Abstract:

A novel amino-functionalized adsorbent material Al-magadiite（abbreviated as AlMag-NH₂） was prepared by hydrothermal synthesis with Al-magadiite（abbreviated as AlMag） as matrix and aminopropyltriethoxysilane as functional reagent.The effect of amino-modification process on the structure of the materials and the adsorption effect of Hg²⁺ in aqueous solution were studied.The characteristic results showed that the amino-functional groups were successfully grafted onto AlMag matrix.The functionalized AlMag-NH₂ changed from the initial rosebud morphology to lamellar morphology.The interlayer spacing and average pore diameter increased,the specific surface area decreased slightly and the pH_pzc increased.The experiment conditions were optimized and obtained as follows：the solution pH=5.0,the absorption time was 360 min and the initial mass concentration of Hg²⁺ was 10 mg/L. Under the same optimized conditions,the removal rate of AlMag-NH₂ reached 88.82% and was 2.4 times than the removal rate of AlMag.The Hg²⁺ saturated adsorption capacity of AlMag-NH₂was 20.62 mg/g.The adsorption process was in accordance with the pseudo second order kinetics and Langmuir model,which was mainly chemical adsorption.

Key words: Al-magadiite, amino-functionalization, Hg²⁺, adsorption