Notes

Book Plant-Associated Acidobacteria Encourages Development of Widespread Flying Aquatic Vegetation, Duckweeds.
Nanofiltration concentration leachate is a high concentration organic wastewater with low biodegradability and high toxicity. To explore the feasibility of a combined Heat/UV activated persulfate process on nanofiltration concentrated leachate, the effects of persulfate concentration, initial solution pH before reaction, UV-lamp power and reaction temperature on the removal of organic pollutant were systematically investigated. Results indicated that the maximum rate of chemical oxygen demand (COD), ammonia-nitrogen (NH3-N) and absorbance of organic matter under UV light at 254 nm (UV254) removal from the leachate were 65.4%, 51.4% and 98.1%, respectively, at a persulfate concentration of 18 g L-1, initial solution pH before reaction of 9.0, UV-lamp power of 60 W and temperature of 80 °C. The results of three-dimensional fluorescence and UV254 showed that the removal rates of humic substances contained in the nanofiltration concentrated leachate were over 98%. In addition, the results of free radical scavenging showed that hydroxyl radicals were dominant under alkaline conditions. The results of this study demonstrated that coupling heat and ultraviolet activated persulfate oxidation is a promising technique for the treatment of nanofiltration concentrated leachate.
To investigate the associations between short-term exposure to fine particular matter (PM
) and ischemic stroke (IS) in Yancheng, China, from 2017 to 2019.

We designed a time-series study based on generalized additive models to explore the association of PM
and IS admitted in two major hospitals in Yancheng. We built different lag patterns and conducted stratification analyses by age, gender, and season. Moreover, we examined the robustness of the associations adopting two-pollutant models and fitted the concentration-response curves.

We observed positive and significant associations at lag 0day. Every 10μg/m
increase in PM
(lag0) was associated with 1.06% (95% CI 0.21%-1.91%) increases in hospitalizations for IS. The association remained stable and statistically significant to the adjustment of carbon monoxide and ozone. We observed that the associations were stronger in females and during cold seasons. The overall concentration-response relationship curve was linear positive and increased slowly but rose sharply at higher concentrations in the cold season.

Our study added to the evidence that short-term exposure to PM
may induce IS, and the government should take action to address the air pollution issues and protect susceptible populations.
Our study added to the evidence that short-term exposure to PM2.5 may induce IS, and the government should take action to address the air pollution issues and protect susceptible populations.Subalpine wetland is a mercury (Hg) sensitive ecosystem, but there is poor understanding of Hg behavior in this typical wetland. Here, distribution and speciation of Hg in waters of a subalpine wetland (Dajiuhu) in China were investigated, and an initial model of the Hg geochemical cycle in the wetland was established based on Hg mass balance calculations. Concentrations of both total Hg (THg, 9.52 ± 6.61 ng L-1) and total methyl mercury (TMeHg, 0.34 ± 0.44 ng L-1) in the waters during the wet season were higher than in the dry season. The majority of THg was in dissolved form whereas most TMeHg was in particle form. The geochemical models suggested that, due to the wet deposition and surface runoff, the input of THg and TMeHg into the wetland in the wet season (222 and 2.74 g year-1, respectively) was higher than that in the dry season (57.9 and 1.15 g year-1, respectively). The output of THg and TMeHg from the wetland underground runoff in the wet season was estimated to be 154 and 2.51 g year-1, respectively, and in the dry season was 15.9 and 0.43 g year-1, respectively. Other losses of Hg were due to volatilization of Hg0 from the sediment water (30.5 and 12.5 g year-1 in the wet and dry seasons, respectively). selleck inhibitor The flux of the settling of particulate Hg in the wet season was higher than that in the dry season. The fluxes of Hg diffusion from the porewater were relatively low in comparison to the fluxes of inflows and wet deposition. The flux of oxidation was higher than reduction, while the flux of methylation was higher than demethylation. These results indicated that the elevated levels of THg and MeHg in the Dajiuhu wetland are a consequence of rainfall and surface runoff inputs.Chromium (Cr) pollution in soil is a global problem owing to its wide industrial use. The mobility, toxicity, and crop uptake of Cr depends on its valence state. Cr(VI) is highly mobile and toxic whereas Cr(III) is generally considered immobile and less toxic. We performed a pot experiment to investigate the combined effects of rice straw-derived biochar and water management on transformation of Cr and its uptake by rice in contaminated soils. The main plots had water management treatments of alternating wetting and drying (AWD) and continuous flooding (CF), and the subplots had three levels of straw biochar (0, 5, and 10 g kg-1). The results showed that water management and the addition of biochar had a significant effect on the dynamics of soil redox potential (Eh), pH, dissolved organic carbon (DOC), and Fe(II) concentration. As these parameters are important factors affecting Cr transformation in paddy soils, the dynamics of the Cr(III) and Cr(VI) concentrations were clearly different under different treatments. The highest reduction of Cr(VI) was observed in the treatment with CF water management in combination with 10 g kg-1 of biochar amendment, which resulted in a 62% reduction of Cr(VI) to Cr(III) in soil. The alterations in the oxidation state of Cr greatly affected its accumulation in the rice grains. The CF combined with 10 g kg-1 of biochar treatment, caused the Cr concentration in rice grains to be 66.2% lower compared with that of the unamended control under AWD water management. Possibly owing to the reduction in phytotoxic effects of Cr(VI), the combined treatment showed an improvement in rice grain weight. In conclusion, the combination of 10 g kg-1 of biochar amendment and CF water management may potentially be used in Cr-contaminated soil to mitigate the impacts of Cr contamination on rice production.
Website: https://www.selleckchem.com/products/OSI-906.html