Gómez Rosa, Kinley S.

Profile Picture

Filters

20211
Reset filters

Settings

Citations

Publication Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    Publication
    DFT analysis of faujasite zeolite substituted with Cu, Ni, and Zn for the adsorption of emerging contaminants
    (2021-12-10) Gómez Rosa, Kinley S.; Curet Arana, María C.; College of Engineering; Hernández Maldonado, Arturo; Martínez Iñesta, María; Department of Chemical Engineering; Vicente Velez, Nancy V.
    Emerging contaminants (ECs) are pollutants of growing concern because a significant amount of these contaminants does not count with regulations and could cause undesirable effects on humans and ecosystems, even when they are at low concentrations. The ECs analyzed in this work are acetylsalicylic acid (ASA), bisphenol A (BPA), caffeine (CAF), carbamazepine (CAR), clofibric acid (CA) and salicylic acid (SA). Because water treatment plants do not remove or degrade ECs efficiently using their conventional procedures, a cost-effective method for the removal of these contaminants is necessary. Adsorption is a promising method for the removal of these pollutants due to their low implementation cost, high efficiency, and simple operating design. The faujasite zeolite (FAU) is an adsorbent material with structures characterized by frameworks of SiO4 and AlO4 linked together and surrounding a cation. In this analysis, FAU was exchanged with the transition metal cations copper (Cu), nickel (Ni) and zinc (Zn). To study the adsorption of the ECs in FAU, a DFT analysis was made using ωB97XD as the functional, and the basis sets 6-31+g** for Si, O, C, N, Cl and H and LANL2DZ for the metal cations. Three different structures of FAU, where the positions of the aluminum atoms changed, were analyzed to determine the most stable one. The selected structure was then used to perform the adsorption analyses in vacuum and considering the effect of the solvent. Results show that the ECs molecules interact with the metal cation in FAU structure through their most electronegative sites. Furthermore, it was determined that for some ECs (i.e. ASA, CAR and SA) both the isolated species and the adsorbed complexes are most stable in solvent, but the interaction is more favorable in vacuum, while for others (i.e. CAF and CA), the isolated species are most stable in vacuum but the interaction between the EC molecule and FAU is more favorable in solvent. Based on the interaction energies, the most favorable adsorption in M-FAU is that with CAR, while the least favorable one is with SA. NBO analyses showed that the charge transfer during the adsorption occurs from the M-FAU to the EC molecules.