Environmental science. Advances最新文献

Pore-water electrical conductivity (ECw) is the ideal indicator of soil salinity in agriculture, as it directly represents the salinity experienced by plant roots. However, its practical application is limited by its dependence on soil water content and the labour-intensive, destructive, costly, and time-consuming process of pore-water extraction and analysis, especially for large-scale field applications. Ground-penetrating radar (GPR) and electromagnetic induction (EMI) provide non-destructive, time-efficient, and cost-effective alternatives for estimating soil properties and state variables. This study aimed to develop a method for estimating ECw by integrating GPR and EMI techniques using both stochastic and deterministic approaches at the field scale. EMI and GPR surveys were conducted before and after controlled irrigations, and soil samples were collected for laboratory analysis as ground truthing. The stochastic approach involved developing multiple linear regression (MLR) models, whereas the deterministic approach involved modifying and evaluating Archie's equation. The MLR models demonstrated high predictive accuracy, with an R² of 0.75 between measured and predicted ECw values. Both approaches provided reliable ECw predictions, with low root mean square error (RMSE) during evaluation (<1.67 mS m⁻¹ for MLR and <2.65 mS m⁻¹ for Archie's equation). However, the parameters in Archie's equation deviated from laboratory-estimated values and required modifications. At the study site, the stochastic approach outperformed the deterministic approach. Future research should focus on refining these models to improve their applicability across different soil types and conditions, aiming to improve the accuracy and reliability of soil salinity assessments in various agricultural landscapes.

This study focused on measuring 80 target per- and poly-fluoroalkyl substances (PFAS) in brain samples from various marine mammals, including: harbor seal, gray seal, harp seal, harbor porpoise, white-sided dolphin, white-beaked dolphin, and True's beaked whale, all collected from the St. Lawrence Estuary and Gulf. A total of 34 PFAS compounds were detected in these mammals. The geometric mean of the detected PFAS levels ranged from 0.02 ng g⁻¹ wet weight (ww) to 41 ng g⁻¹ ww. Notably, the detection frequency for PFOS was very high at 97.5%. For individual long-chain C9 to C13 perfluorocarboxylic acids (PFCAs), the detection frequencies ranged from 77% to 95%. In contrast, the detection frequencies for C3 to C6 PFCAs specifically PFHxA, PFBA, and PFPrA were much lower, ranging from 2.5% to 5%. This indicates a greater tendency for long-chain PFCAs to accumulate compared to shorter-chain variants. Additionally, a higher occurrence of PFSAs and PFCAs was observed across all species examined. Interesting findings emerged regarding species at higher trophic levels, such as the white-sided dolphin, white-beaked dolphin, and True's beaked whale, which exhibited significant levels of fluorinated alkyl substance acids (FASAs) and their alternatives (FASAAs). In a comparative analysis of PFAS distribution in liver, muscle, and brain tissues, correlation analysis revealed that concentrations in these tissues are positively correlated with each other. This study highlights concerns regarding the impact of PFAS on marine aquatic systems and potential neurocognitive impacts on their brain functions.

Two ordered microporous carbons (0.83 nm and 1.55 nm) were synthesized for the first time via a modified silica template method, enabling the adjustment of the carbon microporous structure, which is a limitation of the conventional zeolite template method. Dye adsorption showed that its removal rate increased with decreasing pore size.

This paper provides a Panarctic review of the regulations, loads, and treatment of wastewater (WW) discharged in the Arctic region. WW regulation principles and practices vary across the Arctic nations, being based either on effluent quality criteria (Canada, Sweden and Cruise ships), recipient-based criteria (Greenland, Norway), or a combination of the two (Alaska, Faroe Islands, Finland, Iceland, Russia). Conventional centralized treatment, ranging from preliminary screening to advanced/tertiary treatment, is applied to 59% of Arctic WW. Natural centralized systems, including ponds, lagoons, wetlands, and infiltration systems, are used for the treatment of 5% of the WW in the region, while 16% is treated on-site, mostly using septic tanks, sometimes affiliated with drain fields, but small package plants and infiltration systems are also in use. Between 14–20% of Arctic WW is discharged without any treatment in line with the global regions with the highest WWT service levels. However, Arctic treatment systems frequently fail to meet regulations or have reduced requirements, and secondary treatment level or higher is accomplished for only 19% of the total WW in the Arctic region, compared to 86% in Europe and North America overall. Where treatment is absent or deficient, discharge of WW may contribute to the environmental degradation of receiving waters and pose the risk of exposure of local fauna and humans to chemical contaminants and pathogens. Ecosystem impacts have been described for communities with above 2000 inhabitants; however, more studies are needed. Most sludge in the Arctic region is landfilled or used as landfill coverage, also leaving risk of exposure. It is recommended to establish cross-regional collaboration to exchange knowledge and experience on solutions and practice, and to introduce an aligned legislation and monitoring framework to reduce the environmental footprint and the risk of exposure of WW in the region.

Water pollution from organic contaminants is one of the biggest problems affecting the globe today. Conventional wastewater treatment systems have been used many times to solve world water pollution problems. This study focuses on the development of Cu doped TiO₂/g-C₃N₄ heterojunction nanocomposites to improve the effectiveness of visible light harvesting, increase charge separation and transfer efficiency, and enhance photocatalytic activity for the degradation of organic contaminants. The synthesized photocatalysts were extensively analysed using XRD, FTIR, BET, UV DRS, PL, SEM, TEM, and XPS methodologies. The superior photocatalyst (Cu-TiO₂/g-C₃N₄) achieved the highest photocatalytic degradation efficiency for BPA, MB, CR, and EBT under visible light irradiation. The rate constant for photocatalytic degradation of BPA over the Cu-TiO₂/g-C₃N₄ photocatalyst was 10.83, 8.86 and 3.48 fold greater than that of pure TiO₂, pristine g-C₃N₄, and Cu-TiO₂ photocatalysts, respectively. The rate constant decreased with the introduction of AO and TBA as they scavenge holes and hydroxyl radicals, respectively. The increased photocatalytic activity of the ternary photocatalyst is attributed to improved electron–hole pair separation and the creation of the type-II heterojunction structure. The photocatalytic parameters of BPA demonstrate that the Cu-TiO₂/g-C₃N₄ photocatalyst could be used in real-world wastewater treatment applications.

The consequences of acid mine drainage (AMD) are apparent in water and sediment of the upper reaches of the Crocodile River (West) system, which is located in the western basin of the Witwatersrand mountain chain in South Africa. Another significant indicator for metal and metalloid pollution in aquatic systems is biota. In particular, in the case of AMD-impacted areas, which occur worldwide, biota could serve as an important bioindicator of contamination and also be useful in terms of remediation of pollutants. We investigated the content of Fe, Ni, Cu, Zn, As, Se, Ag, Cd, Hg, and Pb in the liver and muscle tissue of 4 fish species (Oreochromis mossambicus, Labeobarbus polylepis, Labeobarbus marequensis, and Clarias gariepinus) and in roots and stems of macrophytes Pontederia crassipes, Typha sp. and Phragmites australis taken from selected sites in the system. Metals and metalloids were analyzed in freeze-dried and acid-digested samples using graphite furnace atomic absorption spectroscopy, cold vapor atomic absorption spectroscopy, and total reflection X-ray fluorescence spectroscopy. We determined that the mean levels of Fe, Ni and Cu were increased in the roots of Typha sp. and P. crassipes at sites influenced by AMD. Both macrophytes could also be used for phytoremediation of Ni, Cu and Cd, with bioaccumulation factors above 1 at all study sites ranging from 1.1 (Cu) to 21 (Cd) for Typha sp. and 2.7 (Ni) to 25 (Cd) for P. crassipes. Plants were found to be better bioindicators for AMD than fish due to homeostatic regulation of Ni, Cu, and Zn in fish at chronic low-level pollution. An exception was the liver tissue of O. mossambicus, which accumulated high levels of Ni (2.98 ± 1.24 mg kg⁻¹ dw), Cu (184 ± 124 mg kg⁻¹ dw) and Ag (2.01 ± 0.51 mg kg⁻¹ dw), demonstrating its bioindicative potential for these metals. Our study allowed a detailed look at an AMD influenced river system, revealing results that clearly demonstrate the consequences of chronic low-level pollution, although water melioration is in place.

Short-chain chlorinated paraffins (SCCPs) are widely found in the environment. However, limited information exists on the inter-media exchange and migration of SCCPs in the same region. In this study, a comprehensive survey of SCCPs was performed on various environmental substrates (including the surface soil, groundwater, and air) from a large petrochemical park in the Yangtze River Delta, and a total of 24 congener groups were measured. The SCCP concentrations, spatial variations, congener group profiles, and environmental behaviors during the water–land–atmosphere cycle in a typical industrial area were investigated. The ΣSCCP concentrations in the surface soil and groundwater within the petrochemical factory and in the atmosphere in the petrochemical factory perimeter were 108–745 ng g⁻¹, 1133–2994 ng L⁻¹ and 12.1–30.5 ng m⁻³, respectively. The concentrations and homologue patterns of SCCP significantly varied across different sampling sites, which was attributed to the distances between the sampling sites and workshops, as well as the diverse CP products or byproducts involved in the processing activities. The congener profile revealed that C₁₀Cl_8,9 and C₁₃Cl_8,9 were the major SCCP homologue groups in the soil within the petrochemical park, whereas C₁₀Cl_5–7 and C₁₃Cl_5–7 were the predominant congeners in the groundwater, and C_12,13Cl_7,8 was the dominant SCCP congener group in the atmosphere around the petrochemical park. With respect to the air-soil and soil–water exchange behaviors, the majority of fugacity fraction values for the air–soil and soil–groundwater samples were less than 0.3 and greater than 0.7, respectively, indicating the dominant deposition of SCCP congeners from the air to the soil and permeation into groundwater from the soil within the petrochemical park. To date, the preliminary risk assessments have indicated that SCCPs pose a low ecological risk in the petrochemical zone and pose a low risk to humans through dust ingestion and dermal contact.

Micro/nanoplastics (MNPs) are widespread and developing environmental pollutants that can interact synergistically with organic pollutants (OPs) in terrestrial ecosystems, posing potential threats to the soil–plant ecosystem. This comprehensive review delves into the profound understanding of interactions between MNPs and OPs in the soil–plant system and their integrated impact on the soil–plant environment. The mechanisms of adsorption between OPs and MNPs primarily include hydrophobic interactions, π–π stacking, hydrogen bonding, pore filling, electrostatic forces, and van der Waals forces. Critical parameters influencing the adsorption behavior of MNPs to OPs encompass the physicochemical properties of the MNPs, the features of the OPs, and the inherent properties of the soil–plant system. The synergistic effects of MNPs and OPs may alter harmful impacts on the soil–plant system by influencing plant growth and development, physiological responses, and photosynthesis. Implementing source control measures, conducting in-depth technical analyses, and enforcing policy implementation are crucial steps towards preventing MNPs and OPs contamination in soil–plant systems. This study provides a basis for evaluating the possible threats posed by the co-occurrence of MNPs and OPs, providing valuable insights into their implications for organisms ranging from humans to entire ecosystems.

Polycarbonate (PC) is a widely used thermoplastic. Therefore, the amount of waste produced is notable. The exploitation of such waste is of great interest nowadays in the industry and academic society, due to its contribution to environmental pollution and other negative consequences. Herein, the possibility of using PC scrap as a raw material in 3D printing (material extrusion – MEX) is reported. The efficacy of the PC polymer after six thermomechanical courses was evaluated. The effect on rheology, mechanical performance, and thermal behavior is reported. The morphological characteristics were also assessed through scanning electron microscopy, while two quality metrics, i.e., geometrical accuracy and 3D printing structure porosity of the parts, were investigated through micro-computed tomography. The findings were correlated to report the impact of thermomechanical processing on the PC polymer properties. A 9% tensile strength increase compared to the virgin polymer is reported (third round), while the flexural strength was improved by 14% (second round). Then the strength declined. It was lower than that of the virgin material on the sixth thermomechanical repetition. The findings showed that the life of PC can be extended through thermomechanical recycling for 3D printing applications.