Electroadsorptive Removal of Gaseous Pollutants

Abstract

Adsorption is a consequence of surface energy distribution, and the existence of electrostatic bonding suggests that the presence of an external electric field may affect adsorbate/adsorbent interactions. Nevertheless, this aspect has been poorly studied in the literature, except under non-thermal plasma or corona discharge conditions. After having demonstrated in our previous work that the adsorption kinetics of gaseous organic compounds can be enhanced by the presence of an external applied electric field, in this study, we focus on the influence of the electric field on adsorbent and adsorptive interactions. By using a commercially available activated carbon cloth, in addition to increasing the adsorbent mass transfer coefficient by virtue of the increasing intensity of the applied electric field, the results suggest that adsorbent morphology is only influenced by the formation of new surface functional groups. Moreover, enhanced adsorption kinetics and capacity may result from the electrohydrodynamic force induced by the movement of charged and neutral particles towards the adsorbent, as confirmed by the reversibility of the process. Such enhancement results in a negligible increase, of about 3%, in adsorption capacity (i.e., from 91 mmol m−2 Pa−1 for only adsorption to 94 mmol m−2 Pa−1 in the presence of the applied electric field), but also in a dramatic doubling of adsorption kinetics (i.e., from 0.09 min−1 for only adsorption to 0.19 min−1 in the presence of the applied electric field). In reality, the application of an electric field to an activated carbon cloth leads to faster adsorption kinetics, without substantially altering its adsorption capacity.

Multifunctional Lightweight Mortars for Indoor Applications to Improve Comfort and Health of Occupants: Thermal Properties and Photocatalytic Efficiency

“…Active control systems are generally more effective than passive systems for the control of IAQ, but they have a substantial energy loss that can be reduced by the addition of passive systems in the environment (Trník et al, 2016). Moreover, the combination of multiple techniques to improve IAQ, and in particular to remove pollutants, may result in a more efficient synergistic effect than the sum of the individual ones (Pierpaoli et al, 2017(Pierpaoli et al, , 2019a. To remove pollutants, titanium dioxide (TiO 2 ) is the most studied photocatalytic agent, because of its chemical inertness, nontoxicity, and low cost.…”