模板法合成介孔硅酸钙及其对重金属离子的吸附性能  

Synthesis of mesoporous calcium silicate by template method and its adsorption performance for heavy metal ions

作　　者：刘立华[1] 杨刚刚[1] 王易峰 李童[1] 唐安平[1] 

机构地区：[1]湖南科技大学化学化工学院,理论有机化学与功能分子教育部重点实验室,分子构效关系湖南省普通高等学校重点实验室,湘潭411201

出　　处：《环境化学》2016年第9期1943-1951,共9页Environmental Chemistry

基　　金：国家自然科学基金(51378201)资助~~

摘　　要：以硝酸钙和硅酸钠为原料,采用模板法制备了介孔硅酸钙.探讨了不同模板剂(十二烷基磺酸钠、十六烷基三甲溴化铵、P123和十六烷基三甲溴化铵-四甲基氢氧化胺)对介孔硅酸钙孔径和表面形貌的影响,通过X射线衍射(XRD)、扫描电镜(SEM)、BET表面分析和红外光谱(FT-IR)等对其结构进行了表征,考察其对含Pb^(2+)和Cu^(2+)模拟废水的吸附性能和解吸再生性能,并与活性炭的吸附性能进行比较.结果表明,采用十六烷基三甲溴化铵模板剂为模板合成的硅酸钙具有介孔结构,为狭缝孔,孔径主要介于4—50 nm之间,比表面积达158.13 m^2·g^(-1);在298 K下,对Pb^(2+)和Cu^(2+)的吸附容量分别为1.833 mmol·g-1和6.557 mmol·g-1,远比在相同吸附条件下活性炭的吸附容量高.介孔硅酸钙吸附重金属离子为放热反应,主要是表面羟基与重金属离子间配位化学作用.经过5次洗脱再生,对Pb^(2+)的平衡吸附量和吸附率仅分别降低了0.102 mmol·g-1和4.2%,表明其具有优良的吸附/再生性能,有望成为优良的重金属离子吸附材料.Mesoporous calcium silicate was prepared from calcium nitrate and sodium silicate by the template method. The effects of different templates （sodium dodecyl sulfate, cetyl trimethyl ammonium bromide, P123 and cetyl trimethyl ammonium bromide-tetramethyl ammonium hydroxide） on the pore size and surface topography of mesoporous calcium silicate were investigated. The calcium silicate synthesized was characterized by the X-ray diffraction （XRD）, scanning electron microscopy （SEM）, Brunauer-emmett-teller （BET） and Fourier transformed infrared spectroscopy （FT-IR）. The adsorption performance of mesoporous calcium silicate for Pb2＋and Cu2＋, desorption regeneration performance were studied, and the adsorption effect for Pb2＋ and Cu2＋ was compared with activated carbon. The results show that the mesoporous calcium silicate synthesized using cetyl trimethyl ammonium bromide as a template had amesoporous slit-pore structure with a specific surface area of 158.13 mE.·g-1, and pore size mainly distributed in 4-- 50 nm. The adsorption capacities for Pb2＋ and Cu2＋ were 1.833 and 6.557 mmol· g-1 at 298 K,respectively, far more than activated carbon under the same adsorption conditions. The adsorption of the heavy metal ions was an exothermic reaction, mainly resulting from the coordination action of hydroxyl groups on the surface of calcium silicate with heavy metal ions. The adsorption capacity and removal rate for Pb2＋ only decreased by 0. 102 mmol·g-1 and 4.2% respectively after 5 elution- regeneration cycles, indicating that the mesoporous calcium silicate had excellent adsorption and regeneration performance. It is expected to be an excellent adsorption material for heavy metal ions.

关 键 词：介孔硅酸钙 模板合成法 重金属离子 吸附 

分 类 号：X703[环境科学与工程—环境工程]