A series of mesoporous silicate adsorbents with superior adsorption performance for hazardous chlortetracycline（CTC） were sucessfully prepared via a facile one-pot hydrothermal reaction using low-cost illite/smectit...A series of mesoporous silicate adsorbents with superior adsorption performance for hazardous chlortetracycline（CTC） were sucessfully prepared via a facile one-pot hydrothermal reaction using low-cost illite/smectite（IS） clay,sodium silicate and magnesium sulfate as the starting materials.In this process,IS clay was ＂teared up＂ and then ＂rebuilt＂ as new porous silicate adsorbent with high specific surface area of 363.52 m^2/g（about 8.7 folds higher than that of IS clay） and very negative Zeta potential（- 34.5 mV）.The inert Si- O- Si（Mg,Al） bonds in crystal framework of IS were broken to form Si（Al）- O^- groups with good adsorption activity,which greatly increased the adsorption sites served for holding much CTC molecules.Systematic evaluation on adsorption properties reveals the optimal silicate adsorbent can adsorb 408.81 mg/g of CTC（only 159.7 mg/g for raw IS clay） and remove 99.3%（only 46.5%for raw IS clay） of CTC from 100 mg/L initial solution（pH 3.51;adsorption temperature 30℃;adsorbent dosage,3 g/L）.The adsorption behaviors of CTC onto the adsorbent follows the Langmuir isotherm model,Temkin equation and pseudo second-order kinetic model.The mesopore adsorption,electrostatic attraction and chemical association mainly contribute to the enhanced adsorption properties.As a whole,the high-efficient silicate adsorbent could be candidates to remove CTC from the wastewater with high amounts of CTC.展开更多
There are two aspects in the study of irregular mixed-layer clay minerals: one is the kinds and ratios of their basic structural unit layers and the other is the junction probabilities of the unit layers. Irregular mi...There are two aspects in the study of irregular mixed-layer clay minerals: one is the kinds and ratios of their basic structural unit layers and the other is the junction probabilities of the unit layers. Irregular mixed-layer illite/smectite clay minerals (I/S) are widespread in nature. While studying the clay minerals from the Permian-Triassic (P/T) boundary bed, the authors found that I/S clay minerals are developed in all P/T boundary clay layers in areas from the northwest to southeast of China. Systematic mineralogical studies of the I/S clay minerals from Hunan, Hubei, Sichuan and Zhejiang were made by means of X-ray, infrared spectroscopic, electron microscopic and chemical analyses and a deepened study of the stacking sequences of their structural unit layers was conducted by the MacEwan one—dimentional direct Fourier transform. It was found that the stacking of the illite and smectite crystal layers along the c axis can be derived from Fibonacci sequences. Hence, the authors propose that such I/S clay minerals are possessed of two—dimentional crystal lattice and one—dimentional quasicrystal lattice.展开更多
基金the National Natural Science Foundation of China(Nos.51403221 and 21377135)the Jiangsu Provincial Joint Innovation and Research Funding of Enterprises,Colleges and Institutes(No.BY2015056-01)+1 种基金the Huai'an Cooperative Research Project of the Enterprises,Colleges and Institutes(No.HAC2015005)the Youth Innovation Promotion Association CAS(No.2016370)for financial support of this research
文摘A series of mesoporous silicate adsorbents with superior adsorption performance for hazardous chlortetracycline（CTC） were sucessfully prepared via a facile one-pot hydrothermal reaction using low-cost illite/smectite（IS） clay,sodium silicate and magnesium sulfate as the starting materials.In this process,IS clay was ＂teared up＂ and then ＂rebuilt＂ as new porous silicate adsorbent with high specific surface area of 363.52 m^2/g（about 8.7 folds higher than that of IS clay） and very negative Zeta potential（- 34.5 mV）.The inert Si- O- Si（Mg,Al） bonds in crystal framework of IS were broken to form Si（Al）- O^- groups with good adsorption activity,which greatly increased the adsorption sites served for holding much CTC molecules.Systematic evaluation on adsorption properties reveals the optimal silicate adsorbent can adsorb 408.81 mg/g of CTC（only 159.7 mg/g for raw IS clay） and remove 99.3%（only 46.5%for raw IS clay） of CTC from 100 mg/L initial solution（pH 3.51;adsorption temperature 30℃;adsorbent dosage,3 g/L）.The adsorption behaviors of CTC onto the adsorbent follows the Langmuir isotherm model,Temkin equation and pseudo second-order kinetic model.The mesopore adsorption,electrostatic attraction and chemical association mainly contribute to the enhanced adsorption properties.As a whole,the high-efficient silicate adsorbent could be candidates to remove CTC from the wastewater with high amounts of CTC.
基金A project supported by the National Natural Science Foundation of China (No. 4880082).
文摘There are two aspects in the study of irregular mixed-layer clay minerals: one is the kinds and ratios of their basic structural unit layers and the other is the junction probabilities of the unit layers. Irregular mixed-layer illite/smectite clay minerals (I/S) are widespread in nature. While studying the clay minerals from the Permian-Triassic (P/T) boundary bed, the authors found that I/S clay minerals are developed in all P/T boundary clay layers in areas from the northwest to southeast of China. Systematic mineralogical studies of the I/S clay minerals from Hunan, Hubei, Sichuan and Zhejiang were made by means of X-ray, infrared spectroscopic, electron microscopic and chemical analyses and a deepened study of the stacking sequences of their structural unit layers was conducted by the MacEwan one—dimentional direct Fourier transform. It was found that the stacking of the illite and smectite crystal layers along the c axis can be derived from Fibonacci sequences. Hence, the authors propose that such I/S clay minerals are possessed of two—dimentional crystal lattice and one—dimentional quasicrystal lattice.
