Environmental science. Advances最新文献

Freshwater ecosystems face numerous conservation challenges due to anthropogenic pressures and environmental changes, necessitating advanced monitoring methods for effective conservation strategies. Traditional monitoring approaches have limitations, including low resolution and the inability to address emerging threats or understand the structure–function relationship within ecosystems. This paper explores how Next-Generation Sequencing (NGS) approaches can revolutionize freshwater conservation efforts by integrating unbiased molecular insights into biomonitoring. By leveraging NGS methods a comprehensive understanding of ecosystem dynamics can be achieved. The paper emphasizes the critical link between microbial community composition and ecosystem functioning, highlighting the assessment of functional diversity and activity as key metrics in evaluating ecosystem health. The significant advancements NGS brings to the field enable a proactive approach to conservation strategies and informed management decisions. This paper provides a comprehensive overview of the importance and advancements in integrating NGS methods, marking a paradigm shift in conservation practices and leveraging cutting-edge technologies to safeguard the integrity and resilience of freshwater ecosystems for future generations.

Regulation of chemicals requires knowledge of their toxicological effects on a large number of species, which has traditionally been acquired through in vivo testing. The recent effort to find alternatives based on machine learning, however, has not focused on guaranteeing transparency, comparability and reproducibility, which makes it difficult to assess advantages and disadvantages of these methods. Also, comparable baseline performances are needed. In this study, we trained regression models on the ADORE “t-F2F” challenge proposed in [Schür et al., Nature Scientific data, 2023] to predict acute mortality, measured as LC50 (lethal concentration 50), of organic compounds on fishes. We trained LASSO, random forest (RF), XGBoost, Gaussian process (GP) regression models, and found a series of aspects that are stable across models: (i) using mass or molar concentrations does not affect performances; (ii) the performances are only weakly dependent on the molecular representations of the chemicals, but (iii) strongly on how the data is split. Overall, the tree-based models RF and XGBoost performed best and we were able to predict the log10-transformed LC50 with a root mean square error of 0.90, which corresponds to an order of magnitude on the original LC50 scale. On a local level, on the other hand, the models are not able to consistently predict the toxicity of individual chemicals accurately enough. Predictions for single chemicals are mostly influenced by a few chemical properties while taxonomic traits are not captured sufficiently by the models. We discuss technical and conceptual improvements for these challenges to enhance the suitability of in silico methods to environmental hazard assessment. Accordingly, this work showcases state-of-the-art models and contributes to the ongoing discussion on regulatory integration.

In this study, we evaluated the suitability of elutriation, a method successfully employed in the extraction of microplastics from marine sediments, for the extraction of microplastics from freshwater and terrestrial soils. Five soils were sampled throughout Oklahoma, USA in order to capture a range of sand, silt, clay, and organic matter composition. Each soil was subjected to microplastic extraction with and without elutriation, followed by digestion in 7.5% NaOCl, and then flotation in 6 M ZnCl₂. The mass of each soil was measured after elutriation to determine sample mass reduction, and multiple methods including fluorescence imaging and automated particle counting through ImageJ, Attenuated Total Reflectence-Fourier Transfor Infrared Spectroscopy (ATR-FTIR), and Pyrolysis-coupled Gas Chromatography/Mass Spectrometry (py-GC/MS) were used to determine microplastic quantity, mass, and characteristics. T-test was used to check for statistically-significant differences between methods in terms of mass or particle quantity. For all tested soils, elutriation resulted in greater sample mass reduction than non-elutriated samples, and was between 59.0–97.3% for the tested soils. Furthermore, no statistically significant (p < 0.05) differences were observed in particle quantification or polymer mass between methods, and no differences were observed for polymer or size distribution. Additionally, 33% more polymers were positively identified (R² = 70%) by ATR-FTIR analysis in elutriated samples compared to non-elutriated soils. The mass reduction provided by elutriation allows for the processing of larger sample volumes, leading to greater accuracy and sensitivity in detecting microplastics. As such, we recommend elutriation be performed as a pretreatment step to extract microplastics from soils.

Improving energy security and lowering greenhouse gas emissions need the utilization of renewable resources like biomass. The production of power, heat, and biofuels from biomass has gained significant attention in the current energy scenario. The current study highlights the developments, advancements, and future possibilities of merging thermochemical and biochemical conversion processes for the manufacture of value-added chemicals and green fuels. While biological processes have extensive processing times and low product yields, thermochemical methods are limited by high processing costs and temperature requirements. The integration of thermochemical and biochemical conversion processes facilitates the circular economy and improves resource usage. Despite the wide range of feasible integration scenarios, the majority of research that is now accessible in the literature concentrates on the developments in thermochemical or biochemical processes as a standalone conversion pathway. The present review aids in gaining a basic understanding of potential routes to unlock pathways for complete biomass conversion. Pyrolysis, as well as hybrid conversion techniques, are the most appealing methods from an economic evaluation standpoint. In this work, a techno-economic analysis of the significant conversion processes has also been presented. Examining the environmental impact and costs of alternative waste conversion processes is necessary when obtaining energy from garbage or biomass. So, life cycle assessment (LCA) is a useful method for comparing the environmental effects of various waste-to-energy options. To increase the production of biofuels, further research is required in the areas of feedstock pretreatment, catalyst development, and total production system optimization.

Lead toxicity is a challenge for the large-scale commercial production and the field implementation of photovoltaics. The fabrication of lead-free perovskite solar cells (PSCs) is environmentally acceptable; researchers have investigated the unique perovskite materials that are non-toxic in nature. The recent advancements in PSCs with suitable bandgap energy, optical and electrical features and structural alterations, methods for manufacturing metal electrodes and their internal and external effects have been investigated. Moreover, the toxic lead causes various diseases due to lead spreading in the environment which has been minimized by encapsulation. Incorporation of heterovalent and isovalent materials to reduce lead toxicity and improve stability has been discussed, and encapsulation techniques to avoid deterioration and corrosion have also been discussed. This critical review addresses the stability issues and challenges of PSCs. The intention is to pique the interest of younger researchers already active in this rapidly emerging study area.

Glyphosate (GLY), a versatile herbicide with several applications, has become quite popular for controlling weed growth in residential, commercial, and agricultural settings. Its widespread acceptance has been facilitated by its effectiveness and low cost. However, overuse and improper application of GLY have become an urgent concern, raising questions about potential harm to human health and environmental sustainability. Studies have revealed that GLY exhibits toxic properties that can lead to detrimental consequences for human well-being. These include the potential to induce cancer, contribute to birth defects, and disrupt reproductive functions. Moreover, when exposed to non-target organisms, GLY has been found to inflict adverse impacts on various forms of aquatic life, insects, and essential soil microorganisms. Because of its great solubility and low quantities in soil and water, GLY detection is a difficult process. In response to the concerns surrounding GLY, several detection techniques have been devised, encompassing chromatography, immunoassays, and mass spectrometry. These methods play a crucial role in investigating the ramifications associated with GLY application in agriculture and the environment. The study also emphasizes the need for continued research to fully understand the long-term effects of GLY exposure on human health and the environment.

The release of untreated effluents into waterbodies poses a major threat to the environment and human health. The increasing ratio of demands to rate of supply due to the ever-growing population has resulted in the need for large-scale and efficient manufacturing. One of the pitfalls of the fast-paced industrialisation of textiles is the current negligence towards environmental safety and health concerns. Textile dyes, especially azo dyes, are one of the most toxic industrial pollutants. To date, many conventional treatment methods such as aeration lagoons, filtration, sedimentation, flocculation, and coagulation have been used for degradation. Nevertheless, modern techniques such as bioremediation, phytoremediation, and mycoremediation have been proven to be more efficient and feasible due to their eco-friendly nature. Bioremediation is the process of degradation of effluents using microbes. There are two bioremediation strategies: i.e., ex situ and in situ. In situ bioremediation involves the biological degradation of contaminants to benign products onsite. In the ex situ process, pollutants are removed from the contamination site, and then treated. Bioventing, biosparging, bioslurping, land farming, biopiles, and windrows are some techniques that have been in practice. Various microbiological, ecological, and geological factors affect the rate of bioremediation. To achieve accurate results, the maintenance of an optimal functional range is necessary. Technological advancements have led to new remediation techniques, i.e., nanobioremediation. This review includes insights on the impacts of azo dyes; the principles of bioremediation and its strategies, advantages, and limitations; and future prospects involving nanobioremediation.

Contemporary fashion industry uses numerous dyes and global attention has been drawn to the widespread use, toxicity, carcinogenicity, and bioaccumulation of mixed dyes. Therefore, researchers and scientists are focused on using broad spectrum of photocatalysts to achieve dye remediation with maximum efficiency. Herein, we report the fabrication of novel NiO/Cu₂S/rGO ternary nanocomposites synthesized via the one-step hydrothermal method. The as-synthesized sample was analyzed by applying different analytical techniques, such as XRD, FTIR, UV-DRS, SEM, EDX, elemental mapping, and HRTEM analyses. The results confirmed that the NiO and Cu₂S nanoparticles are decorated on the 2D-rGO nanosheets. An interfacial ternary heterostructure was successfully utilized for the photocatalytic environmental remediation of mixed dye pollutants under UV-light irradiation. Several key factors contribute to the remarkable photocatalytic performance of these heterostructures, including the wide spectrum of the harvested light, good charge separation, and rapid charge transport. The optimized NiO/Cu₂S/rGO ternary nanocomposites exhibited the highest degradation efficiency of 92.4%, 97.9% and 91.6% for RhB, MB and mixed (RhB and MB) dyes, respectively. In contrast, the tentative photocatalytic mechanism pathway, scavengers experiments, recyclability and stability were also investigated. The results reveal that (*O₂⁻) and *OH radical species play a major role under UV-light irradiation. The NiO/Cu₂S/rGO ternary nanocomposites have potential for the effective degradation of organic dyes in industrial wastewater and environmental remediation.

Carbon dots (CDs) are carbon nanoparticles that are typically ∼10 nm in size and feature many properties similar to quantum dots (QDs). Cadmium telluride QDs (CdTeQDs) are a frequently studied QD since their size, and therefore fluorescence spectra, can be easily controlled. However, cadmium is known to be toxic, making its use in consumer goods limited or outright banned in many jurisdictions. While many studies have examined the toxicity of CDs and CdTeQDs, few have directly compared both nanoparticles under the same conditions. Herein, we provide a direct comparison of the toxicity of nitrogen-doped CDs (NCDs), nitrogen, sulfur co-doped CDs (SCDs), and CdTeQDs in the model organism Drosophila melanogaster (fruit fly). No impact on the development of larvae into adult flies from NCDs or SCDs in the 10 – 100 mg kg⁻¹ food range was observed, whereas an EC₅₀ of 46 mg kg⁻¹ CdTeQDs in food was observed. A strong positive correlation was found between the concentration of CdTeQDs in food and the mean pupation and eclosion time, indicating severe developmental delays as CdTeQD concentration increased. Further experiments at sublethal concentrations revealed no significant difference between any of the treatments when evaluating reproductive performance, larval crawling, and fly climbing ability. Gut tube anatomy did differ between control and treatment flies, with all treatment individuals expressing lengthened, and in some cases, distended midguts. This work demonstrates that both NCDs and SCDs are considerably less toxic than CdTeQDs in the 10–100 mg kg⁻¹ food range, further enabling the former's potential applications for biocompatible QD-like nanomaterials.

Hydrostatic photogranulation represents an intriguing phenomenon with potential applications in aeration-free wastewater treatment. In this process, activated sludge batches transform into photogranules, manifesting as either spherical or disk-dominated shapes. Yet, the factors contributing to this morphological diversity remain unknown. Moreover, the impact of morphology on granule structure and physical characteristics remains poorly understood, posing potential implications for photogranulation in reactors that frequently utilize these hydrostatic granules as seeding materials. This study investigates the influence of water quality parameters on hydrostatic photogranulation and its role in shaping granule morphology. Spherical photogranules exhibited lower chlorophyll a concentration (5.97–7.40 mg L⁻¹) and higher Chl a/b ratio (13−14) than disk-shaped photogranules (Chl a concentration: 8.13–11.70 mg L; a/b ratio: <10), indicating a higher cyanobacteria content in disk-shaped granules. Additionally, spherical photogranules showed significantly lower concentrations of EPS proteins and polysaccharides than disk-shaped granules, suggesting enhanced granulation under EPS limitations. Correlation analysis indicates that higher initial NO₃⁻ and total polysaccharides (TPS) increase the likelihood of producing spherical photogranules. Conversely, higher initial Ca²⁺ and Mg²⁺ concentrations were observed in cultivations predominantly producing disks. Furthermore, principal component analysis identified Cl⁻, Na⁺, NH₄⁺, and SO₄²⁻ as key initial water quality indicators and TPS, tCOD, and VSS as important sludge biomass characteristics that distinguished between different photogranule morphologies. Compared to spherical photogranules, disk-dominated photogranules exhibited higher stiffness and shear resistance, potentially due to increased cyanobacterial and EPS contents. Controlling hydrostatic photogranulation to achieve desired photogranule shapes holds potential for customizing seed granules and thus enhancing the OPG wastewater treatment performance.