CONICET | Buscador de Institutos y Recursos Humanos

Arsenic is a natural element of the earth´s crust that in some regions of the world can be present in the water. In particular, in Argentina, it is present in the underground waters in quantities superior to the admitted ones by the national and international norms (10 µg L-1). Its removal from water has been proved using low cost materials, in which the presence of Fe and Al seems to be fundamental. The synthetic mica 4-Na-mica (Na4Si4Al4Mg6O20F4 xH2O) with high cationic exchange capacity and four Na ions for cell unit and his product of mechanical treatment, where the structure was altered exhibiting the aluminum ions might act as a good sorbent for the removal of arsenic. In this work it was characterized, the initial kaolin, the 4-Na-Mica obtained and his product of mechanical treatment, by means of: DRX, SEM, specific surface determination, isoelectric point and cation exchange capacity. The arsenic adsorption capacity was evaluated on the samples of synthetic mica and post mechanical treatment. The obtained results show that both solid adsorbed arsenic. The mica treated mechanically sorbes much more arsenic, needing times of contact of six days to reach his maximum capacity of removal, whereas the not ground mica needs only 2 hours. This can be due to the fact that it presents major quantity of border negatively charged sites that adsorb protons of the solution what produces an increase continued of the pH. As the time of contact increases the ground mica diminishes its charge and consequently the electrostatic repulsion being able to adosrbe a major quantity of species of As. The capacities of removal obtained were a 60,7 % for the mica of game and 96,5 % for the mica activated mechanically, showing the potentiality for his application in the treatment of waters contaminated with As.

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