STUDY OF THE ADSORPTION OF ORGANIC-COMPOUNDS FROM AQUEOUS-SOLUTIONS ONTO GRAFTED CLAYS AND COMPARISON WITH OTHER ADSORBENT MATERIALS

Clays are natural soil components which are able to react with soluble organic compounds in water. The purpose of this work was to study the behaviour of a montmorillonite clay grafted with a quaternary ammonium, so that clay particles have a positive electrokinetic potential. Results of the adsorption capacity onto grafted montmorillonite (bentone SD3) were compared with those obtained onto other clays and onto activated carbon for some solutes: humic acids, salicylic acid, atrazin. Adsorption capacities of humic acids and salicylic acid are depending upon the electrokinetic charge of the adsorbent: ionic or hydrophobic interactions are possible onto grafted montmorillonite. But the adsorption of a molecular compound (atrazin) has no relation with the charge of the material and the physical mechanism is only depending upon the specific material area. Considering these two remarks a selective adsorption could be realized .