Removal of ۲,۴-dichlorophenoxyacetic acid from aqueous solutions by modified magnetic nanoparticles with amino functional groups

The present study was performed on the adsorption of ۲,۴-Dichlorophenoxyacetic acid from aqueous solutions by amine-modified magnetic nanoparticles. The adsorbent was synthesized by the co-precipitation method. The adsorbent properties of Fe۳O۴@SiO۲-NH۲ were investigated using XRD, FTIR, TGA, VSM and TEM. Adsorbent efficacy was studied by investigating the effect of pH, initial concentration of pollutants, and adsorbent dose, and times. Finally, kinetics equations and isotherms models were used to describe the data. The results showed that the highest removal percentage was observed at pH ۶ and the initial concentration ۲۰ mg/l of ۲,۴-Dichlorophenoxyacetic acid. Adsorption capacity was increased by ۶۵.۳% bypassing the time from the beginning of the process to ۶۰ min. The results from the study of isotherms and adsorption kinetics presented that the sorption procedure follows the pseudo-second-order kinetics and the Langmuir isotherm with R۲> ۹۹. The maximum adsorption capacity of Fe۳O۴@SiO۲-NH۲ is ۱۱۶.۳ mg/g. Besides, thermodynamic studies have shown that the adsorption process in the present study is endothermic and spontaneous. The experiments showed that Fe۳O۴@SiO۲-NH۲ synthesized nanoparticles could be an excellent method to remove ۲,۴- Dichlorophenoxyacetic acid contaminants from the aqueous solutions due to the high efficiency, simplicity, and lack of secondary contamination in the solution.

کلیدواژه ها:

Adsorption ، herbicides ، Isotherm ، Kinetics ، water pollution