环境•农林最新文献

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.

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.

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.

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.

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.

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).

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.

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.

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 (q_max: 698–813 mg kg⁻¹) driven by endothermic, entropy-driven adsorption processes. The q_max and adsorption affinity (K_l) increased at higher temperatures to 12.4–13.3% and 19.5–26.6%, respectively. LMWOAs had minimal impact on adsorption isotherm, slightly reducing K_l (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.

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.