Antibiotics have been used in animal feeding for long history.In recent years,much attention has been received for their negative effects on animal and human being as well.Technology has been focused on alternatives o...Antibiotics have been used in animal feeding for long history.In recent years,much attention has been received for their negative effects on animal and human being as well.Technology has been focused on alternatives of antibotics,such as probiotics,oligosaccharides,acidifiers,Chinese herds,chemical drugs,and other environmental measures.Their mechanism,effects,related factors and their prospect in the future were discussed in this paper.展开更多
To investigate geochemical and mineralogical features of sediments from aquifers containing high levels of dissolved arsenic（As） in western Hetao Basin, Inner Mongolia, sediment samples were collected for XRD（X-ray...To investigate geochemical and mineralogical features of sediments from aquifers containing high levels of dissolved arsenic（As） in western Hetao Basin, Inner Mongolia, sediment samples were collected for XRD（X-ray diffraction）, amorphous Fe/Mn oxides, and humic/fulvic acid analyses, in addition to As determination. In the study area, the total As contents in the sediments were in the range 5.3–28.8 mg/kg; while that associated with humic substances in the range 4–9 mg/kg, accounting for 26%–47% of the total As. The results of XRD analysis suggest that clay and silt contain certain small amounts of iron oxides minerals, such as ferrihydrite, hematite and goethite, whereas have higher As and Fe_2O_3 contents. Up to one third of As in the sediments could be extracted by ammonium oxalate, and high As contents were generally found in organic-rich clay or silty clay samples with high FA/HA ratio. As is strongly associated with humic substances and Fe oxyhydroxides, which may be the major sink and source of As in the aquifer sediments.展开更多
Direct chemical oxidation and pure adsorption could not effectively remove p-Arsanilic acid(p-ASA)and the released inor-ganic arsenic.Herein,one novel biochar supported MnFe_(2)O_(4)(MFB)was synthesized and adopted fo...Direct chemical oxidation and pure adsorption could not effectively remove p-Arsanilic acid(p-ASA)and the released inor-ganic arsenic.Herein,one novel biochar supported MnFe_(2)O_(4)(MFB)was synthesized and adopted for p-ASA degradation and synchronous adsorption of the generated inorganic arsenic.The MFB/persulfate(PS)system could remain effective under a wide pH range(3.0-9.0),and the released arsenic could be removed simultaneously by MFB.Mechanism investiga-tion revealed that the functional groups of MFB(i.e.O-C=O and C=O),Fe and Mn oxides on MFB all contributed to PS activation.O_(2)^(·−)and^(1)O_(2)were the main reactive oxygen species(ROS)responsible for p-ASA degradation,and^(1)O_(2)was the predominant ROS.Besides,the MFB possessed superior reusability.Therefore,it is expected to develop a potential method for organic arsenic contaminants removal via an oxidation-adsorption process,and the results could also shed light on the better understanding of the PS activation mechanisms.展开更多
文摘Antibiotics have been used in animal feeding for long history.In recent years,much attention has been received for their negative effects on animal and human being as well.Technology has been focused on alternatives of antibotics,such as probiotics,oligosaccharides,acidifiers,Chinese herds,chemical drugs,and other environmental measures.Their mechanism,effects,related factors and their prospect in the future were discussed in this paper.
基金financially supported by the National Natural Science Foundation of China(No.41572226)
文摘To investigate geochemical and mineralogical features of sediments from aquifers containing high levels of dissolved arsenic（As） in western Hetao Basin, Inner Mongolia, sediment samples were collected for XRD（X-ray diffraction）, amorphous Fe/Mn oxides, and humic/fulvic acid analyses, in addition to As determination. In the study area, the total As contents in the sediments were in the range 5.3–28.8 mg/kg; while that associated with humic substances in the range 4–9 mg/kg, accounting for 26%–47% of the total As. The results of XRD analysis suggest that clay and silt contain certain small amounts of iron oxides minerals, such as ferrihydrite, hematite and goethite, whereas have higher As and Fe_2O_3 contents. Up to one third of As in the sediments could be extracted by ammonium oxalate, and high As contents were generally found in organic-rich clay or silty clay samples with high FA/HA ratio. As is strongly associated with humic substances and Fe oxyhydroxides, which may be the major sink and source of As in the aquifer sediments.
基金the National Natural Science Foundation of China(Grant No.51709103)Natural Science Foundation of Hunan Province,China(Grant Nos.2018JJ3242 and 2021JJ30362)+1 种基金Science and Technology Innovation Leading Plan of High Tech Industry in Hunan Province(Grant No.2021GK4055)Training Program for Excellent Young Innovators of Changsha(Grant No.kq1802020).
文摘Direct chemical oxidation and pure adsorption could not effectively remove p-Arsanilic acid(p-ASA)and the released inor-ganic arsenic.Herein,one novel biochar supported MnFe_(2)O_(4)(MFB)was synthesized and adopted for p-ASA degradation and synchronous adsorption of the generated inorganic arsenic.The MFB/persulfate(PS)system could remain effective under a wide pH range(3.0-9.0),and the released arsenic could be removed simultaneously by MFB.Mechanism investiga-tion revealed that the functional groups of MFB(i.e.O-C=O and C=O),Fe and Mn oxides on MFB all contributed to PS activation.O_(2)^(·−)and^(1)O_(2)were the main reactive oxygen species(ROS)responsible for p-ASA degradation,and^(1)O_(2)was the predominant ROS.Besides,the MFB possessed superior reusability.Therefore,it is expected to develop a potential method for organic arsenic contaminants removal via an oxidation-adsorption process,and the results could also shed light on the better understanding of the PS activation mechanisms.
