The kinetics of α-FeO(OH) formation in weak acidic medium was studied.The effects of the initial concentration,temperature,pH value,partial pres- sure of oxygen,air flow rate and agitating intensity on the oxidation ...The kinetics of α-FeO(OH) formation in weak acidic medium was studied.The effects of the initial concentration,temperature,pH value,partial pres- sure of oxygen,air flow rate and agitating intensity on the oxidation rate of Fe(OH)_2 suspensions have been investigated.It is confirmed that the reaction order for Fe(Ⅱ) is zero at the stage of α-FeO(OH) seeds formation,and about 0.5 at the stage of the seeds growth,and in the whole process partial pres- sure of oxygen appears in first order.The activation energy is determined.The dissolution-oxidation equilibrium which exists in the process of seeds formation has been suggested,by which the zero order reaction for Fe(Ⅱ) and the plateau in the pH-t curve were explained.Physical process is the rate-determining step of the heterogeneous reaction.The study on the kinetics of α-FeO(OH) formation may provide some fundamental informa- tion for the reactor design,the engineering amplifi- cation and the optimization control in the industrial process.展开更多
Silicon iron peach pigment 510B in Mossbauer spectra was analyed,the results show that there are mainly two kinds of iron phase mineral existing in 510B pigment,α FeO(OH) and γ FeO(OH).The Mossbauer spectra of 5...Silicon iron peach pigment 510B in Mossbauer spectra was analyed,the results show that there are mainly two kinds of iron phase mineral existing in 510B pigment,α FeO(OH) and γ FeO(OH).The Mossbauer spectra of 510B sample after being calcined in 1200℃ was also analyzed.展开更多
Three-dimensional flowerlike nanostructured metal oxides attached on the surfaces of Fe-based multi-phase nanocrys- talline ribbons （Fe-MNRs） were prepared by a simple way （through immersing the Fe-MNRs in Orange I...Three-dimensional flowerlike nanostructured metal oxides attached on the surfaces of Fe-based multi-phase nanocrys- talline ribbons （Fe-MNRs） were prepared by a simple way （through immersing the Fe-MNRs in Orange II solution）. It has been found that the as-prepared Fe-MNRs with 3D flowerlike nanostructures （Fe-MNRs ＋ FNs） exhibit good absorption property for a typical heavy metal ion （Cr^VI） in wastewater, while Fe-MNRs do not possess such properties. The Fe-MNRs ＋ FNs could remove 99% CrvI ions from the solution in 40 min, and this adsorption property can be attributed to the ion exchange between Cr^VI and surface hydroxyl groups （O-H） of 3D flowerlike nanostructures. The present result suggests that the Fe-MNRs ＋ FNs, prepared by facile way, possess great potentials in removing heavy metallic ions in wastewater.展开更多
文摘The kinetics of α-FeO(OH) formation in weak acidic medium was studied.The effects of the initial concentration,temperature,pH value,partial pres- sure of oxygen,air flow rate and agitating intensity on the oxidation rate of Fe(OH)_2 suspensions have been investigated.It is confirmed that the reaction order for Fe(Ⅱ) is zero at the stage of α-FeO(OH) seeds formation,and about 0.5 at the stage of the seeds growth,and in the whole process partial pres- sure of oxygen appears in first order.The activation energy is determined.The dissolution-oxidation equilibrium which exists in the process of seeds formation has been suggested,by which the zero order reaction for Fe(Ⅱ) and the plateau in the pH-t curve were explained.Physical process is the rate-determining step of the heterogeneous reaction.The study on the kinetics of α-FeO(OH) formation may provide some fundamental informa- tion for the reactor design,the engineering amplifi- cation and the optimization control in the industrial process.
文摘Silicon iron peach pigment 510B in Mossbauer spectra was analyed,the results show that there are mainly two kinds of iron phase mineral existing in 510B pigment,α FeO(OH) and γ FeO(OH).The Mossbauer spectra of 510B sample after being calcined in 1200℃ was also analyzed.
基金This work was supported by the National Key Basic Research and Development Programme （Grant No.2016YFB0300500） and the National Natural Science Foundation of China （NSFC, Grant Nos. 51571127 and 51771096）.
文摘Three-dimensional flowerlike nanostructured metal oxides attached on the surfaces of Fe-based multi-phase nanocrys- talline ribbons （Fe-MNRs） were prepared by a simple way （through immersing the Fe-MNRs in Orange II solution）. It has been found that the as-prepared Fe-MNRs with 3D flowerlike nanostructures （Fe-MNRs ＋ FNs） exhibit good absorption property for a typical heavy metal ion （Cr^VI） in wastewater, while Fe-MNRs do not possess such properties. The Fe-MNRs ＋ FNs could remove 99% CrvI ions from the solution in 40 min, and this adsorption property can be attributed to the ion exchange between Cr^VI and surface hydroxyl groups （O-H） of 3D flowerlike nanostructures. The present result suggests that the Fe-MNRs ＋ FNs, prepared by facile way, possess great potentials in removing heavy metallic ions in wastewater.
