【摘要】 以1,2-双（三乙氧基硅基）乙烷（BTESE）为前驱体,采用溶胶-凝胶法制备出完整无缺陷的La/Y掺杂二氧化硅膜.采用TG、FTIR、XRD和SEM等手段表征了La/Y掺杂溶胶凝胶的性质、膜的形貌特征和热稳定性.考察了不同La/Y掺杂比和焙烧温度条件下制备的二氧化硅膜对正电荷染料结晶紫、负电荷染料刚果红等染料废水的分离性能.研究结果表明,与纯BTESE-SiO₂膜相比,La/Y掺杂SiO2膜的分离性能有所提高.La/Y为50/50（摩尔比）、焙烧温度为300℃的合成条件下所制备的La50Y50-SiO2膜对染料废水分离性能最佳.在初始质量浓度为5mg/L的结晶紫溶液和20mg/L的刚果红溶液分离过程中,该膜的渗透通量都高于5.0L/（m²·h）,对染料分子的截留率为100%.该膜对负电荷染料刚果红的分离性能优于其对正电荷染料结晶紫的分离性能.在膜分离染料废水过程中,存在分子筛分和静电吸附的协同分离机制.此外,La/Y掺杂二氧化硅膜还表现出优异的耐盐性,表明该膜可用于高盐染料废水处理.更多还原

【Abstract】 La/Y doped silica membranes without defect were successfully prepared by sol-gel method with1,2-bis（triethoxysilyl）ethane（BTESE）as precursors.The properties of silica sols and gels,and morphology and hydrothermal stability of silica membranes were characterized by TG,FTIR,XRD and SEM.The influence of La/Y ratios and calcination temperature on the separation performance through these silica membranes were investigated in positively charged crystal violet and negatively charged Congo red dye wastewater solutions.The results showed that their separation performance was improved for La/Y doped silica membranes,compared with pure BTESE-SiO₂ membrane.And La50 Y50-SiO2 silica membranes exhibited the best separation performance,which were prepared with La/Y ratio as 50/50 and calcinated at 300℃.Moreover,the permeated flux over 5.0 L/（m²·h）and rejection for dye molecules of100% were obtained when the test were conducted with initial concentration of crystal violet at 5 mg/L and that of Congo red at 20 mg/L.The separation performance through the silica membrane in negatively charged Congo red solutions were higher than those in positively charged crystal violet solutions.There were synergistic mechanism of molecular size sieving and electrostatic adsorption effect during the separation process for dyes wastewater treatment.In addition,the La/Y doped silica membranes also exhibited excellent salt tolerance,indicating that these membranes would be used in the high-efficiency separation for high salinity dye wastewater treatment.更多还原