Effects of calcium competition on lead sorption by palm kernel fibre

The kinetics of sorption of a mono-solute of lead ions and of a bi-solute of lead and calcium ions onto palm kernel fibre was investigated in a batch system. The experimental data were analysed based on an intraparticle diffusion equation and a pseudo-second-order mechanism, in both the mono- and bi-solute sorption systems, in order to predict the rate constant of sorption, the equilibrium capacity, and the initial sorption rate. The results indicate that the sorption mechanism is described by a pseudo-second-order equation. Intraparticle diffusion was significant in the lower-concentration systems. In addition, a modified intraparticle diffusion equation was applied to the sorption systems. (c) 2005 Elsevier B.V. All fights reserved.