Role of acidic sites in beta-hexachlorocyclohexane (β-HCH) adsorption by activated carbons: molecular modelling and adsorption–desorption studies

Abstract

The role played by acidic groups on the removal of β-HCH from contaminated water by adsorption on activated is shown.

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

“…Models that correctly describe ACs' morphology, topology and constitution usually do so at a high computational cost. Therefore, the use of small polycycles such as naphthalene [9,20,30], coronene [21,22,[31][32][33][34], and their oxidized derivatives is very popular for theoretical studies that aim to characterize their interactions with variety of molecules. The use of such small models saves computational resources, and allows either an application of a relatively high level of calculations or a thorough exploration of the interactions present in the system under study [22].…”

“…The application of computational chemistry methods allow an economization of the material resources while optimizing the work and security of the researchers and technicians [16]. The influence of surface groups (SG) content over adsorption properties has been reported and studied to some extent theoretically for porous carbons (mainly AC and soot particles) [9,[17][18][19][20][21][22][23] in the last few years employing different AC models. In 2014 Enriquez-Victorero et.…”

Evaluation of the molecular inclusion process of β-hexachlorocyclohexane in cyclodextrins

“…These methods range from advanced oxidation 15 and bioremediation treatments 9,16,17 to the use of activated carbon for the treatment of polluted water. [18][19][20] In spite of these efforts, it is still necessary to increase the efficiency of the separation methods used; this has promoted the search for new alternatives, such as the formation of host-guest complexes with cyclodextrins.…”

Role of Basic Surface Groups of Activated Carbon in Chlordecone and β-Hexachlorocyclohexane Adsorption: A Molecular Modelling Study

“…In this sense, the theoretical modeling can help to understand the adsorption process and may lead to improvements in the AC selection process. In fact, in previous works by our research group, theoretical studies employing the multiple minima hypersurface (MMH) [20,21] computational methodology were undertaken in order to help to understand the influence of acidic AC surface groups (SGs) on CLD [22] and β-HCH [23,24], adsorption. The use of the MMH methodology allows, on one hand, to explore the possible interaction sites of the surface groups of the AC with the water molecules and contaminants, and on the other hand, to calculate the thermodynamic properties of the interacting system.…”

“…Previously, molecular modeling studies of chlordecone and metaldehyde interactions with acidic activated carbon surface functional groups have been published using this methodology [24,29,30]. The present methodology was also used to theoretically evaluate the molecular inclusion process between CLD and cyclodextrins [34].…”