Desenvolvimento de nanocompósito formado por nanopartícula magnética e lignina modificada para remoção do corante azul de metileno

Abstract

This work aims at studying the removal of methylene blue (AZM) from aqueos solutions using MnFe2O4 magnetic nanoparticles (NPM), as well as composites containing these particles modified at the surface with lignin from Pinus and some of its chemical derivatives (carboxymethyl lignin, hydroxymethyl lignin and carboxymethyl hydroxymethyl lignin). The pine wood residue is an available and low cost material that can be used to remove the AZM dye. The X ray diffraction analisis showed that the size of the magnetic nucleous of the particles is around 45 nm. Scannin electron microscopy (MEV) of the samples indicate that the chemical modification on the structure of the lignina affects the modified nanoparticle agregation. Finally, it was shown that for all materials tested there was almost the complete removal of the initial concentration (200 ppm) of methylene blue, independently of the analyzed pH. The Langmuir, Freundlich e Sips isotherms models were applied to experimental data to describe the adsorption process. For the NPM sample, the Freundlich model was better adapted to the process under analysis, since the other samples were better suited to the Sips adsorption isotherm model.