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

Abstract

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

Chemical regeneration of granular activated carbon: preliminary evaluation of alternative regenerant solutions

“…A study conducted by Busquets et al 44 showed that metaldehyde adsorption onto activated carbon was independent of the carbon's specific surface area, which indicated that the adsorption mechanism was more complex than just physisorption. The results from this study also support those reported previously, including both a theoretical study 73 and a laboratory investigation 28 which indicated that metaldehyde adsorption involves hydrogen bonding with carbon surface functional groups, with or without mediation by water molecules. Other phenomena such as van der Waals interactions and the thermodynamic gradients may also be contributory mechanisms for metaldehyde adsorption.…”

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

“…The present methodology was also used to theoretically evaluate the molecular inclusion process between CLD and cyclodextrins [39]. In addition, Jáuregui-Haza et al [40] studied the guest-host complexes of 1-iodochlordecone and β-1-iodo-pentachlorocyclohexane with cyclodextrins to use them as radiotracers of organochlorine pesticides in polluted water.…”

“…Although Gibbs's free energy of association (∆G ASSOC ) is the thermodynamic criteria used to define the spontaneity of a process, the association energy (∆E ASSOC ) was used in this study. This criterion has been profusely used by previous researchers [22,23,29,30,34,35,39,40] since it is computationally simpler compared to ∆G, and it avoids having to calculate the association entropies. It is defined as ∆E ASSOC = E supermolecule − E ref , where E supermolecule is the energy of the formed molecular complex by the activated carbon model (with and without SGs) and the interacting in the studied system molecules (in this case: CLD, β-HCH, and water molecules) and E ref is the energy of the isolated molecules.…”

“…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 coronene [24,29,30,[36][37][38][39][40], and their oxidized derivatives is very popular for theoretical studies that aim to characterize their interactions with a 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 [29].…”

Insights into chemical regeneration of activated carbon for water treatment

“…These groups are known to affect the adsorption of organic compounds onto carbon (Stavropoulos et al, 2008). Previously, both a theoretical study (Ferino-Perez et al, 2019) and a laboratory investigation (Tao and Fletcher, 2013) suggested that metaldehyde adsorption involves hydrogen bonding with carbon surface functional groups, with or without mediation by water molecules. Thus, the reduced availability of these functional groups for metaldehyde to interact with, resulted in a lower capacity of the carbon for metaldehyde.…”