Removal of 2,4-Dichlorophenoxyacetic acid herbicide from aqueous solutions by Functionalization nanoparticles magnetic: Equilibrium, kinetic and thermodynamic studies

Today, the presence of organic and toxic pollutants is considered one of the most serious environmental problems of the world in water resources. Based on this, methods have been developed to treatment wastewater containing toxic pollutants. In recent years, one of the methods considered by researchers is the process of adsorbing contaminants with magnetic nanoparticle. Therefore, the purpose of this study is to investigate the absorption of 2,4-D herbicide from aqueous solution by a Fe3O4@SiO2-NH2 synthesized nanoparticle.
Material & The synthesis of Fe3O4@SiO2-NH2 is done by co-precipitation methods. The characteristics of prepared adsorbent were determined by SEM, FTIR, XRD and EDX. In this study, we have investigated the effects of pH, initial concentration of pollutant, absorbent dose, at the time of 0-120 min on the removal efficiency of 2,4-D from aqueous solutions. Also, the kinetic equations and equilibrium isotherm studies were conducted.
The optimum pH and contact time obtained was 6 and 30 minutes, respectively. Also, increasing contact time from the onset of the process to the balance time of 60 minutes, the absorption capacity of 2,4-D is raised 65.3%. The results of the kinetic equations and isotherms showed that the process of adsorption of the 2,4-D follows the second order kinetic equation and Langmuir isotherm((R2> 0.99). Also, the investigation from thermodynamic parameters showed that the adsorption is endothermic and spontaneous.
The results of the adsorption experiments showed that the application of synthesized nanoparticles Fe3O4@SiO2-NH2 is a good method for the removal of 2,4-D due to quick and easy separation and no secondary pollution in solution.