流动注射分光光度法研究离子强度对活性炭吸附阴、阳离子染料的影响

Study on effect of ionic strength on adsorption of cationic and anionic dyes by activated carbon with flow injection spectrophotometry

运用流动注射分光光度法,考察了不同离子强度(NaCl)下,在水溶液中表面带负电的活性炭分别吸附阴、阳离子染料的动力学行为。实验结果表明,对于所考察的2种阳离子染料和3种阴离子染料,活性炭的表观吸附速率常数均随着离子强度的增大而增大。这种加速吸附效应的出现,主要是因为离子强度的增大促进了活性炭表面与染料之间的非静电力作用。

The effect of ionic strength (NaCl) on the adsorption kinetic behaviors of cationic and anionic dyes on activated carbon which presents a negative surface charge in aqueous solution was studied by flow injection spectrophotometry. The experimental results show that the apparent adsorption rate constants each increase with the rise of ionic strength, when activated carbon adsorbs two cationic dyes and three anionic dyes, respectively. The accelerating effect on adsorption is mainly caused by the enhancement of nonelectrostatic interactions between carbon surface and dye with increasing ionic strength.