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- Adsorption Performance and Mechanism of Cu2+ Adsorption from Aqueous
Solution by Olivine Loaded with Magnesium Oxide Micro Rods
Abstract: Olivine is a natural material with abundant reserves and is considered to have the potential to treat heavy metal ions in water. In this study, a facile precipitation-calcination method was employed to deposit micrometer-sized magnesium oxide (MgO) rods onto the surface of olivine powder (PO). This process yielded a cost-effective MgO-modified olivine composite (MgO@PO400), which was subsequently evaluated for its ability to adsorb Cu2+ from aqueous solutions. The BET-specific surface area of MgO@PO400 was three times higher than that of PO, and the MgO micro-rods were distributed on the material's surface (BET:Brunauer-Emmet-Teller). Adsorption experiments showed that the data fitted well with the pseudo-second-order kinetic model and the Langmuir isotherm model, which indicated that Cu2+ was removed by monolayer chemisorption. In addition, the process was verified to be spontaneous and thermodynamically favorable. The maximum adsorption capacity of MgO@PO400 for Cu2+ was 225.82 mg/g, which was able to exhibit high removal efficiency (84.95–98.05%) for Cu2+ in the pH range of 3 to 5.5, and good immunity to the presence of different coexisting ions in the water, demonstrating that potential for treating complex Cu2⁺-containing wastewater. Various characterization methods verified the adsorption mechanism of MgO@PO400 on Cu2+, and the results showed that the removal of Cu2+ mainly involved ion exchange, surface precipitation and electrostatic attraction. Therefore, MgO@PO400 can be considered a potential adsorbent for removing Cu2+ from aqueous solutions. Graphical Abstract
PubDate: 2025-04-18
- Capturing and In-Situ Conversion of CO2 into Carbonates from Simulated
Marine Engine Exhaust Gases via Various Amino Acid Salts
Abstract: Onboard carbon capture has been recognized as a crucial strategy for mitigating CO2 emissions in the maritime sector. In the present paper, an integrated absorption and mineralization method using a blend of amino acid salts with alkaline minerals was employed to capture and directly convert CO2 into carbonate from simulated marine engine exhaust gas. The primary objective of this study is to evaluate the effects of various amino acid salt categories on the performance of CO2 capture, conversion, and the formation of carbonate polymorphs. The results reveal that specific amino acid salts, particularly the linear potassium glycinate and cyclic potassium proline, in conjunction with magnesium hydroxide, exhibit CO2 capture efficiencies surpassing 80%, accompanied by conversion efficiencies exceeding 95%. Poly amino acid salt potassium arginate, when paired with calcium hydroxide, yields a CO2 capture efficiency of 96.5% and achieves 100% conversion. However, regardless of the type of amino acid salt, the crystallographic forms of magnesium or calcium carbonates exhibit a remarkable uniformity, specifically as nesquhonite and calcite, respectively. Notably, certain sterically hindered amino acid salts, such as potassium valinate and potassium isoleucinate, exhibit a capacity to direct the oriented growth of carbonates, leading to the formation of crystalline particles of substantial size. The research outcomes presented herein offer significant insights for the selection of absorbents within the context of shipborne CO2 capture and mineralization integration technologies, with the objective of achieving high-efficiency absorption and conversion processes alongside the attainment of controllable product morphologies.
PubDate: 2025-04-17
- Adsorption of Cu(II) and Pb(II) Onto a Histosol in Comparison with Its
Humin Fraction
Abstract: This study investigated the adsorption of Cu2+ and Pb2+ onto a histosol (peat soil) as a function of pH and compared it to their adsorption onto its humin fraction. The use of the NICA-Donnan model, considering humic acid and humin as soil reactive solid phases and fulvic acid as reactive dissolved organic matter, satisfactorily described the adsorption behaviour of Cu2+ and Pb2+ onto histosol. Both metals were adsorbed mainly via carboxylic sites of both solid phases with a higher contribution of humic acid. Nevertheless, this study highlighted the significant role of humin, accounting for up to 37% of the overall metallic cation retention onto histosol. Thus, if not the most reactive solid organic matter fraction in soils, humin contributes notably to metal retention. Its contribution should thus be considered as a significant solid organic matter component of soils for a better description and prediction of metal trace element adsorption.
PubDate: 2025-04-17
- Health Risk Assessment of Variable Airborne Bacterial Occurrences at
Different Occupational Sites in Davangere City, India
Abstract: Bioaerosols are associated with widespread health challenges. Many ubiquitous bacteria in the form of bioaerosols are known to be etiological factors in human diseases. This study evaluated the qualitative and quantitative prevalence of indoor and outdoor airborne microbial loads at four different occupational sites in Davanagere city, Karnataka, India, between 2021 and 2023. Various traditional isolation methods and media, including soybean casein digest agar and HiCrome agars, were used in this study. Seasonal variations significantly influenced bacterial loads, with Staphylococcus spp. emerging as the dominant species, particularly in school zones and garden areas. Hospital OTs exhibited fluctuating microbial loads, with Escherichia spp. decreasing significantly, whereas Staphylococcus spp. showed an overall increase. The market and garden sites followed similar trends, with Proteus spp. and Klebsiella spp. decreasing. Hierarchical clustering revealed distinct seasonal patterns, with bacterial proliferation peaking in March–May. Disinfectant efficacy tests revealed that both Savlon and Dettol effectively inhibited most pathogens, with E. coli and P. aeruginosa requiring longer exposure times. These findings highlight the impact of seasonal factors and disinfection strategies on bacterial distribution. In conclusion, seasonal and geographic factors influence microbial distributions, highlighting the importance of monitoring bioaerosols to mitigate bacterial diseases and other associated risks, especially in urban settings.
PubDate: 2025-04-17
- Elutriates and Leachates of Soil Microcosms Contaminated With 2,4-D,
Fipronil, and Their Mixtures Affect the Life‑history Traits of
Ceriodaphnia Silvestrii (Crustacea: Cladocera)
Abstract: Pesticides in soil can migrate to surface water and groundwater. Their behavior and the influence of rainwater on their fate can be studied using ecosystem models, such as microcosms. This study evaluated the impacts of elutriate and leachate from contaminated soil microcosms on the immobility, feeding rate, survival, and reproduction of the Neotropical cladoceran Ceriodaphnia silvestrii. The systems were filled with natural soil and contaminated with 2,4-D and fipronil, both individually and in a mixture, using recommended doses for sugarcane crops. Pesticides were applied once at the beginning of the experiments, and precipitation was simulated twice a week until 21 days of the experiment. Results from the elutriate tests showed a high immobilization for C. silvestrii exposed to fipronil and its binary mixture with 2,4-D, reaching up to 57.5% and 76.25%, respectively. In contrast, acute effects were not observed when organisms were exposed to leachates. Chronic exposure to leachates increased the feeding rates from contaminated treatments. Survival effects were noted solely for 2,4-D, resulting in a 15% reduction, while reproduction decreased in treatments with 2,4-D, fipronil, and their mixture (56%, 42%, and 48%, respectively). These results demonstrate the significant impacts of soil contamination with pesticides on aquatic ecosystems and highlight the importance of evaluating elutriate and leachate in assessing soil ecotoxicity.
PubDate: 2025-04-17
- Shotgun Metagenome Reveals Herbicidal Influence on Antimicrobial
Resistance and Pollutant Degradation in Rice Field Soils
Abstract: Microbes are the most sensitive component of soil, and they are affected by any change in the soil properties caused by land use patterns and the application of pesticides. Exposure to antibiotics and pesticides results in the development of tolerant/degrading and antibiotic-resistant soil microbiomes that can flourish antimicrobial resistance (AMR) in other biota. Therefore, analyzing the emergence of AMR in soil due to anthropogenic activities is a prime concern. Due to comprehensiveness, high resolution, and versatility, a whole metagenome (shotgun) based study was conducted for the assessment of wide range of AMR and pollutant degradation pathway genes in rice field soils under the influence of land use (tillage) changes and herbicide (pendimethalin) application. In the zero tillage herbicide treatment versus zero tillage control groups, beta-lactam, vancomycin, and cationic antimicrobial peptides were the most significantly affected AMR genes, with fold change of 1.19, 1.20, and 1.31, respectively. Similarly, the most affected degradation pathways genes were of dioxin degradation, phosphonate/phosphinate metabolism, atrazine degradation, and benzoate degradation with fold change of 4.00, 2.00, 1.75, and 1.18, respectively. Overall, the study reveals an increase in AMR and pollutant degradation ability of soil microbial flora due to tillage and herbicide treatment. Pollutant degradation will aid in restoring soil health and environmental sustainability, whereas addressing AMR signifies the need for adequate monitoring and regulations to mitigate the spread of AMR. Henceforth, the outcomes would contribute in developing sustainable agricultural practices in rice fields to reduce the AMR load and enhance the efficacy of pollutant degradation in soils. Graphical Abstract
PubDate: 2025-04-17
- Functionalized Polyethylene Terephthalate Nanofiber Adsorbents for
Prospective Metal Recovery from Spent Lithium-Ion Batteries
Abstract: The lack of economically viable and environmentally friendly recycling processes to recover valuable metals from spent lithium-ion batteries (LIBs) has resulted in an environmental pollution and a high risk of metal resource shortage. Among various approaches, adsorption using electrospun nanofiber adsorbents has attracted research interest due to several distinctive properties. This study synthesized electrospun polyethylene terephthalate (PET) nanofiber adsorbent which was functionalized with Di-2-ethylhexyl phosphoric acid (DEHPA) to recover Ni, Co, or Mn metal ions. The pristine and modified electrospun nanofibers were characterized using Fourier Transform Infrared spectroscopy (FTIR)-Attenuated Total Reflection (ATR), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Thermogravimetric Analysis (TGA), and X-ray Diffraction (XRD). The adsorption kinetics and capacity of the modified PET-DEHPA nanofibers were obtained at optimum pH 4; 60 min of contact time and 100 mg/L initial metal concentration. The adsorption capacity of PET-DEHPA nanofibers for Ni, Co and Mn metal ions was 80 mg/g, 98 mg/g, and 118 mg/g, respectively. The selectivity of Mn over Ni and Co metal ions was also examined at pH 4 and showed that the recovery efficiencies were 5%; 11% and 58% for Ni, Co and Mn, respectively. Thus, indicating that the modified PET-DEHPA nanofiber was selective for Mn ions. The desorption and regeneration were also studied in solutions of nitric acid and Ni, Co and Mn ions, and results showed that PET-DEHPA nanofiber was able to withstand over 5 cycles, highlighting its potential in economic viability and sustainability. Overall, this study presents a new and promising approach for recycling Mn ions from solutions of spent LIBs.
PubDate: 2025-04-17
- Impact of Bisphenol A on Zebrafish Embryos and Mitigation Using Mangrove
Botanicals
Abstract: Bisphenol A (BPA) is a widely used component in plastics, BPA leaches into food and water, under conditions with pH changes or increased temperatures. This current study focuses on the evaluation BPA induced developmental toxicity in zebrafish embryos. And estimation of mangrove Avicennia marina (AM) and Avicennia officianalis (AO) leaf extracts for their nullifying properties against BPA these embryos. BPA-induced detrimental effects on embryo pigmentation and mortality are concentrations and time-dependent. The lethal concentration 50 (LC50) value for BPA was determined as 12.5 µg/mL. Co-treatment studies with AM and AO extracts alongside BPA did not significantly nullify toxicity; however, AO showed delayed hatching and increased mortality rates compared to AM. The apoptotic assays showed the induction of neurotoxicity and reduced fluorescence in brain cells and nerves in BPA-exposed larvae. However, AM and AO extracts at 25 µg/mL showed significant protective effects in brain cells and spinal regions akin to control. AO demonstrated superior neuroprotective effects, highlighting its potential as a nullifying agent against BPA-induced neurodegeneration. Fungal stains used, showed significant reduction in BPA present in the solution, proving its BPA degrading capabilities. Future studies could explore the molecular mechanisms underlying these effects and optimize concentrations for enhanced nullification of BPA-induced toxicity. Graphical Abstract
PubDate: 2025-04-17
- A Comprehensive Review of Forty Adsorption Isotherm Models: An In-depth
Analysis of Ten Statistical Error Measures
Abstract: Adsorption is a pivotal process in environmental cleanup and wastewater treatment due to its simplicity, cost-effectiveness, and sustainability. The quantification of adsorption is often expressed through Adsorption Isotherms, which model the substance adsorbed by a substrate at equilibrium. Understanding single, multi-component, and competitive adsorption isotherms is crucial for designing effective water treatment systems. Experimental data modeling plays a significant role in predicting adsorption mechanisms. This review explores isotherm models'foundational knowledge and practical applications, offering insights into their conceptual framework and utility. It covers single and multi-component contexts, extensively discussing various isotherm models and their parameters. The debate over linearization in adsorption equations is addressed, highlighting factors influencing parameter determination such as linearization method, experimental error, and data range. The paper elucidates techniques like linear and nonlinear regression analysis and error functions for optimal adsorption data analysis, providing a comprehensive understanding of the subject. Graphical Abstract
PubDate: 2025-04-16
- Enhanced Adsorption of Pb(II) by Potassium Permanganate Modified Spent
Coffee Grounds: Isotherms, Kinetics, and Optimization via Box-Behnken
Design
Abstract: The novel adsorbent of KMnO4-modified spent coffee grounds (KMnO4-SCGS) was successfully synthesized for the adsorption of Pb(II). Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and other characterization measurements were employed to evaluate the physical and chemical properties of KMnO4-SCGS. The results demonstrated that the adsorption behavior of Pb(II) was best fitted by the pseudo-second-order, Ritchie, and Langmuir isothermal models, indicating that the surface of KMnO4-SCGS was composed of homogeneous adsorption. The surface complexes with manganese oxide (MnOx) and oxygen-containing functional groups, along with electrostatic interaction, physical adsorption, and ion exchange, played significant roles in the adsorption of Pb(II). The Langmuir maximum adsorption capacity for Pb(II) was 203.8 mg/g for KMnO4-SCGS, which was approximately 11.73 times higher than that of SCGS, and it remained over 80% after five cycles. Finally, the Box-Behnken design was utilized to optimize the results. Therefore, the modification of spent coffee grounds by KMnO4 is a feasible approach for the adsorption of Pb(II). Graphic Abstract
PubDate: 2025-04-16
- Microwave Synthesis of Ag@MoS2 in NADES medium for the Dispersive Micro
Solid Phase Extraction of Atrazine in environmental samples
Abstract: A simple-to-operate, environmentally friendly method has been developed for novel Ag sphere synthesis in NADES media to achieve spherical form and for green synthesis that was modified with MoS2 nanoparticles. Ag@MoS2 was designed as an adsorbent for a rapid and economical dispersive micro solid phase extraction approach at trace levels. The Analytical parameters pH (5.0), sorbent mass (10 mg), extraction time (2.5 min), eluent volume (5 mL), eluent type (acetonitrile), and sample volume (10 mL) were optimized. The detection limit was found to be 0.6 μg L–1 and the technique’s linearity ranged from 2.1 to 250 μg L–1. The suggested approach has several benefits, including selectivity, precision, and rapidity. It is used practically to identify ATZ in lake water, fish farming water, tap water, allspice and rosehip. The ATZ recovery was sufficient, averaging between 91 and 107%. The method had an overall score of 0.57 on the AGREE scale.
PubDate: 2025-04-16
- Deterioration of Water Quality Between 2017 and 2021 in the Coronel
Aquifer, Chile
Abstract: The Coronel aquifer, located in Chile (36°S – 37°S), has experienced significant water quality deterioration, primarily due to environmental factors and anthropogenic pressures, including increased industrial activities, rising temperatures, and reduced precipitation. These factors synergistically contribute to higher pollutant concentrations. Fluctuations in metal ion levels, particularly total iron and total manganese, have frequently exceeded the regulatory limits for human consumption (0.3 mg L−1 and 0.1 mg L−1, respectively). In response, companies exploiting these aquifers have intensified the search for alternative water sources with better quality. This study analyzed the interannual and seasonal patterns of water quality in the Coronel aquifer, focusing on the hydrogeological sectors of common use (HSCU) in North and South Coronel, alongside hydrogeological measurements and environmental variables. The findings revealed that the North Coronel HSCU is predominantly affected by allochthonous organic pollutants (NO3−), whereas the South Coronel HSCU is impacted by metal pollutants (Fe and Mn). Metal ion concentrations exhibited pronounced interannual and seasonal dynamics, peaking during the summer when precipitation drops below 100 mm month−1 and average monthly temperatures exceed 14 °C. In contrast, NO3− levels did not demonstrate a clear interannual or seasonal pattern. The study suggests that anthropogenic pressures in both HSCU may facilitate the presence of these contaminants.
PubDate: 2025-04-16
- Effect of Low-Molecular-Weight Organic Acids and Silicon on Arsenic
Adsorption and Desorption in a Paddy Soil of Bengal Delta Plain: Insights
from Thermodynamics and Equilibrium Modeling
Abstract: The transfer of arsenic (As) from contaminated soil to the human body through rice represents a health catastrophe in the Bengal Delta Plain (BDP), emphasizing the need for a deeper understanding of the indispensable factors influencing the mobility and retention of As in the paddy soils of BDP. This study examined the effects of temperature and rice root-secreted low-molecular-weight organic acids (LMWOAs), at field-relevant levels, on As adsorption and desorption, while evaluating the influence of silicon (Si) on As desorption in BDP paddy soil, using thermodynamic analysis and equilibrium modeling. Arsenic adsorption and desorption experiments were conducted at two temperatures (20 and 35 °C) with and without LMWOAs, and the effect of Si (0–100 mg L⁻1) on As desorption was evaluated. The adsorption data were analyzed using a newly developed R package, “AdIsMF” for linear and nonlinear Freundlich and Langmuir isotherm models. Results revealed a considerable adsorption capacity (qmax: 698–813 mg kg⁻1) driven by endothermic, entropy-driven adsorption processes. The qmax and adsorption affinity (Kl) increased at higher temperatures to 12.4–13.3% and 19.5–26.6%, respectively. LMWOAs had minimal impact on adsorption isotherm, slightly reducing Kl (1.14 to 0.98 L mg⁻1) alone, but significantly impacting the energetics of As adsorption. The linear Langmuir model outperformed others in model selection criteria and accuracy measures, indicating monolayer adsorption on homogeneous surfaces. The adsorption mechanism was inferred to be predominantly chemisorption, supported by physisorption. Desorption studies revealed irreversible As binding to soil, with greater desorption at lower temperatures. Silicon concentrations above 1 mg L⁻1 significantly enhanced As mobility, with cumulative desorption reaching 31.5% under 100 mg L⁻1 Si. These findings underscore the importance of soil temperature, i.e. rice cultivation season, on As availability, and dose-optimization of Si amendments to mitigate As risks in paddy systems.
PubDate: 2025-04-16
- Experimental Study on the Engineering Properties and Resistivity of Clay
Contaminated by Alkali and Heavy Metal Ions
Abstract: The enrichment of metal ions on the surface of clay particles significantly leads to the loosening of the particle surface structure, thereby weakening the macroscopic engineering properties of the clay. In this study, sodium ions (Na⁺) and potassium ions (K⁺) as monovalent metal ions, along with lead ions (Pb2⁺) and zinc ions (Zn2⁺) as divalent metal ions, were selected as metal ion contaminants. The focus was to investigate their effects on the microstructural morphology, macroscopic engineering properties, and electrical properties of the clays. The aim of the study is to clarify the relationship between the valence state and concentration of these four types of metal ions and the engineering properties of clay, and to predict the engineering properties of metal-ion-contaminated clay using resistivity parameters. The results indicate that the incorporation of metal ions reduces the average particle size, transforming the soil structure from flaky to a honeycomb form. Under the same loading conditions, metal-ion-contaminated clay exhibits a lower void ratio. As the concentration of metal ions increases, pore volume decreases, thereby enhancing soil compressibility. Alkali metal ions primarily influence the soil structure through a dispersive effect, while heavy metal ions exert a cohesive effect. Monovalent alkali metal-ion-contaminated clay demonstrates larger compression coefficients across all load levels, whereas heavy metal-contaminated soils exhibit higher compression coefficients under low loads. Furthermore, the shear strength and cohesion of metal-ion-contaminated clay are lower than those of field-state clay. At lower concentrations, the internal friction angle may exceed that of field-state clay; however, as the concentration of metal ions increases, the shear strength, internal friction angle, and cohesion significantly decrease. The presence of metal ions also reduces soil resistivity, which declines at a diminishing rate with increasing concentration. At lower ion concentrations, monovalent alkali metal ions have a slightly stronger effect on reducing resistivity compared to divalent heavy metal ions. Resistivity parameters effectively reflect the compressibility and shear characteristics of metal-ion-contaminated clay, revealing a negative linear correlation between resistivity and compression ratio under uniaxial loading, while a positive linear correlation exists with shear strength, internal friction angle, and cohesion. These insights provide a basis for the rapid evaluation of engineering characteristics in metal-ion-contaminated clay.
PubDate: 2025-04-16
- Litter Input-Induced Variability in Greenhouse Gas Emissions Across the
Organic Horizon and Mineral Soils
Abstract: The addition of litter may induce greenhouse gas (GHG) emissions to varying degrees depending on the mineral soil and the organic horizon. An assessment was made to deduce the impact of different litter addition rates on soil GHG emissions, physicochemical properties, and the abundance of functional genes involved in carbon and nitrogen cycles in both the organic horizon and mineral soil. Compared with soil without litter amendment, cumulative CO2 emissions increased by 6.85% to 11.87% in organic soil and by 16.66% to 54.43% in mineral soil. However, there was no significant difference in cumulative N2O emissions in the organic soil layers. Cumulative N2O emissions increased by 26.03% to 172.63% in the mineral soil. Soil dissolved organic carbon (DOC) increased by 21.63% to 40.87%, while NO3− decreased by 22.03% to 57.24% with litter input. Furthermore, soil pH and dissolved organic nitrogen decreased by 1.34% to 3.19% and 13.28% to 21.51%, respectively, whereas NH4+ increased by 40.28% to 81.04% in the mineral soil compared with with soil without litter addition. Following litter amendments, changes in N2O emissions were mainly driven by variations in soil physicochemical properties in the mineral soil, whereas in the organic horizon soil, they were influenced by the amoA2 gene. In the organic horizon soil, both labile (xylA, a xylose isomerase-related gene) and recalcitrant (chiA, an endochitinase-related gene) carbon degradation genes, along with DOC, played a dominant role in soil CO2 emissions. The recalcitrant carbon degradation related gene (lig, a lignin degradation related gene), along with DOC and pH, contributed to CO2 emissions in the mineral soil. This study enhances our understanding of how GHG emissions respond to litter accumulation in the organic horizon and mineral soil and highlights the importance of litter management in mitigating GHG emissions in agricultural environments.
PubDate: 2025-04-16
- Use of Allium Cepa Test in the Ecotoxicological Evaluation of Sanitary
Sewage at Different Stages of Treatment in Two Municipal Wastewater
Treatment Plants (WWTP)
Abstract: This study aimed to evaluate and compare the ecotoxicity of effluent from two WWTPs that use different biological technologies to treat the sewage: i) anaerobic treatment (ANA), and ii) aerobic treatment (AER) as the main system operation, using A. cepa as test organism. The samples were analyzed for their cytotoxic, genotoxic, and mutagenic potentials. It was found that influent of the both WWTPs exhibited cytotoxic, genotoxic, and mutagenic indicators comparable to the positive control, which was conducted using the herbicide Trifuralin. The treated sewage from both WWTPs met the release standards for COD (chemical oxygen demand), under 250.0 mg/L, and NH4-N, under 20.0 N mg/L, required by current legislation for industrial effluent. The results indicated that effluent from AER presented 11.5 ± 0.5% of mitotic index (MI), 0.3 ± 0.5% of chromosomal aberrations (CAI) and 0% of mutagenicity (Muti), these results are statistically equal to the negative control treatment, conducted with distilled water. The effluent from WWTP ANA showed 10.7% of MI, statistically lower than the negative control, 0.4 ± 0.1% of CAI and 0% Muti, statistically equal to that presented by the negative control. It was concluded that both aerobic and anaerobic biologic technologies were effective in meeting the discharge standards established by legislation and in reducing the ecotoxicological potential of sanitary sewage, highlighting the importance of wastewater treatment in the prevention of diseases and environmental damage.
PubDate: 2025-04-16
- Temporal Distribution of Microplastics and other Anthropogenic Particles
in Abiotic Compartments of a Coastal Lagoon from the Atlantic Coast
Abstract: This study characterizes anthropogenic particles (AP) and microplastics (MP) in treated wastewater, sea surface, water column and intertidal sediments from the Arcachon Bay (France) at four seasons. Their morphometric characteristics, polymer types and concentrations were described. Concentrations showed some seasonal variations that may be related to anthropogenic factors like tourism or fishing. Overall, 2687.4 ± 1335.2 AP.m−3 (614.7 ± 481.4 MP.m−3) were found in wastewater and we estimated that 127.4 ± 41.6 million of AP (30.0 ± 25.2 million of MP) could enter the Atlantic Ocean each day via the wastewater system. Mean concentrations at sea surface, in water column and intertidal sediments were respectively 0.79 ± 1.64 AP.m−3 (0.62 ± 1.30 MP.m−3), 778.90 ± 370.95 AP.m−3 (319.2 ± 214.6 MP.m−3) and 86.93 ± 67.77 AP.kg−1 (16.1 ± 19.1 MP.kg−1 dry weight). Finally, we proposed insights about sources of AP and MP based on their characteristics (e.g. textiles, tyres, fishing).
PubDate: 2025-04-16
- Soaked Activated Coke Waste Ameliorates Saline-Alkali Soils via Selective
Salt Ion Adsorption and Enhances Maize Growth
Abstract: Activated coke waste (ACW), a byproduct of industrial desulfurization and denitrification, consists of fine particles (< 1 mm) with a porous structure, high specific surface area, and pH ~ 5, rendering it a candidate for saline-alkali soil remediation. However, its inherent excess salts and contaminants restrict direct agricultural application. In this study, ACW was treated with a dilute nitric acid solution to remove excess salts and contaminants, yielding the soaked activated coke waste (SACW) sample. The research systematically examined the adsorption properties and mechanisms of SACW for salt ion removal by solution experiment. Additionally, soil cultivation experiments were conducted to evaluate its potential in improving plant growth within saline-alkali soils. Compared to raw ACW, SACW exhibited reduced pH and electrical conductivity (EC), elevated oxygen-to-carbon (O/C) ratio, and expanded pore volume. SACW displayed ion adsorption selectivity in the order of SO₄2⁻> Na⁺> Cl⁻. Isothermal adsorption analysis revealed that Na⁺ and Cl⁻ adsorption aligned with the Langmuir model, whereas SO₄2⁻ adsorption adhered to the Freundlich model. Application of SACW (≥ 10 g kg⁻1) effectively improved saline-alkali soil properties by lowering pH and salinity, enhancing soil aggregate stability, and promoting nutrient utilization efficiency. Notably, SACW-treated soils supported maize plants with significantly increased height and biomass (13.94% and 159.28% higher, respectively; P ≤ 0.05) compared to untreated controls. These benefits stemmed from improved nutrient availability and reduced salt stress-induced plasma membrane damage. These findings validate SACW as a sustainable, functional amendment for reclaiming saline-alkali ecosystems and boosting crop productivity.
PubDate: 2025-04-15
- High-Altitude CO2 Flux in Cropland and Grassland of Eastern Qilian
Mountains, China: Variation and Driving Factors
Abstract: Understanding soil carbon dynamics in climate-sensitive alpine ecosystems is critical for addressing global warming challenges. This study systematically investigated CO2 flux patterns and drivers in cropland and grassland ecosystems (2000–2020) across China's eastern Qilian Mountains through integrated field monitoring, remote sensing and modeling. Results revealed rapid vertical CO2 flux intensification at − 10 to − 20 cm depths, with cropland and grassland soils exhibiting 623–1,252 ppm and 690–1,133 ppm respectively, which is 4–5 times higher than atmospheric levels, driven by microbial activity and pore structure transitions. Principal Component Analysis identified soil nutrient interactions explaining 69.6% of soil biogeochemical variance, where subsequent altitude-nutrient interaction analysis revealed elevation-driven soil organic carbon (SOC, R2 = 0.7253, p
PubDate: 2025-04-15
- Facile Green and Hydrothermal Synthesis of ZnO Nanorods using Eucalyptus
Extract: Photocatalytic Degradation of Cationic Dye
Abstract: The present study aimed to use Eucalyptus leaves extract for the green synthesis of ZnO oxide (ZnO) nanorods (NRs) using the hydrothermal method. The X-ray diffraction (XRD) patterns confirmed that the ZnO NRs had a hexagonal crystal structure with high crystal quality. FTIR analysis revealed the presence of functional groups associated to the formation of ZnO NRs. The optical band gap was calculated using the Tauc plot. Scanning electron microscopy (SEM) revealed rod-like morphology of the as-fabricated ZnO, which is further confirmed by the transmission electron microscopy (TEM) analysis. Furthermore, the biosynthesized ZnO NRs were used as photocatalysts for degradation of Rhodamine B (RhB) dye under ultraviolet radiation. Based on these results, ZnO NRs with a concentration of 20 mL of the eucalyptus extract revealed exceptional performance with a photocatalytic degradation rate of 94.77% under UV irradiation for 90 min. According to these results, wastewater can be treated effectively via the designed catalysts using the green and facile synthesis techniques.
PubDate: 2025-04-14
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