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12 pages, 882 KB  
Article
Optimization of Ibuprofen Route and Dosage to Enhance Protein-Bound Uremic Toxin Clearance During Hemodialysis
by Víctor Joaquín Escudero-Saiz, Elena Cuadrado-Payán, María Rodríguez-García, Gregori Casals, Lida María Rodas, Néstor Fontseré, María del Carmen Salgado, Carla Bastida, Nayra Rico, José Jesús Broseta and Francisco Maduell
Toxins 2026, 18(1), 37; https://doi.org/10.3390/toxins18010037 - 11 Jan 2026
Viewed by 393
Abstract
Protein-bound uremic toxins (PBUT), particularly indoxyl sulphate (IS) and p-cresyl sulphate (pCS), are poorly removed by conventional haemodialysis because of their strong albumin binding. These toxins are associated with cardiovascular morbidity and mortality in haemodialysis patients. Displacer molecules such as ibuprofen enhance PBUT [...] Read more.
Protein-bound uremic toxins (PBUT), particularly indoxyl sulphate (IS) and p-cresyl sulphate (pCS), are poorly removed by conventional haemodialysis because of their strong albumin binding. These toxins are associated with cardiovascular morbidity and mortality in haemodialysis patients. Displacer molecules such as ibuprofen enhance PBUT clearance by competing for albumin-binding sites, but the optimal dose and route of administration remain unclear. The aim of this study was to evaluate the effect of different ibuprofen doses, infusion durations, and routes of administration on the removal of IS and pCS during on-line hemodiafiltration (OL-HDF). In this prospective, single-centre, crossover study, 21 chronic haemodialysis patients receiving intradialytic analgesia underwent nine OL-HDF sessions. Ibuprofen was administered at two doses (400 or 800 mg) either in the arterial pre-filter line (infusion over 1 h, 2 h, or 3 h) or in the venous post-filter line (30 min). Reduction ratios (RR) of total IS and pCS were determined by LC-MS and corrected for haemoconcentration. Statistical analysis included repeated-measures ANOVA with post-hoc testing. Baseline RR for IS and pCS were 53.7 ± 9.9% and 47.1 ± 10.9%, respectively. The highest RR was achieved with 800 mg ibuprofen infused via the arterial line over 2 h (IS: 60.8 ± 8.6%; pCS: 57.8 ± 9.7%). All arterial-line 800 mg regimens and the 3-h 400 mg infusion significantly improved pCS clearance versus baseline; IS clearance improved significantly only with arterial-line 800 mg regimens and with the 400 mg 3-h infusion. Infusion rate (1–3 h) had no significant effect on RR within the same dose group. Pain scores decreased significantly after dialysis regardless of ibuprofen regimen. Arterial-line administration of ibuprofen enhances total IS and pCS removal during OL-HDF, with higher doses yielding greater clearance. Prolonged low-dose infusion appears similarly effective for pCS and may reduce systemic exposure, potentially lowering toxicity risk. These findings support the arterial line as the preferred route for displacer administration in clinical practice. Full article
(This article belongs to the Special Issue Uremic Toxins and Chronic Kidney Disease)
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18 pages, 3043 KB  
Article
Antibacterial and Antioxidant Performance of Natural Textile Dyes for Children’s Wear
by Diana Santiago, Behnaz Mehravani, Cátia Alves, Isabel Cabral, Joana Cunha, Andrea Zille and Jorge Padrão
Appl. Sci. 2026, 16(1), 307; https://doi.org/10.3390/app16010307 - 28 Dec 2025
Viewed by 379
Abstract
Children’s skin is highly sensitive and prone to irritation, allergies, and infections, requiring special consideration in textile selection. Although clothing serves as a protective barrier, it can also pose a risk when dyed with toxic chemical colourants. This study explores the potential of [...] Read more.
Children’s skin is highly sensitive and prone to irritation, allergies, and infections, requiring special consideration in textile selection. Although clothing serves as a protective barrier, it can also pose a risk when dyed with toxic chemical colourants. This study explores the potential of multifunctional natural dyes as safer alternatives for children’s clothing, particularly for those with dermatological conditions. Cotton knitted fabrics were dyed through exhaustion with extracts of madder root (Rubia tinctorum L.), pomegranate peel (Ppe, Punica granatum L.), oxidised logwood (Logox, Haematoxylum campechianum L.), and tannin from quebracho (Schinopsis lorentzii Griseb.), both individually and in various combinations with or without potassium aluminium sulphate dodecahydrate (alum). The combination of madder and Ppe demonstrated the most promising multifunctional performance, being classified as a weak disinfectant against S. aureus (3.7 log reduction) and showing the highest antioxidant activity (92.6 ± 2.56% 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical reduction), while maintaining excellent results after washing. Moreover, these natural formulations expanded the achievable colour palette from each dye while maintaining moderate wash fastness. The results highlight the relevance of these findings to textile and fashion designers, offering sustainable tools for creating health-conscious, visually appealing garments. This research reinforces the potential of natural dyes and biomordants in developing functional textiles that support children’s wellbeing and environmental responsibility. Full article
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17 pages, 4039 KB  
Article
Characteristics of Microbial Communities in Sediments from Culture Areas of Meretrix meretrix
by Fengbiao Wang, Yue Zhu, Chaozhong Xin, Shuai Han, Haopeng Hu, Longyu Liu, Jinmeng Bao, Xuan Zhang, Lei Li and Mei Jiang
Diversity 2025, 17(12), 848; https://doi.org/10.3390/d17120848 - 10 Dec 2025
Viewed by 334
Abstract
This study examined the sediment microbial communities at 12 stations within the Meretrix meretrix farming area in Rudong, Jiangsu Province, utilising high-throughput sequencing. It elucidates the ecological relationships between the sediment microbial communities and the primary physical and chemical factors influencing the farming [...] Read more.
This study examined the sediment microbial communities at 12 stations within the Meretrix meretrix farming area in Rudong, Jiangsu Province, utilising high-throughput sequencing. It elucidates the ecological relationships between the sediment microbial communities and the primary physical and chemical factors influencing the farming water and sediment. The results indicated that the microbial communities comprised 55 phyla. The Shannon index ranged from a minimum of 8.97 to a maximum of 9.96, while the Simpson index varied from 0.996 to 0.997, indicating a uniform species distribution. β diversity analysis revealed significant spatial diversity among the communities. Dominant bacterial groups included Proteobacteria (25.2–38%) and Desulfobacterota (10.4–14.4%), with Desulfobacterota reaching a peak of 14.4% at tidal creek station S2, reflecting the sulphate reduction process associated with organic pollution input. At the genus level, Woesia (9.15–17.16%), Desulfobacterota, and Subgroup_22 were identified as core functional bacteria. Redundancy analysis indicated that phosphate and nitrate were the primary drivers of community variation, accounting for a cumulative interpretation rate of 43.2%. Spearman correlation analysis confirmed that fine-grained sediments were more likely to store organic matter, significantly promoting the colonisation of AQS1 (p < 0.05) and Cohaesibacter (p < 0.05), while inhibiting Puniceispirillales (p < 0.01). An alkaline environment positively selects for sulphur-cycling bacteria, such as Desulfatiglans (p < 0.05). This study provides technical support for the regulation of sediment environments and the promotion of healthy clam culture practices. Full article
(This article belongs to the Special Issue Aquatic Biodiversity and Habitat Restoration)
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17 pages, 7260 KB  
Article
A Novel Method for the Synthesis of Tin(II) Sulphide Using Tin(II) Sulphate Precursor via H2-Mediated Ultrasonic Spray Pyrolysis
by Hanwen Chung, Srecko Stopic and Bernd Friedrich
Materials 2025, 18(24), 5497; https://doi.org/10.3390/ma18245497 - 6 Dec 2025
Viewed by 502
Abstract
This study presents a novel approach for the synthesis of tin(II) sulphide (SnS) by integrating ultrasonic spray pyrolysis (USP) with hydrogen reduction (HR), using tin(II) sulphate (SnSO4) as a precursor. The method combines aerosol droplet generation using ultrasonic atomisation at 1.7 [...] Read more.
This study presents a novel approach for the synthesis of tin(II) sulphide (SnS) by integrating ultrasonic spray pyrolysis (USP) with hydrogen reduction (HR), using tin(II) sulphate (SnSO4) as a precursor. The method combines aerosol droplet generation using ultrasonic atomisation at 1.7 MHz with gas-phase reduction in a tube reactor under H2-N2 mixed gas flow. Thermochemical assessment indicated that SnS formation is thermodynamically favourable from 400 to 1000 °C, in reasonable agreement with experimental results. XRD analysis confirmed the formation of SnS as the main phase accompanied by SnO2 as a secondary product without SnSO4 when conducting USP-HR at 1000 °C. SEM images revealed flake-like, spherical, and agglomerated morphologies, with EDS confirming distinct Sn-S regions. This study demonstrates the feasibility of producing SnS powder using a simple precursor system and a clean reducing environment. The process offers a scalable and controllable synthesis route for SnS materials, providing an alternative to conventional substrate-based deposition techniques. Further optimisation of reaction temperature and residence time is expected to enhance phase purity and reduce agglomeration. Full article
(This article belongs to the Section Energy Materials)
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26 pages, 3502 KB  
Article
Evolution of a Dystrophic Crisis in a Non-Tidal Lagoon Through Microphyte Blooms
by Francesca Polonelli, Marco Leporatti Persiano, Chiara Melillo and Mauro Lenzi
Phycology 2025, 5(4), 78; https://doi.org/10.3390/phycology5040078 - 1 Dec 2025
Viewed by 303
Abstract
In July–August 2024, a severe dystrophic process occurred in the Orbetello lagoon (Italy). This study reports the following: (1) the macroalgal biomass and the sediment labile organic matter (LOM) between 2018 and 2024; (2) the water temperature and dissolved oxygen values between June [...] Read more.
In July–August 2024, a severe dystrophic process occurred in the Orbetello lagoon (Italy). This study reports the following: (1) the macroalgal biomass and the sediment labile organic matter (LOM) between 2018 and 2024; (2) the water temperature and dissolved oxygen values between June and September 2024 and the T-mean, T-max, and T-min in July and August between 2013 and 2024; (3) the list of microphyte taxa that occurred during the dystrophy; (4) satellite images documenting the evolution of the dystrophic process. The results suggest that the dystrophy was caused by the decay of a large macroalgal mass and high accumulations of LOM in the sediment, which triggered anaerobic processes, particularly intense sulphate-reductive activity. This virulent process was facilitated by a record increase in temperatures (with T-min and T-max higher than those of the previous years), in a context of poor hydrodynamics, typical of non-tidal lagoons. Microphyte blooms, which occurred during the dystrophy, were at the basis of the evolution of the phenomenon, allowing for the most critical phase to be overcome through intense oxygen production. Microphytic blooms, with intense water colouring, although constituting an evident sign of a eutrophic/hypertrophic state of the lagoon, could lead to a rapid evolution of the dystrophy and mitigate the environmental conditions. Full article
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18 pages, 3333 KB  
Article
Assessing Different Passive Treatment Pathways of Acid Mine Drainage in an Ecologically Engineered Wetland After a Veldfire
by Paul Oberholster, Yolandi Schoeman, Anna-Maria Botha, Petri Oberholster and Jacques Maritz
Processes 2025, 13(11), 3494; https://doi.org/10.3390/pr13113494 - 30 Oct 2025
Viewed by 527
Abstract
In this paper, different physiochemical and biological indicators were tested to determine and compare the water quality of the Zaalklapspruit ecologically engineered wetland before and after a veldfire. Five sampling sites and a reference site 2.2 km upstream of an acid mine drainage [...] Read more.
In this paper, different physiochemical and biological indicators were tested to determine and compare the water quality of the Zaalklapspruit ecologically engineered wetland before and after a veldfire. Five sampling sites and a reference site 2.2 km upstream of an acid mine drainage (AMD)-decanting coal mine were selected and sampled before and after the veldfire. The “black box” method was also employed to determine the percentage change in the selected in- and outflow variables before and after the veldfire. After the veldfire, Al was reduced by 97.43%. The same trend was observed for Fe, which decreased by 99.65% at the outflow, and Mn and sulphate levels decreased by 98.41% and 68.16%. Possible pathways of the reduction in acid mine drainage impacts on the wetland were identified after the veldfire, including the increase in waterflows during the wet season causing a dilution factor, and phycoremediation by macroalgae drifting mats that accumulate metals and ash slurry from the burned-out macrophyte plant material that may have increased the wetland’s alkalinity. A comprehensive framework for the digital twinning and monitoring of the effects of natural disasters on wetlands is also presented. Full article
(This article belongs to the Section Environmental and Green Processes)
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17 pages, 2277 KB  
Article
Mitigating Microbiologically Influenced Corrosion of Iron Caused by Sulphate-Reducing Bacteria Using ZnO Nanoparticles
by Harith Ambepitiya, Supun Rathnayaka, Yashodha Perera, Chamindu Jayathilake, Himashi Ferdinandez, Ajith Herath, Udul Sanjula, Aishwarya Rathnayake, Charitha Basnayaka and Eustace Fernando
Processes 2025, 13(10), 3239; https://doi.org/10.3390/pr13103239 - 11 Oct 2025
Viewed by 2653
Abstract
Microbiologically Influenced Corrosion (MIC) significantly endangers steel infrastructure, particularly in marine and buried environments, causing considerable economic and environmental damage. Sulphate-reducing bacteria (SRB) are primary supporters of MIC, accelerating iron corrosion through hydrogen sulfide production. Conventional mitigation strategies, including protective coatings and cathodic [...] Read more.
Microbiologically Influenced Corrosion (MIC) significantly endangers steel infrastructure, particularly in marine and buried environments, causing considerable economic and environmental damage. Sulphate-reducing bacteria (SRB) are primary supporters of MIC, accelerating iron corrosion through hydrogen sulfide production. Conventional mitigation strategies, including protective coatings and cathodic protection, often face challenges such as limited effectiveness against SRB and the aggressiveness of saltwater corrosion. This study explores a novel approach by directly introducing zinc oxide (ZnO) nanoparticles into the microbial medium to inhibit SRB activity and reduce MIC. Iron metal coupons were immersed in seawater under three conditions: control (seawater only), seawater with SRB, and SRB with ZnO nanoparticles. These coupons were used as electrodes in microbial fuel cells to obtain real-time voltage readings. At the same time, corrosion was evaluated using cyclic voltammetry (CV), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), mass loss, and pH measurements. Results demonstrate that ZnO nanoparticles significantly inhibited SRB growth, as confirmed by the antibiotic susceptibility test (ABST). It was revealed that the corrosion rate increased by 21.3% in the presence of SRB compared to the control, whereas the ZnO-added electrode showed a 21.7% reduction in corrosion rate relative to the control. SEM showed prominent corrosive products on SRB-exposed coupons. ZnO-added coupons exhibited a protective layer with grass-like whisker structures, and EDX results confirmed reduced sulfur and iron sulfide deposits, indicating suppressed SRB metabolic activity. ABST confirmed ZnO’s antimicrobial properties by producing clear inhibition zones. ZnO nanoparticles offer the dual benefits of antimicrobial activity and corrosion resistance by forming protective self-coatings and inhibiting microbial growth, making them a scalable and eco-friendly alternative to traditional corrosion inhibitors. This application can significantly extend the lifespan of iron structures, particularly in environments prone to microbial corrosion, demonstrating the potential of nanomaterials in combating microbiologically influenced corrosion (MIC). Full article
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27 pages, 6729 KB  
Article
Process Route for Electric Arc Furnace Dust (EAFD) Rinse Wastewater Desalination
by Hedviga Horváthová, Eduardo Henrique Rotta, Tatiane Benvenuti, Andréa Moura Bernardes, Andrea Miskufova and Zita Takáčová
Processes 2025, 13(9), 2919; https://doi.org/10.3390/pr13092919 - 12 Sep 2025
Viewed by 609
Abstract
This study introduces a two-step treatment method for synthetic and real electric arc furnace dust (EAFD) wastewater, integrating sorption with Mg–Al layered double hydroxides (LDHs) and electrodialysis (ED). The hydrotalcite (LDH), mainly Mg6Al2(CO3)OH16·4H2O [...] Read more.
This study introduces a two-step treatment method for synthetic and real electric arc furnace dust (EAFD) wastewater, integrating sorption with Mg–Al layered double hydroxides (LDHs) and electrodialysis (ED). The hydrotalcite (LDH), mainly Mg6Al2(CO3)OH16·4H2O (hydrotalcite-2H), was characterized by XRD, FTIR, SEM, and EDX, confirming its layered structure and ion-exchange capacity. Calcination at 550 °C was identified as optimal, enhancing sorption efficiency while retaining rehydration potential. Sorption tests demonstrated high effectiveness in removing multivalent ions, achieving over 99% elimination of Ca2+, SO42−, and Pb2+ ions and Cr from both synthetic and real wastewater. In contrast, monovalent ions such as Na+ and K+ were not effectively removed, except for partial removal of Cl. To overcome this limitation, electrodialysis was applied in the second step, successfully targeting the remaining monovalent ions and achieving more than 95% conductivity reduction. A key challenge of ED, salt precipitation caused by calcium and sulphate in the concentrate, was effectively mitigated by the prior LDH treatment. The combined process minimized scaling risks, improved overall ion removal (above 97% for Na+ and K+), and produced low-salinity effluents (0.84 mS cm−1), suitable for reuse in hydrometallurgical operations. These findings demonstrate that coupling LDH sorption with electrodialysis provides a sustainable and efficient strategy for treating high-salinity industrial wastewaters, particularly those originating from EAFD processes. Full article
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22 pages, 5553 KB  
Article
Sandblasting Wood as a Technique of Simulated Weathering
by Marko Petrič, Luka Albreht, Eli Keržič, Jaka Levanič, Matjaž Pavlič and Jernej Skerbiš
Appl. Sci. 2025, 15(18), 9919; https://doi.org/10.3390/app15189919 - 10 Sep 2025
Viewed by 689
Abstract
While most efforts are aimed at preventing the surface roughening and colour change of wood due to weathering, some customers, mainly for decorative reasons, want wooden objects and elements to give the impression that they have been weathered for a long time. In [...] Read more.
While most efforts are aimed at preventing the surface roughening and colour change of wood due to weathering, some customers, mainly for decorative reasons, want wooden objects and elements to give the impression that they have been weathered for a long time. In this study, the simulated weathering of numerous softwoods as well as ring-porous and diffuse-porous woods by sandblasting and greying with iron sulphate was investigated. Calculations of the correlations between wood density, orientation, mass loss and thickness reduction by sandblasting were performed, and the difference between the hardness of late and early wood and the surface profile parameter Pt showed that the surface profiles correlate strongly with mass loss, especially in the tangential orientation. Softwoods appeared to be the most promising for simulated profiling, especially spruce and larch with tangential surfaces. Among the ring-porous woods, oak and sweet chestnut also delivered good results. Full article
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21 pages, 65608 KB  
Article
Saline Peatland Degradation in the Mezzano Lowland: 66 Years of Agricultural Impacts on Carbon and Soil Biogeochemistry
by Aaron Sobbe, Valentina Brombin, Enzo Rizzo and Gianluca Bianchini
Land 2025, 14(8), 1621; https://doi.org/10.3390/land14081621 - 9 Aug 2025
Viewed by 931
Abstract
The conversion of wetlands into croplands often leads to significant losses of peat soil salinity and soil organic matter (SOM), though quantifying these changes is challenging due to limited historical data. In this study, we compared current soil physicochemical properties with rare historical [...] Read more.
The conversion of wetlands into croplands often leads to significant losses of peat soil salinity and soil organic matter (SOM), though quantifying these changes is challenging due to limited historical data. In this study, we compared current soil physicochemical properties with rare historical data from the Mezzano Lowland (ML) in Northeastern Italy, a former wetland drained over 60 years ago. The transformation, which affected approximately 18,100 hectares, was achieved through the construction of a network of drainage canals and pumping stations capable of removing large volumes of water, enabling intensive agricultural use. Results showed a marked decrease in electrical conductivity (EC) and sulphate concentration, indicating extensive salt leaching from the upper peat soil layers. EC dropped from historical values up to 196 mS/cm (1967–1968) to a current maximum of 4.93 mS/cm, while sulphate levels declined by over 90%. SOM also showed significant depletion, especially in deeper layers (50–100 cm), with losses ranging from 50 to 60 wt%, due to increased aeration and microbial activity post-drainage. These climatic and environmental changes, including a marked reduction in soil salinity and sulphate concentrations due to prolonged leaching, have likely shifted the Mezzano Lowland from a carbon sink to a net source of CO2 and CH4 by promoting microbial processes that enhance methane production under anaerobic conditions. To detect residual peat layers, we used Ground-Penetrating Radar (GPR), which, combined with soil sampling, proved effective for tracking long-term peat soil changes. This approach can inform sustainable land management strategies to prevent further carbon loss and maintain peat soil stability. Full article
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14 pages, 504 KB  
Article
Comparative Efficacy of pHA130 Haemoadsorption Combined with Haemodialysis Versus Online Haemodiafiltration in Removing Protein-Bound and Middle-Molecular-Weight Uraemic Toxins: A Randomized Controlled Trial
by Shaobin Yu, Huaihong Yuan, Xiaohong Xiong, Yalin Zhu and Ping Fu
Toxins 2025, 17(8), 392; https://doi.org/10.3390/toxins17080392 - 5 Aug 2025
Cited by 1 | Viewed by 1756
Abstract
Protein-bound uraemic toxins (PBUTs), such as indoxyl sulphate (IS) and p-cresyl sulphate (PCS), are poorly cleared by conventional haemodialysis (HD) or haemodiafiltration (HDF). Haemoadsorption combined with HD (HAHD) using the novel pHA130 cartridge may increase PBUT removal, and this trial aimed to compare [...] Read more.
Protein-bound uraemic toxins (PBUTs), such as indoxyl sulphate (IS) and p-cresyl sulphate (PCS), are poorly cleared by conventional haemodialysis (HD) or haemodiafiltration (HDF). Haemoadsorption combined with HD (HAHD) using the novel pHA130 cartridge may increase PBUT removal, and this trial aimed to compare its efficacy and safety with HDF in patients with end-stage renal disease (ESRD). In this single-centre, open-label trial, 30 maintenance HD patients were randomized (1:1:1) to HDF once every two weeks (HDF-q2w), HAHD once every two weeks (HAHD-q2w), or HAHD once weekly (HAHD-q1w) for 8 weeks, with the primary endpoint being the single-session reduction ratio (RR) of IS. The combined HAHD group (n = 20) demonstrated a significantly greater IS reduction than the HDF-q2w group (n = 10) (46.9% vs. 31.8%; p = 0.044) and superior PCS clearance (44.6% vs. 31.4%; p = 0.003). Both HAHD regimens significantly reduced predialysis IS levels at Week 8. Compared with HDF, weekly HAHD provided greater relief from pruritus and improved sleep quality, with comparable adverse events among groups. In conclusion, HAHD with the pHA130 cartridge is more effective than HDF for enhancing single-session PBUT removal and alleviating uraemic symptoms in patients with ESRD, with weekly application showing optimal symptomatic benefits. Full article
(This article belongs to the Section Uremic Toxins)
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16 pages, 4109 KB  
Article
Spatiotemporal Analysis and Physicochemical Profiling of PM10 and PM2.5 in Slovenia
by Maja Ivanovski, Ivan Anžel, Darko Goričanec and Danijela Urbancl
Atmosphere 2025, 16(5), 540; https://doi.org/10.3390/atmos16050540 - 2 May 2025
Cited by 3 | Viewed by 1484
Abstract
Particulate matter (PM10 and PM2.5) is a key contributor to urban air pollution and poses significant health risks, particularly in densely populated areas. While conventional air quality monitoring focuses on particle size and concentration, this study emphasizes the importance of [...] Read more.
Particulate matter (PM10 and PM2.5) is a key contributor to urban air pollution and poses significant health risks, particularly in densely populated areas. While conventional air quality monitoring focuses on particle size and concentration, this study emphasizes the importance of understanding chemical composition and emission sources for effective air pollution management. PM samples were collected between 2019 and 2022 at two locations in the Republic of Slovenia: a traffic-dominated urban site and an industrial area. Annual average PM10 concentrations ranged from 14 to 34 µg/m3, and those of PM2.5 ranged from 9 to 22 µg/m3. In addition to decreasing annual concentrations, a notable reduction in exceedance days was observed between 2019 and 2022, indicating the effectiveness of recent air quality improvement measures. Meteorological data and statistical models were used to assess environmental influences on PM variability. Advanced SEM-EDS analysis revealed substantial seasonal and spatial differences in particle composition, with key elements such as silicon (4.3–28.4%), carbon (13.1–61.7%), and trace amounts of lead and zinc varying across sites and particle types. Mineral dust (Si, Al, Ca, Fe, Mg), originating from soil resuspension, construction, and Saharan dust, was dominant. Combustion-related particles containing C, Pb, Zn, and Fe oxides were associated with vehicle emissions, industrial processes, and biomass burning. Secondary aerosols, such as sulphates and nitrates, showed seasonal trends, with higher concentrations in summer and winter, respectively. The results confirm that PM levels are driven by complex interactions between local emissions, weather conditions, and seasonal dynamics. The study supports targeted policy measures, particularly regarding residential heating and traffic emissions, to improve air quality. Full article
(This article belongs to the Section Air Quality)
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27 pages, 3186 KB  
Review
Anaerobic Bioremediation of Acid Mine Drainage Using Sulphate-Reducing Bacteria: Current Status, Challenges, and Future Directions
by Ditiro Mafane, Tholiso Ngulube and Mamasegare Mabel Mphahlele-Makgwane
Sustainability 2025, 17(8), 3567; https://doi.org/10.3390/su17083567 - 15 Apr 2025
Cited by 14 | Viewed by 6841
Abstract
Biological reduction of sulphates has gradually replaced unit chemical processes for the treatment of acid mine drainage (AMD), which exerts a significant environmental impact due to its elevated acidity and high concentrations of heavy metals. Bioremediation is optimally suited for the treatment of [...] Read more.
Biological reduction of sulphates has gradually replaced unit chemical processes for the treatment of acid mine drainage (AMD), which exerts a significant environmental impact due to its elevated acidity and high concentrations of heavy metals. Bioremediation is optimally suited for the treatment of AMD because it is cost-effective and efficient. Anaerobic bioremediation employing sulphate-reducing bacteria (SRB) presents a promising solution by facilitating the reduction of sulphate to sulphide. The formed can precipitate and immobilise heavy metals, assisting them in their removal from contaminated wastewater. This paper examines the current status of SRB-based bioremediation, with an emphasis on recent advances in microbial processes, reactor design, and AMD treatment efficiencies. Reviewed studies showed that SRB-based bioreactors can achieve up to 93.97% of sulphate reduction, with metal recovery rates of 95% for nickel, 98% for iron and copper, and 99% for zinc under optimised conditions. Furthermore, bioreactors that used glycerol and ethanol as a carbon source improved the efficiency of sulphate reduction, achieving a pH neutralisation from 2.8 to 7.5 within 14 days of hydraulic retention time. Despite the promising results achieved so far, several challenges remain. These include the need for optimal environmental conditions, the management of toxic hydrogen sulphide production, and the economic feasibility of large-scale applications. Future directions are proposed to address these challenges, focusing on the genetic engineering of SRB, integration with other treatment technologies, and the development of cost-effective and sustainable bioremediation strategies. Ultimately, this review provides valuable information to improve the efficiency and scalability of SRB-based remediation methods, contributing to more sustainable mining practices and environmental conservation. To ensure relevance and credibility, relevance and regency were used as criteria for the literature search. The literature sourced is directly related to the subject of the review, and the latest research, typically from the last 5 to 10 years, was prioritised. Full article
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37 pages, 14137 KB  
Article
Origin of Siderite and Baryte in a Carbonate-Replacement Ag-Pb-Zn-Cu Sulphide Deposit: Walton, Nova Scotia, Canada
by Chaneil J. Wallace, Daniel J. Kontak, Elizabeth C. Turner and Mostafa Fayek
Minerals 2025, 15(3), 327; https://doi.org/10.3390/min15030327 - 20 Mar 2025
Viewed by 2320
Abstract
Siderite and baryte are common non-sulphide phases in sedimentary exhalative (SEDEX) deposits, but their formation remains poorly understood. Siderite is important as an exploration vector in some deposits, whereas baryte is important as a S source in some deposits. The past-producing Walton deposit [...] Read more.
Siderite and baryte are common non-sulphide phases in sedimentary exhalative (SEDEX) deposits, but their formation remains poorly understood. Siderite is important as an exploration vector in some deposits, whereas baryte is important as a S source in some deposits. The past-producing Walton deposit (Nova Scotia, Canada) consists of two ore types: (1) a sulphide body primarily hosted by sideritised Viséan Macumber Formation limestone (0.41 Mt; head grade of 350 g/t Ag, 4.28% Pb, 1.29% Zn, and 0.52% Cu), and (2) an overlying massive baryte body of predominantly microcrystalline baryte (4.5 Mt of >90% baryte). This study used optical microscopy, SEM-EDS, cathodoluminescence (CL), LA-ICP-MS, and SIMS sulphur isotope analysis of siderite and baryte to elucidate their origin and role in deposit formation. Siderite replaces limestone and contains ≤9 wt. % Mn, is LREE-depleted (PAAS-normalised REEY diagrams), and has low (<20) Y/Ho ratios. Sideritisation occurred due to dissimilatory iron reduction (DIR) that led to the breakdown of Fe-Mn-oxyhydroxides and organic matter, as indicated by light δ13CVPBD values and negative Y anomalies. The baryte body is dominated by a microcrystalline variety that locally develops a radial texture and coarsens to a tabular variety; it also occurs intergrown with, and as veins in, massive sulphides. Based on fluid inclusion data from previous studies, the coarser baryte types grew from a hot (>200 °C) saline (25 wt. % NaCl) fluid containing CO2-CH4 and liquid petroleum. Marine sulphate δ34SVCDT values typical of the Viséan (~15‰) characterise the baryte body and some tabular baryte types, whereas heavier (~20‰) and lighter (~10‰) values typify the remaining tabular types. The variations in tabular baryte relate to distinct zones identified by CL imaging and are attributed to the sulphate-driven anaerobic oxidation of methane (SDAOM) and oxidation of excess H2S after sulphide precipitation. These results highlight the importance of hydrocarbons (methane and organic matter) in the formation of both the siderite and the baryte at Walton and that DIR and the SDAOM can be important contributing processes in the formation of SEDEX deposits. Full article
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18 pages, 2986 KB  
Article
Influence of Electrolyte Composition on the Semiconductor–Electrolyte Interface (SEI) Built-In for Enhanced Photoelectrochemical (PEC) Processes
by Bartłomiej Leks, Aleksandra Parzuch, Nabila Nawaz, Justyna Widera-Kalinowska, Krzysztof Bienkowski and Renata Solarska
Molecules 2025, 30(4), 885; https://doi.org/10.3390/molecules30040885 - 14 Feb 2025
Cited by 2 | Viewed by 1525
Abstract
The relentless consumption of fossil fuels and soaring CO2 emissions have plunged the world into an energy and environmental crisis. As society grapples with these challenges, the demand for clean, renewable, and sustainable energy solutions has never been more urgent. However, even [...] Read more.
The relentless consumption of fossil fuels and soaring CO2 emissions have plunged the world into an energy and environmental crisis. As society grapples with these challenges, the demand for clean, renewable, and sustainable energy solutions has never been more urgent. However, even though many efforts have been made in this field, there is still room for improvement concerning efficiency, material stability, and catalytic enhancement regarding kinetics and selectivity of photoelectrochemical (PEC) processes. Herein, we provide the experimental proof for the enhancement of the photocurrent efficiency by the critical focus on semiconductor–electrolyte interface (SEI) properties. By tailoring electrolyte composition, researchers can unlock significant improvements in catalytic efficiency and stability, paving the way for advanced PEC technologies. In this study, we investigate the influence of electrolyte composition on SEI properties and its impact on PEC performance. By employing electrolytes enriched with carbonates, borates, sulphates, and alkali cations, we demonstrate their profound role in optimising photoelectrochemical CO2 reduction reaction (CO2RR) efficiency. Central to this work is Cu2O—an affordable, highly promising photocatalyst. While its potential is undeniable, Cu2O’s inherent instability and diverse reduction products, ranging from CH3OH to CO, HCOOH, CH3COOH, and CH3CH2OH, have hindered its widespread adoption in PEC CO2 reduction (CO2RR). Our approach leverages a straightforward yet powerful electrodeposition method, enabling a deeper exploration of SEI dynamics during photocatalysis. Key parameters, such as carbonate concentration, local pH, alkali cation presence, anionic geometry, CO2 solubility, and electrolyte conductivity, are systematically investigated. The findings reveal the formation of a unique “rigid layer” at the photocatalyst surface, driven by specific cation–anion interactions. This rigid layer plays a pivotal role in boosting PEC performance, offering a new perspective on optimising, among other PEC processes, CO2RR catalytic efficiency. This profound study bridges a critical knowledge gap, shedding light on the dual influence of cations and anions on SEI properties and PEC CO2RR. By unravelling these intricate interactions, we provide a roadmap for designing next-generation PEC systems. These insights pave the way for sustainable energy advancements, inspiring innovative strategies to tackle one of the most pressing challenges of our time. Full article
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