Prediction of breakthrough curves for adsorption of lead(II) on activated carbon fibers in a fixed bed

The breakthrough curves were measured for the adsorption of aqueous Pb(NO3)(2) on activated carbon fibers (ACFs) in a fixed-bed adsorber. With the adsorption equilibrium constant and the intraparticle diffusivity determined from separate experiments in a batch tank, the breakthrough curves were predicted by the orthogonal collocation method. By the analysis of the effects of intraparticle and external mass transfer resistances as well as the axial dispersion on the breakthrough curves, the axial dispersion is confirmed to be the main parameter that controls the adsorption dynamics. Based on this analysis, the quasi-lognormal distribution approximation for linear isotherms and the constant pattern profiles solution for nonlinear isotherms were presented to predict the breakthrough curves for ACF fixed beds. In addition, the effluent pH curves were discussed with the changes of experimental conditions. (C) 2000 Elsevier Science Ltd. All rights reserved.