Molecular modelling of emerging contaminants adsorption in subunits of metal-organic frameworks

Emerging Contaminants (ECs) are compounds recently introduced in the environment and associated with the modern lifestyle. Many of these substances arrive in water bodies by sewage, presenting toxic effects to living organisms. Since conventional water treatment methodologies are not able to remove them, adsorptive methods using Metal-Organic Frameworks (MOFs) as adsorbents are quite promising for this purpose. Therefore, understanding the adsorptive mechanisms involving these materials is important to design optimized adsorbents. In this work, the adsorption properties of MOF subunits were evaluated for the ECs atrazine, caffeine, and triclosan using computational simulations based on Density Functional Theory. The choice of the metallic subunit showed to be determinant to the MOFs design, since the ECs coordinate in these sites, besides the possibility of establishing hydrogen bonds. The adsorption of possible coexisting species (Cl-, HSO4-, and H2PO4-) was also investigated and observed as relevant interferents to be considered in the adsorptive methodologies.