The Qinghai Lake in North China is the largest interior plateau lake in Central Asia, and is sensitive to climate change and the environmental effects of Tibetan Plateau uplift. An almost continuous 626 m long sedimen...The Qinghai Lake in North China is the largest interior plateau lake in Central Asia, and is sensitive to climate change and the environmental effects of Tibetan Plateau uplift. An almost continuous 626 m long sediment core was drilled in an in-filled part of the southern lake basin in the Scientific Drilling at Qinghai Lake.展开更多
Detailed rock magnetic investigations and mineralogical analysis were conducted on lacustrine sediments recovered from Zoigê Basin, eastern Tibetan Plateau. Greigite, with fine and homogenous grain size, is found...Detailed rock magnetic investigations and mineralogical analysis were conducted on lacustrine sediments recovered from Zoigê Basin, eastern Tibetan Plateau. Greigite, with fine and homogenous grain size, is found as a main magnetic carrier, which is suspected to be of biochemical origin. In contrast to some reports, greigite within the sediments is not oxidized even after exposure to air for a few years, which could be due to the fact that greigite is sealed by silicate.展开更多
Environmentally friendly iron catalysts have attracted widespread attention in the heterogeneous Fenton-like reaction based on peroxymonosulfate(PMS)for the degradation of emerging pollutants in water,while it has alw...Environmentally friendly iron catalysts have attracted widespread attention in the heterogeneous Fenton-like reaction based on peroxymonosulfate(PMS)for the degradation of emerging pollutants in water,while it has always suffered from the disadvantage of low catalytic activity.Herein,we successfully pre-pared the magnetic greigite(Fe3 S4)nanosheet with the exposed{011}facet and rich sulfur vacancies(FS-1)through a simple solvothermal method.The degradation rate of metronidazole by the FS-1 acti-vating PMS under visible light irradiation was 2.93,and 4.48 more than those of the Fe3 S4 nanosheet with the exposed{011}facet and poor sulfur vacancies,and Fe3 S4 nanobulk with the exposed{112}facet,respectively.The result of electrochemical analysis and theoretical calculation indicated that the exposed{011}facet of prepared FS-1 offered more active sites to adsorb PMS,and the rich sulfur va-cancies on the surface accelerated the electron transfer between oxidants and catalyst.This collaborative effect significantly lowered the energy barrier associated with PMS activation,leading to an increased generation of singlet oxygen.Additionally,the degradation mechanism and pathway of metronidazole,including hydroxyethyl cracking,denitrification,and hydroxylation,were explored in detail through theoretical calculations and high-performance liquid chromatography-mass spectrometry,respectively.This work offers insight into boosting the catalytic performance of environmentally friendly iron-based catalysts.展开更多
基金supported by the National Natural Science Foundation of China(grants No.40599420,40872114 and 41140028)the National Basic Research Program of China(grant No.2010CB833400)+1 种基金the Central University Research Foundation(grant No.310827152014)the State Key Laboratory of Loess and Quaternary Geology
文摘The Qinghai Lake in North China is the largest interior plateau lake in Central Asia, and is sensitive to climate change and the environmental effects of Tibetan Plateau uplift. An almost continuous 626 m long sediment core was drilled in an in-filled part of the southern lake basin in the Scientific Drilling at Qinghai Lake.
基金This work was supported by the National Natural Science Foundation of China (Grant No.49872058), Chinese Academy of Sciences, State Committee of Education and the Lab of Lake & Sediments and Environment, Chinese Academy of Sciences. First author thanks f
文摘Detailed rock magnetic investigations and mineralogical analysis were conducted on lacustrine sediments recovered from Zoigê Basin, eastern Tibetan Plateau. Greigite, with fine and homogenous grain size, is found as a main magnetic carrier, which is suspected to be of biochemical origin. In contrast to some reports, greigite within the sediments is not oxidized even after exposure to air for a few years, which could be due to the fact that greigite is sealed by silicate.
基金supported by the National Natural Science Foun-dation of China(NSFC No.22176151)the Wuhan University of Technology Independent Innovation Research Fund Graduate Free Exploration Project(No.104972024JYS0005).
文摘Environmentally friendly iron catalysts have attracted widespread attention in the heterogeneous Fenton-like reaction based on peroxymonosulfate(PMS)for the degradation of emerging pollutants in water,while it has always suffered from the disadvantage of low catalytic activity.Herein,we successfully pre-pared the magnetic greigite(Fe3 S4)nanosheet with the exposed{011}facet and rich sulfur vacancies(FS-1)through a simple solvothermal method.The degradation rate of metronidazole by the FS-1 acti-vating PMS under visible light irradiation was 2.93,and 4.48 more than those of the Fe3 S4 nanosheet with the exposed{011}facet and poor sulfur vacancies,and Fe3 S4 nanobulk with the exposed{112}facet,respectively.The result of electrochemical analysis and theoretical calculation indicated that the exposed{011}facet of prepared FS-1 offered more active sites to adsorb PMS,and the rich sulfur va-cancies on the surface accelerated the electron transfer between oxidants and catalyst.This collaborative effect significantly lowered the energy barrier associated with PMS activation,leading to an increased generation of singlet oxygen.Additionally,the degradation mechanism and pathway of metronidazole,including hydroxyethyl cracking,denitrification,and hydroxylation,were explored in detail through theoretical calculations and high-performance liquid chromatography-mass spectrometry,respectively.This work offers insight into boosting the catalytic performance of environmentally friendly iron-based catalysts.
