Rainstorms drive the carbon dioxide emissions during the algae-growing season in a large eutrophic lake.

Lakes are sources of atmospheric carbon dioxide (CO), contributing to global climate change. Temporal variations in lake CO emissions are pronounced, with algal growth and precipitation identified as important drivers. Eutrophic lakes often act as atmospheric CO sinks during the growing season.

Inland water greenhouse gas emissions offset the terrestrial carbon sink in the northern cryosphere.

Climate-sensitive northern cryosphere inland waters emit greenhouse gases (GHGs) into the atmosphere, yet their total emissions remain poorly constrained. We present a data-driven synthesis of GHG emissions from northern cryosphere inland waters considering water body types, cryosphere zones, and seasonality. We find that annual GHG emissions are dominated by carbon dioxide ([Formula: see text] teragrams of CO; [Formula: see text]) and methane ([Formula: see text] teragrams of CH), while the nitrous oxide emission ([Formula: see text] gigagrams of NO) is minor.

Seasonal and annual variations of sediment trapping and particulate organic carbon burial in Yellow River reservoirs.

The Yellow River is distinguished by the highest sediment load in mainland China and significant siltation in artificial reservoirs along its main channel, reducing water availability, sediment trapping, and carbon burial in the hydrological project. Since 2002, the Water Sediment Regulation Scheme (WSRS) has been progressively implemented as a hydraulic management strategy to mitigate reservoir sedimentation in the middle-lower basin reservoirs. However, this substantial release of sediment and water has also affected river morphology, carbon burial, and sediment trapping.

Unraveling the Pollution and Discharge of Aminophenyl Sulfone Compounds, Sulfonamide Antibiotics, and Their Acetylation Products in Municipal Wastewater Treatment Plants.

Aminophenyl sulfone compounds (ASCs) are widely used in various fields, such as the pharmaceutical and textile industries. ASCs and their primary acetylation products are inevitably discharged into the environment. However, the high toxicity of ASCs could be released from the deacetylation of acetylation products.

Biogeography and impact of nitrous oxide reducers in rivers across a broad environmental gradient on emission rates.

Microbial communities that reduce nitrous oxide (NO) are divided into two clades, nosZI and nosZII. These clades significantly differ in their ecological niches and their implications for NO emissions in terrestrial environments. However, our understanding of NO reducers in aquatic systems is currently limited.

Identification and Coexposure of Neonicotinoid Insecticides and Their Transformation Products in Retail Cowpea ().

There is growing evidence that the transformation products of emerging contaminants in foodstuffs may pose a health risk to humans. However, the exact identities, levels, and estimated dietary intake (EDI) of neonicotinoid transformation products in crops remain poorly understood. We established an extended suspect screening strategy to investigate neonicotinoid insecticides and their transformation products in retail cowpea from 11 cities in Hainan Province, China.

Global methane emissions from rivers and streams.

Methane (CH) is a potent greenhouse gas and its concentrations have tripled in the atmosphere since the industrial revolution. There is evidence that global warming has increased CH emissions from freshwater ecosystems, providing positive feedback to the global climate. Yet for rivers and streams, the controls and the magnitude of CH emissions remain highly uncertain.

Unexpected low CO emission from highly disturbed urban inland waters.

Constituents and functionality of urban inland waters are significantly perturbed by municipal sewage inputs and tailwater discharge from wastewater treatment plants. However, large knowledge gaps persist in understanding greenhouse gas dynamics in urban inland waters due to a lack of in situ measurements. Herein, via a 3-year field campaign (2018-2020), we report river and lake CO emission and related aquatic factors regulating the emission in the municipality of Beijing.

Source-oriented ecological and resistome risks associated with geochemical enrichment of heavy metals in river sediments.

Heavy metals (HMs) pose ecological and resistome risks to aquatic systems. To efficiently develop targeted risk mitigation strategies, apportioning HM sources and assessing their source-oriented risks are essential. Although many studies have reported risk assessment and source apportionment of HMs, yet few have explored source-specific ecological and resistome risks associated with geochemical enrichment of HMs in aquatic environments.

Differences in structure and composition of soil humic substances and their binding for polycyclic aromatic hydrocarbons in different climatic zones.

Humic substances (HSs) play important roles in the transport and bioavailability of hydrophobic organic compounds (HOCs) in soils. The sorption of HOCs depends on the compositions and structures of HSs which may differ in different climatic zones, however, the sorption behavior of HOCs by HSs in soils from different climatic zones is poorly understood. In this study, different HS fractions (humic acids-HAs, fulvic acids-FAs and humin-HM) in soils from different climatic zones were extracted and used as sorbents for polycyclic aromatic hydrocarbons (PAHs).

Hydrodynamic and geochemical controls on soil carbon mineralization upon entry into aquatic systems.

Erosion is the most widespread form of soil degradation and an important pathway of carbon transfer from land into aquatic systems, with significant impact on water quality and carbon cycle. However, it remains debatable whether erosion induces a carbon source or sink, and the fate of eroded soil carbon in aquatic systems remains poorly constrained. Here, we collect 41 representative soils from seven erosion-influenced basins and conduct microcosm simulation experiments to examine the fate of soil carbon under three different scenarios.

Indirect nitrous oxide emission factors of fluvial networks can be predicted by dissolved organic carbon and nitrate from local to global scales.

Streams and rivers are important sources of nitrous oxide (N O), a powerful greenhouse gas. Estimating global riverine N O emissions is critical for the assessment of anthropogenic N O emission inventories. The indirect N O emission factor (EF ) model, one of the bottom-up approaches, adopts a fixed EF value to estimate riverine N O emissions based on IPCC methodology.

The importance of hydrology in routing terrestrial carbon to the atmosphere via global streams and rivers.

SignificanceStream/river carbon dioxide (CO) emission has significant spatial and seasonal variations critical for understanding its macroecosystem controls and plumbing of the terrestrial carbon budget. We relied on direct fluvial CO partial pressure measurements and seasonally varying gas transfer velocity and river network surface area estimates to resolve reach-level seasonal variations of the flux at the global scale. The percentage of terrestrial primary production (GPP) shunted into rivers that ultimately contributes to CO evasion increases with discharge across regions, due to a stronger response in fluvial CO evasion to discharge than GPP.

Unexpectedly minor nitrous oxide emissions from fluvial networks draining permafrost catchments of the East Qinghai-Tibet Plateau.

Streams and rivers emit substantial amounts of nitrous oxide (NO) and are therefore an essential component of global nitrogen (N) cycle. Permafrost soils store a large reservoir of dormant N that, upon thawing, can enter fluvial networks and partly degrade to NO, yet the role of waterborne release of NO in permafrost regions is unclear. Here we report NO concentrations and fluxes during different seasons between 2016 and 2018 in four watersheds on the East Qinghai-Tibet Plateau.

Substantial decrease in CO emissions from Chinese inland waters due to global change.

Carbon dioxide (CO) evasion from inland waters is an important component of the global carbon cycle. However, it remains unknown how global change affects CO emissions over longer time scales. Here, we present seasonal and annual fluxes of CO emissions from streams, rivers, lakes, and reservoirs throughout China and quantify their changes over the past three decades.

Intense methane ebullition from urban inland waters and its significant contribution to greenhouse gas emissions.

The evasions of methane (CH) and carbon dioxide (CO) from inland waters represent substantial fluxes of greenhouse gases into the atmosphere, offsetting a large part of the continental carbon sink. However, the CH and CO emissions from urban inland waters are less constrained. In particular, ebullitive CH emissions from these waters are poorly understood.

Groundwater as a limited carbon dioxide source in a large river (the Yangtze River).

Groundwater discharge to river networks makes up a major source of riverine CO emission, available evidence however comes mainly from headwater streams which are directly connected to terrestrial ecosystems and spatially limited in terms of system size. Here relying on coupled water and CO mass balances, we quantified the groundwater-mediated CO input to the Yangtze River mainstem on an annual basis, where the mass balance of water provided physical constraints on CO exchange between the river and groundwater. A landscape topographic control of the groundwater-river interaction was proposed where mountain reaches preferentially receive water and CO discharge from the groundwater while plain alluvial reaches predominantly lose water to the aquifers.

Enhanced nitrogen loss from rivers through coupled nitrification-denitrification caused by suspended sediment.

Present-day estimations of global nitrogen loss (N-loss) are underestimated. Commonly, N-loss from rivers is thought to be caused by denitrification only in bed-sediments. However, coupled nitrification-denitrification occurring in overlying water with suspended sediments (SPS) where oxic and anoxic/low oxygen zones may coexist is ignored for N-loss in rivers.

Using 15N, 17O, and 18O to determine nitrate sources in the Yellow River, China.

Many previous studies have used δ(15)N and δ(18)O of nitrate (δ(15)NNO3 and δ(18)ONO3) to determine the nitrate sources in rivers but were subject to substantial uncertainties and limitations, especially associated with evaluating the atmospheric contribution. The Δ(17)O of nitrate (Δ(17)ONO3) has been suggested as an unambiguous tracer of atmospheric NO3(-) and may serve as an additional nitrate source constraint. In the present study, triple nitrate isotopes (δ(15)NNO3, Δ(17)ONO3, and δ(18)ONO3) were used for the first time to assess the sources and sinks of nitrate in the Yellow River (YR) basin, which is the second longest river in China.

Black carbon (BC) in urban and surrounding rural soils of Beijing, China: spatial distribution and relationship with polycyclic aromatic hydrocarbons (PAHs).

The concentrations of black carbon (BC), total organic carbon (TOC) and polycyclic aromatic hydrocarbons (PAHs) have been determined in soils from urban and rural areas of Beijing. The rural area can be divided into plain and mountainous areas which are close to and relatively far from the urban area, respectively. Concentration of BC (5.

Polycyclic aromatic hydrocarbons in urban soils of different land uses in Beijing, China: distribution, sources and their correlation with the city's urbanization history.

A total of 127 surface soil samples (0-20 cm) were collected from Beijing's urban district and determined for 16 polycyclic aromatic hydrocarbons (PAHs). The mean concentration of summation SigmaPAHs was 1802.6 ng g(-1) with a standard deviation of 1824.

Distribution and sources of DDTs in urban soils with six types of land use in Beijing, China.

The concentrations of dichlorodiphenyltrichloroethanes (DDTs) were investigated for urban soil samples collected from business area (BU), classical garden (CL), culture and educational area (CU), large public green space (LA), residential area (RE), and roadside area (RO) in Beijing. The DDTs concentrations ranged from 0.03 to 1282.