environmental behavior by exploring the role of trust and perceived justice in households’ waste recycling practices. Trust and social justice are context-sensitive; studying them in different contexts provides new knowledge on motivating recycling motivation. The research is based on semi-structured interviews (n = 40) on household recycling practices in Latvia. Research results demonstrate that a lack of institutional trust and perceived social injustice concerning household waste recycling practices appear in several contexts: trust in an individual’s capacity to recycle, trust in their peers’ capacity to recycle, trust in the efficiency of the recycling system, trust in the capacity of the waste management company to recycle, trust in waste management policy, and trust in information on recycling. Lack of trust in waste management is linked to perceived social injustice as waste management policy is criticized for not being accessible and putting too much responsibility on households, and this can serve as a critical barrier to household recycling. This study reveals which elements of the waste management system are related to a higher risk of social injustice and lack of trust in the perspective of households, thus signaling where changes in the system or providing end-users more information are needed to make the waste-sorting process more efficient. The findings of the study indicated a few directions for further improvements in the waste management system: ensuring the financial availability of recycling services, reassessment of the responsibilities of the stakeholders, and working toward raising awareness of the recycling and waste management system. Full article

The increasing demand for sustainable construction materials has driven the exploration of alternative fillers in asphalt production. Traditional asphalt mixtures rely heavily on natural aggregates and petroleum-based binders, contributing to environmental degradation. This study proposes an innovative solution by utilizing Crushed Recycled Marble Stone Powder (CRMSP) as a sustainable filler in SBS polymer-modified asphalt containing high volumes of recycled tire rubber, addressing both resource depletion and waste management concerns. A total of 10 asphalt mixes were formulated with varying CRMSP content (0–100% as a replacement for conventional filler) and SBS polymer (3–5%), and their performance was evaluated through Marshall stability, flow, volumetric properties, and dynamic modulus tests. The results demonstrate that incorporating CRMSP up to 75% significantly enhances asphalt’s mechanical properties. The 75% CRMSP mix showed superior stability (19.2 kN, 24.1% improvement), flow (4.6 mm, 4.5% improvement), and resistance to rutting (lowest rut depth: 0.18 mm, 16.7% reduction) compared to the control mixture. Dynamic modulus testing further confirmed the improved resistance to deformation, with the 75% CRMSP mix exhibiting the highest modulus (6.9 GPa, 15.0% improvement). This research highlights the potential of CRMSP as an innovative and eco-friendly alternative filler, improving asphalt performance while reducing environmental impact. By offering a sustainable way to recycle marble waste and tire rubber, this study paves the way for greener, cost-effective asphalt formulations. Future studies should focus on real-world applications, durability, and long-term performance to validate the potential of CRMSP-modified asphalt in commercial use. Full article