活性炭及硅藻土对染料的吸附特性研究

采用活性炭、硅藻土、氢氧化镁改性硅藻土对1种阳离子染料和2种阴离子染料进行了吸附研究.BET液氮吸附法测定结果显示硅藻土改性后的比表面积增大而平均孔径降低;染料吸附结果表明:硅藻土改性后对天龙红(TR)及雷马素金黄(RGY)两种阴离子染料的吸附性能提高,而对阳离子染料亚甲基蓝的吸附性能降低;改性硅藻土对天龙红的吸附容量大于活性炭,而对雷马寨金黄及亚甲基蓝的吸附容量低于活性炭;采用准一级、准二级两种吸附动力学模型对染料的吸附动力学数据进行了拟合,结果显示改性硅藻土及活性炭的染料吸附过程更符合准二级动力学模型.

Study on the Adsorption of Dyes Using Diatomite and Activated Carbon

Batch experiments were carried out for comparing the adsorption capability of 1 cationic dye and 2 anionic dyes onto diatomite,Mg(OH)2-modified diatomite and activated carbon.The BET surface area analysis showed that the modification of diatomite slightly increased its surface area while decreased its average pore diameter.The dye adsorption results indicated that the modification of diatomite increased its adsorption capacity for the anionic dyes,Telon red(TR)and Ramazol golden yellow(RGY).The adsorption capacity of modified diatomite for TR was higher than that of activated carbon while lower for RGY and methylene blue than that of activated carbon.2 kinetics models.pseudo-first order and pseudo-second order,were then used to study the adsorption kinetics.It was found that the kinetics of adsorption could be better described with the pseudo-second-order model for the modified diatomite and activated carbon.