On the removal of s-triazine herbicides from waters using commercial low-cost granular carbons

The adsorption capacities of three low-cost granular active carbons, used in a water treatment facility for the removal of the triazine herbicides propazine, prometryn and prometon, was evaluated. Kinetic studies showed that the three carbon samples used could be suitable in practice for the treat- ment of moderate contents of the herbicides in contaminated waters. The appa- rent adsorption rate constants were calculated. Equilibrium studies showed that the data fit the Frumkin isotherm. The results show that in the adsorption pro- cess there are repulsive lateral interactions that depend mainly on the adsorbate molecules rather than the nature or distribution of the adsorption sites. Such lateral interactions seem to be established mainly between the isopropyl groups of adjacent molecules, being of the same order for the three molecules.