Extração seletiva de Mn(II) utilizando sementes de Moringa oleífera como bioadsorvente

Abstract

In this study, a method using Moringa oleifera seeds as bioadsorbents for selective retention of Mn(II) was developed. The variables studied were pH, particle size, mass and contact time, being the pH the most important variable in the separation process. After, adsorption isotherms were constructed in order to evaluate the adsorptive capacity of the material and the characteristics of the adsorption process. The results were: pH 3,0, particle size ≤ 180 μm, adsorbent mass equal to 1.0 g and time of contact 15 minutes. Data of Mn(II) removal were adjusted to Langmuir model, obtaining qmax (mg g -1) of 10.35. Characterization techniques such as infrared spectroscopy, thermal analysis and scanning electron microscopy and theory adsorption multielement were used in physic chemical evaluation of Moringa oleífera seeds. The method was applied to the selective extraction of manganese in water samples and the accuracy of the method was evaluated using reference material (drinking water reference certified material, APS 1075). The values obtained showed high agreement with the certified values, demonstrating the efficiency of the proposed method.