巯基改性SBA-15的制备及其对Cr6+的吸附

Thiohydroxy-functionalized Mesoporous Materials: Preparation and its Adsorption to Cr6+

环境中存在的重金属铬对人体健康有严重的危害,本研究采用水热共缩聚法制备了一种对Cr6+有较高吸附能力的介孔材料SBA-15-SH。经红外光谱证实,通过使用改性硅源3-巯丙基三甲氧基硅烷,对SBA-15成功实现了巯基改性。经扫描电子显微镜(SEM)和透射电子显微镜(TEM)观察,所制备的材料呈棒状,具有均匀的孔道结构,孔径约为7 nm。将制备材料用于重金属Cr6+的吸附,研究了吸附时间、环境温度、Cr6+溶液pH和初始浓度以及吸附剂用量对吸附剂吸附性能的影响。研究表明:该材料吸附Cr6+的平衡吸附时间约10 min,吸附过程符合Langmuir方程与伪二级动力学模型。当Cr6+溶液pH为4.0、吸附温度在25~45℃时,介孔材料SBA-15-SH对Cr6+吸附量最大,达到6.85 mg/g。将本方法用于自来水和工业废水中Cr6+的吸附,回收率介于95%~105%之间。

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%.