巯基改性SBA-15的制备及其对Cr⁶⁺的吸附

Chromium ion accumulation in environment is a health hazard to human being. A thiohydroxy-functionalized mesoporous material SBA-15-SH as adsorbent was prepared by the hydrothermal polycondensation method in this study. When 3-mercaptopropyltrimethoxysilane was used as the silicon source, SBA-15 was successfully modified with the thiohydroxy group confirmed by FTIR. This designed mesoporous material was rod-like with regular and well-defined channel systems of 7 nm. The adsorption capacity of SBA-15-SH to Cr⁶⁺ was affected by the adsorption temperature, Cr⁶⁺ solution pH and its initial concentration together with the adsorbent dosage. The adsorption equilibrium was reached in 10 min which obeyed the Langmuir adsorption equation and the pseudo second-order kinetic mode. The maximum adsorption capacity of SBA-15-SH to Cr⁶⁺ was 6.85 mg/g when the Cr⁶⁺ solution pH and adsorption temperature was controlled at 4.0 and 25-45 ℃, respectively. This functionalized mesoporous material was successfully applied in spiked tap-water and industrial waste water, and the recovery rate can reach 95%-105%.