Síntesis y caracterización de nano partículas de magnetita (Fe3o4) para un estudio en la remoción de metales pesados (Zn, Pb, Cr) presentes en el agua, como fortalecimiento a los procesos de tratamiento convencionales.

Abstract

In this work, an effective adsorbent was synthesized for the elimination of some heavy metal ions such as Cr, Zn and Pb from water, by the method of co-precipitation of ferric and ferrous salts under the presence of nitrogen gas and with the help of a precipitating agent (NaOH), thus obtaining a reaction according to the chemical formula of magnetite, Fe+3[Fe+2 Fe3+ ]O4. The crystallographic characterization of the material was carried out by means of XRD obtaining an average crystal size of 6.9851 nm, in the superficial chemical characterization of the adsorbent was found predominance of basic sites 2,119 (meq/g), on acids 1,506 (meq/g) and the pH was determined at the point of zero load which has a value of 9,2. The surface area of the adsorbent was estimated by isotherms, where it is shown that the adsorption of the magnetite nanoparticles followed the Langmuir model and a surface area of 1190.3908 m2/g was obtained. The adsorption of metal ions in water was determined by atomic absorption spectrophotometry, resulting in a maximum adsorption percentage of magnetite towards Cr+ , Zn+ and Pb+ at pH 3 of 96.1713 and 95.7856%; 99.6479 and 99.5136%; 99.8993 and 99.6014%; for a time of 60 and 120 min respectively, in the case of pH 7, slightly lower results were obtained but with a good percentage of removal of 97.6837 and 97.0515% for Cr; 99,9473 and 93,6272% for Zn and finally 98,2007 and 90,7694% for Pb at times of 60 and 120 min. Experimental data show that synthesized magnetite nanoparticles have good efficiency and can quantitatively remove heavy metal ions from water