流动注射分光光度法研究离子强度对活性炭吸附阴离子染料的影响

利用流动注射分光光度法技术，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3种阴离子染料的动力学行为．利用固-液相互作用方程，求取了活性炭-染料相互作用能．比较了无机盐中阳离子的种类对吸附影响的差异．结果表明：对于3种阴离子染料，离子强度的增大都起到加速吸附的作用：表现吸附速率常数、活性炭-染料相互作用能与离子强度三者之间存在密切的内在联系：在相同离子强度下，二价阳离子对吸附的加速作用要比一价阳离子的显著，但在同价阳离子之间这种作用的差别较小．

THE STUDY ON EFFECT OF IONIC STRENGTH ON THE ADSORPTION OF ANIONIC DYES ON ACTIVATED CARBON WITH FLOW INJECTION-SPECTROPHOTOMETRY METHOD

The effect of ionic strength (NaCl) on the adsorption kinetic behaviors of three anionic dyes on activated carbon which presents a negative surface charge in aqueous solution was studied by flow injection-spectrophotometry method. The interaction energies between activated carbon and dyes were obtained by solid-liquid interaction equation. The difference between effects of the kinds of cations of inorganic salts on adsorption was discussed. The results show that the increase of ionic strength has an accelerating effect on the adsorption of three anionic dyes, furthermore, an intrinsic correlation exists between the apparent adsorption rate constant, activated carbon-dye interaction energy and ionic strength. At the same ionic strength, the accelerating effects of divalent cations on adsorption are far stronger than those of univalent cations, but there is less difference in accelerating effect between cations of the same valence number.