Water Organic Pollution and Eutrophication Influence Soil Microbial Processes, Increasing Soil Respiration of Estuarine Wetlands: Site Study in Jiuduansha Wetland

<div><p>Undisturbed natural wetlands are important carbon sinks due to their low soil respiration. When compared with inland alpine wetlands, estuarine wetlands in densely populated areas are subjected to great pressure associated with environmental pollution. However, the effects of water pollution and eutrophication on soil respiration of estuarine and their mechanism have still not been thoroughly investigated. In this study, two representative zones of a tidal wetland located in the upstream and downstream were investigated to determine the effects of water organic pollution and eutrophication on soil respiration of estuarine wetlands and its mechanism. The results showed that eutrophication, which is a result of there being an excess of nutrients including nitrogen and phosphorus, and organic pollutants in the water near Shang shoal located upstream were higher than in downstream Xia shoal. Due to the absorption and interception function of shoals, there to be more nitrogen, phosphorus and organic matter in Shang shoal soil than in Xia shoal. Abundant nitrogen, phosphorus and organic carbon input to soil of Shang shoal promoted reproduction and growth of some highly heterotrophic metabolic microorganisms such as β-Proteobacteria, γ-Proteobacteria and Acidobacteria which is not conducive to carbon sequestration. These results imply that the performance of pollutant interception and purification function of estuarine wetlands may weaken their carbon sequestration function to some extent.</p></div

The sampling zones station and basic hydrographic and vegetation properties^a.

<p>^a The elevation data provided by East China Normal University estuary.</p><p>^b Tidal waterlogging time calculated according to the data in the tide table.</p><p>^c S: Shang shoals, X: Xia shoals.</p><p>^d Vegetation biomass data provided by State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University.</p><p>The sampling zones station and basic hydrographic and vegetation properties<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126951#t001fn001" target="_blank">^a</a>.</p

Soil microbial respiration (SMR), Dehydrogenase (DHA) and glycosidase (Gly) in Shang shoal and Xia shoal.

<p>S1~S3: three samples in Shang shoal, X1~X3: three samples in Xia shoal. Different capital letters (A, B) above the error bar represent significant difference between two areas at the 0.01 level.*The values were averaged by all sites in four seasons in each zone.</p

Map of the study areas of the Yangtze River estuary.

<p>Map of the study areas of the Yangtze River estuary.</p

Seasonal average sites value of Soil respiration (SR) in Shang shoal and Xia shoal.

<p>S1~S3: three samples in Shang shoal, X1~X2: three samples in Xia shoal. Different capital letters (A, B, C, D) above the error bar represent significant difference between two areas at the 0.01 level.</p

Basic physical and chemical properties of the sampling zones^a.

<p>^a Seasonal average value</p><p>^b S: Shang shoals of Jiuduansha, X: Xia shoals of Jiuduansha.</p><p>^c SOC: soil organic carbon. NH₃-N: ammonia nitrogen. AP: available phosphorous.</p><p>^d Different capital letters means the significant difference between S and X at 0.01 level, different lower-case letters means the significant difference between X and S at 0.05 level. Errors were reported as the standard deviation (SD) of the mean of 9 points in each study zone.</p><p>Basic physical and chemical properties of the sampling zones<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126951#t003fn001" target="_blank">^a</a>.</p

Path analysis between SMR^a and basic physical and chemical properties.

<p>^aData of SMR in average value from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126951#pone.0126951.g003" target="_blank">Fig 3</a>.</p><p>^bData of pH, salinity, moisture, NH₃-N, AP and SOC from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126951#pone.0126951.t003" target="_blank">Table 3</a>.</p><p>Path analysis between SMR<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126951#t004fn001" target="_blank">^a</a> and basic physical and chemical properties.</p

Content of nitrogen and phosphorus and organic carbon in tidal waters of two sampling zones^a.

<p>^a Seasonal average value</p><p>^b S: Shang shoals of Jiuduansha, X: Xia shoals of Jiuduansha.</p><p>^c TOC: total organic carbon. NH3-N: ammonia nitrogen.NO3-N: nitrate nitrogen. TP: total phosphorous.</p><p>^d The results reported for each study zone are the means of the sampling points in the zone. Errors were reported as the standard deviation (SD) of the mean 9 points in each study zone. Different capital letters means the significant difference between S and X at 0.01 level, different lower-case letters means the significant difference between X and S at 0.05 level.</p><p>Content of nitrogen and phosphorus and organic carbon in tidal waters of two sampling zones<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126951#t002fn001" target="_blank">^a</a>.</p

Scalable Production of Hydrophilic Graphene Nanosheets via in Situ Ball-Milling-Assisted Supercritical CO₂ Exfoliation

The scalable production of large quantities of defect-free graphene nanosheets (GNs) with low cost and excellent properties is essential for practical applications. Despite the highly intense research of this area, the mass production of graphene nanosheets with high solubility remains a key challenge. In the present work, we propose a scalable exfoliation process for hydrophilic GNs by ball-milling-assisted supercritical CO₂ exfoliation in the presence of poly­(vinylpyrrolidone) via the synergetic effect of chemical peeling and mechanical shear forces. The exfoliation difficulty has been reduced due to the intercalation effects of supercritical CO₂ molecules. With the ball-milling assistance, the modifier has been introduced onto the edge or/and surface of the GNs. The process results in hydrophilic GNs with little damage to the in-plane structure. The GNs can be dispersed in various solvents with a concentration of up to 0.854 mg/mL (water) and remain stable for several months

DataSheet1_Synthesis of perovskite-type high-entropy oxides as potential candidates for oxygen evolution.docx

High-entropy materials offer a wide range of possibilities for synthesizing new functional ceramics for different applications. Many synthesis methods have been explored to achieve a single-phase structure incorporating several different elements, yet a comparison between the synthesis methods is crucial to identify the new dimension such complex ceramics bring to material properties. As known for ceramic materials, the synthesis procedure usually has a significant influence on powder morphology, elemental distribution, particle size and powder processability. Properties that need to be tailored according to specific applications. Therefore, in this study perovskite-type high-entropy materials (Gd0.2La0.2–xSrxNd0.2Sm0.2Y0.2) (Co0.2Cr0.2Fe0.2Mn0.2Ni0.2)O3 (x = 0 and x = 0.2) are synthesized for the first time using mechanochemical synthesis and a modified Pechini method. The comparison of different syntheses allows, not only tailoring of the constituent elements of high-entropy materials, but also to optimize the synthesis method as needed to overcome limitations of conventional ceramics. To exploit the novel materials for a variety of energy applications, their catalytic activity for oxygen evolution reaction was characterized. This paves the way for their integration into, e.g., regenerative fuel cells and metal air batteries.</p