Explaining the interactions between metaldehyde and acidic surface groups of activated carbon under different pH conditions

Publication date: Available online 21 April 2019Source: Journal of Molecular Graphics and ModellingAuthor(s): Anthuan Ferino-Pérez, Juan José Gamboa-Carballo, Zhuojun Li, Luiza C. Campos, Ulises Jáuregui-HazaAbstractMetaldehyde (MA) is an organic compound widely used in agriculture all around the world as molluscicide. There are growing concerns that relatively high levels of MA have been detected in surface water, which could be ascribed to the fact that it is transparent to common wastewater treatment processes. A theoretical study of the influence of activated carbon (AC) surface groups (SGs) on MA adsorption is done in order to help to understand the process and to evaluate the influence of the acid SGs over the adsorption in AC filters. Multiple Minima Hypersurface methodology was employed in order to study the interactions of the MA with acid SGs (hydroxyl and carboxyl) at acidic and neutral pH, and at different hydration conditions explicitly taking into account the solvent influence. Selected structures were re-optimized using Density Functional Theory and posteriorly refined to achieve a well-defined electron density to characterize the interactions by the Quantum Theory of Atoms in Molecules approach. The obtained results showed that the presence of SGs enhances the adsorption process. The deprotonated carboxyl and hydroxyl SGs of AC models show the strongest interactions, suggesting greater adsorption at neutral pH which is in concordance with experimental data....
Source: Journal of Molecular Graphics and Modelling - Category: Molecular Biology Source Type: research