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[Objective] Climate change directly affects global wind speed changes and the efficiency of wind energy resource utilization. Analyzing wind speed historical changes is one of the important topics for climate change response, efficient resource utilization, ecological security management, and sustainable social development. [Methods] Using the ERA5-Land grid reanalysis wind speed dataset at the 0.1° resolution from the European Center for Medium Range Weather Forecasts (ECMWF) and methods such as least squares, Theil-Sen slope estimation, and MK trend test to study the annual, seasonal, and monthly average wind speed trends and the evolution of suitable wind power areas over the past 72 years from 1950 to 2021 worldwide. [Results] (1) The global mean land surface wind speed increases slightly at an overall rate of 0.020 m/(s·10a) from 1950 to 2021. (2) The surface wind speed changes on a global scale exhibit significant spatial differences, especially remarkable in Africa and Antarctica in comparison with other continents. (3) As the seasonal changes, the land surface wind speed in winter season shows the significant changes, with a changing rate of 0.033 m/(s·10a). As the months changes, December, January and June exhibit particularly noticeable variations of surface wind speed. The global mean land surface wind speed has a mean rate of change of 0.073 m/(s·10a) and -0.066 m/(s·10a) for significant increases and decreases, respectively, in the regions passing the 95% significance test; and it has the mean rate of change of 0.080 m/(s·10a) and -0.071 m/(s·10a) for extremely significant increases and decreases, respectively, for the region passing the 99% highly significant test. The monthly average wind speed change rate and range in Antarctica are relatively large, affecting significantly the global average wind speed change rate and area assessment. (4) The global wind power energy density has slightly increased, with an average growth rate of 3.017 W/(m2·10a). The increase was most significant in January and December of the year, reaching 7.086 W/(m2·10a) and 6.660 W/(m2·10a), respectively. Antarctica and Africa lead in increasing wind power density for electricity generation, at 14.107 W/(m2·10a) and 4.652 W/(m2·10a) respectively. Asia stands out as the only continent with an overall decrease, while the remaining four continents show minor changes. [Conclusion] There were significant regional, seasonal, and monthly differences in global land surface wind speed changes. In order to accurately support climate change response, resources and ecological protection, and efficient development, dynamic monitoring and detailed analysis of changes in land surface wind speed and wind energy density in each region is still needed.

To understand the occurrence differences and main sources of microplastics in surface sediments in Yangzong Lake and surrounding farmland soil, samples were collected at 24 surface sediments sampling points and 11 farmland soil sampling sites in June 2022. Density flotation was used to separate microplastics in the samples, and microscopic examination and compositional identification of microplastics were carried out using stereoscopic microscope and Raman spectrometer, respectively. As shown by the results, the abundance of microplastics in the surface sediments and farmland soil was (323.7± 115.6) items/kg and (93.0±50.1) items/kg, respectively, and microplastics were spatially distributed mainly in the northern and central regions. Fibers was the common shape of microplastics, accounting for 76.28% and 69.79% of the total number of microplastics in surface sediments and farmland soil, respectively. The amount of fragments in farmland soil was 11.73 percentage points higher than that of surface sediments, and the amount of granular in farmland soil was 5.57 percentage points lower than that of surface sediments. Blue and transparent were common colors of microplastics, and both account for 92.36% and 86.41% of the combined amount in surface sediments and farmland soil, respectively. Small particle size (<1 mm) microplastics dominate, and the amount of small particle size microplastics in surface sediments was 14.21 percentage points higher than farmland soil. As revealed by Raman spectroscopy results, the proportion of microplastics composed of polyethylene terephthalate and polyester in surface sediments was 11.84% and 7.84% higher than that of farmland soil. The amount of polypropylene microplastics was 16.57 percentage points lower than that of farmland soil. Combined with the human activities in the surrounding area, it was inferred that microplastics in the surface sediments might mainly come from fishing gear and textiles, and microplastics in farmland soil might mainly come from mulching, pesticide bags and plastic bottles. [ABSTRACT FROM AUTHOR]

Groundwater in many parts of the world is contaminated with arsenic and nitrate. To date no technology is available that canin situremediate arsenic and nitrate pollution of groundwater using one single bacterial species. In this study, a novel anaerobic nitrate-dependent Fe(II)-oxidizing bacterium,Clostridiumsp. strain PXL2, was isolated from anoxic activated sludge. The strain PXL2 could efficiently oxidize Fe(II) associated with the reduction of nitrate. Scanning Electron Microscope (SEM), X-ray diffraction (XRD) and Fourier Transform Infrared Spectrometry (FTIR) analysis showed that strain PXL2 formed nanosize and poorly crystalline Fe(III) oxides which encrusted the cells, with the viability and function of the cells might being inhibited by the encrustation of Fe(III) oxides. It was found that strain PXL2 was an excellent candidate microbe for bioremediation of nitrate and arsenic pollution. It could effectively and simultaneously remove As(III) and nitrate from water due to its Fe(II) oxidation and denitrtification activity. 40.6–100% of NO3−was removed from an initial concentration of 12.3 mM. High concentrations of As(III) decreased nitrate removal. With initial concentrations of 10 μM, 65 μM and 125 μM As(III), 100% of As(III) was removed in a 20 d treatment. Arsenic was removed by adsorption to the biogenic Fe(III) oxides but not by adsorption to the cells. Strain PXL2 was also able to oxidize As(III) to less mobile and less toxic As(V) and this may significantly enhance the performance of bioremediation of arsenic pollution. Anaerobic nitrate-dependent Fe(II)-oxidizing species, such as strain PXL2, has great application potential forin situremediation of nitrate and metal(loid)s polluted groundwater with advantages of high efficiency and low cost. [ABSTRACT FROM AUTHOR]

Acidithiobacillus ferrooxidansis a commonly used bacterial species for leaching gold ores to recover gold. The pH ofA. ferrooxidansbioleachates drastically changes from around 2.0 during bioleaching to about pH 8.0 as the cells are discharged together with the mine tailings containing high levels of Hg. It is not known how such a large pH shock would affect the properties of bacterial extracellular polymeric substances (EPS) and the transport of Hg in the mine tailings. In this study, the biochemical composition, molecular distribution, fluorescence properties and Hg(II) complexation by EPS ofA. ferrooxidanscultured at pH 2 and 8 were investigated. It was found that pH shock significantly altered the composition of EPS.A. ferrooxidansyielded more EPS under acid conditions than basic conditions. The acidic EPS contained more macromolecular proteins but less polysaccharide in comparison with the basic EPS. Phosphodiester functional groups in phospholipids and polysaccharides were found in the acidic EPS but not in the basic EPS. One tryptophan protein-like peak and one aromatic protein-like peak were identified in fluorescence spectra of the acidic EPS. Two aromatic protein-like peaks were identified from the fluorescence spectra of the basic EPS. The tryptophan protein-like substances in the acidic EPS interacted with Hg(II) and formed relatively stable complexes but with weak binding ability whereas the fluorescent aromatic protein-like substances in the acidic EPS did not bind Hg(II). However the aromatic protein-like substances in the basic EPS had a strong binding ability for Hg(II). The significant differences in composition and Hg complexation ability between EPS from acidic and basic environments indicate that a large pH shock during leaching of gold may exert a considerable impact on the behavior and fate of Hg in the mining areas. [ABSTRACT FROM AUTHOR]

Abstract: This study demonstrated that excess Ca2+ increased the toxicity of Hg2+ to PSII of cyanobacterium Synechocystis sp. using fast rise chlorophyll fluorescence test. Excess Ca2+ increased the inhibitory effect of Hg2+ on O2 evolution. Exposure to Hg2+ caused increase in functional antenna size (ABS/RC), trapping rate of reaction center (TR0/RC), dissipated energy flux per reaction center (DI0/RC) and maximum quantum yield of non-photochemical deexcitation ( ), indicating that some reaction centers were transformed to dissipation sinks under Hg2+ stress. Hg2+ stress slowed down electron transport on both donor side and acceptor side and caused accumulation of P680 +. Excess Ca2+ intensified all the Hg2+ toxic effects on PSII function and led to dysfunction of PSII. The number of reaction centers that were transformed into dissipation sinks increased with increasing Ca2+ concentration. [Copyright &y& Elsevier]

Abstract: Amoxicillin is one of the widely used antibiotics of environmental concern. This study shows that amoxicillin has toxic effects on the photosynthesis of Synechocystis sp. Its inhibitory effects on photosystem II (PSII) of Synechocystis sp. were investigated by using a variety of in vivo chlorophyll fluorescence tests. The inhibitory effects of amoxicillin on PSII activity of Synechocystis sp. are concentration-dependent. Amoxicillin exposure leads to slowing down of electron transport on both donor side and acceptor side and causes accumulation of P680+. QA − reoxidation test revealed that amoxicillin hinders electron transfer from QA − to QB/QB − and more QA − is oxidized through S2(QAQB)− charge recombination. Analysis of PSII heterogeneity demonstrated that an exposure to amoxicillin increases the proportion of inactive PSII (PSIIX) centers and the proportion of PSII centers with small antenna (PSIIβ). These changes finally result in deterioration of full photosynthesis performance. [Copyright &y& Elsevier]

The inhibitory effect of Cr(VI) on the PSII of Synechocystis sp. was studied. Cr(VI) reduced O2 evolution and inhibited the water-splitting system in PSII. S-states test and flash induction test showed that Cr(VI) exposure increased the proportion of inactivated PSII (PSIIX ) and PSIIβ reaction centers, which increased the fluxes of dissipated energy. JIP test and QA (-) reoxidation test demonstrated that Cr(VI) treatment induces inhibition of electron transport from QA (-) to QB /QB (-) and accumulation of P680 (+) . More QA (-) had to be oxidized through S2 (QA QB )(-) charge recombination and oxidation by PQ9 molecules in PSII under Cr(VI) stress. These changes finally decreased the index of photosynthesis performance., (© 2009 Phycological Society of America.)