3D hierarchical porous-structured biochar aerogel for rapid and efficient phenicol antibiotics removal from water

The appearance and contamination of phenicol antibiotics (PABs), such as chloramphenicol (CAP), florfenicol (FF) and thiamphenicol (TAP), in aqueous solutions has aroused public concerns in recent years due to its negative impact on human health and ecological system. In this study, a 3D porous-structured biochar aerogel (3D-PBA) with large BET surface area (2607 m2/g) was synthesized, and applied on PABs removal. Notably, to the best of our knowledge, among all the reported carbon-based adsorbents, 3D-PBA shows the record high adsorption capacity toward target PABs. The adsorption capacity for CAP, FF and TAP was measured to be 786.1, 751.5 and 691.9 mg/g at 298 K, respectively. The Langmuir-Freundlich isotherm model can better describe the adsorption isotherm data. Specifically, 2 mg/L PABs can be completely removed within 10 min, and over 90% PABs can be removed within 10 min even when the initial concentration was as high as 40 mg/L. Adsorption mechanism of PABs on 3D-PBA was fully determined using XPS and FTIR. As a result, the pore-filling effect, π-π/n-π EDA interaction and electrostatic interaction played a crucial role, and it also accompany with hydrogen bonding interaction. Furthermore, the synergistic action of hydrophobic interaction also acts as indispensable role during the adsorption process. Overall, the 3D-PBA can act as an efficient candidate for ultrafast PABs removal.