Resumen

TUESTA, Erika G., VIVAS, Magali, SUN, Rosario et al. Modificación química de arcillas y su aplicación en la retención de colorantes. Rev. Soc. Quím. Perú, ene./mar. 2005, vol.71, no.1, p.26-36. ISSN 1810-634X.

A termoacid treatment was applied to a natural clay, from the central region of Peru, with high content of esmectites. The clay activated in acid solution of HCl 2N to 90 °C was proven like adsorbent material of used azo color type in the textile industry. The effects of the activation on the structure and composition of the clay were followed by FRX, SEM, DRX, specific area BET and FTIR. The main results of this characterization showed that it was a type of smectite called montmorillonite with a Si/Al relation of 5,39. After being put under a termoactivation process, the superficial area was increased from 66 to 90 m 2 /g, and the basal spaced one (interlayer space) increased of 11.79 Å until 16.06 Å. The study of the adsorption phenomenon was made with the following coloring: red 80 and blue 71. The results show that the activated clay can increase its capacity of adsorption of textile coloring in 30 times with respect to the natural clay . The isotherms, as much for the coloring red as the coloring blue, are isothermal of type L for systems liquid-solid; both isotherms show favorable adsorptions since too low concentrations of equilibrium the tendency of the curve is increasing. For a time of balance of 15 min, a gram of activated clay could adsorb 75 mg of coloring blue and 30 mg of coloring red.

Palabras llave: clay; smetite; bentonite; adsorption; azo colors; activated clays.