Carbonaceous aerosols (CA) have a high impact on air quality and climate. However, the composition and spatial variability of CA in the marine boundary layer (MBL) remain understudied, especially in the remote regions. Here, atmospheric organic carbon (OC) and elemental carbon (EC) measurements using DRI Model 2001 Thermal/Optical Carbon Analyzer in the MBL were performed during the Chinese Antarctic (2019-2020) and Arctic (2021) research expedition, spanning about 160 latitudes.
View Article and Find Full Text PDFPlant litter input is an important driver of soil/sediment organic carbon (SOC) turnover. A large number of studies have targeted litter-derived C input tracing at a global level. However, little is known about how litter carbon (C) input via various plant tissues affects SOC accumulation and mineralization.
View Article and Find Full Text PDFRivers and streams contribute significant quantities of methane (CH) to the atmosphere. However, there is a lack of CH flux and ebullitive (bubble) emission data from urban rivers, which might lead to large underestimations of global aquatic CH emissions. Here, we conducted high-frequency surveys using the boundary layer model (BLM) supplemented with floating chambers (FCs) and bubble traps to investigate the seasonal and diurnal variability in CH emissions in a eutrophic urban river and to evaluate whether the contribution of bubbles is important.
View Article and Find Full Text PDFVegetable consumption is a potential toxin exposure pathway for humans. Studies have recognized that vegetables can uptake organic contaminants via roots and translocate pollutants to their aerial parts. However, the aerial parts might also directly uptake polycyclic aromatic hydrocarbons (PAHs) from contaminated soils.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
March 2020
While nitrogen (N) fixation is an important process in nitrogen (N) biogeochemical cycling, supplying a significant portion of the N in natural ecosystems, few quantitative constraints exist concerning its contribution to the N enrichment and export from river ecosystems. This study estimates the N fixation rates of urban rivers in the Yangtze Estuary area using acetylene reduction. The results demonstrate that the prominent spatiotemporal variability of river N fixation rates is driven by various environmental factors.
View Article and Find Full Text PDFTaking 12 typical intertidal zones along the eastern coast of China as the research object, indoor tide simulation experiments were conducted to measure exchange fluxes of nitrate nitrogen (NO-N) and ammonia nitrogen (NH-N) between overlying water and sediments, to investigate their spatial distribution, and to clarify controlling factors such as salinity, temperature, and organic matter. Results showed that the total NO-N flux was -2.91-3.
View Article and Find Full Text PDFThe concentrations, sources, and health risks of 16 United States Environmental Protcction Agency(USEPA) priority polycyclic aromatic hydrocarbons (PAHs) in vegetables (leafy lettuce, amaranth, water spinach, and Shanghai green), in soils inside and outside the vegetable greenhouse, and in wet deposition were investigated by conducting an experiment on facility cultivation. The results showed that the average concentrations of total PAHs in vegetables and soils were 99.27 ng·gand 128.
View Article and Find Full Text PDFThe concentrations of Cd, Zn, Pb, Cu, Hg, and As in vegetables collected from the industrial areas in suburban Shanghai were analyzed before and after washing. Results showed that the average concentrations (fresh weight) of Cd, Zn, Pb, Cu, Hg, and As in washed vegetables were 0.023, 4.
View Article and Find Full Text PDFDietary consumption of contaminated vegetables may contribute to polycyclic aromatic hydrocarbon (PAH) exposure in humans; however, this exposure pathway has not been examined thoroughly. This study aims to characterize the concentrations of PAHs in six types of vegetables grown near industrial facilities in Shanghai, China. We analyzed 16 individual PAHs on the US EPA priority list, and the total concentration in vegetables ranged from 65.
View Article and Find Full Text PDFVegetable fields have a high risk of heavy metal contamination from pollution sources in suburban and industrial areas of cities. Eighty-seven soil samples, 106 leafy vegetables and 48 road dust samples were collected from industrial areas of Shanghai, China. We studied the levels of heavy metals, health risk through consumption of leafy vegetables, and sources of Pb in soils, road dust and leafy vegetables.
View Article and Find Full Text PDFThe concentrations and distribution of polycyclic aromatic hydrocarbons (PAHs) in urbanized river networks are strongly influenced by intensive land use, industrial activities and population density. The spatial variations and their influencing factors of 16 priority PAHs were investigated in surface water, suspended particulate matter (SPM) and sediments among areas under different intensive land uses (industrial areas, agricultural areas, inner city, suburban towns and island areas) in the Shanghai river network, East China. Source apportionment was carried out using isomer ratios of PAHs and Positive Matrix Factorization (PMF).
View Article and Find Full Text PDFRoad dusts and agricultural soil samples were collected from eight sites close to steel mills, chemical plants, and municipal solid waste incinerator in suburban Shanghai. Sixteen polycyclic aromatic hydrocarbons (PAHs) in the United States Environmental Protection Agency (US EPA) priority controlled list were analyzed quantitatively using GC-MS. The total PAH concentrations ranged from 0.
View Article and Find Full Text PDFIn order to investigate the pollution levels of PCBs in urban artificial lake, fourteen PCB congeners in sediments and soils of Dishui Lake and its river system were quantified by GC/MS, and then the distributions, sources and ecological risk of PCBs were discussed. The results showed that the concentrations of ∑ PCBs in sediments and soils ranged from 0.65-16.
View Article and Find Full Text PDFNitrogen (N) is a dominant macronutrient in many river-dominated coastal systems, and excess concentrations can drive eutrophication, the effects of which can include hypoxia and algal blooms. The Yangtze River in China transports a large amount of dissolved inorganic N. Therefore, it is important to understand the role of the marsh and mudflat areas within the estuary on processing this exogenous N load.
View Article and Find Full Text PDFTwenty-three surface sediment samples were collected from Dishui Lake and its surroundings, and 16 polycyclic aromatic hydrocarbons (PAHs) were analyzed using GC-MS. The distribution characteristics, possible sources and ecological risk were investigated. The results show that the concentrations of total PAHs range between 11.
View Article and Find Full Text PDFSoils and sediments of different origins were collected, which included the cropland soils surrounding Dishui Lake, the sediments from rivers, the sediments of wetland and the sediments in Dishui Lake. These samples were used for the experiment of phosphorus isothermal adsorption. The results of this experiment were analyzed and fitted.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
September 2014
The purpose of this research was to thoroughly analyze the influences of environmental factors on denitrification processes in urban riparian soils. Besides, the study was also carried out to identify whether the denitrification processes in urban riparian soils could control nonpoint source nitrogen pollution in urban areas. The denitrification rates (DR) over 1 year were measured using an acetylene inhibition technique during the incubation of intact soil cores from six urban riparian sites, which could be divided into three types according to their vegetation.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
September 2014
Water in the Yangtze Estuary is fresh most of the year because of the large discharge of Yangtze River. The Qingcaosha Reservoir built on the Changxing Island in the Yangtze Estuary is an estuarine reservoir for drinking water. Denitrification rate in the top 10 cm sediment of the intertidal marshes and bare mudflat of Yangtze Estuarine islands was measured by the acetylene inhibition method.
View Article and Find Full Text PDFFoliar and roadside dust samples were collected from five sites along the outer-ring highway of Shanghai, one of the biggest metropolitan areas of China, to assess heavy/toxic metal contamination. Concentrations of Zn, Cu, Ni, As, and Hg in foliar dust were higher than in roadside dust, whereas concentrations of Pb and Cd were higher in roadside dust. In the roadside dust, average concentrations of all metals except As in foliar and roadside dust samples were significantly above the background values of soil in Shanghai: the ratios between the average of samples and background values of Shanghai were in the order: Cd (25.
View Article and Find Full Text PDFFour typical rainfalls were monitored in two different research areas of Wenzhou Municipality. Concentrations of BOD5 and COD in six different urban runoffs were measured. In addition the event mean concentration (EMC), M (V) curve and BOD5/COD of pollutant were calculated.
View Article and Find Full Text PDFGlobal nitrogen (N) enrichment has resulted in increased nitrous oxide (N(2)O) emission that greatly contributes to climate change and stratospheric ozone destruction, but little is known about the N(2)O emissions from urban river networks receiving anthropogenic N inputs. We examined N(2)O saturation and emission in the Shanghai city river network, covering 6300 km(2), over 27 months. The overall mean saturation and emission from 87 locations was 770% and 1.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
November 2013
Storm runoff from six types of underlying surface area during five rainfall events in two urban study areas of Wenzhou City, China was investigated to measure phosphorus (P) concentrations and discharge rates. The average event mean concentrations (EMCs) of total phosphorus (TP), total dissolved phosphorus (TDP), and particulate phosphorus (PP) ranged from 0.02 to 2.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
September 2013
The aims of this paper were to survey the total Hg levels and distribution character in intertidal sediment in continental coast of Shanghai, and identify the environment factors that might influence the sediment Hg concentrations, and to assess the pollution degree and potential ecological risk of Hg in sediment. Eighty-eight surface sediment samples and 18 sediment cores were collected for Hg contamination analysis. Physicochemical properties including Eh, particle size, content of total organic carbon (TOC), and acid volatile sulfide (AVS) were also measured.
View Article and Find Full Text PDFThe concentration and ecological risk of Polycyclic aromatic hydrocarbons (PAHs) were investigated in thirty-three surface soil samples collected from cultivated land in Chongming Island in July 2008. Those samples were extracted using an accelerated solvent extractor (ASE) and determined by GC-MS. Results showed that the concentrations of PAHs ranged between 24.
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