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In order to reveal the effects of reducing the amount of novel nano-carbon humic acid water-retaining fertilizer (CSF) on soil microbial community structure and citrus groWh. [Method] In this study, conventional fertilization was as the control (KC1) in Wanzhou citrus orchard of Three Gorges Reservoir area. CSF reductions by 0% (KC2), 10% (KC3), 20% (KC4), 30% (KC5) and 40% (KC6) were used to analyze the changes of soil bacterial community structure, citrus yield and quality. [Result] The results showed that the observed species, Shannon index, Chao1 index and PD_whole_tree of KC6 were higher than those of KC1, and were the same as KC2. The abundance of Xanthomonadaceae was the highest in KC5. Compared with KC1, the Xanthomonadaceae in KC3, KC4 and KC6 was significantly decreased, and the levels of Nitrosomonadaceae and Pseudomonasaceae were higher than that of KC1 after the treatment of KC6. Sphingomonas in different reduction treatments was lower than that of KC1, but Burkholderia and Pseudomonas were significantly higher than those of KC1. It was found that the similarity among treatments was small after bacterial community similarity clustering analysis, and citrus yield increased somewhat after CSF fertilization reduction. When CSF fertilization reduced by 30%, citr [ABSTRACT FROM AUTHOR]

To improve the safety and efficiency of the Se/CO/H2O redox process, five ionic liquids (1-butyl-3-methylimidazolium tetrafluoroborate, [bmin][BF4], 1-propyl-3-methylimidazolium tetrafluoroborate, [pmim][BF4], 1-ethyl-2,3-dimethylimidazolium tetrafluoroborate, [bdmim][BF4], N-ethylimidazolium tetrafluoroborate, [eim][BF4], and 1-butyl-3-methyl-imidazolium trifluoromethanesulfonate, [bmim][OTf]) were used as solvents instead of dimethyl formamide. The effect of the structure of anions and cations in ionic liquid, and water content on the Se reduction rate was investigated. In addition, the Se reduction pathway was also explored using UV-vis spectroscopy. The results show that the Se reduction rate is significantly increased by ∼1.4 times using [bmim][BF4], mainly by activating the water molecules. [ABSTRACT FROM AUTHOR]

Here, we aim to determine the distribution, ecological risk and sources of heavy metals and metalloids in the surface sediments of the Xiangjiang River, Hunan Province, China. Sixty-four surface sediment samples were collected in 16 sites of the Xiangjiang River, and the concentrations of ten heavy metals and metalloids (Mn, Zn, Cr, V, Pb, Cu, As, Ni, Co, and Cd) in the sediment samples were investigated using an inductively coupled plasma mass spectrometer (ICP-MS) and an atomic fluorescence spectrophotometer (AFS), respectively. The results showed that the mean concentrations of the ten heavy metals and metalloids in the sediment samples followed the order Mn > Zn > Cr > V > Pb > Cu > As ≈ Ni >Co > Cd. The geoaccumulation index ( I ), enrichment factor (EF), modified degree of contamination (mC), and potential ecological risk index ( RI) revealed that Cd, followed by Pb, Zn, and Cu, caused severely contaminated and posed very highly potential ecological risk in the Xiangjiang River, especially in Shuikoushan of Hengyang, Xiawan of Zhuzhou, and Yijiawan of Xiangtan. The Pearson's correlation coefficient (PCC) analysis, principal component analysis (PCA), and hierarchical cluster analysis (HCA) indicated that the ten heavy metals and metalloids in the sampling sediments of the Xiangjiang River were classified into three groups: (1) Cd, Pb, Zn, and Cu which possibly originated from Shuikoushan, Xiawan, and Yijiawan clustering Pb-Zn mining and smelting industries; (2) Co, V, Ni, Cr, and Al from natural resources; and (3) Mn and As. Therefore, our results suggest that anthropogenic activities, especially mining and smelting, have caused severe contamination of Cd, Pb, Zn, and Cu and posed very high potential ecological risk in the Xiangjiang River. [ABSTRACT FROM AUTHOR]