弱碱式溶胶凝胶法钛柱撑膨润土工艺条件优化

Study on Adsorption of Dye Wastewater by Ti-pillared Bentonite

以改性的钠基膨润土和硫酸钛为原料,通过弱碱式溶胶凝胶法,对影响TiO2在膨润土层间置换过程因素:矿浆浓度、反应温度、搅拌强度、搅拌时间、焙烧温度进行了正交实验;通过模拟染料废水实验,对改性材料的光催化降解性能进行了研究。实验数据表明:五个过程因子的影响顺序是焙烧温度>矿浆浓度>水浴温度>搅拌时间>搅拌转速,优化工艺方案为矿浆浓度为0.029%,搅拌时间为45min,焙烧温度在600℃,水浴温度为90℃,搅拌转速为5.232m/s。通过XRD、SEM、EDS表征方法对所得样品进行孔结构、组成的表征:改性膨润土依然保持层状结构特性,并且层间距很大的比例由1.70nm打开到3.35nm;钛含量的重量百分比为整体8.86%和层间21.30%表明TiO2已渗入膨润土层间结构。

TiO2 pillared bentonite are synthesized from Na-bentonite and titanium sulfate by weak basetype sol-gel method.The orthogonal experiment conditions are as follows：calcinations temperature,pulp density,water-bath temperature,stirring time and stirring rate.By the photocatalytic degradation reaction,the influence sequence of experimental conditions is as following：calcinations temperature pulp density water-bath temperature stirring time stirring rate.The optimal conditions are：pulp concentration 3 g of 100 mL solution;reaction time 45 min;calcination temperature 600 ℃;water-bath temperature 90 ℃ and stirring rate 5.232 m/s.The composite material is characterized by XRD,SEM and EDS.It is found that pillared bentonite still remains the layered structure and the space of layers is almost opened from 1.70 nm to 3.35 nm.In the EDS analysis,the weight percentages of Ti are 8.86% in total and 21.30% between layers,which shows that the TiO2 particles pillar into the layer of bentonite.