Sorption of apolar pesticides by units of benzoic acid propyl ester in cyclic phosphazene

The effects of temperature, pH and agitation time (equilibrium) on the adsorption process of different pesticides on N₃P₃(OC₆H₄COOCH₂CH₂CH₃)₆ was studied. With optimal conditions experimental, the adsorption isotherms have been realized with through Langmuir and Freundlich models. Pesticides are compounds used mainly in agriculture to control various species (plants, insects, worms, fungi). Due to their physicochemical properties, they can remain for a long time in the application sites, bioaccumulating and moving between environmental compartments which generate various environmental problems. The results obtained showed a physisorption mechanism for the fve pesticides studied, with higher sorption for: azinphos methyl (93,5 mg kg^-1), carbaryl (290.5 mg kg^-1) and carbofuran (580.5 mg kg^-1) at 20 ° C, according to the models used.