Environmental Science and Ecotechnology最新文献

Nature's contributions to people (NCP) encompass both the beneficial and detrimental effects of living nature on human quality of life, including regulatory, material, and non-material contributions. Globally, vital NCPs have been deteriorating, accelerated by changes in both natural and anthropogenic drivers over recent decades. Despite the often inevitable trade-offs between NCPs due to their spatially and temporally uneven distributions, few studies have quantitatively assessed the impacts of different drivers on the spatial and temporal changes in multiple NCPs and their interrelationships. Here we evaluate the effects of precipitation, temperature, population, gross domestic product, vegetation restoration, and urban expansion on four key regulatory NCPs—habitat maintenance, climate regulation, water quantity regulation, and soil protection—in Nei Mongol at the county level. We observe increasing trends in climate regulation and soil protection from 2000 to 2019, contrasted with declining trends in habitat maintenance and water quantity regulation. We have identified the dominant positive and negative drivers influencing each NCP across individual counties, finding that natural drivers predominantly overpowered anthropogenic drivers. Furthermore, we discover significant spatial disparities in the trade-off or synergy relationships between NCPs across the counties. Our findings illustrate how the impacts of various drivers on NCPs and their interrelationships can be quantitatively evaluated, offering significant potential for application in various spatial scales. With an understanding of trade-offs and scale effects, these insights are expected to support and inform policymaking at both county and provincial levels.

The size and composition of particulate matter (PM) are pivotal in determining its adverse health effects. It is important to understand PM's retention by plants to facilitate its atmospheric removal. However, the distinctions between the size and composition of naturally fallen PM (NFPM) and leaf-deposited PM (LDPM) are not well-documented. Here we utilize a single-particle aerosol mass spectrometer, coupled with a PM resuspension chamber, to analyze these differences. We find that LDPM particles are 6.8–97.3 % larger than NFPM. Employing a neural network algorithm based on adaptive resonance theory, we have identified distinct compositional profiles: NFPM predominantly consists of organic carbon (OC; 31.2 %) and potassium-rich components (19.1 %), whereas LDPM are largely composed of crustal species (53.9–60.6 %). Interestingly, coniferous species retain higher OC content (11.5–13.7 %) compared to broad-leaved species (0.5–1.2 %), while the levoglucosan content exhibit an opposite trend. Our study highlights the active role of tree leaves in modifying PM composition beyond mere passive capture, advocating for a strategic approach to species selection in urban greening initiatives to enhance PM mitigation. These insights provide guidance for urban planners and environmentalists in implementing nature-based solutions to improve urban air quality.

The pathogen Pseudomonas syringae, responsible for a variety of diseases, poses a considerable threat to global crop yields. Emerging biocontrol strategies employ antagonistic microorganisms, utilizing phyllosphere microecology and systemic resistance to combat this disease. However, the interactions between phyllosphere microbial dynamics and the activation of the plant defense system remain poorly understood. Here we show significant alterations in phyllosphere microbiota structure and plant gene expression following the application of biocontrol agents. We reveal enhanced collaboration and integration of Sphingomonas and Methylobacterium within the microbial co-occurrence network. Notably, Sphingomonas inhibits P. syringae by disrupting pathogen chemotaxis and virulence. Additionally, both Sphingomonas and Methylobacterium activate plant defenses by upregulating pathogenesis-related gene expression through abscisic acid, ethylene, jasmonate acid, and salicylic acid signaling pathways. Our results highlighted that biocontrol agents promote plant health, from reconstructing beneficial microbial consortia to enhancing plant immunity. The findings enrich our comprehension of the synergistic interplays between phyllosphere microbiota and plant immunity, offering potential enhancements in biocontrol efficacy for crop protection.

In-channel vegetation is ubiquitous in aquatic environments and plays a critical role in the fate and transport of solutes and particles in aquatic ecosystems. Recent studies have advanced our understanding of the role of vegetation in solute flow and particle transport in aquatic ecosystems. This review summarizes these papers and discusses the impacts of emergent and rigid vegetation on the surface flow, the advection and dispersion of solutes, suspended load transport, bedload transport, and hyporheic exchange. The two competing effects of emergent vegetation on the above transport processes are discussed. On the one hand, emergent vegetation reduces mean flow velocity at the same surface slope, which reduces mass transport. On the other hand, at the same mean flow velocity, vegetation generates turbulence, which enhances mass transport. Mechanistic understanding of these two competing effects and predictive equations derived from laboratory experiments are discussed. Predictive equations for the mean flow velocity and turbulent kinetic energy inside an emergent vegetation canopy are derived based on force and energy balance. The impacts of emergent vegetation on the advection-dispersion process, the suspended load and bedload transport, and the hyporheic exchange are summarized. The impacts of other vegetation-related factors, such as vegetation morphology, submergence, and flexibility, are briefly discussed. The role of vegetation in transporting other particles, such as micro- and macro-plastics, is also briefly discussed. Finally, suggestions for future research directions are proposed to advance the understanding of the dynamic interplays among natural vegetation, flow dynamics, and sedimentary processes.

Micro/nanoplastics (MNPs) are detected in human liver, and pose significant risks to human health. Oral exposure to MNPs derived from non-biodegradable plastics can induce toxicity in mouse liver. Similarly, nasal exposure to non-biodegradable plastics can cause airway dysbiosis in mice. However, the hepatotoxicity induced by foodborne and airborne biodegradable MNPs remains poorly understood. Here we show the hepatotoxic effects of biodegradable polylactic acid (PLA) MNPs through multi-omics analysis of various biological samples from mice, including gut, fecal, nasal, lung, liver, and blood samples. Our results show that both foodborne and airborne PLA MNPs compromise liver function, disrupt serum antioxidant activity, and cause liver pathology. Specifically, foodborne MNPs lead to gut microbial dysbiosis, metabolic alterations in the gut and serum, and liver transcriptomic changes. Airborne MNPs affect nasal and lung microbiota, alter lung and serum metabolites, and disrupt liver transcriptomics. The gut Lachnospiraceae_NK4A136_group is a potential biomarker for foodborne PLA MNP exposure, while nasal unclassified_Muribaculaceae and lung Klebsiella are potential biomarkers for airborne PLA MNP exposure. The relevant results suggest that foodborne PLA MNPs could affect the “gut microbiota-gut-liver” axis and induce hepatoxicity, while airborne PLA MNPs could disrupt the “airway microbiota-lung-liver” axis and cause hepatoxicity. These findings have implications for diagnosing PLA MNPs-induced hepatotoxicity and managing biodegradable materials in the environment. Our current study could be a starting point for biodegradable MNPs-induced hepatotoxicity. More research is needed to verify and inhibit the pathways that are crucial to MNPs-induced hepatotoxicity.

Nitrogen oxides (NO_x), significant contributors to air pollution and climate change, form aerosols and ozone in the atmosphere. Accurate, timely, and transparent information on NO_x emissions is essential for decision-making to mitigate both haze and ozone pollution. However, a comprehensive understanding of the trends and drivers behind anthropogenic NO_x emissions from China—the world's largest emitter—has been lacking since 2020 due to delays in emissions reporting. Here we show a consistent decline in China's NO_x emissions from 2020 to 2022, despite increased fossil fuel consumption, utilizing satellite observations as constraints for NO_x emission estimates through atmospheric inversion. This reduction is corroborated by data from two independent spaceborne instruments: the TROPOspheric Monitoring Instrument (TROPOMI) and the Ozone Monitoring Instrument (OMI). Notably, a reduction in transport emissions, largely due to the COVID-19 lockdowns, slightly decreased China's NO_x emissions in 2020. In subsequent years, 2021 and 2022, reductions in NO_x emissions were driven by the industry and transport sectors, influenced by stringent air pollution controls. The satellite-based inversion system developed in this study represents a significant advancement in the real-time monitoring of regional air pollution emissions from space.

Plastic waste discarded into aquatic environments gradually degrades into smaller fragments, known as microplastics (MPs), which range in size from 0.05 to 5 mm. The ubiquity of MPs poses a significant threat to aquatic ecosystems and, by extension, human health, as these particles are ingested by various marine organisms including zooplankton, crustaceans, and fish, eventually entering the human food chain. This contamination threatens the entire ecological balance, encompassing food safety and the health of aquatic systems. Consequently, developing effective MP removal technologies has emerged as a critical area of research. Here, we summarize the mechanisms and recently reported strategies for removing MPs from aquatic ecosystems. Strategies combining physical and chemical pretreatments with microbial degradation have shown promise in decomposing MPs. Microorganisms such as bacteria, fungi, algae, and specific enzymes are being leveraged in MP remediation efforts. Recent advancements have focused on innovative methods such as membrane bioreactors, synthetic biology, organosilane-based techniques, biofilm-mediated remediation, and nanomaterial-enabled strategies, with nano-enabled technologies demonstrating substantial potential to enhance MP removal efficiency. This review aims to stimulate further innovation in effective MP removal methods, promoting environmental and social well-being.

Fruits, vegetables, and dairy products are typically the primary sources of household food waste. Currently, anaerobic digestion is the most used bioprocess for the treatment of food waste with concomitant generation of biogas. However, to achieve a circular carbon economy, the organics in food waste should be converted to new chemicals with higher value than energy. Here we demonstrate the feasibility of medium-chain carboxylic acid (MCCA) production from expired dairy and beverage waste via a chain elongation platform mediated by lactate. In a two-stage fermentation process, the first stage with optimized operational conditions, including varying temperatures and organic loading rates, transformed expired dairy and beverage waste into lactate at a concentration higher than 900 mM C at 43 °C. This lactate was then used to produce >500 mM C caproate and >300 mM C butyrate via microbial chain elongation. Predominantly, lactate-producing microbes such as Lactobacillus and Lacticaseibacillus were regulated by temperature and could be highly enriched under mesophilic conditions in the first-stage reactor. In the second-stage chain elongation reactor, the dominating microbes were primarily from the genera Megasphaera and Caproiciproducens, shaped by varying feed and inoculum sources. Co-occurrence network analysis revealed positive correlations among species from the genera Caproiciproducens, Ruminococcus, and CAG-352, as well as Megasphaera, Bacteroides, and Solobacterium, indicating strong microbial interactions that enhance caproate production. These findings suggest that producing MCCAs from expired dairy and beverage waste via lactate-mediated chain elongation is a viable method for sustainable waste management and could serve as a chemical production platform in the context of building a circular bioeconomy.