Removal of carbendazim from fruit conditionning waters by adsorption on different materials

The main aim of this work is to test different materials (activated carbon and other more "rustic" materials like clay and coal) as potential adsorben ts in order to evaluate their adsorption capacity for carbendazime. The exp eriments were realized with certified carbendazim. or with benlate solution s left to change long enough to suppose all the benomyl converted into carb endazim. The results were introduced through adsorption kinetic and isother m forms or interpreted according to the Langmuir model. They pointed out th at final elimination percentages of certified carbendazim don't exceed 55%. But even the activated carbon remains the most effective adsorbent, clay a nd coal present an interesting adsorption capacity, 45% for clay (but its p erformance is varied), 35% for coal. The presence of formulation additives has an inhibitive effect whatever the materials is. Some adsorption attempt s with clay and coal mixtures (100 mg l (-1) of each one) were realized, th ere isn't a cumulative adsorption, final percentages of elimination are abo ut 45%. Characterization attempts of the adsorbents pointed out that all th e materials have a negative global surface charge. But clay possesses a sur face charge far more negative than coal, sodipolary lap of carbendazim. can further the adsorption. The measures of surface functions according to Boe hm titration and capillary rising technique showed that coal differentiates from the other materials by its high capacity to establish Lifshitz-Van de r Waals interactions. Carbendazim molecule can present a dipolary moment wh ich could lead to the formation of hydrogen bonds. But results of capillary rising are to be considered by surface unities that could explain the supe rior adsorption capacity of clay (internal surface : 800m(2) g(-1)).