Science of the Total Environment最新文献

Polymetallic nodules containing manganese, iron, and other metals are found in the seafloor. Leachates of polymetallic nodules can be discharged into seawater during ocean mining, disrupting marine ecosystems and causing adverse effects on marine organisms. Here, we investigate the acute and chronic effects of two polymetallic nodule leachates on the life-history parameters (mortality, development, and fecundity) and transcriptional differences of detoxification, antioxidant, and reproduction-related genes for cytochrome P450, glutathione S-transferase, and vitellogenin in the marine copepod Tigriopus koreanus. We also examine single and combined effects for six metals whose concentrations differ between the two leachates. No significant changes in mortality were observed, but developmental time was significantly shortened and fecundity increased in T. koreanus in response to exposure to the leachates. No adverse effects on physiological parameters were seen, but transcriptional differences by leachates were evident. In addition, manganese and iron in the leachates improved copepod development when they were combined with other metals. The findings of this study elucidate the potential impact of polymetallic nodule leachates on marine copepods.

Cadmium (Cd) is a toxic heavy metal widespread in rice paddies and threatens food safety and human health. Foliar exposure represents a cost-effective, simple, and time-independent approach to enhance rice resistance and minimize Cd accumulation. Herein, foliar spraying of carbon dots (CDs) was found to significantly reduce Cd accumulation in rice roots and shoots by 31.51 % and 17.93 %, respectively. Gene expression and mineral nutrient analyses indicated that CDs exposure inhibited Cd uptake by suppressing OsNramp1 and increasing competition of Fe and Mn with Cd for OsNramp5. Besides, CDs exposure down-regulated OsHMA2 for Cd transport from roots to aerial parts and up-regulated OsHMA3 for Cd vacuole sequestration. Additionally, CDs treatment promoted rice root development by increasing root biomass, cell walls, and mechanical resistance, which helped to anchor rice plants and impede Cd uptake. Furthermore, CDs spraying increased the organic carbon content and altered the microbial communities in the rice rhizosphere by increasing root exudation. This process facilitated the binding of dissolved Cd in pore water to organic matter and iron‑manganese oxides, ultimately reducing the bioavailability of Cd. This study underscores the effectiveness and mechanism of simple foliar spraying of CDs to mitigate Cd accumulation in rice.

Biochar is a carbonaceous material that can be amplified into nano-biochar (N-BC) using different physicochemical techniques. Contrary to bulk biochar, nano-biochar, and have better physicochemical characteristics, including a large specific surface area, pore properties, distinctive nanostructure, and high catalytic activity. The spotlight of this review is to contribute up-to-date information on the scaling up of biochar into nano-biochar through various sustainable techniques. This review paper is a compilation of research on nano-biochar from biochar including preparation, distinctive characteristics, and intended applications in the environmental and agricultural sectors, along with some other cutting-edge applications, which are all covered in detail in this review paper and also provides the knowledge gap that will be useful for future investigation and development.

The presence of pharmaceutical and personal care products (PPCPs) in the environment poses a significant threat to environmental resources, given their potential risks to ecosystems and human health, even in trace amounts. While mathematical modelling offers a comprehensive approach to understanding the fate and transport of PPCPs in the environment, such studies have garnered less attention compared to field and laboratory investigations. This review examines the current state of modelling PPCPs, focusing on their sources, fate and transport mechanisms, and interactions within the whole ecosystem. Emphasis is placed on critically evaluating and discussing the underlying principles, ongoing advancements, and applications of diverse multimedia models across geographically distinct regions. Furthermore, the review underscores the imperative of ensuring data quality, strategically planning monitoring initiatives, and leveraging cutting-edge modelling techniques in the quest for a more holistic understanding of PPCP dynamics. It also ventures into prospective developments, particularly the integration of Artificial Intelligence (AI) and Machine Learning (ML) methodologies, to enhance the precision and predictive capabilities of PPCP models. In addition, the broader implications of PPCP modelling on sustainability development goals (SDG) and the One Health approach are also discussed. GIS-based modelling offers a cost-effective approach for incorporating time-variable parameters, enabling a spatially explicit analysis of contaminant fate. Swin-Transformer model enhanced with Normalization Attention Modules demonstrated strong groundwater level estimation with an R² of 82 %. Meanwhile, integrating Interferometric Synthetic Aperture Radar (InSAR) time-series with gravity recovery and climate experiment (GRACE) data has been pivotal for assessing water-mass changes in the Indo-Gangetic basin, enhancing PPCP fate and transport modelling accuracy, though ongoing refinement is necessary for a comprehensive understanding of PPCP dynamics. The review aims to establish a framework for the future development of a comprehensive PPCP modelling approach, aiding researchers and policymakers in effectively managing water resources impacted by increasing PPCP levels.

Grassland is an important component of terrestrial ecosystems and plays a crucial role in the global carbon cycle. PhytOC (phytolith-occluded organic carbon) is an extremely important long-term and stable carbon pool in terrestrial ecosystems. Southwest China karst soil exhibits obvious characteristics of alkalinity, high silicon content, and rich calcium, which can significantly influence the characteristics and mechanisms of PhytOC sequestration in vegetation. To elucidate the sequestration characteristics and mechanisms of PhytOC in the karst grasslands, three typical karst grasslands of tropical shrub tussock (TST), warm-temperate shrub tussock (WST), and mountain meadow (MM) from Guizhou province of southwest China were studied. The following results and conclusions were obtained that: 1) the range of PhytOC content of aboveground plant parts, underground roots, and soil in the karst grasslands was 4.03-16.54 g·kg^-1, 10.67-33.92 g·kg^-1, and 0.63-1.89 g·kg^-1, respectively. The underground roots are an important site for phytolith carbon sequestration in grassland ecosystems, and the PhytOC content of underground roots may be higher than that of the aboveground parts. 2) The PhytOC sequestration rate of vegetation was 7.34-15.93 kg·ha^-1·yr^-1, and the annual sequestration amount of PhytOC of the whole grasslands in southwest China could reach 0.48 × 10³-1.48 × 10³ t CO₂. Compared to grasslands in non-karst regions of China, karst grasslands in southwest China have a higher sequestration rate of PhytOC in vegetation and a greater capacity for phytolith carbon sequestration. 3) Soil available silicon, pH, and stoichiometric characteristics of C, N and P nutrients significantly affected the phytolith carbon sequestration of vegetation and the soil accumulation of PhytOC in the karst grasslands. The research results are of great significance for estimating the phytolith carbon sequestration capacity of grassland ecosystems and for grassland construction and management based on enhancing carbon sequestration.

Activated sludge (AS) in wastewater treatment plants is one of the largest artificial microbial ecosystems on earth and it makes enormous contributions to human societies. Viruses are an important component in AS with a high abundance. However, their communities and functionalities have not been as widely explored as those of other microorganisms, such as bacteria. This gap is mainly due to technical challenges in effective viral concentration, extraction, and sequencing. In this study, we compared four kinds of concentration methods, two sequencing approaches, and four identification bioinformatic tools to evaluate the whole analysis workflow for viruses in AS. Results showed flocculation, filtration, and resuspension (FFR) could get the longest DNA lengths and ultracentrifugation obtained the highest DNA yields for viruses in AS. Based on the results of present study, FFR and tangential flow filtration with the membrane pore size of 100 kDa were most recommended to concentrate viruses in AS samples with huge volumes. Besides, different concentration methods could get different viral catalogs and thus multiple methods should be combined to get the whole picture of viruses in the system. In addition, geNomad was the most recommended identification tool for viruses in the present study and the long-read sequencing could improve the assembly statistics of viruses when compared with the short-read sequencing. For the 8192 viral operational taxonomic units in this study, 95.1 % of them were phages and belonged to the same lineage at the order level of Caudovirales. Virulent phages dominated the AS system and Pseudomonadota were the main host. Taken together, this study provides new insights into methods selection for virus research of AS.

Natural volatile organic compounds (NVOCs) and airborne microorganisms are important elements in urban forest air that affect air quality and human health. In this study, the Zhuyu Bay urban forest in Yangzhou was selected as the research object, and gas chromatography-mass spectrometry (GC-MS) was used to detect the composition of NVOCs in different forest stands. Terpenes, heterocyclic compounds, and esters accounted for the highest proportions. We then explored the effects of NVOCs on the physiological health of each forest stand and used Kyoto Encyclopedia of Genes and Genome enrichment analysis to identify beneficial secondary metabolites. Among the identified compounds, alpha-phellandrene 1, azulene, and other terpenoids were found to possess antibacterial, anti-inflammatory, and antioxidant properties. Heterocyclic compounds, such as 4-Pyridinecarboxylic acid and visnagin, showed significant effects in the treatment of diseases. In addition, we collected and analyzed culturable airborne microorganisms in different forest stands and found that the bamboo forest had the lowest number of culturable airborne microorganisms. To further explore the influence of urban microclimates on air microorganisms and NVOCs, a partial least squares path modelling (PLS-PM) analysis was conducted. Air negative oxygen ion is an important factor affecting NVOCs, and Air moisture has a significant positive effect on bacteria proportion.

The El Niño Southern Oscillation (ENSO) is a worldwide climate phenomenon impacting temperatures and precipitation regimes across the globe. Previous studies have shown this climate phenomenon to influence Malaysian Borneo's hydroclimate. In the context of a changing climate and increasingly strong extreme ENSO events, understanding the influence of ENSO on this region, and its evolution through time, is essential to better constrain the future impacts it will have on the Maritime Continent's hydroclimate. Here, we used coupled δ¹⁸O and Sr/Ca records from massive corals' carbonate calcium skeletons to build a proxy for past hydroclimate: δ¹⁸O_seawater (δ¹⁸O_sw) and compensate for the limited dependable instrumental data in most of the 20th century. We assessed our two 90 and 60-year-long δ¹⁸O_sw records' quality as proxies for regional hydroclimate by correlating them with different instrumental salinity datasets before performing moving windowed correlations with the NINO3.4 index, an indicator of ENSO state. Results show that agreement between geochemical proxies and instrumental data highly depends on the chosen dataset, study site location, period, and monsoon season, with stronger agreement with more recent data, pointing towards insufficient data quality when going far back in time. More importantly, when correlated against the NINO3.4 index, our δ¹⁸O_sw records showed a growing correlation for most of their respective lengths. From the 1980s, we found an increasing influence of ENSO on the local hydroclimate with correlation coefficients r > 0.8 during the wet monsoon season. Our findings highlight the differences in results depending on the chosen observational dataset, time scale, or period of the year, and stress the importance of such geochemical archives to better understand the impacts of ENSO across periods predating reliable instrumental data. More importantly, our findings show how the concurrent evolution of the IOD, and the PDV affect ENSO and ultimately, northwestern Borneo's hydroclimate through their teleconnections.

China's soil is experiencing significant microplastic contamination. We developed a machine-learning model to assess microplastic pollution from 1980 to 2050. Our results showed that the average abundance of microplastics in topsoil increased from 45 items per kilogram of soil in 1980 to 1156 items by 2018, primarily due to industrial growth (39 %), agricultural film usage (30 %), tire wear (17 %), and domestic waste (14 %). During the same period, microplastic levels in cropland rose from 98 to 2401 items per kilogram of soil, and exposure levels for the Chinese population increased from 808 to 3168 items per kilogram. By 2050, a reduction in the use of agricultural films is expected to decrease cropland contamination by half. However, overall levels are anticipated to remain steady due to other persistent sources, indicating a continued spread of microplastics into subterranean environments, water bodies, and human systems. This study highlights China's microplastic challenges and suggests potential global trends, emphasizing the need for increased awareness and intervention worldwide.

The restoration of mangroves in urban environments can increase the risk of contaminant exposure and subsequent health effects to resident biota, yet this risk is rarely considered in mangrove restoration programs. Here we assessed the influence of sediment chemistry on contaminant bioaccumulation in shore crabs from restored and natural mangroves in urban environments compared to a reference site. The concentrations of some trace elements were several-fold higher in the sediment and crab tissues of the urban restored site compared to the natural reference site (Cd = 6×, Co = 7×, Cr = 4×, Mn = 30×, and Ni = 18× greater in sediments, while Cd = 4×, Co = 2×, Cr = 2×, Mn = 6×, and Ni = 3× greater in crab tissues). NMR-based metabolomics on crabs revealed higher abundances of proline and glutamate at urban sites, which may be indicative of physiological stress from trace element contamination. Choice experiments were used to test habitat selectivity by crabs from each population, and showed that crabs avoided sediments from the contaminated urban sites. Our results suggest that restoring mangroves in contaminated environments could create ecological sinks, where animals take residence in the new habitat but are exposed to sediment-based contaminants, with potential implications for organism and population health.