• 关键词：氨基改性SBA-15  吸附  有序介孔材料  Cd²⁺  热力学特征

• 基金项目：西北农林科技大学青年科研专项基金项目 (No.08080271);陕西省自然科学基金 (No. 2005C105)

• 李荣华
• 西北农林科技大学 理学院,杨凌 712100

• 岳庆玲
• 河南科技学院 资源与环境学院,新乡 453003

• 孟昭福
• 西北农林科技大学 理学院,杨凌 712100

• 张增强
• 西北农林科技大学 理学院,杨凌 712100

• 摘要：以硅酸钠为硅源,三嵌聚合物Pluronic P123为模板剂,采用水热-后期接枝的合成方法,制备出氨基改性SBA-15.用透射电镜、X射线衍射、氮气吸附-解吸和红外光谱等手段对其结构进行了表征.在此基础上,以改性SBA-15为吸附剂,通过批实验讨论了吸附时间、体系初始 pH值和温度等对水溶液中Cd²⁺吸附的影响,并讨论了吸附过程的热力学特征. 结果表明,合成的SBA-15具有规则多孔特征.SBA-15介孔材料对Cd²⁺的吸附受体系pH控制;未改性的SBA-15对Cd²⁺的吸附量极小,氨基改性可以显著增强SBA-15对Cd²⁺的吸附能力.向100 mL浓度为 112.5 mg·L^-1和10 mg·L^-1的Cd²⁺溶液中加入0.1 g吸附剂,于298 K、80 r·min ^{- 1}、pH=7.0的条件下恒温振荡4 h, 改性SBA-15对溶液中Cd²⁺的吸附很迅速,并在30 min内达到吸附平衡;随着体系温度的升高,改性SBA-15对Cd²⁺的吸附量增加.吸附等温线可用Langmuir模型描述,在 298 K时最大吸附量为0.687 mmol·g^-1.对吸附热力学参数ΔG⁰、ΔH⁰和ΔS⁰的计算表明,吸附过程是吸热的自发过程.研究表明, 氨基改性SBA-15是一种对水体中Cd²⁺具有良好吸附能力的新型吸附剂.

• Abstract：The amino-modified ordered mesoporous material SBA-15 was synthesized by a hydrothermal grafting method using sodium silicate as silica source and triblock poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) copolymer Pluronic P123 as template. The synthesized mesoporous SBA-15 samples were characterized by TEM, X-ray diffraction, FTIR and N₂ adsorption-desorption. The SBA-15 and modified SBA-15 samples were used as sorbents to adsorb Cd²⁺ ions from aqueous solution. The effect of experimental parameters, such as pH, contact time and temperature were examined and the adsorption thermodynamics was also calculated. The results showed that under the same conditions, the maximum adsorption value for Cd(II) was higher than that of the unmodified mesoporous silica. The adsorption process was controlled by system pH. Adsorption equilibrium was reached within 30 minutes when 0.1 g sorbent was added into 100 mL solution which contained 112.5 and 10 mg·L^-1 Cd²⁺ at pH 7.0, 298 K, 80 r·min^-1 and 4 h contact time. The adsorption capacity increased with temperature. The Langmuir model can be used to describe the adsorption isotherms. The adsorption capacity of NH₂-SBA-15 was 0.687 mmol·g^-1, which is comparable to the adsorption capacity of various adsorbents reported in the literature. Thermodynamic parameters of the adsorption process, such as ΔG⁰, ΔH⁰ and ΔS⁰ indicated that the overall adsorption process was endothermic and spontaneous. The study indicated that the amino-modified ordered mesoporous material SBA-15 is a potential sorbent which could be used in the treatment of cadmium contaminated wastewater.

• Key words：amino-modified SBA-15  adsorption  ordered mesoporous materials  Cd²⁺  thermodynamics

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