The infl uence law of clay on mortar fluidity mixed with polycarboxylate superplasticizer was studied. Several methods of inhibiting clay adsorption of polycarboxylate superplasticizer were discussed. The experimental...The infl uence law of clay on mortar fluidity mixed with polycarboxylate superplasticizer was studied. Several methods of inhibiting clay adsorption of polycarboxylate superplasticizer were discussed. The experimental results show that clay has signifi cant effect on the dispersion of polycarboxylate superplasticizer and montmorillonite clay has more signifi cant impact on mortar fluidity than other clays. The pH value and the salts of the solution can affect the adsorption of clay to polycarboxylate superplasticizer. The incorporation of a small amount of sodium hydroxide solution, sodium silicate or cationic surfactants can improve the effect of the clay on the dispersion of polycarboxylate superplasticizer.展开更多
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
基金Funded by the National Natural Science Foundation of China(50872151)the Beijing Municipal Education Commission Program Projects and Beijing University of Civil Engineering and Architecture,Dr.Fund
文摘The infl uence law of clay on mortar fluidity mixed with polycarboxylate superplasticizer was studied. Several methods of inhibiting clay adsorption of polycarboxylate superplasticizer were discussed. The experimental results show that clay has signifi cant effect on the dispersion of polycarboxylate superplasticizer and montmorillonite clay has more signifi cant impact on mortar fluidity than other clays. The pH value and the salts of the solution can affect the adsorption of clay to polycarboxylate superplasticizer. The incorporation of a small amount of sodium hydroxide solution, sodium silicate or cationic surfactants can improve the effect of the clay on the dispersion of polycarboxylate superplasticizer.
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.
