Effect of Surface Charge on Chromium Removal by Magnetic Harvesting en 3rd International Conference on Polyol mediated Synthesis (25-27 Junio 2018).

Abstract

In order to understand the influence of the surface charge in the adsorption mechanism of iron oxide magnetic nanoparticles, the removal of chromium from aqueous solution was investigated in a batch experimental setup. Synthesis of the 14 nm width magnetic nanoparticles (Fe3O4) was performed via a microwave reactor and then, the surface charge was varied by grafting with tetraethyl orthosilicate (TEOS) and (3aminopropyl) triethoxysilane (APTES). Different experimental approaches were applied to show mechanistic aspects, such as adsorption isotherms and kinetics studies. Adsorption equilibrium studies showed that Fe3O4@TEOS barely remove the chromium from de media, while chromium adsorption with Fe3O4 and Fe3O4@TEOS@APTES, followed the Langmuir model with a maximum adsorption capacity of 15 and 30 mg of Cr/g of NPs, respectively. The kinetics of the interactions was best described by pseudo-second-order mechanism.