Search Results (123)

The sustainable management of olive wastes represents an important environmental challenge. Biochars and hydrochars derived from biomass are promising adsorbents for removing emerging pollutants from water. In the present work, olive stone wastes were converted into biochar and hydrochar by using pyrolysis (500 °C for 30 min) and hydrothermal carbonization (HTC) processes (220 °C for 10 h). Then, the obtained materials were physically activated by using CO₂ gas (750 °C for 30, 60 and 180 min). Various analytical techniques were applied for the chemical, textural and structural characterization of these carbonaceous materials (i.e., ultimate and proximate analysis, scanning electron microscopy (SEM), BET surface area, Raman spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy). Afterwards, the selected activated biochar and hydrochar were applied for the removal of amoxicillin from aqueous solutions. The experimental results show that the generated hydrochar has many microspheres on its surface and inside, while the produced biochar exhibits a porous structure with irregular forms. CO₂ physical activation has induced an important improvement of the biochar and hydrochar’s structural, textural, and surface chemistry properties. For instance, the activated biochar samples show a highly porous structure, with large specific surface areas that increase with the burn-off, reaching 1349.3 m² g⁻¹ following 3 h of activation. Regarding the activated hydrochar samples, they exhibit a spherical morphological structure with an important specific surface area, which increased to 846.7 m² g⁻¹ after 3 h of activation. Moreover, both activated materials have an amorphous structure with low oxygen surface groups. The selected novel CO₂-activated biochar and hydrochar efficiently remove amoxicillin from aqueous solutions under wide experimental conditions, with adsorption capacities of 386.4 and 215.9 mg g⁻¹, respectively. These efficiencies are higher than those reported for various activated biochars derived from lignocellulosic biomass, from sewage sludge, and from animal manure. Future research works are required to assess these materials’ effectiveness in treating real pharmaceutical effluents, to optimize the regeneration of the amoxicillin-loaded materials, and to design full-scale devices for a real application. Full article

The persistence of pesticide residues in food and water poses a significant challenge to global food safety, particularly under the pressures of intensive agriculture and climate variability. Despite significant progress in developing adsorbent materials for pesticide remediation, most approaches remain chemically optimized but geographically blind. This review introduces the concept of geo-adaptive design of carbon-based adsorbents, emphasizing that remediation materials should be tailored to the regional profiles of pesticide use, environmental conditions, and available biomass precursors. Pesticide contamination patterns vary widely across climates and agricultural systems, resulting in distinct chemical signatures that determine adsorption behavior. Simultaneously, locally abundant agro-industrial byproducts, such as walnut shells, rice husks, olive stones, or fruit pomace, offer sustainable carbon sources for region-specific materials. By correlating pesticide structure, adsorbent surface chemistry, and environmental parameters, geo-adaptive materials can be designed to maximize efficiency, selectivity, and sustainability in environmental remediation contexts, including the treatment of pesticide-contaminated soils and water streams. In addition, these materials may be integrated into food processing and packaging systems, where they can function as localized, low-cost mitigation strategies aligned with circular economy principles. The review highlights how regionally optimized carbon materials could connect advances in environmental remediation with the practical needs of food technology, leading toward food safety strategies that are both globally relevant and locally adaptable. Full article

In the present study, we evaluate the CO₂ uptake capacities of four activated carbons (ACs) obtained from olive stones. Two of the samples were generated using a chemical process utilizing phosphoric acid, thereafter undergoing carbonization in a nitrogen steam, yielding both granular and pellet forms, designated CH-ACG-410 and CH-ACP-410, respectively. The third sample, labeled CO-ACG-390, was produced by carbonization under a steam-nitrogen flow, while the fourth sample, designated PH-ACG-850, was prepared by a physical process involving water vapor at 850 °C. The carbon materials obtained in granular and pellet form were subjected to textural characterization using N₂ and CO₂ adsorption isotherms at 77 K and 273 K, respectively. Additionally, surface chemistry was analyzed using FTIR, Boehm titration, and TPD-MS. The materials were also assessed for CO₂ adsorption in a binary mixture consisting of 10% CO₂ and 90% N₂ at two temperatures, 25 and 50 °C. The results demonstrated that all prepared adsorbents exhibited competitive CO₂ capture performance, with the CH-ACP-410 sample (pellet form), showing the highest adsorption capacities, achieving approximately 4.6 wt. % at 25 °C and 2.2 wt. % at 50 °C. This superior behavior can be attributed to the conditioning methods applied to this material, which significantly influenced its textural properties and, consequently, its CO₂ adsorption capability. Full article

Background/Objectives: The consumption of olive oil and olives has been steadily increasing, leading to growing interest in the sustainable management of by-products such as olive stones. This work aimed to contribute to the development of valorization strategies by studying the chemical composition and biological potential of olive stone extracts, using both conventional and eco-friendly extraction methods with various solvents. Methods: Several extracts were prepared and chemically characterized regarding their fatty acid and phenolic profiles by GC-FID and HPLC-DAD-MS/MS, respectively. Their antioxidant, cytotoxic and antiproliferative activities were also evaluated. Results: n-Hexane Soxhlet extract yielded higher concentrations and a broader range of fatty acids when compared to the chloroform-methanol Folch extract. Oleic, palmitic, and linoleic acids were the predominant fatty acids in the extracts. A large variety of phenolic compounds were identified in extracts obtained by microwave-assisted extraction (MAE), including several flavonoids, small phenolic compounds, secoiridoids (nuezhenide and oleuropein), and hydroxytyrosol. MAE hydroalcoholic extracts showed high total phenolic content (TPC), antioxidant activity by the oxygen radical absorption capacity (ORAC) and hydroxyl radical scavenging capacity (HOSC) assays. Moreover, the aqueous ethanol (50%) and aqueous methanol (80%) extracts displayed low cytotoxicity toward the non-malignant Caco-2 cell line (IC₅₀ values of 1.29 and 1.40 mg/mL, respectively), while both induced complete loss of viability in the HT-29 human colon adenocarcinoma cell line at 0.63 mg/mL. Conclusions: These findings highlight the potential of olive stone as a valuable source of bioactive compounds with antioxidant and selective antiproliferative properties. The results support their further exploration in the development of sustainable valorization strategies for olive industry by-products. Full article

The present study aims to investigate the feasibility of utilizing olive stone powder (OSP), an agricultural by-product, as a modifier for bituminous binders. OSP was incorporated into a neat bitumen at dosages of 2%, 4%, 6%, and 8% by weight, and the modified binders were subjected to comprehensive laboratory tests along with the unmodified reference binder. The evaluation framework included physical, rheological, and chemical characterization tests. The results of physical tests indicate that, although the addition of OSP led to a slight increase in binder stiffness, it effectively reduced temperature susceptibility while maintaining workability within acceptable limits. Rheological results showed that OSP modification improved rutting resistance at high temperatures, while low-temperature performance was preserved at 2% and 4% OSP contents; however, increased stiffness at higher dosages (6% and 8%) may increase thermal cracking susceptibility. Chemical analyses confirmed that OSP was homogeneously dispersed within the bitumen matrix and improved binder behavior primarily through physical interactions, while also enhancing thermal stability. Overall, the results indicate that OSP behaves as a biopolymer-based, filler-like modifier and provides performance improvements primarily through physical structuring. With these characteristics, OSP offers an environmentally friendly and economical solution for bituminous binders and represents a promising option for sustainable pavement materials. Full article

Olive is a self-incompatible species that usually produces one-seeded drupes, although double-seeded fruits and seedless fruit due to seed abortion may occur. This study evaluated the effects of different pollinizers on seeding pattern in three self-incompatible cultivars: ‘Arbosana’, ‘Koroneiki’ and ‘Sikitita’. Fruit and seed set, seed abortion, double seeding and seed weight were analyzed. Maternal effects were confirmed with significant differences between cultivars. ‘Sikitita’ produced a higher-than-expected proportion of double-seeded fruit, whereas ‘Arbosana’ and ‘Koroneiki’ produced fewer. In contrast, ‘Koroneiki’ showed a higher incidence of empty endocarps, while ‘Sikitita’ produced fewer. Paternal effects on seeding pattern were generally not significant, although marginal differences were observed in ‘Arbosana’ and ‘Koroneiki’ depending on pollination treatment. Some pollination crosses were more successful, with ‘Sikitita’ pollen fathering most seeds in ‘Koroneiki’ and ‘Arbosana’, with reciprocal success for ‘Arbosana’ pollen in ‘Sikitita’. A striking discovery was that different fathers often sired twin seeds within one single fruit. Finally, seed number affected fruit development. Thus, total seed and endocarp mass increased as viable seed number did. Fruits with aborted seeds had smaller stones, whereas stones enclosing two seeds were heavier. Seed, endocarp, pulp and fruit weights were positively correlated across cultivars and pollination conditions. Full article

The presence of emerging contaminants in water has led to a need for the development of new materials and treatments. Four low-cost adsorbents derived from lignocellulosic biomass waste (pine nut shells and olive stones) were prepared via chemical treatment (with H₃PO₄ or NaOH) followed by thermal activation (at 550 °C under N₂). Characterization of the bioadsorbents was carried out using N₂ adsorption–desorption isotherms, FTIR and Raman spectroscopic analyses, and pHpzc determination. The electrostatic interactions between the adsorbent surface and the dyes were determined, and it was found that the interactions in both adsorbents were attractive for the methylene blue and repulsive for methyl orange, at pH basic or neutral. The performance of the obtained activated carbons was evaluated at lab scale with two dyes (methylene blue and methyl orange), and a comparison was made between both adsorbents and with commercial charcoal. The H₃PO₄-activated adsorbents exhibited higher adsorption capacities (up to 300 mg/g for methylene blue and 285 mg/g for methyl orange), with adsorption efficiencies close to 100%. More than 10 adsorption–desorption cycles were performed, with efficiencies exceeding 85%. The good reusability shown by the H₃PO₄-activated adsorbents suggests significant potential for industrial application; namely, in the removal emerging contaminants from urban wastewater. It should be noted that the adsorption efficiency decreased after the fifth cycle, indicating a gradual reduction in performance over time (although it remained above 85% in the performed experiments). This study aims to achieve the goal of zero waste and contribute to the circular economy through the sustainable use of residual biomass. Full article

This research employed “Response Surface Methodology (RSM)” to assess the effectiveness of electrocoagulation (EC) in treating olive mill wastewater (OMW) before applying adsorption with olive stone biochar (OS) as a sustainable adsorbent. Several parameters, including reaction time, current density (CD), inter-electrode distance, and the number of electrodes, were optimized. Analysis using Minitab 22.2 resulted in robust regression models with high coefficients of determination (R²). The optimal parameters were CD of 12.41 mA/cm², a time of 45.61 min, an inter-electrode spacing of 1 cm, and a maximum of 6 electrodes, resulting in an energy consumption (ENC) of 9.85 kWh/m³. Significant pollutant percentage removals were achieved: 72.32% for total Kjeldahl nitrogen (TKN), 80.74% for turbidity, 57.44% for total phenol (TPh), 56.9% for soluble chemical oxygen demand (COD_soluble), and 56.6% for total chemical oxygen demand (COD_total). After the EC, the adsorption of pollutants was conducted using OS biochar that was generated through the pyrolysis of OS at a temperature of 500 °C. FTIR analysis of the biochar revealed key absorption bands that indicated the presence of inorganic compounds, aromatic C=C, and phenolic groups O-H. The integrated EC and adsorption (ECA) process demonstrated markedly higher efficiencies, with TPh removal reaching 61.41%, turbidity reduction at 81.92%, TKN reduction at 77.78%, COD_soluble reduction at 70.31%, COD_total reduction at 65.1%, and project cost of $2.88/m³. The ECA process presents a promising treatment approach for OMW. Full article

Polylactic acid (PLA) is a widely used bio-based polymer, although its application is limited by mechanical brittleness and low thermal resistance. PLA-based biocomposites reinforced with waste materials are gaining attention due to their sustainability, but their durability under degradation conditions remains a key concern. In this work, PLA biocomposites containing 0, 1, and 3% wt. of Olive-stone Biomass Ash (OBA) were manufactured and characterized both (1) after manufacture and (2) after laboratory-accelerated weathering (including UV exposure, heat, and humidity). The results obtained were analyzed to evaluate the influence of ash incorporation on degradation resistance (measured through Carbonyl Indices, CI), mechanical properties (tensile strength), thermal (Thermogravimetric Analysis—Differential Scanning Calorimetry, TGA-DSC), structure (Fourier Transform Infrared Spectroscopy, FT-IR), morphology (Scanning Electron Microscopy, SEM) and appearance (colorimetry and gloss). Key quantitative findings include a 35% reduction in tensile strength for raw PLA after 1000 h weathering exacerbated to 48% and 50% with 1% and 3% OBA incorporation, respectively. Degradation indices showed increased hydroxyl formation, with HI values ranging from 0.38 to 2.80 for PLA, while for biocomposites HI rose up to 5.85 for PLA with 3% OBA. Subsequently, a solid-state reaction was model-fitted from experimental data obtained by means of TGA analysis for determining the kinetic triplet (pre-exponential factor, the activation energy, and the reaction mechanism). Finally, the Acceleration Factor (AF), which combines the effects of radiation, temperature, and humidity to predict long-term material performance, is addressed analytically. Full article

Composite flours have been increasingly introduced in bakery products, aiming to enhance their nutritional value and reduce overdependence on imported wheat. Crackers are popular snack items, with potential to affect body weight and health status. This study aimed to examine the effects of different flour types, specifically pulses (chickpea, lupin, yellow split pea and cowpea), agricultural by-products (grape seeds and olive stones) and cereals (barley), on flour functionality, dough quality and final product characteristics compared with wheat flour (control) at various substitution levels. The functional properties of the composite flours were associated with the properties of dough and the characteristics of the crackers. Barley flour produced crackers with significantly higher hardness and lightness (L*) compared to the control, whereas chickpea flour had a similar but non-significant trend for both hardness and L* value. In contrast, high-level olive stone formulations yielded softer textures and the highest total color difference (ΔE), followed by grape seed crackers, which also exhibited high ΔE values and reduced hardness. The effects of composite flours on product texture were mediated by water absorption capacity and the compositional characteristics of the added flours. Crackers prepared with composite flours generally resulted in darker and diverse color profiles as well as low water activity and moisture values. Overall, the findings indicate that variations in composite flour type and substitution level influence product quality, allowing targeted modification of specific cracker attributes. Full article

Nowadays construction sector continues to face major environmental challenges, largely due to the consumption of natural resources, energy, and water, as well as the generation of waste and emissions into the environment. In Andalusia (Spain), the olive oil industry plays a central role in the economy, generating large volumes of waste and by-products, including olive stones. Due to their physical characteristics, olive stones represent a potential substitute for conventional aggregates in cement mortars, which are not subjected to restrictive technical standards as concrete. This study evaluates the technical feasibility of cement mortars prepared by replacing 10% and 20% of conventional sand (by volume) with four different types of olive stones. Tests were carried out on setting times, consistency, density, and air content, in fresh state, as well as on capillarity, density, and flexural and compressive strengths, in hardened state, using a conventional mortar as reference, with favorable results. Mortars could be classified according to the harmonized standards for masonry, rendering and plastering, and flooring and screed mortars, and for the applications described in the Spanish Building Code (CTE). This progress in knowledge would further support the integration of the construction sector into the fields of sustainability and circular economy. Full article

Major historic olive tree cultivars around the Mediterranean originate from the Jordan area and possess a proven abiotic stress tolerance; however, they were unexplored from the diversity perspective. Therefore, historic olive tree accessions from three northern regions—Irbid (i), Jerash (J), and Ajloun (A)—were analyzed using DNA molecular markers to identify and study their genetic relationships and genetic structure. DNA molecular markers of inter-simple sequence repeats (ISSR) were used. A total of 3150 data entries (859 present and 2291 absent) were generated with fragment sizes ranging from 350 to 2000 bp. Data entries were evaluated with UPGMA and population genetic structure analysis. The results showed that similarity among the investigated sixty-three accessions ranged from 9% between J14 and i20 up to 100% between ‘J11’ and ‘J12’ and between A8 and A9. The discriminating power values for ISSR_807, ISSR_810, and ISSR_825 were 0.70, 0.61, and 0.83, respectively. A generated dendrogram showed ten major clades, while the genetic structure could resolve four unique genetic pools: one for Irbid, one for Jerash, and two for Ajloun. In addition, analysis of 19 phenotypic parameters covering leaf, fruit, stone, and flesh was able to confirm the molecular data. Phenotypic and ISSR data were analyzed using PCA, cluster, and Mantel tests. ISSR markers showed clear genetic differentiation among groups, whereas phenotypic traits displayed lower variation but a significant correlation with molecular diversity. Promising accessions with either pure or admixture genetic makeup were identified. The resolved genetic structure of the investigated historic olive accessions would open new frontiers for olive breeding and utilization, helping to overcome current production challenges and climate change limitations. Full article

The growing accumulation of non-biodegradable petrochemical plastics and increasing food waste present urgent environmental and public health challenges. This study addresses both issues by developing biodegradable food packaging films from agar and starch, enhanced with antimicrobial properties by incorporating silver nanoparticles. The innovation of this work is the synthesis of novel agar–starch–silver nanoparticle coatings, where the contained nanoparticles were produced via green methods using two agro-industrial by-products of Greek olive oil production—olive stone extract and olive mill wastewater—as reducing agents. The morphology of the novel coatings was confirmed using transmission electron microscopy combined with energy-dispersive X-ray spectroscopy, revealing nanoscale particles with variable sizes. Additional film characterization was performed through Fourier-transform infrared spectroscopy, scanning electron microscopy coupled with energy-dispersive spectroscopy, and surface profilometry. Infrared spectroscopy analysis suggested the presence of functional groups responsible for nanoparticle stabilization, while energy-dispersive X-ray spectroscopy revealed silver aggregation in both olive stone extract and olive mill wastewater-derived films. Profilometry showed that films with olive mill wastewater-based nanoparticles had a rougher surface than those synthesized from olive stone extract. Antibacterial efficacy was tested against Escherichia coli (Gram-negative) and Staphylococcus epidermidis (Gram-positive) using a spot-on-film assay with high (10⁶ CFU/film) and low (10³ CFU/film) bacterial loads. After 72 h of incubation at 4 °C, both film types showed strong antibacterial activity at high bacterial concentrations, demonstrating their potential for active food packaging. These findings highlight a promising approach to sustainable food packaging within the circular economy, utilizing agricultural waste to create biodegradable materials with effective antimicrobial functionality. Full article

Water pollution from pharmaceutical and textile industries urgently requires effective treatment solutions due to environmental and health risks. Effective treatment methods are desperately needed for water pollution from the textile and pharmaceutical industries because of the dangers to the environment and human health. To treat these micropollutants, the optimized granular activated carbon (OGAC) produced from olive fruit stones was utilized as an adsorbent in this study. The central composite design (CCD) of response surface methodology (RSM) was statistically used to optimize the operating factors for rhodamine B (RhB) and thiamphenicol (THI) removal efficiency on the optimized granular activated carbon. This study evaluated the influence of factors such as the solution’s pH, initial RhB and THI concentration, and OGAC dose, along with their interactions to model outcomes and determined optimal adsorption conditions on OGAC. The adsorption kinetic data will be analyzed using the intra-particle diffusion, pseudo-second-order, and pseudo-first-order models. Equilibrium data will be analyzed using the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherms. The adsorption thermodynamics of the various systems under investigation will also be examined. Finally, a study on OGAC regeneration has been conducted. Results showed that THI and RhB removal is primarily influenced by pH, initial pollutant concentration, and dose. RSM indicated the optimal adsorption parameters for THI and RhB on OGAC as pH = 5.7, an initial concentration of C₀ = 2.5 mg/L, and a dose of 6 g/L. The kinetic study revealed that THI and RhB retention on OGAC generally follows a pseudo-second-order kinetic model, indicating chemisorption as the primary mechanism controlling adsorption. The adsorption isotherm data analysis showed that chemisorption has a significant role in the THI and RhB adsorption process on OGAC. Furthermore, thermodynamic parameters suggest that THI adsorption on OGAC is exothermic, while RhB adsorption is endothermic. Activated carbon regeneration tests demonstrated its cost-effectiveness, and activated carbon was successfully regenerated over three cycles, achieving efficiencies of 62.39% for RhB and 59.6% for THI. These results demonstrate that the studied OGAC is an effective adsorbent for THI and RhB removal. Full article

This review concentrates on the bioactive potential of two significant agri-food by-products: coffee by-products (coffee pulp and husk, spent coffee grounds, and silverskin) and olive by-products (olive mill wastewater, pomace, stones, and leaves). These residues are produced in substantial quantities, and despite their considerable application potential, they remain predominantly underutilized, thereby contributing to environmental burdens and economic losses. Their richness in bioactive compounds is unequivocal. Specifically, coffee by-products are abundant in caffeine and chlorogenic acids, whereas olive by-products serve as excellent sources of oleuropein, hydroxytyrosol, and tyrosol. Such compounds possess health-promoting properties and are promising active ingredients for cosmetic formulations, owing to their antioxidant, anti-aging, UV protective, antimicrobial, emollient, and moisturizing effects. This review not only compiles the bioactive compounds present in these by-products and explores their potential applications but also examines the extraction methods employed for their recovery. Both conventional techniques (solvent extraction) and green extraction technologies (ultrasound-assisted extraction, microwave-assisted extraction, and supercritical fluid extraction) are discussed. These innovative and environmentally friendly approaches enhance extraction efficiency and are aligned with sustainability objectives. In this context, the importance of incorporating natural ingredients into cosmetic products is emphasized, both to meet regulatory and environmental standards and to satisfy the increasing consumer demand for safer, more effective, and environmentally sustainable formulations. Full article