Heterogeneous photocatalytic degradation of γ-HCH on soil surfaces was carried out to evaluate the photocatalytic effectiveness of α-Fe 2O 3 and TiO 2 toward degrading γ-HCH on soil surfaces. After being spiked ...Heterogeneous photocatalytic degradation of γ-HCH on soil surfaces was carried out to evaluate the photocatalytic effectiveness of α-Fe 2O 3 and TiO 2 toward degrading γ-HCH on soil surfaces. After being spiked with γ-HCH, soil samples were loaded with α-Fe 2O 3 or TiO 2 and exposed to UV-light irradiation. Different catalyst loads, 0%, 2%, 5%, 7%, and 10% (wt.)α-Fe 2O 3; 0%, 0.5%, 1%, 2:(wt.)TiO 2, were tested for up to 7 d irradiation. The effects of soil thickness, acidity, and humic substances were also investigated. The obtained results indicated that the γ-HCH photodegradation follows the pseudo-first-order kinetics. The addition of α-Fe 2O 3 or TiO 2 accelerates the photodegradation of γ-HCH, while the photodegradation rate decreases when the content of α-Fe 2O 3 exceeds 7%(wt.). The degradation rate increases with the soil pH value. Humic substances inhibit the photocatalytic degradation of γ-HCH. Pentachlorocyclohexene, tetrachlorocyclohexene, and trichlorobenzene are detected as photodegradation intermediates, which are gradually degraded with the photodegradation evolution.展开更多
Thermodynamic models of calculating mass action concentrations for structural units or ion couples in RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions were developed based on the ion and...Thermodynamic models of calculating mass action concentrations for structural units or ion couples in RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions were developed based on the ion and molecule coexistence theory at 298.15 K.A transformation coefficient is needed to compare the calculated mass action concentration and the reported activity because they are obtained at different standard states and concentration units.The results show that the transformation coefficients between the calculated mass action concentrations and the reported activities of the same structural units or ion couples in RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions change in a very narrow range.The transformed mass action concentrations of structural units or ion couples in RbCl-H2O binary system are in good agreement with the reported activities. The transformed mass action concentrations of RbCl and RbNO3 in RbCl-RbNO3-H2O ternary solution are also in good agreement with the reported activities,aRbCl and 3RbNOa,with different total ionic strengths as 0.01,0.05,0.1,0.5,1.0,1.5,2.0,3.0 and 3.5 mol/kg,respectively.All those results mean the developed thermodynamic model of strong electrolyte aqueous solutions can reflect structural characteristics of RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions and the mass action concentration also strictly follows the mass action law.展开更多
Synthetic method of solid superacid TiSiW 12 O 40 /TiO 2 was described.The synthesis of iso amyl propionate catalyzed by TiSiW 12 O 40 /TiO 2 has been studied and the factors influencing on the yield is discussed.It s...Synthetic method of solid superacid TiSiW 12 O 40 /TiO 2 was described.The synthesis of iso amyl propionate catalyzed by TiSiW 12 O 40 /TiO 2 has been studied and the factors influencing on the yield is discussed.It shows that it’s an excellent catalyst,the yield of the iso amyl propionate can be over 77% when the molar ratio of iso amyl alcohol and propionic acid is 1.2,the quality of TiSiW 12 O 40 /TiO 2 is equal to 1.5% feed stock,the reaction time is 80min and the reaction temperature is about 103～107℃.展开更多
文摘Heterogeneous photocatalytic degradation of γ-HCH on soil surfaces was carried out to evaluate the photocatalytic effectiveness of α-Fe 2O 3 and TiO 2 toward degrading γ-HCH on soil surfaces. After being spiked with γ-HCH, soil samples were loaded with α-Fe 2O 3 or TiO 2 and exposed to UV-light irradiation. Different catalyst loads, 0%, 2%, 5%, 7%, and 10% (wt.)α-Fe 2O 3; 0%, 0.5%, 1%, 2:(wt.)TiO 2, were tested for up to 7 d irradiation. The effects of soil thickness, acidity, and humic substances were also investigated. The obtained results indicated that the γ-HCH photodegradation follows the pseudo-first-order kinetics. The addition of α-Fe 2O 3 or TiO 2 accelerates the photodegradation of γ-HCH, while the photodegradation rate decreases when the content of α-Fe 2O 3 exceeds 7%(wt.). The degradation rate increases with the soil pH value. Humic substances inhibit the photocatalytic degradation of γ-HCH. Pentachlorocyclohexene, tetrachlorocyclohexene, and trichlorobenzene are detected as photodegradation intermediates, which are gradually degraded with the photodegradation evolution.
基金Project supported by Publication Foundation of National Science and Technology Academic Books of China
文摘Thermodynamic models of calculating mass action concentrations for structural units or ion couples in RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions were developed based on the ion and molecule coexistence theory at 298.15 K.A transformation coefficient is needed to compare the calculated mass action concentration and the reported activity because they are obtained at different standard states and concentration units.The results show that the transformation coefficients between the calculated mass action concentrations and the reported activities of the same structural units or ion couples in RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions change in a very narrow range.The transformed mass action concentrations of structural units or ion couples in RbCl-H2O binary system are in good agreement with the reported activities. The transformed mass action concentrations of RbCl and RbNO3 in RbCl-RbNO3-H2O ternary solution are also in good agreement with the reported activities,aRbCl and 3RbNOa,with different total ionic strengths as 0.01,0.05,0.1,0.5,1.0,1.5,2.0,3.0 and 3.5 mol/kg,respectively.All those results mean the developed thermodynamic model of strong electrolyte aqueous solutions can reflect structural characteristics of RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions and the mass action concentration also strictly follows the mass action law.
文摘Synthetic method of solid superacid TiSiW 12 O 40 /TiO 2 was described.The synthesis of iso amyl propionate catalyzed by TiSiW 12 O 40 /TiO 2 has been studied and the factors influencing on the yield is discussed.It shows that it’s an excellent catalyst,the yield of the iso amyl propionate can be over 77% when the molar ratio of iso amyl alcohol and propionic acid is 1.2,the quality of TiSiW 12 O 40 /TiO 2 is equal to 1.5% feed stock,the reaction time is 80min and the reaction temperature is about 103～107℃.
