Green synthesis of functionalized iron nano particles and molecular liquid phase adsorption of ametryn from water

Second generation herbicide ametryn [2-(ethylamino)-4-isopropylamino-6-methyl-thio-s-triazine] is being used to control broadleaf weeds and annual grasses in sugarcane, bananas, maize and pineapple fields; contaminating water resources. The adsorption method of ametryn removal was presented using functionalized iron nano particles as adsorbent. This adsorbent was prepared by green method, functionalized with 1-butyl-3-methylimidazolidium bromide and characterized by FT-IR, SEM and XRD techniques. Residual ametryn in water was analyzed by optimized HPLC. The optimized batch experiment parameters were 30.0 mu g/L, 30.0 min, 7.0, 2.5 g/L and 20.0 degrees C as concentration, contact time, adsorbent amount and temperature. Adsorption data followed Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models. Thermodynamic parameter such as Delta G degrees, Delta H degrees and Delta S degrees were -6.05, -6.11 and -6.15 kJ/mol at 20, 25 and 30 degrees C temperatures; -6.68 kJ/mol and -2.45 x 10(-3) kJ/mol K. These values indicated sorption spontaneous and exothermic. Pseudo-second order and liquid film diffusion mechanisms of the adsorption were proposed. Developed sorption method was speedy, environmental friendly and inexpensive due to its nature to be used under natural conditions of water resources. The method work at natural water resources pHs with low adsorbent amount and agitating time. The sorption method may be used for the removal of ametryn from any water body at large and economic scale. (C) 2016 Published by Elsevier B.V.