Volcanic Glass and its Uses as Adsorbent

Abstract

Volcanic glasses are an amorphous phyllosilicates formed by the fast cooling of the magma. The physicochemical properties of volcanic glasses are directly related to their chemical composition. Thus, the rhyolitic magma, which presents the highest SiO 2 percentage, displays a high viscosity, which leads to explosive eruptions by the ex-solution of H 2 O, CO 2 , and SO 2 , when the pressure diminishes generates a macroporous structure with interesting applications in construction, as abrasive, acoustic, filter as well as in the agriculture field. The macroporosity of volcanic glass allows to host large molecules as biomolecules, tensoactives, or dyes. On the other hand, the existence of hydroxyl groups in this amorphous aluminosilicate also favors the adsorption of cations and anions, so the volcanic glass is an economical adsorbent to retain heavy metals or radioactive cations.