Search Results (23)

The increasing generation of municipal waste and the depletion of natural mineral resources have intensified the search for sustainable alternatives for construction materials within the framework of the circular economy. While waste glass, industrial residues, and selected municipal waste fractions have been extensively investigated individually as raw materials for lightweight aggregates, their simultaneous incorporation into a single ceramic matrix remains largely unexplored. To address this research gap, the present study investigates the feasibility of producing lightweight ceramic aggregates through the simultaneous incorporation of three municipal waste streams street sweeping waste (SSW), waste glass, and bulky waste into a clay-based ceramic matrix. Three ceramic mixtures containing different proportions of these waste materials were prepared, pelletized, and fired at 1100 °C. The produced aggregates were characterized in terms of loose bulk density, water absorption, total heavy metal concentrations, and heavy metal leachability, while the bulky waste was additionally characterized by loss on ignition to determine its organic matter content. All produced aggregates satisfied the requirements of PN-EN 13055-1 for lightweight aggregates, with loose bulk densities ranging from 442.9 to 543.1 kg m⁻³, comparable with commercially available expanded clay lightweight aggregates. Water absorption varied between 32.93% and 56.61%, with mixture composition explaining approximately 88% of the observed variance (one-way ANOVA, p < 0.001). Loss-on-ignition analysis revealed that bulky waste contained approximately 98.8 wt.% organic matter, confirming its effectiveness as a pore-forming additive during firing. Environmental assessment of the optimum mixture indicated limited mobility for most investigated heavy metals after thermal treatment; however, chromium leachability slightly exceeded the adopted reference value, indicating the need for further optimization of the ceramic composition. Overall, the developed lightweight aggregate represents a promising alternative to conventional lightweight aggregates and contributes to resource recovery, waste valorization, and the implementation of circular economy principles in the construction sector. Future research should focus on chromium speciation, mechanical performance, long-term durability, life cycle assessment, and pilot-scale production to support future industrial application. Full article

This study evaluates the effect of decorative ceramic screen printing on the optical and photovoltaic performance of glass covers intended for building-integrated photovoltaics (BIPV). Nine ceramic-printed glass samples with different colors and optical densities were compared with a 4 mm Optiwhite reference glass and a bare silicon solar cell. The samples were characterized by UV-VIS-NIR spectrophotometry, energy-dispersive X-ray spectroscopy (EDS), and electrical measurements under simulated AM 1.5G irradiation at 1000 W/m². The optical results showed that the Optiwhite reference provided the highest transmittance, whereas the printed samples exhibited lower transmission, typically in the range of 60–80% in the visible region, depending on the coating type. Among the decorative variants, sample 1 showed the highest transparency, while sample 6 exhibited the lowest transmittance. The spectral behavior of the coated glasses indicates that the ceramic layers modify the photon flux reaching the solar cell through wavelength-dependent absorption and scattering effects. The photovoltaic measurements confirmed a clear relationship between decorative coating and electrical performance. Relative to the Optiwhite-covered reference cell, the printed samples showed power losses ranging from approximately 17% to 32%, with sample 1 achieving the highest maximum power among the decorative variants at 1.41 W, and sample 4 the lowest at 1.16 W. The main electrical effect of the ceramic coatings was a reduction in short-circuit current, whereas the open-circuit voltage remained nearly constant across the tested samples. EDS analysis identified the presence of ceramic-layer constituents associated with silica-, zinc-, titanium-, iron-, cobalt-, aluminum-, and fluorine-containing compounds, supporting the interpretation of vitrified decorative coatings formed during high-temperature processing. Overall, the results demonstrate that decorative ceramic printing can provide a practical compromise between architectural appearance and photovoltaic output when the optical density of the coating is appropriately controlled. Full article

Ion-exchange-strengthened 0.7 mm aluminosilicate glass offers a promising route to lightweight, mechanically robust front covers for building-integrated photovoltaic (BIPV) modules, but systematic characterization at sub-millimeter thicknesses remains limited. This study investigated 100 × 60 × 0.7 mm glass samples subjected to Na⁺/K⁺ ion exchange (6 h, 430 °C, KNO₃) and characterized mechanical and optical properties relevant to BIPV applications. Depth of layer (DOL) was cross-validated using three independent methods, mass gain diffusion modeling (31–37 μm), elasto-optic measurements (FSM-6000: 38–42 μm), and EDS Na/K depth profiling (35–40 μm), confirming consistent strengthened layer depth of 35–40 μm. Surface compressive stress measured 733 MPa (Series 2) and 773 MPa (Series 3), significantly exceeding conventional PV cover glass (490–515 MPa, 1 mm thickness). Vickers hardness increased by 17.7% (490 → 596 HV, p < 0.0001), demonstrating enhanced damage tolerance. Spectrophotometric analysis (200–2400 nm) showed transmittance >91% (380–2000 nm) and >92% (600–2000 nm) for both as-received and strengthened glass, confirming no optical degradation (p = 0.29–0.41). The 78–83% mass reduction relative to standard 3.2–4 mm glass, combined with superior CS/DOL and preserved optical performance, establishes ion-exchanged 0.7 mm aluminosilicate glass as a strong material-level candidate for next-generation lightweight BIPV modules. Future work requires module-scale mechanical validation (bending, impact testing per EN/IEC standards) and techno-economic assessment to verify system-level benefits. Full article

This article presents a narrative, traditional literature review summarizing current research on the integration of digital technologies in waste management. The study examines how intelligent technologies, including Geographic Information Systems, Big Data analytics, and artificial intelligence, can improve energy efficiency, support sustainable resource use, and enhance the development of low emission and circular waste management systems. The reviewed research shows that the combination of spatial analysis, large-scale data processing, and predictive computational methods enables advanced modeling of waste distribution, the optimization of collection routes, intelligent sorting, and the forecasting of waste generation. Geographic Information Systems support spatial planning, site selection for waste facilities, and environmental assessment. Big Data analytics allows the integration of information from Internet of Things sensors, global positioning systems, municipal databases, and environmental registries, which strengthens evidence-based decision making. Artificial intelligence contributes to automatic classification, predictive scheduling, robotic sorting, and the optimization of recycling and energy recovery processes. The study emphasizes that the integration of these technologies forms a foundation for intelligent waste management systems that reduce emissions, improve operational efficiency, and support sustainable urban development. Full article

With the acceleration of urbanization, the coupling relationship between the built environment and urban safety hazards has become increasingly prominent. Irrational spatial structures and resource allocations may aggravate safety hazards and negatively affect residents’ quality of life, thus requiring urgent scientific evaluation and optimization. However, existing studies mostly focus on linear correlation analysis, which makes it difficult to reveal the complex nonlinear mechanisms among multidimensional environmental factors. Taking Cracow (Kraków), Poland as the study area, this research utilizes multi-source spatial data to quantify environmental features such as transportation, socioeconomic conditions, visual landscapes, and public services, in order to uncover their role in the formation of safety hazards. An XGBoost-based safety hazard prediction model is constructed, and SHAP interpretability analysis, together with two-dimensional partial dependence plots (2D PDPs), are introduced to systematically explore the synergistic gains, marginal effects, and resource allocation thresholds of key variables. The results indicate that variables such as average housing price, distance to the nearest police station, and average population density contribute significantly to hazard prediction, and that certain combinations of variables exhibit strong synergistic effects in reducing hazards within medium-range intervals. The study concludes that integrating machine learning with interpretability analysis can not only effectively identify the spatial features associated with high levels of safety hazards, but also provide quantifiable and actionable optimization pathways for urban planning and safety hazard governance. This research further underscores the role of managing urban safety hazards as a key pillar in the sustainable development of cities by linking safety hazard modeling with spatial governance strategies that promote inclusive, resilient, and livable urban environments. Full article

The study presents a developed process for producing monocalcium phosphate from hydroxyapatite ash, a by-product of meat-bone meal incineration. The process integrates technological and environmental synergies, enabling efficient recycling of both materials and energy. Waste hydroxyapatite ash, obtained as an intermediate by-product of the meat-bone meal process, is converted into high-quality monocalcium phosphate. Furthermore, waste heat from incineration is recovered, improving energy efficiency and reducing costs. Preliminary economic analysis indicates that the process is highly profitable, with an annual production capacity of 21,700 tons at a cost of $924 per ton, compared to a market price of $1400 per ton. The total production cost is estimated at $20,058,947, while total sales are projected to reach $30,380,000, yielding a profit of $10,321,053 (34% profit margin). The proposed method is consistent with the principles of the Circular Economy and Cleaner Production, promoting sustainability by reducing waste, lowering resource consumption, and enhancing energy efficiency. The developed technology is both environmentally friendly and economically viable, offering a promising pathway for efficient monocalcium phosphate production and a blueprint for industrial-scale implementation. Full article

The presented research aims to find a data-driven formula for the compressive stress–strain behaviour of closed-cell aluminium foams with respect to the apparent density of the material. This is a continuation and new development of an earlier study by the authors. In the previous step, 500 artificial neural network models were built and trained on experimental results from compression tests and then evaluated based on, among other factors, mean absolute relative errors for training and verification stages. In this step, the evaluation of networks is amended, and criteria are introduced that are connected with the mechanical characteristics of the material, i.e., the plateau stress and quasi-elastic gradient. A weighted condition of all measures is proposed. Based on the amended conditions, a neural network model with a weighted mean absolute relative error of $\cong 5\%$ is chosen and presented, together with the mathematical equation for its stress–strain–density relationship $\sigma =f\left(\epsilon ,\rho \right)$ over a range of material apparent densities $\rho \in ⟨0.2;0.3⟩ \mathrm{g}/{\mathrm{c}\mathrm{m}}^3$. Experimental relationships for compressive strength and plateau stress are also presented. Full article

This paper presents a detailed analysis of the thermal and flammability properties of polylactide- (PLA) and poly(ethylene terephthalate)- (PET) based polymer blends with biofillers, such as calcium lignosulfonate (CLS), lignosulfonamide (SA) and lignosulfonate modified with tannic acid (BMT) and gallic acid (BMG). Calorimetric studies revealed the presence of two glass transitions, one cold crystallization temperature, and two melting points, confirming the partial immiscibility of the PLA and PET phases. The additives had different effects on the temperatures and ranges of phase transformations—BMT restricted PLA chain mobility, while CLS acted as a nucleating agent that promoted crystallization. Thermogravimetric analyses (TGA) analyses showed that the additives significantly affected the thermal stability under oxidizing conditions, some (e.g., BMG) lowered the onset degradation temperature, while the others (BMT, SA) increased the residual char content. The additives also altered combustion behavior; particularly BMG that most effectively reduced flammability, promoted char formation, and extended combustion time. CLS reduced PET flammability more effectively than PLA, especially at higher PET content (e.g., 65% reduction in PET for 2:1/CLS). SA inhibited only PLA combustion, with strong effects at higher PLA content (up to 76% reduction for 2:1/SA). BMT mainly reduced PET flammability (48% reduction in 1:1/BMT), while BMG inhibited PET more strongly at lower PET content (76% reduction for 2:1/BMG). The effect of each additive also depended on the PLA:PET ratio in the blend. FTIR analysis of the char residues revealed functional groups associated with decomposition products of carboxylic acids and aromatic esters. Ultimately, only blends containing BMT and BMG met the requirements for flammability class FV-1, while SA met FV-2 classification. BMG was the most effective additive, offering enhanced thermal stability, ignition delay, and durable char formation, making it a promising bio- based flame retardant for sustainable polyester materials. Full article

Processing of meat waste into meat and bone meal generates wastewater that must be properly treated to minimize its environmental impact. In addition to its high organic load, it contains microorganisms, including pathogens, that pose a threat to human health. In this study, wastewater from meat and bone meal production was treated using the Fenton process with a variable Fe²⁺/H₂O₂ mass ratio ranging from 1:2 to 1:10, followed by neutralization with lime milk. A microbiological analysis was performed on both the raw wastewater and the liquid fractions obtained after treatment, along with additional analyses of selected physicochemical parameters. The identification of isolated microorganisms was carried out using the MALDI-TOF MS technique. Qualitative analysis of the treated wastewater samples showed the presence of microorganisms belonging to the genera Staphylococcus, Enterococcus, Alcaligenes, and Pseudomonas. Staphylococcus aureus and Alcaligenes faecalis were present in each of the treated samples. The Fenton process effectively reduced the total number of microorganisms, with the lowest counts of 1.3 × 10² CFU/mL and 3.2 × 10² CFU/mL found in wastewater samples treated with Fe²⁺/H₂O₂ mass ratios of 1:8 and 1:10, which correlated with higher doses of hydrogen peroxide. Full article

This study proposes an innovative model for animal waste utilization in the largest Polish meat utilization plant, which assumes an integrated system that processes one part of the meat waste by anaerobic digestion and the second part into meat and bone meal via the hydrothermal method. The solution is based on implementing the concept of industrial symbiosis, using a purposefully directed flow of materials, waste, and energy to create a closed recycling cycle. This study analyzes the key strategic, organizational, and technical circular economy activities that enable the transformation of waste into valuable materials and energy, thanks to the use of closed-loop materials and energy cycles. It estimates the integrated system’s investment costs and economic and environmental outcomes. The presented method allows for biogas production from the bio-fermentation of 160,000 t/y of animal waste; this would more than cover the heat requirements for obtaining 110,000 t/y of meat and bone meal using the hydrothermal method. Full article

Direct lithium extraction from unconventional resources requires the development of effective adsorbents. Crown ether-containing materials have been reported as promising structures in terms of lithium selectivity, but data on adsorption in real, highly saline brines are scarce. Crown ether-grafted graphene oxides were synthesized using 2-hydroxymethyl-12-crown-4, hydroxy-dibenzo-14-crown-4 and epichlorohydrin as a source of anchoring groups. The obtained carbonaceous materials were used to prepare chitosan–polyvinyl alcohol composites. The prepared materials (and intermediate products) were characterized using FTIR, XRD, Raman spectroscopy and SEM-EDS methods. Adsorption tests were performed in a pure diluted LiCl solution ([Li] = 200 mg/kg) as well as in a real, highly saline oilfield brine ([Li] ≈ 220 mg/kg), and the distribution coefficients (K_d) were determined. The obtained results show that K_d in pure LiCl solution was in the range of 0.9–75.6, while in brine it was in the range of 0.2–2.3. The study indicates that the high affinity for lithium in pure LiCl solution is mostly associated with the non-selective interaction of lithium ions with the graphene oxide matrix (COOH groups). It was also shown that the application of dibenzo-14-crown-4 moiety to graphene oxide modification groups increases the affinity of the composite material for lithium ions compared to an analogous material containing 12-crown-4-ether groups. Full article

This work discusses the drivers and barriers (legal, chemical, biological, technical) related to implementing a circular economy model in the tire sector in Poland. The aim of this work was to identify and prioritize key factors determining the implementation of the circular economy business model, both among tire manufacturers and recyclers. The analysis of aspects facilitating the implementation of circular economy and the assessment of this type of project in organizations was the basis for identifying the most important factors in the development of eco-innovation in the tire industry. The research process used bibliometric analysis, empirical research based on a questionnaire and in-depth interviews of tire industry employees, and opinions of experts participating in a group interview. Research has indicated that the key to success in implementing the circular economy is to change actual business practices. The basic drivers of circular economy implementation in the tire sector are legal requirements and an organization’s profit associated with the use of circular economy actions. High environmental requirements and regulations that support a circular economy are key factors stimulating eco-innovative methods, but in most cases, these are more of a concern for recyclers than tire manufacturers. This study identified and hierarchized the determinants for implementing a circular economy model and indicated key factors influencing the development of eco-innovations among recyclers and tire manufacturers in Poland. Full article

Hard bone disease is a clinical problem affecting more than 20 million people annually worldwide, with significant health, social, and economic consequences. For successful integration of any implant, the key aspects are bone regeneration, osseointegration at the bone–implant interface, and the mitigation of inflammation. The purpose of this research work is to demonstrate an innovative material system and method of biomaterial preparation for regenerative medicine. A number of studies were carried out for both hydroxyapatite powder and composites. Wet-precipitated synthesized hydroxyapatite was compared to commercial products through accurate physicochemical studies that confirmed the high purity of the obtained calcium phosphate without any impurities. Ti/HAp composites before and after sintering were compared by XRF, XRD, SEM, EDS, PSA, and roughness measurements, and the Vickers microhardness was analyzed. The fabrication of the biomaterial was based on a bottom-up approach, which involved fabricating HAp particles with specific morphologies using powder metallurgy (PM) to sinter Ti composites. The resulting gradient structures consisting of two compositions (5%HAp%5CMC and 10%HAp10%CMC) mimic the structure of bone tissue. The created pores of 10–100 µm in size will allow bone cells to penetrate the implant and regenerate bone. In turn, the introduction of hydroxyapatite into the material reduces the microhardness of the composite and introduces properties such as bioactivity. The developed composite material contains a combination of Ti alloy and hydroxyapatite (HAp), creating an excellent biomaterial that promotes bone growth and eliminates the problem of implant loosening by integrating it into the bone. This material requires further research, especially biological research. However, it shows promising potential for further experiments. Full article

Restoring the structures and functions of tissues along with organs in human bodies is a topic gathering attention nowadays. These issues are widely discussed in the context of regenerative medicine. Excipients/delivery systems play a key role in this topic, guaranteeing a positive impact on the effectiveness of the drugs or therapeutic substances supplied. Advances in materials engineering, particularly in the development of hydrogel biomaterials, have influenced the idea of creating an innovative material that could serve as a carrier for active substances while ensuring biocompatibility and meeting all the stringent requirements imposed on medical materials. This work presents the preparation of a natural polymeric material based on pullulan modified with silymarin, which belongs to the group of flavonoids and derives from a plant called Silybum marianum. Under UV light, matrices with a previously prepared composition were crosslinked. Before proceeding to the next stage of the research, the purity of the composition of the matrices was checked using Fourier-transform infrared (FT-IR) spectroscopy. Incubation tests lasting 19 days were carried out using incubation fluids such as simulated body fluid (SBF), Ringer’s solution, and artificial saliva. Changes in pH, electrolytic conductivity, and weight were observed and then used to determine the sorption capacity. During incubation, SBF proved to be the most stable fluid, with a pH level of 7.6–7.8. Sorption tests showed a high sorption capacity of samples incubated in both Ringer’s solution and artificial saliva (approximately 350%) and SBF (approximately 300%). After incubation, the surface morphology was analyzed using an optical microscope for samples demonstrating the greatest changes over time. The active substance, silymarin, was released using a water bath, and then the antioxidant capacity was determined using the Folin–Ciocâlteu test. The tests carried out proved that the material produced is active and harmless, which was shown by the incubation analysis. The continuous release of the active ingredient increases the biological value of the biomaterial. The material requires further research, including a more detailed assessment of its balance; however, it demonstrates promising potential for further experiments. Full article

In recent years, a growing demand for biomaterials has been observed, particularly for applications in bone regenerative medicine. Bone tissue engineering (BTE) aims to develop innovative materials and strategies for repairing and regenerating bone defects and injuries. Polysaccharides, due to their biocompatibility, biodegradability as well as bioactivity, have emerged as promising candidates for scaffolds or composite systems in BTE. Polymers combined with bioactive ceramics can support osteointegration. Calcium phosphate (CaP) ceramics can be a broad choice as an inorganic phase that stimulates the formation of new apatite layers. This review provides a comprehensive analysis of composite systems based on selected polysaccharides used in bone tissue engineering, highlighting their synthesis, properties and applications. Moreover, the applicability of the produced biocomposites has been analyzed, as well as new trends in modifying biomaterials and endowing them with new functionalizations. The effects of these composites on the mechanical properties, biocompatibility and osteoconductivity were critically analyzed. This article summarizes the latest manufacturing methods as well as new developments in polysaccharide-based biomaterials for bone and cartilage regeneration applications. Full article