Sorption Mechanisms of Organic Compounds by Carbonaceous Materials: Site Energy Distribution Consideration

Abstract

Sorption of naphthalene, lindane, and atrazine on 10 kinds of carbonaceous materials which included four kinds of graphene, three kinds of graphite, two kinds of carbon nanotubes and one kind of mesoporous carbon was investigated. The approximate sorption site energy distributions were calculated based on Dubinin-Ashtakhov (DA) model. The average sorption site energy and standard deviation of the site energy distribution were deduced and applied to analyze the interaction between sorbents and sorbates, and the sorption site heterogeneity. The introduction of oxygen-containing functional groups to the sorbents caused a decrease in their average sorption energy for the studied compounds. However, relative to the decrease in average site energy, the reduction in number of sorption sites as indicated by surface area more strongly reduced their sorption capacity to the tested carbonaceous materials based on the result of the linear regression analysis. Sorption site heterogeneity of the sorbents decreased as their oxygen contents increased, which is attributed to the better dispersion of the oxygen-containing materials as indicated by their TEM images. The method proposed in this study to quantify the average sorption site energy and heterogeneity is helpful for a better understanding of the sorption mechanisms of organic pollutants to carbonaceous materials.

Different binding characteristics of ciprofloxacin to iron mineral surfaces: Thermodynamic evidence and site energy distribution analysis

“…The peak of the energy distribution curve was expressed as F ( E 0 * ), and the site energy ( E 0 * ) corresponding to the position of the peak had the highest occurring frequency, which could help to describe the interaction between solute molecules and adsorbents (Shen et al., 2015). It was generally believed that the right side of E 0 * in the energy distribution was the high‐energy region and the left side was the low‐energy region (Huang et al., 2018).…”

“…The theory of site energy distribution (SEDT) could provide more comprehensive information on adsorption mechanisms from the perspective of energy (Zhang et al., 2014), such as the energy distribution of high‐ and low‐energy adsorption sites (Huang et al., 2018) and the heterogeneity of the adsorbent surface (Shen et al., 2015). At sites on the mineral surface, functional groups are bound in different patterns and might consequently exhibit different adsorption affinities (Dale et al., 2015; Trivedi et al., 2001).…”

Model fitting of sorption kinetics data: Misapplications overlooked and their rectifications

“…It may be mentioned that the modified pseudosecond-order rate equation (Eq. 9) also work when other sorption isotherm models (e.g., the Temkin, Dubinin-Ashtakhov, 54 and Sips isotherms) are applicable. In such cases, the appropriate sorption isotherm needs to be used to represent the instantaneous concentration dependent Q e in the rate equation.…”

Interaction mechanisms of antibiotic sulfamethoxazole with various graphene-based materials and multiwall carbon nanotubes and the effect of humic acid in water

“…The presence of sp 2 hybridized nanocarbons in these materials contribute to their outstanding features, which trigger the interest of both the scientific and technological communities [5]. Given their hydrophobicity and large surface area, graphene and CNTs are promising sorbents for removing various organic chemicals, such as aromatic amines, PAHs, and pesticides [6][7][8][9][10].…”