Abstract
This research included the preparation of a new type of activated carbon using the stems of eucalyptus trees obtained from the forests of the city of Mosul. It was found that this type of prepared carbon is of the nano type whose particle size is less than (100 nm), as its particle sizes ranged from (41.11, 58.64, 65.27 nm). This type of carbon was used to remove Vitavax pesticide, (in which the active substance is the carboxine) from its aqueous solutions. This research included the application of the Freundlich and Langmuir isotherms, and the results showed that the practical data of the system under study follows more of the Langmuir isotherms. This is indicated by the high (R²) values, where the R² value of Freundlich was (0.9825), while the Langmuir value of R² was (0.991). The thermodynamic study of adsorption in the system under consideration showed that it is a spontaneous process through (negative Go∆) values and leads to greater uniformity after the adsorption process, in addition to the force that controls the bond between the pesticide and the carbon surface, are physical forces (∆H = -8.558). The research also included the application of four kinetic models on the practical data of the system under study, namely, pseudo-first-order, pseudo-second-order, and intra particle diffusion. The results showed that the adsorption system used in this research follows the pseudo second-order reaction equation, and that the process of intra particle molecular diffusion is not the only mechanism that dominates the adsorption process.
