Search Results (249)

The main advantage of using biomass for energy generation is the reduction in carbon dioxide emissions. For a fast reduction effect, it is important to use biomass characterised by an annual growth cycle. These may be fallen leaves. The fuel properties of the leaves can change during the growth period. These changes can result from both the natural growth process and environmental factors—particulate matter adsorption. The main objective was to determine changes in the characteristics of leaves and needles during the growth period (from May to October). Furthermore, to determine the effect of adsorbed particulate matter, the washing process was carried out. Studies were carried out for three tree species: Norway maple, horse chestnut and European larch. Proximate and ultimate analysis was performed and mercury content was determined. During the growth period, beneficial changes were observed: an increase in carbon content and a decrease in hydrogen and sulphur content. The unfavourable change was a significant increase in ash content, which caused a decrease in calorific value. The increase in ash content was caused by adsorbed particulate matter. They were mostly absorbed by the tissues of the needle and leaves and could not be removed by washing the surface. Full article

Gasification of municipal solid waste and other biogenic residues (e.g., biomass and biowaste) is increasingly recognized as a promising thermochemical pathway for converting non-recyclable fractions into valuable energy carriers, with applications in electricity generation, district heating, hydrogen production, and synthetic fuels. This paper provides a comprehensive analysis of major gasification technologies, including fixed bed, fluidized bed, entrained flow, plasma, supercritical water, microwave-assisted, high-temperature steam, and rotary kiln systems. Key aspects such as feedstock compatibility, operating parameters, technology readiness level, and integration within circular economy frameworks are critically evaluated. A comparative assessment of incineration and pyrolysis highlights the environmental and energetic advantages of gasification. The valorization pathways for main product (syngas) and by-products (syngas, ash, tar, and biochar) are also explored, emphasizing their reuse in environmental, agricultural, and industrial applications. Despite progress, large-scale adoption in Europe is constrained by economic, legislative, and technical barriers. Future research should prioritize scaling emerging systems, optimizing by-product recovery, and improving integration with carbon capture and circular energy infrastructures. Supported by recent European policy frameworks, gasification is positioned to play a key role in sustainable waste-to-energy strategies, biomass valorization, and the transition to a low-emission economy. Full article

Faxonius limosus is an invasive alien crayfish species that has a negative effect on aquatic biodiversity. Using its meat as food could help reduce its ecological impact while providing a protein source. In order to do that, the initial step was to determine safety and nutritional parameters of crayfish meat. Samples from two localities were analyzed for energy value, moisture, ash, protein, fat, carbohydrates, fatty acid and amino acid composition, and macro- and micro-mineral content. Moreover, an online survey was conducted in order to evaluate the public’s current knowledge about invasive alien species and willingness to consume crayfish meat as a food product. Heavy metal concentrations (Hg, Pb, Cd) were below European Commission limits, confirming safety. The meat had a high protein content (16.68%), low fat (0.22%), and a favorable fatty acid profile with notable levels of omega-3 polyunsaturated fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Predominant macro-minerals were K, Na, Ca, Mg, and P, while Zn, Cu, Fe, and Mn were the most abundant micro-minerals. Even though most participants (79.7%) were not informed about Faxonius limosus, the majority expressed willingness to participate in the assessment of new products made from invasive crayfish. These findings suggest that F. limosus meat is a nutritionally valuable and safe alternative protein source, with potential for sustainable food production and ecological management. Full article

Renewable energy sources are presented as a key solution to today’s energy needs, but they also generate waste that can have a negative impact on the environment. In particular, fly ash from the incineration of municipal solid waste (MSW), classified as hazardous by European regulations, is often deposited in landfills due to its lack of usefulness. This research proposes its valorisation in geopolymers, combining it with mining to create a sustainable material with a high industrial waste content. Firstly, all the wastes involved were characterised, which allowed for the development of a high-quality geopolymer from mining residue activated with 5% NaOH. This material was enriched with up to 50% fly ash (in increasing percentages) with the aim of making it inert, retaining it in the geopolymer matrix, and observing its effect on the final material. The physical and mechanical properties of the geopolymers obtained were evaluated, demonstrating that they do not produce contaminating leachates. The results indicate the feasibility of developing a geopolymer with up to 20% fly ash, obtaining a building material comparable to traditional ceramics, suitable for commercialisation, with a lower environmental impact and in line with the principles of the circular economy. Full article

As one of Europe’s rare floodplain forest ecosystems, the İğneada Longos Forests face increasing ecological pressures; this study examines land use and land cover (LULC) changes in the İğneada Longos Forests, a protected national park in Turkey, between 1984 and 2014, while also assessing future climate change impacts under different shared socioeconomic pathways (SSPs). In this context, the MaxEnt model, which exhibits a very high sensitivity, was used to determine the land use/land change and the change in natural distribution habitats of the forest tree species in the İğneada Longos Forests, which constitute the research area, due to the effects of climate change. The analysis of forest management plans revealed significant LULC shifts, including wetland loss, cropland expansion, and declines in pioneer tree species, such as the lowland maple and the European ash, due to anthropogenic pressures and increasing droughts. Climate modeling using the Emberger and De Martonne indices projected severe aridity by 2100, with Mediterranean climate dominance expanding (up to 89.25% under SSP3–7.0) and humid zones disappearing. These changes threaten biodiversity, carbon sequestration capacity, and ecosystem stability, particularly in floodplain forests, which are critical for carbon storage. The findings underscore the urgent need for adaptive conservation strategies, stakeholder collaboration, and climate-resilient forest management to mitigate ecological degradation and sustain ecosystem services under escalating climate stress. Full article

Reducing carbon dioxide emissions is a key priority in the European Union, which aims to achieve carbon neutrality by 2050. Construction has a key role to play in this effort, as it is responsible for a significant proportion of greenhouse gas emissions, especially due to cement production. At the same time, waste reuse emerges as a key strategy within the circular economy, another pillar of European policies. By valuing byproducts and waste, such as construction and demolition waste (CDW), it is possible to reduce the extraction of natural resources, amount of waste sent to landfills, and emissions associated with the production of new materials. This study, with the main objective of evaluating the possibility of using CDW as supplementary cementitious materials, emerges as a possible solution to reduce these problems. Two CDW treatment methods were used: (i) mechanical grinding and (ii) calcination. The mechanical grinding method, even with the use of laboratory equipment, has shown that it is possible to obtain CDW particles with characteristics suitable for replacing cement. For the calcination process, temperatures between 600 °C and 800 °C were the most suitable. The results proved that the replacement of cement by CDW in pastes resulted in suitable behavior for the construction industry, having revealed an incorporation content of up to 25% CDW, a compressive strength and strength activity index higher than that found for pastes developed with fly ash. Regarding the calcination process, this revealed an improvement in the compressive strength of the developed pastes, resulting in an increase in strength activity index of between 7 and 10%. Full article

The combustion of hard coal and lignite in power and combined heat and power plants generates significant amounts of coal fly ash (CFA), a waste material with variable properties. CFA naturally contains radionuclides, specifically naturally occurring radioactive materials (NORMs), which pose potential radiological risks to the environment and human health during their storage and utilization, including their incorporation into building materials. Although global research on the radionuclide content in CFA is available, there is a clear gap in detailed and current data specific to Central and Eastern Europe and notably, a lack of a systematic analysis investigating the influence of installed power plant capacity on the concentration profile of these radionuclides in the generated ash. This study aimed to fill this gap and provide crucial data for the Polish energy and environmental context. The objective was to evaluate the concentrations of selected radionuclides (²³²Th, ²²⁶Ra, and ⁴⁰K) in coal fly ash samples collected between 2020 and 2023 from 19 Polish power and combined heat and power plants with varying capacities (categorized into four groups: S1–S4) and to assess the associated radiological risk. Radionuclide concentrations were determined using gamma spectrometry, and differences between groups were analyzed using non-parametric statistical methods, including PERMANOVA. The results demonstrated that plant capacity has a statistically significant influence on the concentration profiles of thorium and potassium but not radium. Calculated radiological hazard assessment factors (Ra_eq, H_ex, H_in, IAED) revealed that although most samples fall near regulatory limits (e.g., 370 Bq kg⁻¹ for Ra_eq), some exceed these limits, particularly in groups S1 (plants with a capacity less than 300 MW) and S4 (plants with a capacity higher than 300 MW). It was also found that the frequency of exceeding the annual effective dose limits (IAEDs) showed an increasing trend with the increasing installed capacity of the facility. These findings underscore the importance of plant capacity as a key factor to consider in the radiological risk assessment associated with coal fly ash. This study’s outcomes are crucial for informing environmental risk management strategies, guiding safe waste processing practices, and shaping environmental policies within the energy sector in Central and Eastern European countries, including Poland. Full article

The Iberian Pyrite Belt (IPB) contains the world’s largest massive sulfide deposit, and, due to extensive mining developed during the last 200 years, large amounts of mining waste have been abandoned in this area, with roasted pyrite ash being the focus of this study. Polymetallic mining is also classified as a NORM (naturally occurring radioactive material) activity, thus the main objective of this work was to develop a radiological and physicochemical characterization of this waste (mineral phases, elemental and radionuclide concentrations) in order to perform a valorization diagnosis of this material. The composition of this waste strongly depends on its origin (mine), and is mainly formed by iron oxides (hematite, Fe₂O₃) and heavy metals and metalloids such as As, Pb, Zn, and Cu, in levels 2–4 orders of magnitude higher than those of undisturbed soils, depending on each particular element. However, the average natural radionuclide levels are similar to those of unperturbed soils (around 30 Bqkg⁻¹ of ²³⁸U-series, 50 Bqkg⁻¹ of ²³²Th, and 70 Bqkg⁻¹ for ⁴⁰K), thus they are below the limits established by European Union regulations to require radiological control during their future valorization. As the main potential applications of roasted pyrite ash, the valorization diagnosis indicates that it can be used as a source of Fe (FeCl₃ or FeSO₄), or an additive in the manufacturing of cements, pigments, etc. Full article

Consumers’ growing concern about sustainability and health affects their food choices as long as there is acceptance in terms of sensory aspects. The challenge of finding new sustainable food sources with a smaller ecological footprint makes seaweed a candidate for human consumption, considering that they are poorly exploited marine food resources in European countries. Therefore, this study aimed to evaluate the effect of the inclusion of different seaweeds (wakame and sea spaghetti) in three traditional Portuguese recipes, namely octopus salad (SP and SPW), monkfish rice with prawns (AT and ATW) and stewed cuttlefish with white beans and clams (FC and FCE), regarding their acceptance and nutritional aspects. Sensory and physicochemical analyses were carried out using reference methods. The results showed that the modified recipes with seaweeds (SPW, ATW, and FCE) were well accepted by a nontrained sensory panel and did not change nutritional aspects in terms of macronutrient content, ash, and sodium. However, the inclusion of wakame contributed to an increase in the potassium content in octopus salad (SPW) and monkfish rice (ATW). In short, sensory results highlighted the potential for seaweed inclusion in Portuguese traditional recipes without compromising its identity. Future work should evaluate the partial substitution of fish/mollusks with seaweed in traditional recipes to improve the sustainability and nutritional contribution of these recipes. Full article

Fraxinus angustifolia, the main ash species in Croatia in terms of economic and ecological importance, is affected by a severe dieback initially attributed to the fungal pathogen Hymenoscyphus fraxineus. Recently, another pathogen, Diplodia fraxini, has been shown to play a key role in ash dieback in several European countries. Therefore, because the dieback symptoms of ash trees observed in Croatia are typical of Botryosphaeriaceae attacks, the aim of this study was to define the etiology of F. angustifolia dieback. To this end, symptomatic shoots and branches and cross-sections of the main stem were sampled from 20 symptomatic trees at eight locations and analyzed for the presence of D. fraxini and other possible fungal pathogens. Diplodia fraxini was the fungus most frequently associated with branch cankers and dieback; it was isolated from 17 trees in all sites monitored, and its pathogenicity towards F. angustifolia was confirmed. The fungus was also associated with wood necrosis at the base of the trunk in two trees. Other fungi, namely H. fraxineus, Diaporthe eres, Diplodia seriata, Botryosphaeria dothidea, Armillaria gallica, and Lentinus tigrinus, were isolated sporadically. Full article

The characterization of historical tailings bodies is crucial for optimizing environmental management and resource recovery efforts. This study investigated the Bielatal tailings dam (Altenberg, Germany), examining its internal structure, material distribution influenced by historical flushing technology, and the spatial distribution of valuable elements. To evaluate the tailings resource potential, drill core sampling was conducted at multiple points at a depth of 7 m. Subsequent analyses included geochemical characterization using sodium peroxide fusion, lithium borate fusion, X-ray fluorescence (XRF), and a scanning electron microscope with energy dispersive X-ray spectroscopy (SEM-EDX). Particle size distribution analysis via a laser particle size analyzer and wet sieving was conducted alongside milieu parameter (pH, Eh, EC) analysis. A theoretical assessment of the tailings’ potential for geopolymer applications was conducted by comparing them with other tailings used in geopolymer research and relevant European standards. The results indicated average concentrations of lithium (Li) of 0.1 wt%, primarily hosted in Li-mica phases, and concentrations of tin (Sn) of 0.12 wt%, predominantly occurring in cassiterite. Particle size analysis revealed that the tailings material is generally fine-grained, comprising approximately 60% silt, 32% fine sand, and 8% clay. These textural characteristics influenced the spatial distribution of elements, with Li and Sn enriched in fine-grained fractions predominantly concentrated in the dam’s central and western sections, while coarser material accumulated near injection points. Historical advancements in mineral processing, particularly flotation, had significantly influenced Sn distribution, with deeper layers showing higher Sn enrichment, except for the final operational years, which also exhibited elevated Sn concentrations. Due to the limitations of X-ray fluorescence (XRF) in detecting Li, a strong correlation between rubidium (Rb) and Li was established, allowing Li quantification via Rb measurements across varying particle sizes, redox conditions, and geological settings. This demonstrated that Rb can serve as a reliable proxy for Li quantification in diverse contexts. Geochemical and mineralogical analyses revealed a composition dominated by quartz, mica, topaz, and alkali feldspars. The weakly acidic to neutral conditions (pH 5.9–7.7) and reducing redox potential (Eh, 570 to 45 mV) of the tailings material indicated a minimal risk of acid mine drainage. Preliminary investigations into using Altenberg tailings as geopolymer materials suggested that their silicon-rich composition could serve as a substitute for coal fly ash in construction; however, pre-treatment would be needed to enhance reactivity. This study underscores the dual potential of tailings for element recovery and sustainable construction, emphasizing the importance of understanding historical processing techniques for informed resource utilization. Full article

Freshwater fish species play an important role in global aquaculture. Currently, sturgeon, carp, and tilapia are at the forefront of this industry. However, as human populations continue to grow, the demand for new sources of animal protein increases, making the use of other freshwater species in aquaculture essential. The pikeperch (Sander lucioperca) is one of the most promising fish species for European aquaculture, but its usage has been hindered by a lack of effective larval-rearing protocols. Most studies focus on using cultured or nutrient-rich zooplankton for larval cultivation, while natural zooplankton from the local environment are rarely used. In this study, we aim to investigate the nutritional requirements of pikeperch larvae by describing the taxonomic diversity and biochemical composition of zooplankton collected from a natural oligotrophic lake in Northwest Russia. The chemical composition of zooplankton is characterized by a high protein content (up to 70% of dry matter), a moderate lipid content (up to 25%), and a deficiency of certain fatty acids and amino acids. Specifically, there is a low concentration of docosahexaenoic acid and methionine. The dry matter content in the zooplankton averages 10%, with nitrogen-free extracts accounting for 4% and ash making up 4%. These biochemical parameters meet the nutritional requirements of freshwater pikeperch larvae, with the notable exception of the lower levels of DHA and methionine, which are typically characteristic of freshwater zooplankton. This information sheds light on the nutritional requirements of pikeperch larvae and the development of more efficient rearing methods. Full article

The high consumption of concrete makes it a priority target for environmental goals. When supplementary cementing materials were introduced, important progress was made toward achieving these goals, with fly ash (FA) making a major contribution in this regard. Given the current situation, it has become necessary to identify an alternative to this material as a result of the shutdown of coal-fired power plants across the European Union. In this sense, glass powder (GP) has shown promising results. This research focused on reducing the dosage of Portland cement (PC) as extensively as possible in concrete formulations, through high incorporations (until 70%) with different dosages of binder to evaluate various applications without compromising its strength and durability. The results obtained are encouraging. With only 150 kg/m³ of PC, 46.42 MPa was obtained, and with 250 kg/m³ of PC, 71.50 MPa was obtained, both at 90 days. Durability was not significantly compromised in the tests carried out and even obtained better results in some tests. The findings suggest that a substantial replacement of PC with GP could serve as a feasible option for lowering the PC content or even substituting FA, promoting a reduction in CO₂ emissions and energy consumption, and making concrete more sustainable. Full article

Many ecosystems have been altered since European colonization, resulting in the loss of historical ecosystems along with information about historical ecosystems. Tree density estimation from historical land surveys with alignment to expert classifications of historical vegetation strengthen reconstructions of vegetation history through research triangulation. For the midwestern United States, we extended historical tree density estimates (≥12.7 cm in diameter) to contextualize expert classifications of vegetation types in Illinois and Minnesota, part of the historical Great Plains grasslands with very frequent fire exposure, and Indiana and southern Michigan, which were more protected from fire. We also identified a tree density threshold between grasslands and savannas and contrasted density estimates with two alternate density estimates. After refining expert-classified vegetation types, out of 14 major historical ecosystems in this region, 11 were grasslands, savannas, or woodlands. The three additional ecosystems were American beech (Fagus grandifolia) closed woodlands and forests in Indiana and American beech-oak (Quercus) closed woodlands and forests and tamarack (Larix laricina) and ash (Fraxinus) swamp forests in southern Michigan. Because tree densities in the grasslands of Illinois and Minnesota did not exceed 4 trees/ha and tree densities in the savannas of Indiana, Michigan, and Minnesota ranged from 23 trees/ha to 78 trees/ha, around 15 trees/ha may be a reasonable threshold between grasslands and savannas. Density estimates generally matched with two other sources of density estimates, despite using different approaches, supporting the reliability of density estimation. Anchoring density estimates from land surveys to other sources of historical vegetation establishes the validity of density estimation, while supplementing expert-classified ecosystems. Full article

Forest wood biomass is a key renewable resource for advancing energy transition and mitigating climate change. This review analyzes the physicochemical properties of forest biomass from major European tree species to assess their suitability for bioenergy applications. This study encompasses key parameters, such as moisture content, ash content, volatile matter, fixed carbon, elemental composition, bulk density, and energy content (HHV and LHV). This review analyzed data from 43 publications and extracted 140 records concerning the physicochemical properties of the most common European forest species used for bioenergy. The most commonly represented species were Quercus robur, Eucalyptus spp., and Fagus sylvatica. Moisture content, referring to fresh matter, ranged from 5% to 65%; ash content, referring to a dry basis, ranged from 0.2% to 3.5%; and higher heating value (HHV), referring to dry matter, ranged from 17 to 21 MJ kg⁻¹. This study highlights variability among species and underscores the importance of standardizing biomass characterization methods and the scarcity of data on bulk density and other key logistical parameters. These findings emphasize the need for consistent methodologies and species-specific selection strategies to optimize sustainability and efficiency in forest biomass utilization for bioenergy. Full article