Search Results (2,340)

Cement production is a carbon-intensive process that contributes significantly to global greenhouse gas emissions. Approximately 50–60% of these emissions result from limestone calcination, while 30–40% result from fossil fuel combustion in kilns. This study presents a multi-objective optimization (MOO) framework that integrates raw mix design and alternative fuel blending to simultaneously reduce production costs and carbon dioxide (CO₂) emissions while maintaining clinker quality. A hybrid Genetic Algorithm–Linear Programming (GA-LP) model was developed to navigate the balance between economic and environmental objectives under stringent chemical and operational constraints. The approach models the impact of raw materials and fuel ash on critical clinker quality indices: the Lime Saturation Factor (LSF), Silica Modulus (SM), and Alumina Modulus (AM). It incorporates practical constraints such as maximum substitution rates and specific fuel compositions. A case study inspired by a medium-sized African cement plant demonstrates the utility of the model. The results reveal a Pareto front of optimal solutions, highlighting that a 20% reduction in CO₂ emissions from 928 to 740 kg/ton clinker is achievable with only a 24% cost increase. Optimal strategies include 10% fly ash and 30–50% alternative fuels, such as biomass, tire-derived fuel (TDF), and dynamic raw mix adjustments based on fuel ash contributions. Sensitivity analysis further illustrates how biomass cost and LSF targets affect clinker performance, emissions, and fuel shares. The GA-LP hybrid model is validated through process simulation and benchmarked against African case studies. Overall, the findings provide cement producers and policymakers with a robust decision-support tool to evaluate and adopt sustainable production strategies aligned with net-zero targets and emerging carbon regulations. Full article

Industrial wastewater pollution has reached acute levels in the environment; consequently, scientists are developing new sustainable treatment methods. Lignocellulosic biomass (LB) stands as a promising raw material because it originates from agricultural waste, forestry residues, and energy crop production. This review examines the application of nanomaterials derived from lignocellulosic resources in wastewater management, highlighting their distinctive physical and chemical properties, including a large surface area, adjustable porosity structure, and multifunctional group capability. The collection of nanomaterials incorporating cellulose nanocrystals (CNCs) with lignin nanoparticles, as well as biochar and carbon-based nanostructures, demonstrates high effectiveness in extracting heavy metals, dyes, and organic pollutants through adsorption, membrane filtration, and catalysis mechanisms. Nanomaterials have benefited from recent analytical breakthroughs that improve both their manufacturing potential and eco-friendly character through hybrid catalysis methods and functionalization procedures. This review demonstrates the ability of nanomaterials to simultaneously turn waste into valuable product while cleaning up the environment through their connection to circular bioeconomic principles and the United Nations Sustainable Development Goals (SDGs). This review addresses hurdles related to feedstock variability, production costs, and lifecycle impacts, demonstrating the capability of lignocellulosic nanomaterials to transform wastewater treatment operations while sustaining global sustainability. Full article

Cement manufacturing is the second largest anthropogenic source of Hg emissions in the environment. Therefore, the establishment of analytical methodologies that can be utilized in the determination of Hg concentration from cement raw materials and cement is of great importance. The total Hg and Hg thermospecies in cement raw materials and cements were determined by thermal desorption techniques with a Zeeman Hg analyzer. No chemical pre-treatment of samples is required for this technique prior to analysis. An optimum single-stage temperature program was applied to determine total Hg at an optimum heating rate of approximately 5 °C s⁻¹ while Hg thermospecies were determined over four stages at an optimum heating rate of approximately 0.2 °C s⁻¹ per stage from ambient temperature to 720 °C. Total mercury concentrations in cement raw materials ranged between 2.19 ng g⁻¹ and 395 ng g⁻¹, while in cement, concentrations ranged between 1.32 ng g⁻¹ and 31.0 ng g⁻¹. The highest Hg contents were found in dust return (580 ng g⁻¹ and 679 ng g⁻¹). Hg thermospecies determination showed that cement raw materials and cements contain one Hg thermospecies that is released at 20–180 °C while dust return contained one to four Hg thermospecies that could be released at 20–180 °C, 180–360 °C, 360–540 °C, and/or 540–720 °C, thus indicating that new Hg compounds are formed during cement production. Full article

This study addresses the use of porcelain polishing waste as a pyro-expansive agent in clay-based formulations for the production of lightweight aggregates, aiming to reduce the consumption of natural resources and mitigate environmental impacts. In line with circular economy principles and sustainable construction goals, this study investigates the potential use of porcelain polishing waste as a pyro-expansive agent in clay-based formulations for producing sustainable lightweight aggregates. Using the Taguchi method and ANOVA, the effects of key processing parameters were evaluated. The results demonstrated a broad range of volumetric changes, from shrinkage of 40.84% to expansion of 91.69%, depending on the formulation and processing conditions. The aggregates exhibited specific mass values ranging from 0.99 g/cm³ to 2.36 g/cm³, water absorption up to 3.29%, and mechanical strength from 4.57 MPa to 39.87 MPa. Notably, nine of the sixteen experimental conditions met the technical standards for classification as LWA, indicating suitability for applications in high-strength, structural, and non-structural lightweight concretes, as well as lightweight mortars. The performance of these materials was directly linked to the chemical and mineralogical characteristics of the precursors and the proportion of pyro-expansive waste used. Overall, the findings suggest that 50% of the produced aggregates are viable for high-performance concrete applications, offering an environmentally responsible alternative to virgin raw materials and contributing to sustainable waste valorization in the ceramic and construction industries. Full article

Carob is the legume of the carob tree (Ceratonia siliqua L.), which is cultivated in many parts of the Mediterranean area. It is mainly used as animal feed and in the formulations of human foods. Due to the high concentration of sugars in carob pods, this fruit could be used as a raw material to produce distillates. In this study, the effect of the distillation system (Charantais alembic versus Charantais alembic with column) on the chemical and sensory characteristics, as well as on the ethanol yield of carob spirits, was analyzed. The ethanol recovery using Charantais alembic was 74.9%, and for Charantais alembic with column, it was 85.8%. Regarding the chemical composition, esters, furanic compounds, and alcohols were the most abundant compounds in the distillates. Principal component analysis was used to identify the different distillate fractions, first distillations, and residues. Nevertheless, the corresponding distillate fractions for both distillation systems were plotted near to each other due to the similar concentration of the volatile compounds. The spirits obtained from both distillation systems were not differentiated by organoleptic triangular and two-alternative forced-choice (2-AFC) tests according to the results of the semi-trained and professional panels. Both spirits were sensorial characterized as floral, fruity, and alcoholic. Full article

Accurate identification of microplastic polymers in marine environments is essential for tracing pollution sources, understanding ecological impacts, and guiding mitigation strategies. This study presents a comprehensive, explainable-AI framework that uses Raman spectroscopy to classify pristine and weathered microplastics versus biological materials. Using a curated spectral library of 78 polymer specimens—including pristine, weathered, and biological materials—we benchmark seven supervised machine learning models (Decision Trees, Random Forest, k-Nearest Neighbours, Neural Networks, LightGBM, XGBoost and Support Vector Machines) without and with Principal Component Analysis for binary classification. Although k-Nearest Neighbours and Support Vector Machines achieved the highest single metric accuracy (82.5%), k NN also recorded the highest recall both with and without PCA, thereby offering the most balanced overall performance. To enhance interpretability, we employed SHapley Additive exPlanations, which revealed chemically meaningful spectral regions (notably near 700 cm⁻¹ and 1080 cm⁻¹) as critical to model predictions. Notably, models trained without Principal Component Analysis provided clearer feature attributions, suggesting improved interpretability in raw spectral space. This pipeline surpasses traditional spectral matching techniques and also delivers transparent insights into classification logic. Our findings can support scalable, real-time deployment of AI-based tools for oceanic microplastic monitoring and environmental policy development. Full article

The growing consumer awareness of functional foods has increased interest in fermented plant-based products with enhanced nutritional and health-promoting properties. This comprehensive narrative literature review examines the potential of diverse raw materials for tempeh production beyond traditional soybeans, analysing their nutritional composition, bioactive compounds, and functional properties. A structured literature search was conducted on peer-reviewed publications up to July 2025, focusing on tempeh fermentation technology, chemical composition, and bioactive compounds from various substrates using recognised analytical methods according to Association of Official Analytical Collaboration (AOAC) standards. The analysis of over 25 different substrates revealed significant opportunities for enhancing tempeh’s nutritional profile through alternative raw materials including legumes, cereals, algae, seeds, and agricultural by-products. Several substrates demonstrated superior nutritional characteristics compared with traditional soybean tempeh, notably tarwi (Lupinus mutabilis) with exceptional protein content ((32–53% dry matter (DM)) and mung bean (Vigna radiata) exhibiting remarkably high polyphenol concentrations (137.53 mg gallic acid equivalents (GAE)/g DM). Fermentation with Rhizopus oligosporus consistently achieved substantial reductions in anti-nutritional factors (64–67% decrease in trypsin inhibitors, up to 65% reduction in phytates) while maintaining consistent antioxidant activities (39–70% 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition) across most variants. The diversity of bioactive compounds across different substrates demonstrates potential for developing targeted functional foods with specific health-promoting properties, supporting sustainable food system development through protein source diversification. Full article

This study presents a comprehensive mineralogical, chemical, and technological characterization of clay schist samples from Barrancos (southern Portugal), aiming to evaluate their suitability for sustainable ceramic production. The work integrated X-ray diffraction (XRD), X-ray fluorescence (XRF), thermal analysis (TGA, DTA, and dilatometry), and other assays. After simple dry milling, the clay schist samples’ texture supported their use in plastic ceramic pastes but indicated a need for blending with coarser materials to meet extrusion requirements. Mineralogical analysis confirmed a dominance of illite (82%–85%), with minor kaolinite and chlorite. Chemical composition revealed significant Al₂O₃ (21.65%–28.24%) and SiO₂ (52.27%–58.99%) contents, while Fe₂O₃ (4.41%–8.89%) supported their use in red ceramics. The presence of K₂O (up to 5.43%) and Na₂O (up to 1.63%) contribute to the fluxing capacity, promoting vitrification. Cation exchange capacity and specific surface area were low, consistent with the mineralogy dominated by illite and kaolinite. Thermal analysis confirmed the formation of mullite after firing at 1100 and 1150 °C, alongside residual quartz and hematite. The ceramic bodies exhibited progressive densification and strength enhancement with increasing temperature. The mixture of two selected samples showed good mechanical properties and lower porosity, with no efflorescence observed. These results underscore the potential of these schists as sustainable raw materials for ceramic production, promoting regional economic valorization and reducing environmental impact by utilizing local resources. Full article

Macroalgae are valuable natural sources for bioprospection and the development of raw materials applicable to the nutrition, health, and agriculture industries. To build a basis for the sustainable use of marine organisms from the Colombian Caribbean, a preliminary study was conducted focusing on known functional compounds in two genera of macroalgae, including the species Acanthophora spicifera (Rhodophyta), Sargassum ramifolium, and Sargassum fluitans (Ochrophyta). This study included the extraction and identification of polysaccharides using ultrafiltration, nuclear magnetic resonance (¹H-NMR), Fourier-transform infrared spectroscopy (FT-IR), and size exclusion chromatography (SEC); fatty acids by gas chromatographic (GC) profiling; and phenolic composition and antioxidant activity by complementary semi-quantitative methods (ABTS, DPPH, FRAP, and ORAC assays). Carrageenan-type polysaccharides were detected in A. spicifera, while alginate and fucoidan types were found in S. ramifolium and S. fluitans; palmitic acid was the predominant fatty acid in A. spicifera and S. ramifolium, but it was not detected in S. fluitans. S. ramifolium showed the highest ABTS, DPPH, and ORAC activities and phenolic compounds, while S. fluitans exhibited the highest FRAP activity. This study contributes to the chemical knowledge on Colombian macroalgae to establish potential applications in various fields, including biomedicine, cosmetics, functional foods, and nutraceutical ingredients. Full article

Microorganisms, as abundant biological resources, offer significant potential in the development of selenium-enrichment technologies. Selenium-enriched microorganisms not only absorb, reduce, and accumulate selenium efficiently but also produce various selenium compounds without relying on synthetic chemical processes. In particular, nano-selenium produced by these microorganisms during cultivation has garnered attention due to its unique physicochemical properties and biological activity, making it a promising raw material for functional foods and pharmaceutical products. This paper reviews selenium-enriched microorganisms, focusing on their classification, selenium metabolism, and transformation mechanisms. It explores how selenium is absorbed, reduced, and transformed within microbial cells, analyzing the biochemical processes by which inorganic selenium is converted into organic and nano-selenium forms. Finally, the broad applications of selenium-enriched microbial products in food, medicine, and agriculture are explored, including their roles in selenium-rich foods, nano-selenium materials, and disease prevention and treatment. Full article

This study investigates the potential of residual clays from a traditional ceramic-producing region in southern Portugal as raw materials for red ceramic applications. This work aims to support more sustainable ceramic practices through the local valorization of naturally available, underutilized clay resources. A multidisciplinary approach was employed to characterize clays, integrating mineralogical (XRD), chemical (XRF), granulometric, and thermal analyses (TGA/DTA/TD), as well as technological tests on plasticity, extrusion moisture, shrinkage, and flexural strength. These assessments were designed to capture both the intrinsic properties of the clays and their behavior across key ceramic processing stages, such as shaping, drying, and firing. The results revealed a broad diversity in mineral composition, particularly in the proportions of kaolinite, smectite, and illite, which strongly influenced plasticity, water demand, and thermal stability. Clays with higher fine fractions and smectitic content exhibited excellent plasticity and workability, though with increased sensitivity to drying and firing conditions. Others, with coarser textures and illitic or feldspathic composition, demonstrated improved dimensional stability and lower shrinkage. Thermal analyses confirmed expected dehydroxylation and sintering behavior, with the formation of mullite and spinel-type phases contributing to densification and strength in fired bodies. This study highlights that residual clays from varied geological settings can offer distinct advantages when matched appropriately to ceramic product requirements. Some materials showed strong potential for direct application in structural ceramics, while others may serve as additives or tempering agents in formulations. These findings reinforce the value of integrated characterization for optimizing raw material use and support a more circular, resource-conscious approach to ceramic production. Full article

In this work, lightweight aggregates (LWAs) were prepared from an Italian red clay, pumice scraps, and spent coffee grounds. Chemical and physical characterization was first performed on the raw materials and then on the finished products. By studying the thermal behavior of the materials, the correct firing temperature was evaluated. The obtained aggregates were fired in two different modes: in a rotary kiln and in a static kiln; the influence of the firing processes on the finished products was assessed. This study can be useful for industrially scaling up this process. Firing in a rotary kiln reduced the average diameter of the aggregates (negative expansion index), resulting in a higher compressive strength and dry particle density compared to an aggregate containing only clay. The pH and electrical conductivity values address their use in agronomy without causing problems to crops, while the higher compressive strength, density, and porosity values could allow their use in construction. Full article

The cosmetic industry is growing at an impressive rate worldwide. In the cosmetic field, natural-origin ingredients represent the new frontier in this industry. Among the main components of cosmetics, lipids, emulsifiers, rheological modifiers, preservatives, colorants, and antioxidants can be found. These compounds form emulsions, which are among the main cosmetic formulations. An important aspect in this regard is the evaluation of emulsions’ stability over time and emulsions’ production methodology. In this paper, a comparison is made between two emulsion production technologies, the Standard and the “One-Pot” methods, through the characterization of the raw material ABWAX^® Revomul, a multifunctional wax for cosmetic use which consists of a low-melting structuring wax of vegetal origin (Rhus wax) and a natural emulsifier (Polyglyceril-3 Stearate). First, we evaluated the affinity between the wax raw materials and emollients of different chemical nature; then, we analyzed the impact of the production method on the emulsions to identify similarities and differences. ABWAX^® Revomul demonstrated a high level of effectiveness in regard to stabilizing oil-in-water emulsions. This study suggests that from an industrial point of view, the application of the two procedures allows products with different characteristics to be obtained, consequently allowing a specific method to be chosen to obtain the desired product. Full article

The use of chemical fertilizers has significantly increased crop yields but has also led to soil problems such as nutrient imbalance and salinization. In response, organic fertilizers have emerged as a crucial component for sustainable agricultural development. This study was designed to develop an easily applicable organic suspension fertilizer using peanut bran, the primary by-product of peanut oil extraction, as the main raw material. Fourier-transform infrared (FTIR) analysis revealed that 80 °C is the optimal heating temperature for forming a stable peanut-bran suspension. A comprehensive experimental investigation was conducted to evaluate the effects of different peanut bran addition levels, stabilizers, emulsifiers, and suspending agents on the stability of suspension fertilizers. The results identified the optimal suspension fertilizer formulation as comprising 20% peanut bran, 0.5% sodium bentonite, 0.1% monoglyceride, 0.2% sucrose ester, 0.02% carrageenan, and 0.3% xanthan gum. This formulation ensures good stability and fluidity of the suspension fertilizer while maintaining a low cost of 0.134 USD·kg⁻¹. The findings provide a scalable technological framework for valorizing agro-industrial waste into high-performance organic fertilizers. Full article

Phosphogypsum, a byproduct of orthophosphoric acid production, is one of the large-tonnage wastes. Since phosphogypsum mainly consists of CaSO₄ 2H₂O, it can be considered as an alternative gypsum-bearing raw material in the production of gypsum binders. However, its features, such as particle morphology and the presence of impurities, can negatively affect the characteristics of phosphogypsum-based binders. Identification of these factors will allow us to develop methods for their minimization and increasing the efficiency of phosphogypsum use from the required source as a raw material for the production of phosphogypsum-based binders. In this regard, the manuscript contains a comprehensive and comparative analysis of phosphogypsum and natural gypsum, which makes it possible to establish their differences in chemical composition and structural and morphological features, which subsequently affect the properties of the phosphogypsum-based binder. It has been established that the key factor negatively affecting the strength of phosphogypsum-based paste (2.58 MPa) is its high water demand (0.89), which is due to the high values of the specific surface area of the particles and the presence of a large number of conglomerates with significant porosity in phosphogypsum. It has been suggested that preliminary grinding of phosphogypsum can help reduce the amount of water required to obtain fresh phosphogypsum-based paste with a standard consistency and improve its physical and mechanical properties. Full article