Search Results (264)

Construction and demolition activities generate over one-third of all waste produced within the European Union, with the largest fraction being mineral materials, and concrete representing up to 90% of this volume. In this context, the recycling of this type of waste is an important research topic with growing scientific and industrial relevance. While numerous studies have examined the influence of recycled concrete and other industrial waste on the technical performance of Portland cement-based composites, the antimicrobial resistance of these composites remains largely unexplored. Therefore, in this study we evaluate the effects of three different waste materials on the key properties of Portland cement mortar, as well as on its antimicrobial resistance; the investigated waste materials were fly ash (produced in thermal power plants), recycled concrete fines resulted from the mechanical processing of concrete waste generated in construction and demolition activities, as well as dried concrete slurry (a byproduct of concrete batching plants). The partial replacement of Portland cement with these concrete wastes slightly increased the mortar’s workability (up to 4.6%). However, it also led to an 11–12% reduction in compressive strength after 28 days of hardening. After 60 days of curing, the antimicrobial properties of these mortars were evaluated by assessing their effect on planktonic microbial growth and their anti-adherent capacity against the most common pathogenic strains (S. aureus, E. coli, P. aeruginosa, C. albicans, and C. parapsilosis). Antimicrobial assays were performed at two different concentrations of microbial suspensions, and the mortars exhibited significant antibiofilm properties against all strains, especially against E. coli. The study identified mortar formulations in which partial replacement of cement with construction, demolition, and industrial waste materials resulted in compressive strength and antimicrobial resistance comparable to those of conventional reference mortars. These findings highlight the potential to integrate recycled waste into Portland cement-based materials, supporting both structural integrity and microbial resistance and advancing sustainable construction practices. Full article

Food waste poses significant environmental, economic and public health challenges. The black soldier fly (Hermetia illucens) larvae (BSFL) represent a promising solution for organic waste valorisation, converting substrates into protein-rich biomass for animal feed and organic fertiliser. However, the use of food waste as an insect substrate remains prohibited in the European Union due to regulatory and safety concerns. This study evaluated the suitability of heterogeneous food waste for BSFL rearing under industrial conditions by comparing larval performance on a standard Gainesville diet (control) and a blend derived from local restaurant waste (test). The 14-day bioconversion assay assessed bioconversion rate (BCR), feed conversion ratio (FCR), survival rate, average growth rate, and nutritional composition. Compared with the control, the test group showed significantly improved (p < 0.001) BCR (18.34% vs. 11.02%), FCR (5.48 vs. 9.09 kg/kg), survival (69.29% vs. 51.30%), and growth (8.38 vs. 6.59 mg/day). Larvae reared on food waste also exhibited significantly higher protein (19.70% vs. 16.80%), fat (13.70% vs. 7.20%), ash (6.97% vs. 3.51%), carbohydrates (7.00% vs. 3.60%), and fibre (5.20% vs. 2.90%). Overall, heterogeneous food waste is a suitable substrate for BSFL, supporting agrifood sustainability; however, future research should focus on standardisation of these substrates. Full article

Wood ash from biomass power plants and coarse, low-grade sheep wool from farming are underutilized biowastes that are often landfilled. Their valorization could reduce waste and emissions, decrease reliance on virgin materials, and support the circular economy and European Green Deal targets. However, both materials may contain naturally occurring radionuclides, primarily ⁴⁰K, as well as trace uranium and thorium isotopes, with higher concentrations typically found in wood ash due to combustion processes. Assessing their activity concentrations and bioavailability is therefore essential to ensure regulatory compliance and protect public health. This study quantified radionuclide levels in wood ash and sheep wool samples collected in Croatia and evaluated their suitability for agricultural applications. Natural radionuclides (⁴⁰K, ²³²Th, ²³⁸U, ²¹⁴Pb, ²¹⁴Bi, ²²⁶Ra, ²¹⁰Pb, ²¹⁰Po) and ¹³⁷Cs were determined using high-resolution gamma-ray and alpha spectrometry. The influence of different factors on radionuclide content was discussed, and transfer factors within the soil–hay–wool pathway were calculated to assess bioavailability. Measured activity concentrations were consistently low, and transfer factors indicated minimal radionuclide mobility. The results support the safe agricultural reuse of these materials and provide baseline data for radiological safety assessments in sustainable waste management practices. Full article

Ash dieback, caused by the fungus Hymenoscyphus fraxineus, continues to threaten European ash (Fraxinus excelsior), yet the contribution of the leaf microbiome to disease severity remains poorly understood. We surveyed 133 ash trees across nine sites in Northern Ireland, using canopy cover as a proxy for health, and characterised leaf-associated microbial communities using Pacific Biosciences (PacBio) long-read amplicon sequencing (full-length 16S and ITS) and QIIME2-based workflows. Many trees exhibited partial tolerance to ash dieback, with most maintaining stable canopy cover year-on-year, while fewer trees show a decline and a smaller portion showing improvement. Microbial communities were largely stable irrespective of ash health with little difference in alpha diversity (Shannon) or beta diversity (Bray–Curtis PERMANOVA) for either bacteria or fungi. Differential abundance and correlation analyses showed that H. fraxineus was, as expected, negatively associated with canopy cover. Only one fungal species, Papiliotrema flavescens, demonstrated a strong positive association with healthier trees, consistent with previous findings. These results indicate that Northern Ireland hosts a reservoir of ash trees displaying tolerance to ash dieback. While the leaf microbiome does not appear to drive this tolerance at the community level, one fungus, P. flavescens, was correlated with healthier ash. Full article

Maize silage can play a key role in policies aimed at stabilising local energy systems, as it constitutes a critical renewable feedstock for European biogas plants. By providing a dense and predictable source of chemical energy, it supports balance and reliability in the agricultural energy sector. To convert this potential into stable energy production, operators require kinetic models that translate routine silage quality indicators into concrete guidance for digester operation and control. Therefore, the aim of this article was to evaluate the batch kinetics of anaerobic digestion (AD) of maize silage and to select an adequate model for describing biochemical methane potential (BMP) profiles and associated energy recovery in the context of start-up, organic loading rate (OLR), hydraulic retention time (HRT) and feedstock preparation. Ten batches of silage (A–J) were examined, covering a realistic range of pH, electrical conductivity (EC), dry and volatile solids, ash, protein–fat–fibre fractions, fibre composition (NDF, ADF and ADL), derived fractions (hemicellulose, cellulose, and residual organic matter (OM)), C/N ratio and macro-/micronutrient profiles, including trace elements relevant to methanogenesis (Ni, Co, Mo, and Se). BMP tests were carried out in batch mode, and the resulting curves were fitted using the modified Gompertz and a first-order kinetic model. Methane yields of approx. 100–120 m³ CH₄/Mg fresh matter (FM) and 336–402 m³ CH₄/Mg volatile solids (VS), with CH₄ contents of 52–57% v/v, were typical for energy-grade maize silage. Kinetic and energetic behaviours were governed mainly by residual OM and hemicellulose (shortening the lag phase and increasing the maximum methane production rate), the ADL/cellulose ratio (controlling the slower hydrolytic tail), EC and Na/Cl/S (extending the lag phase), and C/N together with Ni/Co/Mo/Se (stabilising methanogenesis). The modified Gompertz model reproduced BMP curves with a pronounced lag phase and asymmetry more accurately (lower error and better information criterion values), and its parameters directly support start-up design, OLR ramp-up and energetic performance optimisation in bioenergy reactors. The novelty of this work lies in combining batch BMP tests, comparative kinetic modelling and detailed silage characterisation to establish quantitative links between kinetic parameters and routine maize silage quality indicators that are directly relevant for biogas plant operation and renewable energy production. Full article

Hymenoscyphus fraxineus is the causal agent of ash dieback, a devastating disease of European ash (Fraxinus excelsior). Although the pathogen is believed to have originated in East Asia and has been confirmed in Japan, European ash trees cultivated in the Sapporo Experimental Forest of Hokkaido University remain asymptomatic despite the presence of H. fraxineus. In this study, we investigated the early infection behavior of H. fraxineus and associated host defense responses by comparing asymptomatic F. excelsior with the susceptible control species F. angustifolia. Leaflets were inoculated with ascospores, and fungal development as well as host responses were examined microscopically during early infection stages. In addition, we analyzed the accumulation of selected coumarins, which have been proposed as candidate compounds associated with ash dieback tolerance, and assessed their effects on ascospore germination. We found that fungal growth was consistently restricted on F. excelsior at 7 days post inoculation, particularly at the stage of invasion into adjacent epidermal cells. Fraxetin was detected in F. excelsior leaflets but not in F. angustifolia, and fraxetin treatment significantly reduced ascospore germination in vitro. While typical markers of induced resistance were not clearly detected at the examined time points, these results indicate that constitutive chemical traits, including fraxetin accumulation, may contribute to early-stage suppression of H. fraxineus growth in F. excelsior. Together, our findings provide insight into early host–pathogen interactions associated with ash dieback tolerance and highlight the potential role of constitutive defenses during initial infection. Full article

Sustainability and nearly zero-energy consumption of new and existing buildings is a keystone in the new guidelines established by the European Commission. Likewise, waste management is in the focus of reducing the impact of industrial processes. The use of industrial byproducts, such as biomass ashes (BA), can be an interesting solution for waste valorization, reducing the carbon footprint and enhancing sustainability. In addition, Phase Change Materials (PCMs) can be used for improving energy efficiency due to their thermal storage capacity. An experimental study on the effect of biomass ash (BA) and PCM on the microstructure, chemical, physical and mechanical properties of cement–lime pastes was carried out. The partial replacement of cement with BA reduced compressive strength although did not substantially modify other paste properties, while the addition of PCM had a huge impact on microstructure and, therefore, physical and mechanical properties. PCM had a remarkable effect on thermal properties, endowing thermal storage capacity and reducing thermal conductivity, and the combination with BA further improved paste thermal properties. Full article

This study assessed the production and characterisation of biochars derived from the pyrolysis and co-pyrolysis of urban biosolids (BSs) combined with two lignocellulosic biomasses: rice husk (RH) and pruning waste (PW). The treatments were conducted at 300, 400, and 500 °C to evaluate the influence of temperature and mass ratio on the physicochemical, structural, and biological properties of the material. Co-pyrolysis significantly improved the material’s properties, enhancing carbon content, surface area, porosity, and pH, while reducing ash and heavy metal concentrations. RH promoted greater porosity and alkalinity, whereas PW increased carbon content and improved maize germination. Biochars produced at 400–500 °C met the stability criterion (H/C < 0.7) set by the International Biochar Initiative (IBI) and the European Biochar Certificate (EBC). However, zinc (Zn) remained the most limiting element for certification. Overall, the findings demonstrate that the co-pyrolysis of BSs with agroforestry biomasses is an effective and sustainable strategy for generating stable and environmentally safe biochars, suitable for use as soil amendments and for the sustainable valorisation of BSs. Full article

Preserving Peruvian cacao germplasm requires preventing the spread of pathogens such as viruses, yet cacao viral diseases in Peru remain poorly studied. In this study, we characterized the viral sequences associated with native cacao trees from the department of Amazonas, northwestern Peru. Leaf samples from two symptomatic plants (mosaic, yellowing, leaf deformation) and one asymptomatic plant were collected from the cacao germplasm bank of the Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas. RNA high-throughput sequencing identified four RNA segments consistent with the genus Emaravirus: RNA1 (7142 nt; replicase P1), RNA2 (2225 nt; glycoprotein P2), RNA3 (1269 nt; nucleocapsid P3), and RNA4 (1286 nt; movement protein P4), sharing 32.6–45.9% amino acid identity with European mountain ash ringspot-associated emaravirus (EMARaV). Phylogenetic analysis of P1–P4 proteins placed this virus in a distinct lineage, confirming it as a novel species, Theobroma cacao emaravirus A (ThCEV-A). Specific RT-PCR detected ThCEV-A in 11 additional accessions, with symptoms including yellow mosaic and mottling. This study documents for the first time the presence of a novel Emaravirus in cacao, highlighting the need to assess its epidemiology, vector(s), and potential impact on cacao production in its center of origin. Full article

Mt. Etna is the highest and most active stratovolcano in Europe, located in Catania (Sicily, Italy). Its persistent degassing, frequent explosions, and lava flows release large amounts of ash and gases into the atmosphere. This study aimed to assess whether chronic exposure to local volcanic emissions leads to an increased internal dose of trace elements (As, Ba, Be, Bi, Cd, Co, Cr, Cu, Hg, Li, Mn, Mo, Ni, Pb, Sb, Se, Sn, Sr, Tl, U, V, W, Zn) in Catania adult residents. To this end, urine samples were collected from 167 individuals residing in Catania and compared with 193 residents of other Sicilian areas located farther from the volcano. Results revealed significantly higher urinary concentrations of As, Hg, Mn, Pb, and Tl in the exposed group, suggesting volcanic activity as a relevant source of exposure. The levels of the other elements were instead affected by other factors such as lifestyle habits and the consumption of specific foods and beverages. The urinary concentrations of trace elements were consistent with reference values reported in other European studies, and the levels remained well within the health-based guidance values. There is evidence of an increased internal dose of a few elements in the Sicilian population exposed to volcano activity, but the observed increases are unlikely to pose a significant health risk. Full article

This study evaluated the physicochemical properties and sensory acceptance of third-generation, potato-based, extruded snacks enriched with mushroom powder (5% and 10%) across different European regions. The mushroom powder was produced from dried button mushrooms (Agaricus bisporus), ground and incorporated into the snack formulations, while control samples contained no mushroom powder. The investigation was conducted in Denmark, Poland, and Spain, involving 230 young adult consumers identified as the target demographic for this snack format. Incorporation of mushroom powder increased protein, fiber, ash, polyphenols, and antioxidant capacity while producing a darker color and crisper texture. Consumer acceptance varied across countries and was significantly influenced by individual differences in food involvement, neophobia, sustainability orientation, and dietary habits. Participants with greater health consciousness and sustainability engagement expressed a higher preference for snacks with greater levels of mushroom enrichment. Overall, moderate mushroom addition (5–10%) provides an optimal balance between enhanced nutritional quality, favorable sensory attributes, and broad consumer appeal, underscoring the potential of mushrooms as sustainable functional ingredients in snack product development. Full article

The Common European ash (Fraxinus excelsior L.) is one of the main species constituting the field protection forest belts in Northeastern Bulgaria. Studies conducted in shelterbelts in Dobrich and Balchik in July 2020 and in Tutrakan and Dulovo in June–July 2022 revealed severe dieback of ash. The observed symptoms included density thinning of the crowns, dieback of branches, presence of sunken necrotic cankers, and light green to yellow foliage and premature defoliation. Parts of the shelterbelts were completely destroyed with 100% tree mortality. To determine whether the invasive Hymenoscyphus fraxineus or other pathogens are present in the ash field protective forest belts in Northeastern Bulgaria, fungal isolation was undertaken. Samples were collected from four locations: Dobrich and Balchik in June 2020, and Tutrakan and Dulovo in June–July 2022. The morphology, temperature–growth rate relationships, and pathogenicity of the two pathogenic fungal species isolated in this study—Diplodia fraxini and Diplodia seriata—were examined. Morphological and physiological studies confirm the molecular identification of the obtained plant pathogens. The Diplodia fraxini isolates (Dobrich 3, Tutrakan 2, and Dulovo 4) showed mycelial growth between 5 °C and 35 °C, with minimal growth at 5 °C (0.20–0.27 mm/day) and an optimum growth rate of 3.9–4.5 mm/day at 20–25 °C. Growth declined sharply above 30 °C, ceasing entirely at 35 °C. In contrast, D. seriata (Dulovo 5) exhibited higher growth rates, showing limited growth above 5 °C (~1 mm/day), and maximum growth of approximately 8 mm/day at 25 °C. Growth in D. seriata remained moderate up to 35 °C and ceased near 40 °C, indicating a broader temperature tolerance and higher upper thermal limit than D. fraxini. The results from the pathogenicity tests show that D. fraxini can cause necrosis on ash—both on leaves and twigs—and is likely involved in the investigated ash decline cases. Further studies of the spread and epidemiology of D. fraxini are needed in order to establish its occurrence on the territory of Bulgaria. Full article

Large amounts of wood waste fly ash (WWFA) are generated in bioenergy plants, yet their potential for reuse in construction materials remains underexplored. In this study, artificial lightweight aggregates (ALWAs) were produced by cold-bonded granulation of WWFA with hydrated lime, followed by carbonation curing (20 °C, 64% RH, 19% CO₂). The aggregates were evaluated according to EN 13055:2016 classification criteria, with testing performed following the relevant European standards, including EN 1097-3 and EN 1097-6 for density and water absorption, EN 1097-11 for crushing resistance, and EN 1367-7 for freeze–thaw resistance. All ALWAs met the lightweight aggregate classification, with bulk densities of 1010.9–1060.0 kg/m³ and crushing resistances up to 2.74 N/mm², exceeding that of lightweight expanded clay aggregate (LECA) (1.26 N/mm²). XRD confirmed CaCO₃ formation, SEM revealed binder- and w/m-dependent porosity and crystal morphology, and freeze–thaw resistance indicated suitability for non-structural applications. These results demonstrate that WWFA-based ALWAs are a sustainable alternative to natural aggregates, combining waste valorization with competitive performance. Full article

Needle cast (Lophodermium seditiosum Minter, Staley & Millar) in Scots pine (Pinus sylvestris L.) and European ash (Fraxinus excelsior L.) dieback (Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz & Hosoya) are among the most destructive forest and tree plantation diseases in Europe, threatening not only targeted plant species but also the whole ecosystem. While considerable research effort has focused on microbial antagonists against ash dieback, comparable investigations into needle cast biocontrol remain virtually absent from the literature. Here, isolated microbial antagonists from European ash and Scots pine were evaluated for their efficacy against respective pathogens. In vitro dual-culture assays revealed bacteria with strong inhibitory effects on pathogen growth, as well as multiple plant growth-promoting traits (PGPTs). It was found that bacteria from the genera of Pantoea, Erwinia, Priestia, and Pseudomonas inhibited the growth of H. fraxineus by ≥70%. Most significantly, our investigation revealed that bacteria isolated from Scots pine, belonging to the genera Pseudomonas, Bacillus, and Priestia, inhibited the growth of L. seditiosum by 50% to 80%, representing one of the first reported bacterial antagonisms for this neglected pathogen. All isolates were positive for at least two PGPTs, primarily due to mineralization of organic phosphate and the production of siderophores. The dual functional traits of isolated bacteria highlight their potential application in integrated forest protection strategies, particularly for the previously overlooked L. seditiosum pathosystem. Full article

The construction industry is one of the largest consumers of resources and a significant contributor to environmental degradation in Europe, accounting for 50% of natural resource use, 34% of waste generation, and 5–12% of greenhouse gas emissions. In response to growing environmental pressures and regulatory demands, the sector needs to adopt sustainable material alternatives. This study examines the potential adoption of rice straw ash in the European construction sector. The research applies a PRISMA-based systematic literature review, integrated with the Multi-Level Perspective (MLP) framework, PESTLE, and SWOT analyses to provide a comprehensive assessment of the socio-technical dynamics influencing its adoption. The findings identify barriers including the absence of standards, fragmented supply chains, and inconsistent material quality. However, it highlights strategic opportunities such as the declining availability of conventional SCMs, alignment with the EU’s regulations and circular economy principles, and growing public awareness of sustainable materials. The study concludes that advancing the transition to RSA will require regulatory support, the development of standards, and coordinated collaboration among stakeholders to achieve large-scale implementation. By integrating multi-dimensional transition factors, this research contributes actionable insights for advancing sustainable material adoption. Full article