Modificación de una arcilla natural a la forma de hierro (III) y evaluación de la adsorción de fosfatos a partir de soluciones acuosas.

Abstract

The present study was carried out with a clay mineral from the outcrop San Cayetano, from the city and province of Loja. In this way, the material was modified to the Fe (III) form, with the purpose to improve its capacity of adsorption of phosphate and it’s evaluate in synthetic wastewater. Through the characterization of mineral, the mineralogical species present, the specific surface area and the point of zero charge (7.31 ± 0.03-P1M1-N, 5.20 ± 0.04-P1M1-Fe) were determined. The experimental assay were carried out based on an optimization, in which a factorial design 22 was applied. A better fit was determined to the Langmuir isotherm model with maximum adsorption capacity of 6.013 mg-P/g. The kinetic study showed a relatively fast adsorption, with equilibrium time of 120 minutes, so that the models applied described better the process controlled by chemical adsorption. Through the desorption test, 18.02% of phosphate was recovered, this value is attributed only to phosphate attached to the mineral by the interaction of coulombic forces.