Synthesis of Nanoporous Materials and their Functionalization for Environmental Applications

Abstract

In this work, W, P and faujasite zeolites were synthesized using fly ash as raw material, a waste material derived of coal fired plants in Mexico. Two different synthesis methods were used. Zeolites were submitted a functionalization treatment exchanging their metallic ions by ammonium, aluminum and ferrous ions. Chemical, structural and textural properties of functionalized zeolites were evaluated. As (V) and As (III) adsorption capacity of modified zeolites were assessed. Changes on their structural properties were no significant. While the textural properties such as pore volume, specific surface area and pore size distribution were dependent of nature of ion exchanged, and the accessibility of extra-framework sites of the zeolites. Functionalization with di and trivalent ions allow changing the zeolitic surface charge. This modification led to increase their ability to adsorb anionic species from aqueous solutions. The results shown that, the adsorption capacity was dependent of zeolite type and their chemical surface nature. W zeolite modified with aluminum ions achieved the highest arsenic (V) adsorption capacity. While ferrous functionalization on W zeolite shown a high affinity to remove As (III) species from aqueous solutions.