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15 pages, 2885 KiB  
Article
Effects of Modified Senna obtusifolia Straw Biochar on Organic Matter Mineralization and Nutrient Transformation in Siraitia grosvenorii Farmland
by Lening Hu, Yinnan Bai, Shu Li, Gaoyan Liu, Jingxiao Liang, Hua Deng, Anyu Li, Linxuan Li, Limei Pan and Yuan Huang
Agronomy 2025, 15(8), 1877; https://doi.org/10.3390/agronomy15081877 - 3 Aug 2025
Abstract
Biochar has garnered considerable attention as a soil amendment due to its unique physicochemical properties. Its application not only enhances soil carbon sequestration but also improves nutrient availability. Incorporating biochar into soil is regarded as a promising strategy for mitigating global climate change [...] Read more.
Biochar has garnered considerable attention as a soil amendment due to its unique physicochemical properties. Its application not only enhances soil carbon sequestration but also improves nutrient availability. Incorporating biochar into soil is regarded as a promising strategy for mitigating global climate change while delivering substantial environmental and agricultural benefits. In this study, biochar was extracted from Siraitia grosvenorii and subsequently modified through alkali treatment. A laboratory incubation experiment was conducted to assess the effects of unmodified (JMC) and modified (GXC) biochar, applied at different rates (1%, 2%, and 4%), on organic carbon mineralization and soil nutrient dynamics. Results indicated that, at equivalent application rates, JMC-treated soils exhibited lower CO2 emissions than those treated with GXC, with emissions increasing alongside biochar dosage. After the incubation, the 1% JMC treatment exhibited a mineralization rate of 17.3 mg·kg−1·d−1, which was lower than that of the control (CK, 18.8 mg·kg−1·d−1), suggesting that JMC effectively inhibited organic carbon mineralization and reduced CO2 emissions, thereby contributing positively to carbon sequestration in Siraitia grosvenorii farmland. In contrast, GXC application significantly enhanced soil nutrient levels, particularly increasing available phosphorus (AP) by 14.33% to 157.99%. Furthermore, partial least squares structural equation modeling (PLS-SEM) identified application rate and pH as the key direct factors influencing soil nutrient availability. Full article
(This article belongs to the Section Soil and Plant Nutrition)
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21 pages, 1458 KiB  
Article
Production of a Biosurfactant for Application in the Cosmetics Industry
by Ana Paula Barbosa Cavalcanti, Gleice Paula de Araújo, Káren Gercyane de Oliveira Bezerra, Fabíola Carolina Gomes de Almeida, Maria da Glória Conceição da Silva, Alessandra Sarubbo, Cláudio José Galdino da Silva Júnior, Rita de Cássia Freire Soares da Silva and Leonie Asfora Sarubbo
Fermentation 2025, 11(8), 451; https://doi.org/10.3390/fermentation11080451 (registering DOI) - 2 Aug 2025
Viewed by 184
Abstract
The cosmetics industry has been seeking to develop products with renewable natural ingredients to reduce the use of or even replace synthetic substances. Biosurfactants can help meet this demand. These natural compounds are renewable, biodegradable, and non-toxic or have low toxicity, offering minimal [...] Read more.
The cosmetics industry has been seeking to develop products with renewable natural ingredients to reduce the use of or even replace synthetic substances. Biosurfactants can help meet this demand. These natural compounds are renewable, biodegradable, and non-toxic or have low toxicity, offering minimal risk to humans and the environment, which has attracted the interest of an emerging consumer market and, consequently, the cosmetics industry. The aim of the present study was to produce a biosurfactant from the yeast Starmerella bombicola ATCC 22214 cultivated in a mineral medium containing 10% soybean oil and 5% glucose. The biosurfactant reduced the surface tension of water from 72.0 ± 0.1 mN/m to 33.0 ± 0.3 mN/m after eight days of fermentation. The yield was 53.35 ± 0.39 g/L and the critical micelle concentration was 1000 mg/L. The biosurfactant proved to be a good emulsifier of oils used in cosmetic formulations, with emulsification indices ranging from 45.90 ± 1.69% to 68.50 ± 1.10%. The hydrophilic–lipophilic balance index demonstrated the wetting capacity of the biosurfactant and its tendency to form oil-in-water (O/W) emulsions, with 50.0 ± 0.20% foaming capacity. The biosurfactant did not exhibit cytotoxicity in the MTT assay or irritant potential. Additionally, an antioxidant activity of 58.25 ± 0.32% was observed at a concentration of 40 mg/mL. The compound also exhibited antimicrobial activity against various pathogenic microorganisms. The characterisation of the biosurfactant using magnetic nuclear resonance and Fourier transform infrared spectroscopy revealed that the biomolecule is a glycolipid with an anionic nature. The results demonstrate that biosurfactant produced in this work has potential as an active biotechnological ingredient for innovative, eco-friendly cosmetic formulations. Full article
(This article belongs to the Special Issue The Industrial Feasibility of Biosurfactants)
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21 pages, 6621 KiB  
Article
Ecological Restoration Reshapes Ecosystem Service Interactions: A 30-Year Study from China’s Southern Red-Soil Critical Zone
by Gaigai Zhang, Lijun Yang, Jianjun Zhang, Chongjun Tang, Yuanyuan Li and Cong Wang
Forests 2025, 16(8), 1263; https://doi.org/10.3390/f16081263 - 2 Aug 2025
Viewed by 144
Abstract
Situated in the southern hilly-mountain belt of China’s “Three Zones and Four Belts Strategy”, Gannan region is a critical ecological shelter belt for the Ganjiang River. Decades of intensive mineral extraction and irrational agricultural development have rendered it into an ecologically fragile area. [...] Read more.
Situated in the southern hilly-mountain belt of China’s “Three Zones and Four Belts Strategy”, Gannan region is a critical ecological shelter belt for the Ganjiang River. Decades of intensive mineral extraction and irrational agricultural development have rendered it into an ecologically fragile area. Consequently, multiple restoration initiatives have been implemented in the region over recent decades. However, it remains unclear how relationships among ecosystem services have evolved under these interventions and how future ecosystem management should be optimized based on these changes. Thus, in this study, we simulated and assessed the spatiotemporal dynamics of five key ESs in Gannan region from 1990 to 2020. Through integrated correlation, clustering, and redundancy analyses, we quantified ES interactions, tracked the evolution of ecosystem service bundles (ESBs), and identified their socio-ecological drivers. Despite a 31% decline in water yield, ecological restoration initiatives drove substantial improvements in key regulating services: carbon storage increased by 6.9 × 1012 gC while soil conservation rose by 4.8 × 108 t. Concurrently, regional habitat quality surged by 45% in mean scores, and food production increased by 2.1 × 105 t. Critically, synergistic relationships between habitat quality, soil retention, and carbon storage were progressively strengthened, whereas trade-offs between food production and habitat quality intensified. Further analysis revealed that four distinct ESBs—the Agricultural Production Bundle (APB), Urban Development Bundle (UDB), Eco-Agriculture Transition Bundle (ETB), and Ecological Protection Bundle (EPB)—were shaped by slope, forest cover ratio, population density, and GDP. Notably, 38% of the ETB transformed into the EPB, with frequent spatial interactions observed between the APB and UDB. These findings underscore that future ecological restoration and conservation efforts should implement coordinated, multi-service management mechanisms. Full article
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19 pages, 5166 KiB  
Article
Investigation of a Volcanic Rock-Derived Coagulant for Water Purification: A Study of Its Preparation Process
by Lei Zhou, Zhangrui Yang, Xiaoyong Liu, Xiaoben Yang, Xuewen Wu, Yong Zhou and Guocheng Zhu
Water 2025, 17(15), 2279; https://doi.org/10.3390/w17152279 - 31 Jul 2025
Viewed by 91
Abstract
Volcanic rock is a natural mineral material which has garnered interest for its potential application in water treatment due to its unique physicochemical properties. In this study, we prepared a polysilicate aluminum chloride (PSAC) coagulant using volcanic rock which exhibited good coagulation–flocculation performance. [...] Read more.
Volcanic rock is a natural mineral material which has garnered interest for its potential application in water treatment due to its unique physicochemical properties. In this study, we prepared a polysilicate aluminum chloride (PSAC) coagulant using volcanic rock which exhibited good coagulation–flocculation performance. Further investigation into the influence of synthetic parameters, such as calcination temperature, reaction time, and alkali types, on the structure and performance of a volcanic rock-derived coagulant was conducted. Techniques including Scanning Electron Microscopy, Energy-Dispersive Spectroscopy, Fourier-Transform Infrared Spectroscopy, and X-Ray Diffraction were utilized to characterize it. Also, a ferron-complexation timed spectrophotometric method was used to study the distribution of aluminum species in the coagulant. Results indicated that the volcanic rock that was treated with acidic and alkaline solutions had the potential to form PSAC with Al-OH, Al-O-Si, Fe-OH, and Fe-O-Si bonds, which influenced the coagulation–flocculation efficiency. An acid leaching temperature of 90 °C, 8 mL of 2 mol/L NaOH, a reaction time of 0.5 h, and a reaction temperature of 60 °C were conducive to the preparation. A higher temperature could result in a higher proportion of Alb species, and, at 100 °C, the Ala, Alc, and Alb were 29%, 24%, and 47%, respectively, achieving a residual turbidity lower than 1 NTU at an appropriate dosage, as well as a reduction of over 0.1 to 0.018 in the level of UV254. The findings of this study provide a feasible method to prepare a flocculant using volcanic rock. Further application is expected to yield good results in wastewater/water treatment. Full article
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31 pages, 10410 KiB  
Article
Integrated Prospectivity Mapping for Copper Mineralization in the Koldar Massif, Kazakhstan
by Dinara Talgarbayeva, Andrey Vilayev, Elmira Serikbayeva, Elmira Orynbassarova, Hemayatullah Ahmadi, Zhanibek Saurykov, Nurmakhambet Sydyk, Aigerim Bermukhanova and Berik Iskakov
Minerals 2025, 15(8), 805; https://doi.org/10.3390/min15080805 - 30 Jul 2025
Viewed by 340
Abstract
This study developed a copper mineral prospectivity map for the Koldar massif, Kazakhstan, using an integrated approach combining geophysical and satellite methods. A strong spatialgenetic link was identified between faults and hydrothermal mineralization, with faults acting as key conduits for ore-bearing fluids. Lineament [...] Read more.
This study developed a copper mineral prospectivity map for the Koldar massif, Kazakhstan, using an integrated approach combining geophysical and satellite methods. A strong spatialgenetic link was identified between faults and hydrothermal mineralization, with faults acting as key conduits for ore-bearing fluids. Lineament analysis and density mapping confirmed the high permeability of the Koldar massif, indicating its structural prospectivity. Hyperspectral and multispectral data (ASTER, PRISMA, WorldView-3) were applied for detailed mapping of hydrothermal alteration (phyllic, propylitic, argillic zones), which are critical for discovering porphyry copper deposits. In particular, WorldView-3 imagery facilitated the identification of new prospective zones. The transformation of magnetic and gravity data successfully delineated geological features and structural boundaries, confirming the fractured nature of the massif, a key structural factor for mineralization. The resulting map of prospective zones, created by normalizing and integrating four evidential layers (lineament density, PRISMA-derived hydrothermal alteration, magnetic, and gravity anomalies), is thoroughly validated, successfully outlining the known Aktogay, Aidarly, and Kyzylkiya deposits. Furthermore, new, previously underestimated prospective areas were identified. This work fills a significant knowledge gap concerning the Koldar massif, which had not been extensively studied using satellite methods previously. The key advantage of this research lies in its comprehensive approach and the successful application of high-quality hyperspectral imagery for mapping new prospective zones, offering a cost-effective and efficient alternative to traditional ground-based investigations. Full article
(This article belongs to the Section Mineral Exploration Methods and Applications)
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19 pages, 775 KiB  
Article
Optimization of Mining Sequence for Ion-Adsorbed Rare Earth Mining Districts Incorporating Environmental Costs
by Lu Yi, Yi Zeng and Minggui Zheng
Sustainability 2025, 17(15), 6871; https://doi.org/10.3390/su17156871 - 29 Jul 2025
Viewed by 137
Abstract
The mining sequence of ionic rare earth mineral mining districts is related to the effective utilization of rare earth mineral resources and the protection of ecological environment. This study establishes an optimization model for the mining sequence of ion-adsorption rare earth mining districts [...] Read more.
The mining sequence of ionic rare earth mineral mining districts is related to the effective utilization of rare earth mineral resources and the protection of ecological environment. This study establishes an optimization model for the mining sequence of ion-adsorption rare earth mining districts that incorporates environmental costs, using the net present value (NPV) of the mining district and the net present value of environmental costs (CE) as objective functions. The model is applied to optimize the mining sequence of Mining District L. The results demonstrate that (1) Four algorithms, namely NSGA-II, NSGA-III, IBEA, and MOEA/D, were selected for comparison. The analysis based on the distribution of solutions, hypervolume values (HV), and computational time revealed that the IBEA exhibited superior performance. (2) The IBEA was employed to solve the multi-objective optimization problem, yielding a set of 30 optimal solutions. Different NPVs corresponded to different CE values, with the CE value increasing correspondingly as the NPV increased. (3) The weighted method was employed to transform the multi-objective optimization problem into a single-objective formulation. Using a genetic algorithm (GA), the optimal solution yielded a decision variable sequence for mining order as [2, 5, 8, 4, 1, 9, 6, 7, 3, 10, 11], with the net present value (NPV) of mining district profits reaching CNY 76,640.65 million and the environmental cost NPV amounting to CNY 19,469.18 million. Compared with the mining sequence optimization scheme that did not consider CE, although the NPV decreased by CNY 3.3266 million, the CE was reduced by CNY 10.6993 million. The mining sequence optimization model with environmental costs constructed in this paper provides a scientific decision-making basis for mining enterprises to consider the mining sequence in mining districts, minimize the damage to the ecological environment, and promote the coordinated progress of resource development and sustainable development. Full article
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27 pages, 940 KiB  
Review
Characteristics of Food Industry Wastewaters and Their Potential Application in Biotechnological Production
by Ivana Nikolić, Kosta Mijić and Ivana Mitrović
Processes 2025, 13(8), 2401; https://doi.org/10.3390/pr13082401 - 28 Jul 2025
Viewed by 550
Abstract
The food industry consumes large amounts of water across various processes, and generates wastewater characterized by parameters like biochemical oxygen demand, chemical oxygen demand, pH, suspended solids, and nutrients. To meet environmental standards and enable reuse or valorization, treatment methods such as physicochemical, [...] Read more.
The food industry consumes large amounts of water across various processes, and generates wastewater characterized by parameters like biochemical oxygen demand, chemical oxygen demand, pH, suspended solids, and nutrients. To meet environmental standards and enable reuse or valorization, treatment methods such as physicochemical, biological, and membrane-based processes are applied. This review focuses on the valorization of food industry wastewater in the biotechnological production of high-value products, with an emphasis on starch-rich wastewater, wineries and confectionery industry wastewater, and with a focus on new technologies for reduces environmental burden but also supports circular economy principles. Starch-rich wastewaters, particularly those generated by the potato processing industry, offer considerable potential for biotechnological valorization due to their high content of soluble starch, proteins, organic acids, minerals, and lipids. These effluents can be efficiently converted by various fungi (e.g., Aspergillus, Trichoderma) and yeasts (e.g., Rhodotorula, Candida) into value-added products such as lipids for biodiesel, organic acids, microbial proteins, carotenoids, and biofungicides. Similarly, winery wastewaters, characterized by elevated concentrations of sugars and polyphenols, have been successfully utilized as medium for microbial cultivation and product synthesis. Microorganisms belonging to the genera Aspergillus, Trichoderma, Chlorella, Klebsiella, and Xanthomonas have demonstrated the ability to transform these effluents into biofuels, microbial biomass, biopolymers, and proteins, contributing to sustainable bioprocess development. Additionally, wastewater from the confectionery industry, rich in sugars, proteins, and lipids, serves as a favorable fermentation medium for the production of xanthan gum, bioethanol, biopesticides, and bioplastics (e.g., PHA and PHB). Microorganisms of the genera Xanthomonas, Bacillus, Zymomonas, and Cupriavidus are commonly employed in these processes. Although there are still certain regulatory issues, research gaps, and the need for more detailed economic analysis and kinetics of such production, we can conclude that this type of biotechnological production on waste streams has great potential, contributing to environmental sustainability and advancing the principles of the circular economy. Full article
(This article belongs to the Special Issue 1st SUSTENS Meeting: Advances in Sustainable Engineering Systems)
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20 pages, 11478 KiB  
Article
Pore Evolution and Fractal Characteristics of Marine Shale: A Case Study of the Silurian Longmaxi Formation Shale in the Sichuan Basin
by Hongzhan Zhuang, Yuqiang Jiang, Quanzhong Guan, Xingping Yin and Yifan Gu
Fractal Fract. 2025, 9(8), 492; https://doi.org/10.3390/fractalfract9080492 - 28 Jul 2025
Viewed by 266
Abstract
The Silurian marine shale in the Sichuan Basin is currently the main reservoir for shale gas reserves and production in China. This study investigates the reservoir evolution of the Silurian marine shale based on fractal dimension, quantifying the complexity and heterogeneity of the [...] Read more.
The Silurian marine shale in the Sichuan Basin is currently the main reservoir for shale gas reserves and production in China. This study investigates the reservoir evolution of the Silurian marine shale based on fractal dimension, quantifying the complexity and heterogeneity of the shale’s pore structure. Physical simulation experiments were conducted on field-collected shale samples, revealing the evolution of total organic carbon, mineral composition, porosity, and micro-fractures. The fractal dimension of shale pore was characterized using the Frenkel–Halsey–Hill and capillary bundle models. The relationships among shale components, porosity, and fractal dimensions were investigated through a correlation analysis and a principal component analysis. A comprehensive evolution model for porosity and micro-fractures was established. The evolution of mineral composition indicates a gradual increase in quartz content, accompanied by a decline in clay, feldspar, and carbonate minerals. The thermal evolution of organic matter is characterized by the formation of organic pores and shrinkage fractures on the surface of kerogen. Retained hydrocarbons undergo cracking in the late stages of thermal evolution, resulting in the formation of numerous nanometer-scale organic pores. The evolution of inorganic minerals is represented by compaction, dissolution, and the transformation of clay minerals. Throughout the simulation, porosity evolution exhibited distinct stages of rapid decline, notable increase, and relative stabilization. Both pore volume and specific surface area exhibit a trend of decreasing initially and then increasing during thermal evolution. However, pore volume slowly decreases after reaching its peak in the late overmature stage. Fractal dimensions derived from the Frenkel–Halsey–Hill model indicate that the surface roughness of pores (D1) in organic-rich shale is generally lower than the complexity of their internal structures (D2) across different maturity levels. Additionally, the average fractal dimension calculated based on the capillary bundle model is higher, suggesting that larger pores exhibit more complex structures. The correlation matrix indicates a co-evolution relationship between shale components and pore structure. Principal component analysis results show a close relationship between the porosity of inorganic pores, microfractures, and fractal dimension D2. The porosity of organic pores, the pore volume and specific surface area of the main pore size are closely related to fractal dimension D1. D1 serves as an indicator of pore development extent and characterizes the changes in components that are “consumed” or “generated” during the evolution process. Based on mineral composition, fractal dimensions, and pore structure evolution, a comprehensive model describing the evolution of pores and fractal dimensions in organic-rich shale was established. Full article
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25 pages, 3460 KiB  
Article
Morphometric, Nutritional, and Phytochemical Characterization of Eugenia (Syzygium paniculatum Gaertn): A Berry with Under-Discovered Potential
by Jeanette Carrera-Cevallos, Christian Muso, Julio C. Chacón Torres, Diego Salazar, Lander Pérez, Andrea C. Landázuri, Marco León, María López, Oscar Jara, Manuel Coronel, David Carrera and Liliana Acurio
Foods 2025, 14(15), 2633; https://doi.org/10.3390/foods14152633 - 27 Jul 2025
Viewed by 415
Abstract
Magenta Cherry or Eugenia (Syzygium paniculatum Gaertn) is an underutilized berry species with an interesting source of functional components. This study aimed to evaluate these berries’ morphometric, nutritional, and phytochemical characteristics at two ripening stages, CM: consumer maturity (CM) and OM: over-maturity. Morphometric [...] Read more.
Magenta Cherry or Eugenia (Syzygium paniculatum Gaertn) is an underutilized berry species with an interesting source of functional components. This study aimed to evaluate these berries’ morphometric, nutritional, and phytochemical characteristics at two ripening stages, CM: consumer maturity (CM) and OM: over-maturity. Morphometric analysis revealed size and weight parameters comparable to commercial berries such as blueberries. Fresh fruits were processed into pulverized material, and in this, a proximate analysis was evaluated, showing high moisture content (88.9%), dietary fiber (3.56%), and protein (0.63%), with negligible fat, indicating suitability for low-calorie diets. Phytochemical screening by HPLC identified gallic acid, chlorogenic acid, hydroxycinnamic acid, ferulic acid, quercetin, rutin, and condensed tannins. Ethanol extracts showed stronger bioactive profiles than aqueous extracts, with significant antioxidant capacity (up to 803.40 µmol Trolox/g via Ferric Reducing Antioxidant Power (FRAP assay). Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopic analyses established structural transformations of hydroxyl, carbonyl, and aromatic groups associated with ripening. These changes were supported by observed variations in anthocyanin and flavonoid contents, both higher at the CM stage. A notable pigment loss in OM fruits could be attributed to pH changes, oxidative degradation, enzymatic activity loss, and biotic stressors. Antioxidant assays (DPPH, ABTS, and FRAP) confirmed higher radical scavenging activity in CM-stage berries. Elemental analysis identified minerals such as potassium, calcium, magnesium, iron, and zinc, although in moderate concentrations. In summary, Syzygium paniculatum Gaertn fruit demonstrates considerable potential as a source of natural antioxidants and bioactive compounds. These findings advocate for greater exploration and sustainable use of this native berry species in functional food systems. Full article
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25 pages, 4401 KiB  
Article
Impact of High Energy Milling and Mineral Additives on a Carbonate–Quartz–Apatite System for Ecological Applications
by Vilma Petkova, Katerina Mihaylova, Ekaterina Serafimova, Rositsa Titorenkova, Liliya Tsvetanova and Andres Trikkel
Materials 2025, 18(15), 3508; https://doi.org/10.3390/ma18153508 - 26 Jul 2025
Viewed by 324
Abstract
In this study, high-energy milled (HEM) samples of natural phosphorites from Estonian deposits were investigated. The activation was performed via planetary mill with Cr-Ni grinders with a diameter of 20 mm. This method is an ecological alternative, since it eliminates the disadvantages of [...] Read more.
In this study, high-energy milled (HEM) samples of natural phosphorites from Estonian deposits were investigated. The activation was performed via planetary mill with Cr-Ni grinders with a diameter of 20 mm. This method is an ecological alternative, since it eliminates the disadvantages of conventional acid methods, namely the release of gaseous and solid technogenic products. The aim of the study is to determine the changes in the structure to follow the solid-state transitions and the isomorphic substitutions in the anionic sub-lattice in the structure of the main mineral apatite in the samples from Estonia, under the influence of HEM activation. It is also interesting to investigate the influence of HEM on structural-phase transformations on the structure of impurity minerals-free calcite/dolomite, pyrite, quartz, as well as to assess their influence on the thermal behavior of the main mineral apatite. The effect of HEM is monitored by using a complex of analytical methods, such as chemical analysis, powder X-ray diffraction (PXRD), wavelength-dispersive X-ray fluorescence (WD-XRF) analysis, and Fourier-transformed infrared (FTIR) analysis. The obtained results prove the correlation in the behavior of the studied samples with regard to their quartz content and bonded or non-bonded carbonate ions. After HEM activation of the raw samples, the following is established: (i) anionic isomorphism with formation of A and A-B type carbonate-apatites and hydroxyl-fluorapatite; (ii) solid-phase synthesis of calcium orthophosphate-CaHPO4 (monetite) and dicalcium diphosphate-β-Ca2P2O7; (iii) enhanced chemical reactivity by approximately three times by increasing the solubility via HEM activation. The dry milling method used is a suitable approach for solving technological projects to improve the composition and structure of soils, increasing soil fertility by introducing soluble forms of calcium phosphates. It provides a variety of application purposes depending on the composition, impurities, and processing as a soil improver, natural mineral fertilizer, or activator. Full article
(This article belongs to the Special Issue Advances in Rock and Mineral Materials—Second Edition)
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22 pages, 5507 KiB  
Article
Experimental Study on the Pore Structure Evolution of Sandstone Under Brine Erosion
by Kang Peng, Tao Wu, Kun Luo, Song Luo, Jiaqi Zhou and Yuanmin Wang
Materials 2025, 18(15), 3500; https://doi.org/10.3390/ma18153500 - 25 Jul 2025
Viewed by 267
Abstract
The mechanical properties of sandstone, a common building material, are influenced by a variety of factors. In the coastal areas of China, groundwater has gradually become salinized into brine, which inevitably alters the original microstructure of rocks and affects the stability of underground [...] Read more.
The mechanical properties of sandstone, a common building material, are influenced by a variety of factors. In the coastal areas of China, groundwater has gradually become salinized into brine, which inevitably alters the original microstructure of rocks and affects the stability of underground structures. To clarify the evolution of the rock microstructure under brine erosion, this study used NMR technology to investigate the pore evolution characteristics of red sandstone under brine erosion. The experimental results show that the water absorption capacity of sandstone is influenced by the solution environment, with the lowest absorption rate occurring in regard to brine. The pores in red sandstone undergo significant changes after brine erosion. Factors such as the composition of the brine and soaking time affect sandstone porosity, with transformations of mini-pores and meso-pores leading to changes in porosity. In addition, XRD tests were carried out on the soaked red sandstone samples to analyze the changes in the main mineral components of the sandstone after brine erosion. Full article
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24 pages, 4612 KiB  
Article
A Privacy Preserving Attribute-Based Access Control Model for the Tokenization of Mineral Resources via Blockchain
by Padmini Nemala, Ben Chen and Hui Cui
Appl. Sci. 2025, 15(15), 8290; https://doi.org/10.3390/app15158290 - 25 Jul 2025
Viewed by 157
Abstract
The blockchain technology is transforming the mining industry by enabling mineral reserve tokenization, improving security, transparency, and traceability. However, controlling access to sensitive mining data remains a challenge. Existing access control models, such as role-based access control, are too rigid because they assign [...] Read more.
The blockchain technology is transforming the mining industry by enabling mineral reserve tokenization, improving security, transparency, and traceability. However, controlling access to sensitive mining data remains a challenge. Existing access control models, such as role-based access control, are too rigid because they assign permissions based on predefined roles rather than real-world conditions like mining licenses, regulatory approvals, or investment status. To address this, this paper explores an attribute-based access control model for blockchain-based mineral tokenization systems. ABAC allows access permissions to be granted dynamically based on multiple attributes rather than fixed roles, making it more adaptable to the mining industry. This paper presents a high-level system design that integrates ABAC with the blockchain using smart contracts to manage access policies and ensure compliance. The proposed model is designed for permissioned blockchain platforms, where access control decisions can be automated and securely recorded. A comparative analysis between ABAC and RBAC highlights how ABAC provides greater flexibility, security, and privacy for mining operations. By introducing ABAC in blockchain-based mineral reserve tokenization, this paper contributes to a more efficient and secure way of managing data access in the mining industry, ensuring that only authorized stakeholders can interact with tokenized mineral assets. Full article
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16 pages, 1319 KiB  
Review
Assessing the Divergent Soil Phosphorus Recovery Strategies in Domesticated and Wild Crops
by Mary M. Dixon and Jorge M. Vivanco
Plants 2025, 14(15), 2296; https://doi.org/10.3390/plants14152296 - 25 Jul 2025
Viewed by 358
Abstract
Plant-essential phosphorus (P) is a sparingly available mineral in soils. Phosphorus fertilizers—produced by the transformation of insoluble to soluble phosphates—are thus applied to agroecosystems. With advancements in commercial agriculture, crops have been increasingly adapted to grow in fertile environments. Wild crop relatives, however, [...] Read more.
Plant-essential phosphorus (P) is a sparingly available mineral in soils. Phosphorus fertilizers—produced by the transformation of insoluble to soluble phosphates—are thus applied to agroecosystems. With advancements in commercial agriculture, crops have been increasingly adapted to grow in fertile environments. Wild crop relatives, however, are adapted to grow in unfertilized soils. In response to these two conditions of P bioavailability (fertilized agroecosystems and unfertilized natural soils), domesticated crops and wild species employ different strategies to grow and develop. It is essential to understand strategies related to P acquisition that may have been lost to domestication, and here we present, for the first time, that across species, modern cultivars engage in physical (i.e., root morphological) mechanisms while their wild relatives promote ecological (i.e., root-microbial) mechanisms. Domesticated crops showcase shallower root system architecture and engage in topsoil foraging to acquire P from the nutrient-stratified environments common to fertilized agroecosystems. Wild species associate with P-cycling bacteria and AM fungi. This divergence in P recovery strategies is a novel delineation of current research that has implications for enhancing agricultural sustainability. By identifying the traits related to P recovery that have been lost to domestication, we can strengthen the P recovery responses by modern crops and reduce P fertilization. Full article
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17 pages, 5410 KiB  
Article
Mineral Phase Transformation and Leaching Behavior During the Roasting–Acid–Leaching Process of Clay-Type Lithium Ore in the Qaidam Basin
by Xiaoou Zhang, Jing Zhao, Yan Li, Dong An, Huaigang Cheng, Yuliang Ma and Huiping Song
Minerals 2025, 15(8), 777; https://doi.org/10.3390/min15080777 - 24 Jul 2025
Viewed by 163
Abstract
To address lithium extraction from clay-type lithium ore from the Qaidam Basin, this study identified key controlling factors through particle fractionation, acid-leaching–roasting experiments, and mineral characterization. The results demonstrate that particle size optimization enriched the lithium to 87.65 ppm, where a 74% leaching [...] Read more.
To address lithium extraction from clay-type lithium ore from the Qaidam Basin, this study identified key controlling factors through particle fractionation, acid-leaching–roasting experiments, and mineral characterization. The results demonstrate that particle size optimization enriched the lithium to 87.65 ppm, where a 74% leaching rate was achieved with 65 ppm extraction, which established intermediate-sized samples as optimal. During acid leaching, adsorbed lithium ions with a phyllosilicate interlayer were released via the ion exchange process instead of mineral dissolution, as verified by the Li-O/S-O peak shifts in the FTIR spectra. The roasting induced hydroxyl elimination, carbonate decomposition, and silicate restructuring but triggered lithium encapsulation via mineral phase reorganization, which caused a sharp leaching rate decline. Effective lithium extraction requires integrated particle size screening, acid-leaching optimization, and roasting-induced phase encapsulation disruption. This study established theoretical foundations for clay-type lithium ore exploitation. Full article
(This article belongs to the Section Mineral Processing and Extractive Metallurgy)
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19 pages, 4349 KiB  
Article
Thermoresponsive Behavior, Degradation, and Bioactivity of Nanohydroxyapatite on Graphene Oxide Nanoscroll-Enhanced Poly(N-isopropylacrylamide)-Based Scaffolds
by Lillian Tsitsi Mambiri, Riley Guillory and Dilip Depan
Polymers 2025, 17(15), 2014; https://doi.org/10.3390/polym17152014 - 23 Jul 2025
Viewed by 304
Abstract
Osteoarthritis and metastatic bone cancers create pathological oxidative environments characterized by elevated reactive oxygen species (ROS). ROS impair bone regeneration by degrading the scaffold and suppressing mineralization. To address these challenges, we fabricated thermoresponsive scaffolds based on poly(N-isopropylacrylamide) (PNIPAAm) incorporating in situ-grown nanohydroxyapatite [...] Read more.
Osteoarthritis and metastatic bone cancers create pathological oxidative environments characterized by elevated reactive oxygen species (ROS). ROS impair bone regeneration by degrading the scaffold and suppressing mineralization. To address these challenges, we fabricated thermoresponsive scaffolds based on poly(N-isopropylacrylamide) (PNIPAAm) incorporating in situ-grown nanohydroxyapatite on graphene oxide nanoscrolls (nHA-GONS) using stereolithography (SLA). Three scaffold formulations were studied: pure PNIPAAm (PNP), PNIPAAm with 5 wt.% nHA-GONS (P5G), and PNIPAAm with 5 wt.% nHA-GONS reinforced with polycaprolactone (PCL) microspheres (PN5GP). Each scaffold was evaluated for (i) swelling and lower critical solution temperature (LCST) using differential scanning calorimetry (DSC); (ii) oxidative degradation assessed using Fourier-transform infrared spectroscopy (FTIR), mass loss, and antioxidant assays; and (iii) mineralization and morphology via immersion in simulated body fluid followed by microscopy. The PN5GP and P5G scaffolds demonstrated reversible swelling, sustained antioxidant activity, and enhanced calcium deposition, which enable redox stability and mineralization under oxidative environments, critical for scaffold functionality in bone repair. PNP scaffolds exhibited copper accumulation, while PN5GP suffered from accelerated mass loss driven by the PCL phase. These findings identify the P5G formulation as a promising scaffold. This study introduces a quantitative framework that enables the predictive design of oxidation-resilient scaffolds. Full article
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