介孔硅酸钙吸附亚甲基蓝性能研究

Research on adsorption properties of methylene blue by mesoporous calcium silicate

以煤矸石提铝尾渣制得的介孔硅酸钙为吸附材料,研究了介孔硅酸钙对亚甲基蓝的吸附性能。考察了亚甲基蓝溶液pH、吸附剂添加量、吸附时间和吸附温度等因素对吸附效果的影响。结果表明,介孔硅酸钙对亚甲基蓝表现出良好的吸附性能,在298 K、pH=11、介孔硅酸钙投加量为0.2 g/L、吸附时间为60 min条件下,亚甲基蓝的去除率达87.33%。介孔硅酸钙对亚甲基蓝的吸附过程符合准二级动力学模型和Langmuir吸附等温线方程,吸附方式为单分子层吸附,饱和吸附量为89.68 mg/g。吸附过程为熵增加的自发过程,升温有利于吸附。吸附焓变ΔH为62.72 kJ/mol,介孔硅酸钙对亚甲基蓝的吸附以化学吸附为主。

The adsorption properties of methylene blue by mesoporous calcium silicate which prepared from alumina-extracted coal gangue were studied.The effect of methylene blue solution pH,adsorbent dosage,adsorption time and temperature on the adsorption capacity were investigated.The results indicated that mesoporous calcium silicate showed good adsorption properties for methylene blue.Under the conditions of 298 K,pH of 11,the dosage of mesoporous calcium silicate of 0.2 g/L and adsorption time of 60 min,the removal rate of methylene blue could reach 87.33%.The adsorption process of methylene blue on mesoporous calcium silicate could be described by the pseudo second order kinetic model and Langmuir adsorption isotherm equation,indicating a monolayer adsorption process with the saturated adsorption capacity of 89.68 mg/g.The thermodynamic analysis showed that the adsorption process was a spontaneous,entropy increase process,and the higher temperature was conducive to the adsorption.The adsorption enthalpy was 62.72 kJ/mol.The adsorption of methylene blue by mesoporous calcium silicate was mainly chemical adsorption.