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Norton Villumsen posted an update 6 days, 6 hours ago
The O2- and OH were major oxidants for pollutant removal in VCN PPAS, which were produced on dual active sites of VCN via two pathways The N vacancy enhanced PMS adsorption and trapped photogenerated electrons for PMS reduction into OH, while the electron-deficient C atoms created by N loss promoted the PMS oxidation into O2-.Polypropylene (PP), a fossil-based polyolefin plastics widely used worldwide, is non-hydrolyzable and resistant to biodegradation as a major source of plastic pollutants in environment. This study focused on feasibility of PP biodegradation in the larvae of two species of darkling beetles (Coleoptera Tenebrionidae) i.e., yellow mealworms (Tenebrio molitor) and superworms (Zophobas atratus) using PP foam with number-, weight-, and size-average molecular weights (Mn, Mw, and Mz) of 109.8, 356.2, and 765.0 kDa, respectively. The tests were conducted in duplicates with respective larvae (300 T. molitor and 200 Z. atratus each incubator) at 25 °C and 65% humidity for over a 35-day period. The larvae of T. molitor and Z. atratus fed with PP foam as sole diet consumed PP at 1.0 ± 0.4 and 3.1 ± 0.4 mg 100 larvae-1 days-1, respectively; when fed the PP foam plus wheat bran, the consumption rates were enhanced by 68.11% and 39.70%, respectively. Gel permeation chromatography analyses of the frass of T. molitor and Z. atratus larvae fed PP only indicated that Mw was decreased by 20.4 ± 0.8% and 9.0 ± 0.4%; Mn was increased by 12.1 ± 0.4% and 61.5 ± 2.5%; Mz was decreased by 33.8 ± 1.5% and 32.0 ± 1.1%, indicating limited extent depolymerization. Oxidation and biodegradation of PP was confirmed through analysis of the residual PP in frass. Depression of gut microbes with the antibiotic gentamicin inhibited PP depolymerization in both T. molitor and Z. see more atratus larvae. High throughput 16S rRNA sequencing revealed that Citrobacter sp. and Enterobacter sp. were associated with PP diets in the gut microbiome of Z. atratus larvae while Kluyvera was predominant in the T. molitor larvae. The results indicated that PP can be biodegraded in both T. molitor and Z. atratus larvae via gut microbe-dependent depolymerization with diversified microbiomes.Due to the enhancement of human activities on the global scale, the total amount of atmospheric nitrogen (N) deposition and the rate keep increasing, which seriously affect the structure and function of terrestrial ecosystems. In order to study the effects of N deposition on the soil structure and function of coastal saline wetlands, we established a long-term nitrogen deposition simulation platform in 2012 in the Yellow River delta (YRD). Herein, we analyzed the composition and diversity of the soil microbial community under different N deposition treatments (LNN, MNN and HNN, which stand for 50 kg N ha-1 yr-1, 100 kg N ha-1 yr-1, and 200 kg N ha-1 yr-1) and in a water-only control (CK). The results showed that with the increasing level of N deposition, α-diversity (Shannon and Simpson indices) decreased significantly, and the composition of the microbial community changed. At the phylum level, compared with CK, the relative abundance of Chloroflexi increased significantly under the treatment of HNN (P = 0.002), but the relative abundance of Chlorobi (P = 0.013) and Verrucomicrobia (P = 0.035) decreased significantly. At the genus level, compared with CK, the relative abundance of Bacillus (P = 0.01) and Halomonas (P = 0.042) increased significantly with HNN treatment. Bacillus and Nitrococcus showed a significant correlation with soil NH4+-N. The results suggest that the response of microorganisms to N deposition treatments varied by the concentration, and the deposition of a high concentration would increase the nutrients in the soil, but reduce the diversity of soil microorganisms, causing a negative impact on the coastal wetland ecosystem of the YRD.The concentrations and distributions of nine novel brominated flame retardants (NBFRs) were analyzed in soil, lichen (Usnea aurantiaco-atra), and moss (Sanionia uncinata) samples collected from the Chinese Antarctic Great Wall Station and surrounding Fildes Peninsula area in west Antarctica. Total NBFR concentrations ranged from 61.2-225 pg/g dry weight (dw) in soil, 283-1065 pg/g dw in moss, and 135-401 pg/g dw in lichen, respectively. Decabromodiphenyl ethane (DBDPE) was the dominant NBFR in all samples, accounting for 65.2%, 50.1%, and 72.4% of cumulative NBFR concentration in soil, moss, and lichen, respectively. The concentrations of NBFRs in plant samples were higher than those in soil, which may be related to plant bioaccumulation. Significant log/log-linear correlations (p less then 0.05) were found between the concentrations of BEHTEBP and total organic carbon (TOC) in soil, and between DBDPE and lipid content in mosses, indicating that TOC and lipid content potentially affect certain NBFRs in Antarctic soil and moss. This study presents the first report on NBFR contamination in soil and various vegetation in Antarctica.Numerous methods have been implemented to evaluate the relationship between environmental factors and respiratory mortality. However, the previous epidemiological studies seldom considered the spatial and temporal variation of the independent variables. The present study aims to detect the relations between respiratory mortality and related affecting factors across Xi’an during 2014-2016 based on a novel geographically and temporally weighted regression model (GTWR). Meanwhile, the ordinary least square (OLS) and the geographically weighted regression (GWR) models were developed for cross-comparison. Additionally, the spatial autocorrelation and Hot Spot analysis methods were conducted to detect the spatiotemporal dynamic of respiratory mortality. Some important outcomes were obtained. Socioeconomic and environmental determinants represented significant effects on respiratory diseases. The respiratory mortality exhibited an obvious spatial correlation feature, and the respiratory diseases tend to occur in winter and rural areas of the study area. The GTWR model outperformed OLS and GWR for determining the relations between respiratory mortality and socioeconomic as well as environmental determinants. The influence degree of anthropic factors on COPD mortality was higher than natural factors, and the effects of independent variables on COPD varied timely and locally. The results can supply a scientific basis for respiratory disease controlling and health facilities planning.The Chinese government has launched a critical battle against soil pollution in recent years to establish an effective pollution prevention and control framework. link2 This study sought to investigate the long-term pollution status of potentially toxic trace elements in urban topsoil nationwide, and to further investigate the effectiveness of pollution control over the past decade. The concentrations of 8 elements (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in urban topsoil in China between 2000-2009 and 2010-2019 were separately collected for comparative analysis. Individual and comprehensive pollution levels of the elements were evaluated at the city, provincial, regional, and national scales, and further spatially mapped using GIS. Combined with PCA, the main factors influencing these elements in soil nationwide were identified. The results revealed a severe situation in terms of potentially toxic trace element accumulation in urban topsoil, where the NNIPIs surpassed 3 in both periods. The elements As, Cd, and Hg were closely associated with industrial activity and coal burning. Hg and, in particular, Cd pollution (NPI > 3) were found to be severe in most of the cities studied. For the elements As, Cu, Pb, and Zn, pollution ranged from slight to moderate (1.0 less then NPI ≤ 3.0), and Cu, Pb, and Zn were related to a significant degree with vehicle use. Soil Cr and Ni were mainly controlled by parent materials of lithogenic origin, and slight pollution was identified (1.0 less then NPI ≤ 2.0). Pollution patterns showed different characteristics across the regions, and those of the same region and the nation hardly changed over time. Mercury pollution was dominant in the northern regions (NW, MYeR, NE, and NC), while Cd pollution was more severe for the south (EC, MYaR, SC, and SW). Notably, the country’s comprehensive pollution level was stable across the two periods, with momentum towards improvement observed over the past decade.Human activities are stimulating the presence of foreign antibiotic-resistance bacteria (ARB) in soils and antibiotic-contaminated soils are increasing continuously in the world. However, little is known about the impacts of foreign ARB on the indigenous bacterial community in antibiotic-contaminated soil. Herein, using a microcosm experiment we studied the soil bacterial community composition and function (presented with niche structure and niche breadth) in the response to a model ARB (multidrug-resistant Escherichia coli) amendment in the absence and presence of tetracycline contamination. Results demonstrated that the ARB amendment increased the diversity and niche breadth and altered the composition and niche structure of the soil bacterial community. link3 Tetracycline contamination further enhanced these impacts probably via increasing the survival of foreign ARB in soil. Interestingly, the ARB-induced changes in the bacterial community composition and function were synchronized, which might be driven by the substantial changes in some core taxa (Proteobacteria, Bacteroidetes, Chloroflexi, and Patescibacteria). Furthermore, the impacts of the foreign ARB on soil bacterial community lasted longer than the survival of ARB in tetracycline-uncontaminated and low contaminated soils, demonstrating that the amendment of foreign ARB into soil likely challenges the stability of the soil bacterial community in a relatively long period. Overall, this study highlighted that antibiotic contamination could aggravate the impacts of the foreign ARB on soil bacterial community composition and function, resulting in the potential risks in reducing soil quality.The external corrosion of cast iron water supply pipes has been associated with the availability of free moisture at the pipe wall. This is difficult to observe or measure for extensive pipe networks such as in major cities. A proxy is soil surface moisture content. This may be estimated using terrain wetness indices with highly accurate elevation data derived from airborne Light Detection and Ranging (LiDAR). Such information was obtained for several pipelines and compared with data from 6 cm deep soil moisture Theta Probe measurements along 12 pipeline transects. Additionally, all soil moisture data (in volumetric water content, %) were combined and separated by thresholds of transect means into low (35%). Good correlations were obtained (R values 0.49-0.93, all with p value less then 0.05). Higher R values were found for wetter conditions (above ~20%). The wetness indices were also found to relate to pipe-wall maximum pitting corrosion rates (mm/yr) when soil classifications were taken into account, with separate trends for clay, silty clay, sandy clay and sand. Some outliers were detected. These were all associated with pipes for which there is evidence of poor workmanship or quality during installation. In total, 25 catchments from inner city to coastal and lakeside suburbs as well as semi-rural regions were assessed. Results show the potential for terrain indices to indicate relative soil wetness in urban areas and thus potential for pipe failure. This is the first study of its kind. This also may assist water authorities to improve life prediction, management and replacement schedules for water supply pipelines and other underground assets.