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A novel macroporous silica-based hexagonal tungsten oxide(h-WO_3/SiO_2) with exchangeable sodium cations located in hexagonal tunnel structure was synthesized by a facile hydrothermal treatment of sodium tungstate dihydrate with 1 mol/L HCl solution. Utilization of the h-WO_3/SiO_2 adsorbent to remove aqueous strontium was investigated under the condition of various p H values, contact time, the initial concentration of metal ions, salt ion concentration, and coexisting ions. According to the experimental data, Sr~(2+) adsorption equilibrium was achieved within 15 min in acidic solution, and the maximum removal capacity of Sr~(2+) occurred at pH 4. The kinetic adsorption of Sr~(2+) on h-WO_3/SiO_2 was controlled by pseudo second-order model, and the saturated adsorption of Sr~(2+) on h-WO_3/SiO_2 was better described by Langmuir and Redlich-Peterson isotherm models compared with the Freundlich isotherm model. The distribution coefficient of Sr~(2+) was more than 2000 cm~3/g in the presence of Ca~(2+), Mg~(2+), La~(2+), and Eu~(2+), indicating that the h-WO_3/SiO_2 showed excellent selectivity towards Sr~(2+) in pH 4.
A novel macroporous silica-based hexagonal tungsten oxide (h-WO_3 / SiO_2) with exchangeable sodium cations located in hexagonal tunnel structure was synthesized by a facile hydrothermal treatment of sodium tungstate dihydrate with 1 mol / L HCl solution. Utilization of the h-WO_3 / SiO_2 adsorbent to remove aqueous strontium was investigated under the condition of various p H values, contact time, the initial concentration of metal ions, salt ion concentration, and coexisting ions. was achieved within 15 min in acidic solution, and the maximum removal capacity of Sr ~ (2+) occurred at pH 4. The kinetic adsorption of Sr ~ (2+) on h-WO_3 / SiO_2 was controlled by pseudo second-order model , and the saturated adsorption of Sr ~ (2+) on h-WO_3 / SiO_2 was better described by Langmuir and Redlich-Peterson isotherm models compared with the Freundlich isotherm model. The distribution coefficient of Sr 2+ was more than 2000 cm ~ 3 / g in the pres ence of Ca2 +, Mg2 +, La2 +, and Eu2 +, indicating that the h-WO3 / SiO2 showed excellent selectivity towards Sr2 + in pH 4.