Removal of 2.4-dichloro phenoxyacetic acid from aqueous solution by adsorption on activated carbon. A kinetic study

The sorption of 2.4-dichloro phenoxyacetic acid (2.4-D) on two different activated carbons was determined using the batch equilibration technique. The calculated slopes of the Freundlich sorption isotherms were significantly less than 1. The (K) values were higher for the activated carbon which has the higher specific surface, and increased with NaCl concentration. The rate of attaining equilibrium of 2.4-D increased with a decrease in adsorbent concentration. Dynamic modelling of the adsorption showed that a first order reversible kinetic model was followed for the adsorption process. The overall rate constant K', the adsorption rate K-1, the desorption rate constant K-2, and the equilibrium constant K-c for the adsorption process were calculated.