Sorption of Sulfamethoxazole on Inorganic Acid Solution-Etched Biochar Derived from Alfalfa

Abstract

The properties of alfalfa-derived biochars etched with phosphoric (PBC) or hydrochloric acid (ClBC) compared with raw materials (BC) were examine in this paper. SEM, FT-IR, XRD, BET and elemental analysis were performed to characterize the micromorphology and chemical structure comprehensibly. The results showed that the porous structure was enhanced, and surface area was increased via etching with inorganic acids. Batch adsorption experiments were performed for sulfamethoxazole (SMX) to biochars. The experimental data showed that modified biochars exhibited higher adsorption capacity for SMX, i.e., the adsorption quantity of ClBC and PBC had risen by 38% and 46%. The impact on pH values suggested that the physisorption, including pore-filling and electrostatic interaction, might be applied to original biochar. In addition, chemisorption also played a role, including hydrogen bonding, π-π electron donor acceptor interaction (π-π EDA), and so on. Furthermore, both pH and coexisting ions also had a certain effect on sorption. Enhancement of the electrostatic attraction between biochar and SMX might also account for the enhanced capacity of SMX at pH＜7, and coexisting ions could decrease the amount of SMX adsorbed onto biochars, mainly because of competition for adsorption sites.

The Adsorption of Corn Stalk Biochar for Pb and Cd: Preparation, Characterization, and Batch Adsorption Study

“…Several absorption peaks appeared at different wavenumbers, representing the existence of different functional groups. For example, the characteristic peak at 3435.06 cm −1 was due to the stretching vibration of -OH groups [20]; the absorbance band at 1158 cm −1 suggested the existence of C-O stretching vibration in the two carbon materials [21]; the band at 1618 cm −1 indicated the stretching vibration of -OH deformation of water and C=O stretching vibration of the carbonyl from the carboxyl group in biochar [22]; the sharp peaks at 2929 cm −1 was associated with the stretching vibration of -CH, -CH 2 , and CH 3 bonds [23,24]. Compared with the FT-IR of origin biochar, the FT-IR biochar after adsorption was detected (Figure 2b).…”

Porous carbon aerogel derived from bacterial cellulose with prominent potential for efficient removal of antibiotics from the aquatic matrix

“…The absorption peaks at 2,055, 768, and 2,932 cm À1 confirmed the existence of accumulated double bonds, ortho-disubstituted benzene rings, and CH 2 . In addition, some weak adsorption peaks (i.e., at 771, 1,046, and 1,052 cm À1 ) could be observed after antibiotic adsorption (Figure 3), which can be attributed to the deformation vibration of the C-H bond and the bending vibration of that bond in the aromatic and heterocyclic rings (Li et al 2021). These results indicated successful antibiotic adsorption on BCCA.…”

“…K d1 was large, indicating rapid adsorption at the beginning of the adsorption process, rapid surface diffusion, and abundant adsorption sites (Prasannamedha et al 2021). The decrease in K d2 was due to the saturation of the adsorbent surface, and the increase in the boundary layer effect and mass transfer resistance, which decreases the diffusion rate in the particle (Li et al 2021). The further decrease in K d3 was due to the small size of the adsorbent, the tardy diffusion rate, the gradual equilibrium of the solid-liquid phase distribution, and the gradual equilibrium of the adsorption process (Li et al 2021).…”

“…The decrease in K d2 was due to the saturation of the adsorbent surface, and the increase in the boundary layer effect and mass transfer resistance, which decreases the diffusion rate in the particle (Li et al 2021). The further decrease in K d3 was due to the small size of the adsorbent, the tardy diffusion rate, the gradual equilibrium of the solid-liquid phase distribution, and the gradual equilibrium of the adsorption process (Li et al 2021). This is consistent with the results of the above-mentioned kinetic fitting analysis.…”

The Effects of Chemical Oxidation and High-Temperature Reduction on Surface Functional Groups and the Adsorption Performance of Biochar for Sulfamethoxazole Adsorption

“…When at pH > 4, SMX − and R-BC700 showed electrostatic repulsion, resulting in a decrease of the adsorption capacity of R-BC700. Although there was electrostatic repulsion, R-BC700 still had an adsorption capacity for SMX, indicative of the presence of other adsorption mechanisms, such as pore filling, hydrogen bonding and surface complexation [43].…”