Bentonite is a kind of natural clay with good exchanging ability. By exchanging its interlamellar cations with various soluble cations, such as quaternary ammonium cations and inorganic metal ions, the properties of n...Bentonite is a kind of natural clay with good exchanging ability. By exchanging its interlamellar cations with various soluble cations, such as quaternary ammonium cations and inorganic metal ions, the properties of natural bentonite can be greatly improved. In this study, hexadecyltrimethylammonium bromide (HDTMA), CaCl2, MgCl2, FeCl3, AlCl3 were used as organic and inorganic pillared materials respectively to produce several kinds of Ca-, Mg-, Fe-, Al-organo pillared bentonites. Sorption of reactive red X-3B on them was studied to determine their potential application as sorbents in wastewater treatment. The results showed that these pillared bentonites had much improved sorption properties, and that the dye solutions’ pH value had some effect on the performance of these inorgano-organo pillared bentonites. Isotherms of reactive X-3B on these pillared bentonites sug-gested a Langmuir-type sorption mechanism.展开更多
Ti-pillared bentonite has been successfully prepared using a modified method that can induce the transformation of TiO2 pillar from amorphous to anatase phase at a low temperature （150℃）. The value of d0.01 =1.94 n...Ti-pillared bentonite has been successfully prepared using a modified method that can induce the transformation of TiO2 pillar from amorphous to anatase phase at a low temperature （150℃）. The value of d0.01 =1.94 nm obtained by Ti-pillared bentonite is larger than that of corresponding raw clay （1.56 nm）. Due to large numbers of Ti-pillars formed, the Ti-pillared bentonite shows an excellent ability in adsorbing Rhodamine B （RB）. The photocatalytic activity and kinetic equation are investigated by decomposing RB solution under the UV irradiation. It is found that the Ti- pillared bentonite shows super photocatalytic activity for the degradation of RB solution compared with the untreated bentonite and pure TiO2, and the kinetic equation of the degradation of RB solution is a 1.5-oder equation.展开更多
Magnetically modified Fe-Al pillared bentonite（Fe3O4/ Fe-Al-Bent） was prepared via chemical co-precipitation method and characterized by powder X-ray diffraction（XRD）, Brunauer-EmmettTeller（BET）, Fourier transfo...Magnetically modified Fe-Al pillared bentonite（Fe3O4/ Fe-Al-Bent） was prepared via chemical co-precipitation method and characterized by powder X-ray diffraction（XRD）, Brunauer-EmmettTeller（BET）, Fourier transform infrared spectroscopy（FTIR） and scanning electron microscopy（SEM）. A series of experiments were carried out to investigate the degradation of Orange II by the obtained heterogeneous catalysts in the presence of H2O2. The experimental result indicated that the synthetic materials had a high catalytic activity and good reusability.展开更多
Pillared clay (PILC) was prepared from Moroccan clay and characterized, and its aqueous thymol adsorption capacities were studied using a batch equilibrium technique. So, we tested the encapsulation of thymol by alumi...Pillared clay (PILC) was prepared from Moroccan clay and characterized, and its aqueous thymol adsorption capacities were studied using a batch equilibrium technique. So, we tested the encapsulation of thymol by aluminum pillared clay (PILC). The PILCs displayed a total surface area of 270 m2/g, a total pore volume of 0.246 cm3/g and an average pore diameter of 8.9 A, which corresponds to the size of Al13 forming the pillars between the clay layers. The adsorption capacity shown by the PILCs for thymol from water is close to 319 mg?g-1 for low solid/liquid ratio (0.2%). This result suggests that the PILCs have both hydrophobic and hydrophilic characteristics, as a result of the presence of silanol and siloxane groups formed during the pillaring and calcination of the PILCs. The experimental data were analyzed by the Freundlich and the Langmuir isotherm types for low values of equilibrium concentration. The rise of the isotherm in this range of concentrations was related to the affinity of thymol for clay sites, and the equilibrium data fitted well with the Freundlich model with maximum adsorption capacity of 319.51 mg/g for a ratio RS/L = 0.2%. Pseudo-first and pseudo-second-order kinetic models were tested with the experimental data and pseudo-first order kinetics was the best for the adsorption of thymol with coefficients of correlation R2 ≥0.986, and the adsorption was rapid with 90% of the thymol adsorbed within the first 20 min.展开更多
基金Project supported by the Scientific Research Foundation for Re-turned Overseas Scholars and the National Natural Science Founda-tion of China (No. 40576080)
文摘Bentonite is a kind of natural clay with good exchanging ability. By exchanging its interlamellar cations with various soluble cations, such as quaternary ammonium cations and inorganic metal ions, the properties of natural bentonite can be greatly improved. In this study, hexadecyltrimethylammonium bromide (HDTMA), CaCl2, MgCl2, FeCl3, AlCl3 were used as organic and inorganic pillared materials respectively to produce several kinds of Ca-, Mg-, Fe-, Al-organo pillared bentonites. Sorption of reactive red X-3B on them was studied to determine their potential application as sorbents in wastewater treatment. The results showed that these pillared bentonites had much improved sorption properties, and that the dye solutions’ pH value had some effect on the performance of these inorgano-organo pillared bentonites. Isotherms of reactive X-3B on these pillared bentonites sug-gested a Langmuir-type sorption mechanism.
基金the National Natural Science Foundation of China （Nos. 40202007, 40573064） the Natural Science Foundation of Guangdong Province （No. 04020017） is gratefully acknowledged.
文摘Ti-pillared bentonite has been successfully prepared using a modified method that can induce the transformation of TiO2 pillar from amorphous to anatase phase at a low temperature （150℃）. The value of d0.01 =1.94 nm obtained by Ti-pillared bentonite is larger than that of corresponding raw clay （1.56 nm）. Due to large numbers of Ti-pillars formed, the Ti-pillared bentonite shows an excellent ability in adsorbing Rhodamine B （RB）. The photocatalytic activity and kinetic equation are investigated by decomposing RB solution under the UV irradiation. It is found that the Ti- pillared bentonite shows super photocatalytic activity for the degradation of RB solution compared with the untreated bentonite and pure TiO2, and the kinetic equation of the degradation of RB solution is a 1.5-oder equation.
基金Funded by the Specialized Research Fund for the Doctoral Program of Higher Education of China(20114219110002)the Natural Science Foundation of Hubei Province(Nos.2014CFB810&2014CFB812)
文摘Magnetically modified Fe-Al pillared bentonite（Fe3O4/ Fe-Al-Bent） was prepared via chemical co-precipitation method and characterized by powder X-ray diffraction（XRD）, Brunauer-EmmettTeller（BET）, Fourier transform infrared spectroscopy（FTIR） and scanning electron microscopy（SEM）. A series of experiments were carried out to investigate the degradation of Orange II by the obtained heterogeneous catalysts in the presence of H2O2. The experimental result indicated that the synthetic materials had a high catalytic activity and good reusability.
文摘Pillared clay (PILC) was prepared from Moroccan clay and characterized, and its aqueous thymol adsorption capacities were studied using a batch equilibrium technique. So, we tested the encapsulation of thymol by aluminum pillared clay (PILC). The PILCs displayed a total surface area of 270 m2/g, a total pore volume of 0.246 cm3/g and an average pore diameter of 8.9 A, which corresponds to the size of Al13 forming the pillars between the clay layers. The adsorption capacity shown by the PILCs for thymol from water is close to 319 mg?g-1 for low solid/liquid ratio (0.2%). This result suggests that the PILCs have both hydrophobic and hydrophilic characteristics, as a result of the presence of silanol and siloxane groups formed during the pillaring and calcination of the PILCs. The experimental data were analyzed by the Freundlich and the Langmuir isotherm types for low values of equilibrium concentration. The rise of the isotherm in this range of concentrations was related to the affinity of thymol for clay sites, and the equilibrium data fitted well with the Freundlich model with maximum adsorption capacity of 319.51 mg/g for a ratio RS/L = 0.2%. Pseudo-first and pseudo-second-order kinetic models were tested with the experimental data and pseudo-first order kinetics was the best for the adsorption of thymol with coefficients of correlation R2 ≥0.986, and the adsorption was rapid with 90% of the thymol adsorbed within the first 20 min.
