Peatland Wildfires Enhance Nitrogen-Containing Organic Compounds in Marine Aerosols over the Western Pacific.

Peatland wildfires contribute significantly to the atmospheric release of light-absorbing organic carbon, often referred to as brown carbon. In this study, we examine the presence of nitrogen-containing organic compounds (NOCs) within marine aerosols across the Western Pacific Ocean, which are influenced by peatland fires from Southeast Asia. Employing ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in electrospray ionization (ESI) positive mode, we discovered that NOCs are predominantly composed of reduced nitrogenous bases, including CHN+ and CHON+ groups.

The various synergistic impacts of precursor emission reduction on PM and O in a typical industrial city with complex distributions of emissions.

The synergistic responses of O and PM to their common precursors remain unclear within industrial cities with complex emissions. In this study, hundreds of scenarios of jointly reduced local NO and VOCs emissions were designed along with the source apportionment techniques embedded in the Comprehensive Air quality Model with extensions (CAMx) system to explore the locally formed O and PM sensitivities to the reduced emissions of NO and VOCs. The results indicate that locally formed O and PM are more connected to local emissions, resulting in unique formation sensitivities.

Elevated nitrogen loadings facilitate carbon dioxide emissions from urban inland waters.

Carbon dioxide (CO) production and emissions from inland waters play considerable roles in global atmospheric CO sources, while there are still uncertainties regarding notable nutrient inputs and anthropogenic activities. Urban inland waters, with frequently anthropogenic modifications and severely nitrogen loadings, were hotspots for CO emissions. Here, we investigated the spatiotemporal patterns of partial pressure of CO (pCO) and CO fluxes (FCO) in typical urban inland waters in Tianjin, China.

Deciphering dissolved organic matter characteristics and its fate in a glacier-fed desert river-the Tarim river, China.

The bioavailable diverse dissolved organic matter (DOM) present in glacial meltwater significantly contributes to downstream carbon cycling in mountainous regions. However, the comprehension of molecular-level characteristics of riverine DOM, from tributary to downstream and their fate in glacier-fed desert rivers remains limited. Herein, we employed spectroscopic and high-resolution mass spectrometry techniques to study both optical and molecular-level characteristics of DOM in the Tarim River catchment, northwest China.

Partitioning urban forest evapotranspiration based on integrating eddy covariance of water vapor and carbon dioxide fluxes.

Partitioning of evapotranspiration (ET) in urban forest lands plays a vital role in mitigating ambient temperature and evaluating the effects of urbanization on the urban hydrological cycle. While ET partitioning has been extensively studied in diverse natural ecosystems, there remains a significant paucity of research on urban ecosystems. The flux variance similarity (FVS) theory is used to partition urban forest ET into soil evaporation (E) and vegetation transpiration (T).

Phosphorus depletion is exacerbated by increasing nitrogen loading in the Bohai sea.

Phosphorus (P) is an essential nutrient for algal growth in nearshore ecosystems. In recent years, there has been a shift in nutrient dynamics in nearshore areas, leading to an exacerbation of P limitation, although the underlying mechanisms remain unclear. This study analyzed the P species and budget in the Bohai Sea (BS) from 2011 to 2020, aiming to explore the intrinsic mechanisms of P limitation in the BS.

Chronic increasing nitrogen and endogenous phosphorus release from sediment threaten to the water quality in a semi-humid region reservoir.

The water quality in the drinking water reservoir directly affects people's quality of life and health. When external pollution input is effectively controlled, endogenous release is considered the main cause of water quality deterioration. As the major nitrogen (N) and phosphorus (P) sources in reservoirs, sediment plays a vital role in affecting the water quality.

Severe flood modulates the sources and age of dissolved organic carbon in the Yangtze River Estuary.

Floods in global large rivers modulate the transport of dissolved organic carbon (DOC) and estuarine hydrological characteristics significantly. This study investigated the impact of a severe flood on the sources and age of DOC in the Yangtze River Estuary (YRE) in 2020. Comparing the flood period in 2020 to the non-flood period in 2017, we found that the flood enhanced the transport of young DOC to the East China Sea (ECS), resulting in significantly enriched ΔC-DOC values.

Climate-forced Hg-remobilization associated with fern mutagenesis in the aftermath of the end-Triassic extinction.

The long-term effects of the Central Atlantic Magmatic Province, a large igneous province connected to the end-Triassic mass-extinction (201.5 Ma), remain largely elusive. Here, we document the persistence of volcanic-induced mercury (Hg) pollution and its effects on the biosphere for ~1.

Iron and silicon modified biochar for enhancing cadmium removal from water: Unveiling the crucial role of iron-induced silicon dissolution.

The interaction mechanisms of silicon (Si) and active ingredient iron (Fe) on cadmium (Cd) removal are still unknown. Herein, the Fe/Si modified biochar (Fe/Si-BC) was synthesized to enhance Cd removal by pre-immersion of Fe and ball milling loading of Si. Detailed characterizations indicated that Fe and Si were successfully introduced into Fe/Si-BC, resulting in the formation of a new metallic silicate (CaFe(SiO)).

Reactivity of unactivated peroxymonosulfate and peroxyacetic acid with thioether micropollutants: Mechanisms and rate prediction.

Thioether compounds, prevalent in pharmaceuticals, are of growing environmental concern due to their prevalence and potential toxicity. Peroxy chemicals, including peroxymonosulfate (PMS) and peroxyacetic acid (PAA), hold promise for selectively attacking specific thioether moieties. Still, it has been unclear how chemical structures affect the interactions between thioethers and peroxy chemicals.

Silicon in paddy fields: Benefits for rice production and the potential of rice phytoliths for biogeochemical carbon sequestration.

Silicon (Si) biogeochemical cycling is beneficial for crop productivity and carbon (C) sequestration in agricultural ecosystem, thus offering a nonnegligible role in alleviating global warming and food crisis. Compared with other crops, rice plants have a greater quantity of phytolith production, because they are able to take up a lot of Si. However, it remains unclear on Si supply capacity of paddy soils across the world, general rice yield-increasing effect after Si fertilizer addition, and factors affecting phytolith production and potential of phytolith C sequestration in paddy fields.

Strategic control of combustion-induced ammonia emissions: A key initiative for substantial PM reduction in Tianjin, North China Plain.

Information on the temporal and spatial variations in the sources of ammonium salts (NH), a crucial alkaline component in PM, is limited. Here, we simultaneously collected PM and gaseous ammonia (NH) samples in both summer and winter from two sites in Tianjin: an urban site (Tianjin University, TJU) and a suburban site (Binhai New-region, BH). NH concentrations, the contents of major water-soluble inorganic ions in PM, and the compositions of ammonium‑nitrogen isotopes (δN-NH) were measured.

Mobility and environmental impact of cadmium (Cd) during weathering of carbonaceous black shales in western Hunan, China.

Carbonaceous black shale generally contains high concentration of Cd, with weathering leading to Cd release to environment. In this study, the mobility of Cd during weathering was quantified using geochemical assessment on black shale from western Hunan, China. Results suggested that Cd was heterogeneously distributed in shale profiles with concentrations ranging from 0.

Escalating Carbon Export from High-Elevation Rivers in a Warming Climate.

High-elevation mountains have experienced disproportionately rapid warming, yet the effect of warming on the lateral export of terrestrial carbon to rivers remains poorly explored and understood in these regions. Here, we present a long-term data set of dissolved inorganic carbon (DIC) and a more detailed, short-term data set of DIC, δC, and organic carbon from two major rivers of the Qinghai-Tibetan Plateau, the Jinsha River (JSR) and the Yalong River (YLR). In the higher-elevation JSR with ∼51% continuous permafrost coverage, warming (>3 °C) and increasing precipitation coincided with substantially increased DIC concentrations by 35% and fluxes by 110%.

Procedures from samples to sulfur isotopic data: A review.

Rationale: Sulfur isotopes have been widely used to solve some key scientific questions, especially in the last two decades with advanced instruments and analytical schemes. Different sulfur speciation and multiple isotopes analyzed in laboratories worldwide and in situ microanalysis have also been reported in many articles. However, methods of sampling to measurements are multifarious, and occasionally some inaccuracies are present in published papers.

Subaerial volcanism broke mid-Proterozoic environmental stasis.

The mid-Proterozoic, spanning 1.8 to 0.8 billion years ago, is recognized as a phase of marine anoxia, low marine primary productivity (MPP), and constrained eukaryotic biodiversity.

Health burden from food systems is highly unequal across income groups.

Food consumption contributes to the degradation of air quality in regions where food is produced, creating a contrast between the health burden caused by a specific population through its food consumption and that faced by this same population as a consequence of food production activities. Here we explore this inequality within China's food system by linking air-pollution-related health burden from production to consumption, at high levels of spatial and sectorial granularity. We find that low-income groups bear a 70% higher air-pollution-related health burden from food production than from food consumption, while high-income groups benefit from a 29% lower health burden relative to their food consumption.

Elucidation of the dominant factors influencing NO emission in water-level fluctuation zones in a karst canyon reservoir, southwest China.

The water-level fluctuations zones (WLFZs) are crucial transitional interfaces within river-reservoir systems, serving as hotspots for NO emission. However, the comprehension of response patterns and mechanisms governing NO emission under hydrological fluctuation remains limited, especially in karstic canyon reservoirs, which introduces significant uncertainty to NO flux assessments. Soil samples were collected from the WLFZs of the Hongjiadu (HJD) Reservoir along the water flow direction from transition zone (T1 and T2) to lacustrine zone (T3, T4 and T5) at three elevations for each site.

Significant accrual of soil organic carbon through long-term rice cultivation in paddy fields in China.

Paddy fields serve as significant reservoirs of soil organic carbon (SOC) and their potential for terrestrial carbon (C) sequestration is closely associated with changes in SOC pools. However, there has been a dearth of comprehensive studies quantifying changes in SOC pools following extended periods of rice cultivation across a broad geographical scale. Using 104 rice paddy sampling sites that have been in continuous cultivation since the 1980s across China, we studied the changes in topsoil (0-20 cm) labile organic C (LOC I), semi-labile organic C (LOC II), recalcitrant organic C (ROC), and total SOC.

Nitrogen isotopic characteristics of aerosol ammonium in a Chinese megacity indicate the reduction from vehicle emissions during the lockdown period.

The role of agricultural versus vehicle emissions in urban atmospheric ammonia (NH) remains unclear. The lockdown due to the outbreak of COVID-19 provided an opportunity to assess the role of source emissions on urban NH. Concentrations and δN of aerosol ammonium (NH) were measured before (autumn in 2017) and during the lockdown (summer, autumn, and winter in 2020), and source contributions were quantified using SIAR.

Effects of Cu(II)-DOM complexation on DOM degradation: Insights from spectroscopic evidence.

The fate of dissolved organic matter (DOM) is primarily governed by its sources, degradation, and transformation processes within the environment. However, the influence of metal-DOM complexation on DOM degradation remains ambiguous. In this study, controlled laboratory experiments were conducted using Cu(II) and natural water from the Duliujian River and the Beidagang Wetland to examine the effects of metal-DOM binding on the degradation pathway of DOM.