Adsorption of water-soluble dye onto functionalized resin

The adsorption of water-soluble dye reactive brilliant blue KN-R onto the f unctionalized resin NKY has been dynamically and thermodynamically investig ated. The adsorption rate constant is obtained from the first-order express ion log(Q(e) - Q) = log Q(e) - k(ad)t/2.303. The adsorption is complex sinc e the equilibrium data are well described by the Langmuir equation, the Fre undlich equation, and the three-parameter equation. The first layer adsorpt ion of KN-R onto NKY is physical, enhanced by a chemical effect, but multil ayer adsorption is typically physical adsorption at normal temperature. The adsorption process is endothermic. The obtained standard free energy chang e and the inferred standard entropy change show that the adsorption of the dye onto NKY can occur spontaneously. Moreover, the effect of pH and temper ature on the adsorption has been explored. The apparent activation energy E -a of the adsorption process has been calculated as well. (C) 2001 Academic Press.