Removal of Sb（V） from copper electrolyte by different sorbents such as activated carbon, bentonite, kaolin, resin, zeolite and white sand was investigated. Adsorption capacity of Sb（V） removal from copper electrol...Removal of Sb（V） from copper electrolyte by different sorbents such as activated carbon, bentonite, kaolin, resin, zeolite and white sand was investigated. Adsorption capacity of Sb（V） removal from copper electrolyte was as follows： white sand 〈 anionic resin 〈 zeolite 〈 kaolin 〈 activated carbon 〈 bentonite. Bentonite was characterized using FTIR, XRF, XRD, SEM and BET methods. The results show specific surface area of 95 m2/g and particles size of 175 nm for bentonite. The optimum conditions for the maximum removal of Sb are contact time 10 min, 4 g bentonite and temperature of 40 ° C. The adsorption of Sb（V） on bentonite is followed by pseudo-second-order kinetic （R2=0.996 and k=9×10？5 g/（mg· min））. Thermodynamic results reveal that the adsorption of Sb（V） onto bentonite from copper electrolyte is endothermic and spontaneous process （ΔGΘ=？4806 kJ/（mol· K）. The adsorption data fit both the Freundlich and Langmuir isotherm models. Bentonite has the maximum adsorption capacity of 10000 mg/g for adsorption of Sb（V） in copper electrolyte. The adsorption of Zn, Co, Cu and Bi that present in the copper electrolyte is very low and insignificant.展开更多
高中英语教材中,部分及物动词常用于“v+sh+of+sth”结构。现对该结构在高中教材中的用法归纳总结如下,供大家参考。 1.rob sb of sth抢走某人的某物 a)On the way home,she was robbed of her purse.在回家的路上, 她被抢了钱包。 b)Th...高中英语教材中,部分及物动词常用于“v+sh+of+sth”结构。现对该结构在高中教材中的用法归纳总结如下,供大家参考。 1.rob sb of sth抢走某人的某物 a)On the way home,she was robbed of her purse.在回家的路上, 她被抢了钱包。 b)The slaves were robbed of their freedom.奴隶们被剥夺了自由。 2.cure sb of sth治愈某人的疾病。展开更多
Alkaline earth metal （Mg,Ca,Sr and Ba）-doped Mo-V-Sb-O x catalysts,prepared by a dry-up method,have been investigated for their catalytic performance in the oxidation of propane under different reaction conditions.T...Alkaline earth metal （Mg,Ca,Sr and Ba）-doped Mo-V-Sb-O x catalysts,prepared by a dry-up method,have been investigated for their catalytic performance in the oxidation of propane under different reaction conditions.The catalysts have been characterized by N2 adsorption-desorption,temperature-programmed desorption （TPD） of NH3,SEM and XRD.Influence of water vapor on the catalytic performance,particularly on the selectivities to acetic acid and acrylic acid,has also been studied.The selectivity to acrylic acid was improved significantly by the doping of alkaline earth metals to Mo-V-Sb-O x catalysts.The surface acidic sites of the catalyst decreased with the doping of the catalyst with alkaline earth metals,which ultimately was found to be beneficial for obtaining high selectivity to acrylic acid.The catalytic activity and product selectivities were found to be influenced by the reaction temperature,C3H8/O2 ratio and space velocity.A significant improvement in the selectivity to acrylic acid has also been observed by the addition of water vapor in the feed of propane and oxygen in the oxidation of propane.展开更多
The effect of FeCl_3 coagulation-filtration on the removal of trace Mo(Ⅵ) from water is investigated in the p H range of 4. 00 to 9. 00 and the effects of sulfate,silicate,phosphate and humic acid( HA) on the process...The effect of FeCl_3 coagulation-filtration on the removal of trace Mo(Ⅵ) from water is investigated in the p H range of 4. 00 to 9. 00 and the effects of sulfate,silicate,phosphate and humic acid( HA) on the process were determined. Overall,the removal of Mo(Ⅵ) is determined by two factors: the content of Fe intercepted from water( Intercepted Fe) and the affinity between Mo(Ⅵ)( or co-existing background constituents) and adsorption sites. At low p H,where the agglomeration of the iron flocs is limited,the former factor is dominant,so the methods that can promote the agglomeration of the iron flocs,such as increasing the p H,adding co-existing constituents( sulfate,phosphate or HA),can increase the removal of Mo(Ⅵ). While at high p H,the second factor dominated. Increasing the p H weakens the affinity between Mo(Ⅵ) and the iron flocs,and co-existing background constituents( sulfate,phosphate,silicate or HA) compete with Mo(Ⅵ) for adsorption sites,both effects result in a decrease in Mo(Ⅵ) removal. The Mo(Ⅵ) removal efficiency of FeCl_3 in natural water decreases as the p H increases from 4. 00 to 9. 00,and it is better to operate the coagulation process at p H 5.00 in the practical water treatment engineering.展开更多
V-Pd/γ-Al2O3-TiO2 catalysts with different vanadium contents were prepared by a combined sol-gel and impregnation method. X-ray diffraction （XRD）, N2 adsorption-desorption （BET）, X-ray photoelectron spectroscopy ...V-Pd/γ-Al2O3-TiO2 catalysts with different vanadium contents were prepared by a combined sol-gel and impregnation method. X-ray diffraction （XRD）, N2 adsorption-desorption （BET）, X-ray photoelectron spectroscopy （XPS） and catalytic removal of ethanol, acetaldehyde and nitrogen oxides at low temperature （〈300 ？C） were used to assess the properties of the catalysts. The results showed that the sample with 1wt% vanadium exhibited an excellent catalytic performance for simultaneous removal of ethanol, acetaldehyde and nitrogen oxides. The conversions of ethanol, acetaldehyde and nitrogen oxides at 250 ？C were 100%, 74.4% and 98.7%, respectively. V-Pd/γ-Al2O3-TiO2 catalyst with 1 wt% vanadium showed the largest surface area and higher dispersion of vanadium oxide on the catalyst surface, and possessed a larger mole fraction of V4＋ species and unique PdO species on the surface, which can be attributed to the strong synergistic effect among palladium, vanadium and the carriers. The higher activity of V-Pd/γ-Al2O3-TiO2 catalyst is related to the V4＋ and Pd2＋ species on the surface, which might be favorable for the formation of active sites.展开更多
基金Kerman-Sarcheshmeh copper electrorefining(Iran)and Islamic Azad University,Yazd Brunch for support to carry out this work
文摘Removal of Sb（V） from copper electrolyte by different sorbents such as activated carbon, bentonite, kaolin, resin, zeolite and white sand was investigated. Adsorption capacity of Sb（V） removal from copper electrolyte was as follows： white sand 〈 anionic resin 〈 zeolite 〈 kaolin 〈 activated carbon 〈 bentonite. Bentonite was characterized using FTIR, XRF, XRD, SEM and BET methods. The results show specific surface area of 95 m2/g and particles size of 175 nm for bentonite. The optimum conditions for the maximum removal of Sb are contact time 10 min, 4 g bentonite and temperature of 40 ° C. The adsorption of Sb（V） on bentonite is followed by pseudo-second-order kinetic （R2=0.996 and k=9×10？5 g/（mg· min））. Thermodynamic results reveal that the adsorption of Sb（V） onto bentonite from copper electrolyte is endothermic and spontaneous process （ΔGΘ=？4806 kJ/（mol· K）. The adsorption data fit both the Freundlich and Langmuir isotherm models. Bentonite has the maximum adsorption capacity of 10000 mg/g for adsorption of Sb（V） in copper electrolyte. The adsorption of Zn, Co, Cu and Bi that present in the copper electrolyte is very low and insignificant.
文摘高中英语教材中,部分及物动词常用于“v+sh+of+sth”结构。现对该结构在高中教材中的用法归纳总结如下,供大家参考。 1.rob sb of sth抢走某人的某物 a)On the way home,she was robbed of her purse.在回家的路上, 她被抢了钱包。 b)The slaves were robbed of their freedom.奴隶们被剥夺了自由。 2.cure sb of sth治愈某人的疾病。
文摘Alkaline earth metal （Mg,Ca,Sr and Ba）-doped Mo-V-Sb-O x catalysts,prepared by a dry-up method,have been investigated for their catalytic performance in the oxidation of propane under different reaction conditions.The catalysts have been characterized by N2 adsorption-desorption,temperature-programmed desorption （TPD） of NH3,SEM and XRD.Influence of water vapor on the catalytic performance,particularly on the selectivities to acetic acid and acrylic acid,has also been studied.The selectivity to acrylic acid was improved significantly by the doping of alkaline earth metals to Mo-V-Sb-O x catalysts.The surface acidic sites of the catalyst decreased with the doping of the catalyst with alkaline earth metals,which ultimately was found to be beneficial for obtaining high selectivity to acrylic acid.The catalytic activity and product selectivities were found to be influenced by the reaction temperature,C3H8/O2 ratio and space velocity.A significant improvement in the selectivity to acrylic acid has also been observed by the addition of water vapor in the feed of propane and oxygen in the oxidation of propane.
基金Sponsored by the State Key Laboratory of Urban Water Resource and Environment(Grant No.HIT,2013TS04)the National Science&Technology Pillar Program,China(Grant No.2012BAC05B02)
文摘The effect of FeCl_3 coagulation-filtration on the removal of trace Mo(Ⅵ) from water is investigated in the p H range of 4. 00 to 9. 00 and the effects of sulfate,silicate,phosphate and humic acid( HA) on the process were determined. Overall,the removal of Mo(Ⅵ) is determined by two factors: the content of Fe intercepted from water( Intercepted Fe) and the affinity between Mo(Ⅵ)( or co-existing background constituents) and adsorption sites. At low p H,where the agglomeration of the iron flocs is limited,the former factor is dominant,so the methods that can promote the agglomeration of the iron flocs,such as increasing the p H,adding co-existing constituents( sulfate,phosphate or HA),can increase the removal of Mo(Ⅵ). While at high p H,the second factor dominated. Increasing the p H weakens the affinity between Mo(Ⅵ) and the iron flocs,and co-existing background constituents( sulfate,phosphate,silicate or HA) compete with Mo(Ⅵ) for adsorption sites,both effects result in a decrease in Mo(Ⅵ) removal. The Mo(Ⅵ) removal efficiency of FeCl_3 in natural water decreases as the p H increases from 4. 00 to 9. 00,and it is better to operate the coagulation process at p H 5.00 in the practical water treatment engineering.
基金supported by the National Natural Science Foundation of China (No. 21073131)the Shanxi Natural Science Foundation(No. 2009011011-3)
文摘V-Pd/γ-Al2O3-TiO2 catalysts with different vanadium contents were prepared by a combined sol-gel and impregnation method. X-ray diffraction （XRD）, N2 adsorption-desorption （BET）, X-ray photoelectron spectroscopy （XPS） and catalytic removal of ethanol, acetaldehyde and nitrogen oxides at low temperature （〈300 ？C） were used to assess the properties of the catalysts. The results showed that the sample with 1wt% vanadium exhibited an excellent catalytic performance for simultaneous removal of ethanol, acetaldehyde and nitrogen oxides. The conversions of ethanol, acetaldehyde and nitrogen oxides at 250 ？C were 100%, 74.4% and 98.7%, respectively. V-Pd/γ-Al2O3-TiO2 catalyst with 1 wt% vanadium showed the largest surface area and higher dispersion of vanadium oxide on the catalyst surface, and possessed a larger mole fraction of V4＋ species and unique PdO species on the surface, which can be attributed to the strong synergistic effect among palladium, vanadium and the carriers. The higher activity of V-Pd/γ-Al2O3-TiO2 catalyst is related to the V4＋ and Pd2＋ species on the surface, which might be favorable for the formation of active sites.
