Heavy metal pollution in water bodies is a serious environmental problem continuously, which requires urgently seeking an efficient and cost-effective solution. Apatite as the most abundant phosphate on earth exhibits...
Heavy metal pollution in water bodies is a serious environmental problem continuously, which requires urgently seeking an efficient and cost-effective solution. Apatite as the most abundant phosphate on earth exhibits remarkable adsorption effect on heavy metals. Based on this, three kinds of apatite adsorbents were prepared in this study by titration co-precipitation method for the removal of heavy metals Pb (II) and Cd (II) from water. In the single system, the maximum adsorption capacity of hydroxyapatite (Hap), chlorapatite (Clap), and fluorapatite (Fap) for Pb (II) was 1597.16 mg/g, 1477.82 mg/g, and 1455.99 mg/g, for Cd (II) were Hap (107.18 mg/g), Clap (79.08 mg/g) and Fap (15.8 mg/g). Pb (II) was more competitive than Cd (II) in binary metal system. Apatite adsorbents mainly remove Pb (II) and Cd (II) from solution by dissolution precipitation, electrostatic attraction, surface complexation and ion exchange. The results of this study show that the three kinds of apatite adsorbents exhibited excellent adsorption performance for Pb (II), and also had a certain removal effect for Cd (II). Therefore, the three kinds of apatite have certain application prospects in heavy metal wastewater treatment.
The low catalytic activity and poor mass transport capacity of platinum group metal free (PGM‐free) catalysts seriously restrict the application of proton‐exchange membrane fuel cells (PEMFCs). Catalysts derived fro...
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The low catalytic activity and poor mass transport capacity of platinum group metal free (PGM‐free) catalysts seriously restrict the application of proton‐exchange membrane fuel cells (PEMFCs). Catalysts derived from Fe‐doped ZIF‐8 could in theory be as active as Pt/C thanks to the high intrinsic activity of FeN 4 ; however, the micropores fail to meet rapid mass transfer. Herein, an ordered hierarchical porous structure is introduced into Fe‐doped ZIF‐8 single crystals, which were subsequently carbonized to obtain an FeN 4 ‐doped hierarchical ordered porous carbon (FeN 4 /HOPC) skeleton. The optimal catalyst FeN 4 /HOPC‐c‐1000 shows excellent performance with a half‐wave potential of 0.80 V in 0.5 m H 2 SO 4 solution, only 20 mV lower than that of commercial Pt/C (0.82 V). In a real PEMFC, FeN 4 /HOPC‐c‐1000 exhibits significantly enhanced current density and power density relative to FeN 4 /C, which does not have an optimized pore structure, implying an efficient utilization of the active sites and enhanced mass transfer to promote the oxygen reduction reaction (ORR).
Human economic activities pose a severe threat to freshwater fish biodiversity in different river basins. Trade makes the impact more mysterious and complex because local threats to biodiversity can be caused by dista...
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Indicine cattle, also referred to as zebu (Bos taurus indicus), play a central role in pastoral communities across a wide range of agro-ecosystems, from extremely hot semiarid regions to hot humid tropical regions. Ho...
Indicine cattle, also referred to as zebu (Bos taurus indicus), play a central role in pastoral communities across a wide range of agro-ecosystems, from extremely hot semiarid regions to hot humid tropical regions. However, their adaptive genetic changes following their dispersal into East Asia from the Indian subcontinent have remained poorly documented. Here, we characterize their global genetic diversity using high-quality whole-genome sequencing data from 354 indicine cattle of 57 breeds/populations, including major indicine phylogeographic groups worldwide. We reveal their probable migration into East Asia was along a coastal route rather than inland routes and we detected introgression from other bovine species. Genomic regions carrying morphology-, immune-, and heat-tolerance-related genes underwent divergent selection according to Asian agro-ecologies. We identify distinct sets of loci that contain promising candidate variants for adaptation to hot semi-arid and hot humid tropical ecosystems. Our results indicate that the rapid and successful adaptation of East Asian indicine cattle to hot humid environments was promoted by localized introgression from banteng and/or gaur. Our findings provide insights into the history and environmental adaptation of indicine cattle.
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