Search Results (157)

This study investigated the valorization of keratin extracted from sheep wool waste for the preparation of PLA/SBS/Keratin composites as potential adsorbents for the removal of chromium (Cr) from synthetic water. A flexible formulation containing 75 wt% PLA and 25 wt% SBS was selected for the incorporation of 10 wt%, 20 wt%, and 30 wt% keratin. The morphology and structural characteristics of keratin and PLA-based composites were analyzed using SEM and FT-IR spectroscopy. The mechanical and thermal properties of the prepared composites were investigated using TGA and DMA analyses. The adsorption experiments revealed that keratin exhibited an adsorption capacity of 57.57 mg g⁻¹ of Cr(VI) removal efficiency, while the PLA/SBS formulation containing 10 wt% keratin achieved a removal efficiency of total Cr of 55.41%. After three regeneration cycles, the removal efficiency decreased by approximately half of the total Cr removal. Full article

Blended polyester (PET)-based textiles comprise a significant portion of post-consumer waste, posing substantial challenges to circular economy initiatives while contributing to microfiber (MF) pollution. Despite the considerable recycling potential of PET textiles, no commercially viable technologies currently exist that can efficiently separate and recycle blended PET-based textile waste on an industrial scale. This review provides a comprehensive analysis of recycling strategies for post-consumer blended PET-based textiles and their subsequent valorization pathways. Mechanical, chemical, and biological recycling processes are mostly not yet market-ready, although chemical approaches are considered particularly promising. The findings highlight a critical need for advanced sorting technologies, enhanced material traceability, and robust MF mitigation strategies to foster circularity and contribute to the United Nations Sustainable Development Goals (SDGs). The results further indicate that mechanical recycling of blended PET textiles leads to significant MF release due to fiber fragmentation, whereas chemical recycling offers the potential for improved material recovery, but remains limited by high energy demand and solvent-related challenges. While closed-loop approaches support true circularity by maintaining textile-to-textile material flows, open-loop pathways repurpose textile waste for high-value non-textile applications. Full article

This study focuses on the evaluation of eco-friendly corrosion inhibitors derived from extracts of Rhus typhina L. leaves, collected in August during the summer season, on OLC45 metal surfaces in a 0.5 M H₂SO₄ corrosive environment. The extracts were obtained using the microwave extraction technique and characterized by HPLC. The protective properties of OLC45 coated with LESRT (leaf extract collected in summer from Rhus typhina L.) were examined by potentiostatic and potentiodynamic polarization procedures and electrochemical impedance spectroscopy (EIS) in 0.5 M H₂SO₄. The application of the Langmuir isotherm revealed high values of the adsorption constant and standard free energies (ΔG°_ads), suggesting a possible mixed adsorption process with an increased tendency toward chemisorption. The influence of temperature on the electrochemical behavior of OLC45 samples in H₂SO₄, both in the absence and presence of two extracts derived from Rhus typhina leaves at a concentration of 1000 ppm, was investigated over the temperature range of 293–333 K. A comparison of the two inhibitors’ effectiveness revealed high inhibitory efficiency, up to 91% at 1000 ppm LESRT₁ (methanol/double-distilled water (50%:50%, v/v)) and 92% for LESRT₂ (ethanol/double-distilled water (50%:50%, v/v)) at 1000 ppm LESRT₂. Full article

The combination of Fourier-transform infrared (FTIR) spectroscopy and machine learning gives a promising result in wheat variety classification. This study aimed to evaluate the contributions of distinct spectral regions and their combinations to classification performance. Out of the full raw spectra of four bread wheat varieties, namely Altindane, Cavus, Flamura-85, and Nevzatbey, 15 spectral datasets were prepared. Artificial Neural Networks (ANN), Support Vector Machines (SVM), Random Forest (RF), and K-Nearest Neighbor (KNN) models were trained and analyzed. The highest classification performance was obtained using spectral regions associated with protein and lipid bands. The highest average accuracy of 0.9895 was shown by the SVM model, while the ANN produced comparable results with lower variability. Additionally, Variable Importance in Projection (VIP) analysis identified the most influential spectral bands in the protein (Amide II, ~1542 cm⁻¹) and carbonyl (1744–1715 cm⁻¹) regions. These findings indicate that classification is driven by chemically meaningful features rather than purely statistical patterns. The approach followed in this study provides an insight that, in FTIR-based classification, when rigorously evaluated using nested cross-validation, spectral region selection can outweigh model complexity. This approach demonstrates strong potential for rapid and non-destructive assessment, especially for real-time applications in grain processing and automated sorting systems. Full article

This study proposes and evaluates a specialized Recreational Water Quality Index (IR-WQI) designed to prioritize the bathers’ safety and comfort. Focusing on the Năvodari–Mamaia sector (2022–2024), the research investigates how different weighting configurations—prioritizing either microbiological safety or physicochemical stability—affect the accuracy of bathing water assessments. The IR-WQI was tested across four scenarios, comparing the sensitivity of a specialized pH-based “bather-comfort” penalty function against models that include salinity as a weighted constant. Results demonstrate high categorical stability, with 93.3% of monitoring sites maintaining their qualitative classification regardless of the weighting scheme. However, the inclusion of salinity was found to inflate quality scores, potentially masking fecal contamination at vulnerable sites. Scenario 1, which prioritizes microbiological indicators (60% weight) and incorporates a pH filter, provides a transparent and conservative diagnostic tool for coastal managers, thereby supporting sustainable tourism and informed decision-making for beach safety. Full article

Spent coffee grounds (SCGs) are one of the most abundant agro-industrial by-products worldwide, with 650 kg generated per ton of green coffee processed, corresponding to an estimated global production of 6.7 million tons in 2022/2023. Improper disposal of SCG raises environmental concerns, while their reuse offers opportunities for sustainable resource management and circular economy strategies. This review examines SCG valorization by addressing their chemical composition, functional properties, and key applications in sectors such as food, agriculture, environmental remediation, bioenergy, and selected industrial fields, including pharmaceuticals, cosmetics, construction materials, and functional devices. In this context, it discusses technological approaches, performance outcomes, and implementation considerations, emphasizing the multifunctional potential of SCGs as a renewable feedstock capable of reducing waste, improving resource efficiency, and generating economic value. By consolidating the current state of knowledge and exploring diverse valorization pathways, this work frames SCG utilization within a circular bioeconomy framework and highlights how innovative applications can transform this widely available waste into sustainable and economically valuable products. Full article

Agri-food processing in Europe generates large quantities of organic residues that remain insufficiently valorized despite their significant biochemical potential. Among these, wastes derived from root vegetables and anthocyanin-rich crops represent a distinct category of non-lignocellulosic biomass characterized by high moisture content, low lignin levels, and substantial concentrations of fermentable carbohydrates and bioactive compounds. This review provides a systematic overview of the origin, composition, and valorization potential of these residues, as well as extraction methods, with particular emphasis on root vegetable processing wastes and pigment-rich agri-food by-products. Valorization options are discussed within an integrated biorefinery perspective, particularly for specific compositional characteristics of the investigated waste streams related to suitable recovery strategies, followed by the conversion of post-extraction residues into secondary products and bioenergy. These options are evaluated in relation to the origin, biochemical profile, and valorization potential of each waste stream, as detailed in the dedicated sections of the review. Cascading utilization strategies are highlighted as a means to improve resource efficiency and reduce environmental burdens compared to single-route treatment options. By integrating information on feedstock characteristics and processing pathways, this review contributes to a better understanding of non-lignocellulosic agri-food wastes and supports the development of sustainable valorization strategies in the European circular bioeconomy. Full article

The aim of this study is to evaluate the biomechanical response of a seated operator subjected to whole-body vibrations generated by two agricultural tractors with different propulsion systems: a diesel model (TD80D) and an electric prototype (TE-0). An integrated experimental–numerical approach was employed, combining triaxial accelerometer measurements under real operating conditions (constant speed of 5 km/h on unprepared terrain) with random vibration response simulations performed in Altair SimSolid. The excitation input for the numerical model was defined using frequency-dependent power spectral density (PSD) functions derived from experimentally measured acceleration signals and scaled to a representative global RMS value. The analysis focused on the distribution of mechanical stress in key anatomical regions of a virtual human dummy in a seated posture, including the foot sole, knee, lumbar region, and head. The results indicate that, under the analysed conditions, the electric tractor (TE-0) exhibits improved vibration attenuation, leading to significant reductions in mechanical stress across all analysed regions, with decreases of up to 56.3% at the foot sole, 50.0% at the knee, 53.3% in the lumbar region, and 91.1% at the head compared to the diesel tractor (TD80D). These findings highlight the relevance of integrating experimental measurements with numerical simulation for assessing operator exposure to vibrations and suggest that electric tractor configurations may provide improved biomechanical comfort under the analysed operating conditions. Full article

Improving energy efficiency and reducing the carbon footprint of crop production are critical for sustainable agriculture, particularly in semi-arid regions where resource use efficiency is essential. This study evaluated the effects of different fertilization strategies on energy use efficiency and carbon footprint in maize production. A field experiment was conducted during the 2023 growing season in Konya Province, Türkiye, using a randomized block design with three treatments and three replications. The treatments included an unfertilized control (U1), inorganic fertilizer application (U2), and liquid animal manure application (U3). The results showed that the highest grain yield was obtained in the liquid manure treatment, which was 2.08 times higher than the unfertilized treatment and 1.18 times higher than the inorganic fertilizer treatment. The highest total energy input was recorded in the inorganic fertilizer treatment (26,235.12 MJ ha⁻¹), while the highest total energy output was observed in the liquid manure treatment (203,154 MJ ha⁻¹). The liquid manure treatment also showed higher net energy efficiency, output–input ratio, carbon efficiency, and carbon sustainability index, while producing the lowest carbon footprint per unit of product. These findings indicate that liquid animal manure can improve maize productivity while enhancing energy efficiency and reducing carbon emissions in semi-arid agroecosystems. Full article

Understanding the soil–plant transfer of both essential and non-essential elements is crucial for evaluating the crop nutritional quality, environmental interactions, and food safety. This study delivered a multiyear and multielement assessment under field conditions of the element uptake, translocation, and accumulation in raspberry (Rubus idaeus L.), based on data collected over two growing seasons (2024–2025) in two contrasting Romanian agroecosystems. Two commercial cultivars (Opal and Delniwa) were investigated under fertilized and unfertilized conditions. The concentrations of essential macroelements such as Ca, Mg, Na, and K, as well as trace elements (Li and Sr), were determined in soils and fruits using ICP-OES and AAS. The soil–fruit transfer was quantified through the transfer factor, assisted by a robust statistical framework which integrated spatial–temporal variability and non-parametric analysis. The results highlighted two contrasting accumulation regimes. The essential macroelements revealed a dynamic uptake pattern driven by the physiological demand, soil availability, and fertilization. K exhibited the highest transfer capacity, while Ca had a restricted translocation to the fruits, due to the intrinsic transport limitations. On the other hand, Li and Sr revealed a constrained accumulation, characterized by low concentrations, weak responsiveness to fertilization, and a strong dependence on the soil geochemical background and interannual dilution processes. The spatial variability between the cultivation sites and year-to-year changes in the dilution intensity was evidenced as the dominant driver of the transfer efficiency, while the varietal differences had a secondary but detectable role, mainly for the Ca–Sr discrimination. Overall, the results evidenced that the multielement accumulation in the raspberries was governed by the interplay between the soil geochemistry, physiological transport constraints, and environmental variability. Furthermore, the research provided a field-based, multiyear evidence supporting improved soil management, cultivar selection, as well as the strategies that may increase the fruit nutritional quality while minimizing the trace element risks. Full article

The quality of bathing waters along the Romanian Black Sea coast is critical to environmental conservation and sustainable tourism development. This study assesses water quality at several key beaches along the Black Sea Littoral in Romania, using a dataset collected from 2022 to 2024 at 20 locations. Two methods are employed for this aim. The first utilizes the Bathing Water Directive (BWD), considering only the E. coli (EC) and Intestinal Enterococci (IE) as pollutants. The second proposes a water quality index (WQI) that considers temperature (T), pH, salinity, nitrite ion (${NO}_2^{-}),$ and ammonia ion (${NH}_4^{+})$ together with EC and IE. Results show that while most beaches meet European Union water quality standards, specific areas, particularly in the Năvodari, Vadu, and Mamaia sectors, exhibit elevated bacterial contamination. The findings underscore the need for enhanced wastewater treatment and stricter monitoring to support the region’s eco-friendly tourism aims. Full article

The recycling of organic waste is a key element of the circular economy, particularly in response to the increasing generation of biodegradable residues. Composting provides a sustainable solution that supports waste management while improving soil fertility; however, its agronomic value depends on the feedstock origin, composting method, and maturity. This study compares three compost types, two home-produced (C1, C2) and one industrial (C3), to assess their suitability for agricultural application. The chemical characterization included macronutrients and micronutrients, heavy metals, and the humus content, while biological performance was evaluated through seed germination and root growth tests. C1 was nutrient-poor, especially in nitrogen and calcium, indicating the need for supplementation. C2 exhibited high potassium and moisture levels but elevated sodium concentrations, suggesting potential salinity issues. C3 showed high calcium and magnesium contents, moderate nitrogen, and low sodium, making it suitable for calcium-demanding crops. Overall, the home-produced composts demonstrated superior humus quality and more positive effects on plant development than the industrial compost, highlighting their potential as sustainable soil amendments. Full article

Following the COVID-19 pandemic, researchers have increasingly focused on monitoring the spread of the virus and improving methods to detect changes in the SARS-CoV-2 genome. Although clinical surveillance provides direct and reliable results, it has limited applicability. Wastewater-based epidemiology (WBE) has therefore emerged as a valuable, non-invasive complementary tool for disease surveillance. It provides a comprehensive picture of virus circulation in a population, including asymptomatic individuals and those who do not seek healthcare. In addition, it facilitates early detection of outbreaks and the collection of epidemiologic data at the community level. However, WBE also presents technical challenges, including variations in sampling and testing protocols, the presence of inhibitors that affect viral RNA extraction, and the need for standardised procedures between studies. These challenges should be addressed for possible future infectious disease outbreaks. One of the challenges facing researchers was to develop efficient methods that could overcome the extraction and detection problems related to inhibitors present in wastewater. To this aim, this systematic review highlights the potential use of WBE, the variety of techniques, and the most effective methods for the detection and quantification of SARS-CoV-2 in wastewater samples. A reproducible electronic search of the literature was conducted in the Web of Science (WoS) and PubMed databases for articles published between 2020 and 2024. Our search revealed that the majority of observed WBE applications emphasised a correlation between SARS-CoV-2 RNA concentration trends in wastewater and epidemiological data. Another relevant issue that the articles often discussed and compared was the techniques used in different steps of sample processing, such as sample collection, concentration and detection, hence the lack of standardised procedures. This paper provides a framework regarding previous research on WBE to gain a better understanding that will lead to functional solutions. Full article

The rapid increase in organic waste generation poses significant environmental challenges and highlights the limitations of conventional waste management practices. In this context, black soldier fly (Hermetia illucens) larvae (BSFL) have emerged as a promising biological tool for valorizing organic residues within circular bioeconomy frameworks. This review provides an integrated analysis of BSFL-based bioconversion systems, focusing on the biological characteristics of BSFL, suitable organic waste streams, and the key process parameters influencing waste reduction efficiency, larval biomass production, and frass (the residual material from larval bioconversion) yield. The performance of BSFL in converting organic waste is assessed with emphasis on substrate characteristics, environmental conditions, larval density, and harvesting strategies. Environmental and economic implications are discussed in comparison with conventional treatments such as landfilling, composting, and anaerobic digestion. Special attention is given to the nutritional composition of BSFL and their valorization as sustainable protein and lipid sources for animal feed and emerging human food applications, while frass is highlighted as a nutrient-rich organic fertilizer and soil amendment. Finally, current challenges related to scalability, safety, regulation, and social acceptance are highlighted. By linking waste management, resource recovery, and sustainable protein production, this review clarifies the role of BSFL and frass in resilient and resource-efficient food and waste management systems. Full article

The increasing amount of multilayer packaging waste poses significant environmental challenges and calls for sustainable valorization solutions. This study aimed to investigate the acoustic properties of composite materials produced by hot-pressing multilayer waste without the addition of binders or other substances. The waste was carefully cleaned and shredded into square or strip-like geometries, and the composite material plates were compressed at different temperatures (120 °C, 125 °C, 130 °C, 135 °C, and 140 °C) under a constant pressure of 5 MPa. The sound absorption coefficients were evaluated for representative samples, with results analyzed as a function of constituent geometry and processing temperature. Experimental results indicate that the pressing temperature critically affects the internal structure of the material, while waste shape exhibits a frequency-dependent influence on the absorption coefficient. The resulting composite materials display low porosity, which limits internal sound absorption and promotes sound wave reflection, indicating that these materials are more suitable for sound insulation rather than acoustic absorption. These results highlight the potential of multilayer packaging waste-based composites as a sustainable solution for noise control applications and highlight the importance of processing parameters in tailoring their acoustic performance. Full article