Adsorption of Furazolidone, D-Cycloserine, and Chloramphenicol on Granular Activated Carbon Made from Corn Stover

In this paper, corn stover was used as the raw material to synthesize granular activated carbon (GAC), which was used to remove antibiotics in wastewater. Furazolidone (FZD), D-cycloserine (DCL), and chloramphenicol (CHP) were selected as the testing compounds, and the adsorption capacity of GAC toward them was evaluated based on adsorption kinetics and isotherms. The pseudo-second-order model fitted the kinetics well. The Weber-Morris intraparticle diffusion model and the Boyd kinetic model proved the main controlling step for the adsorption process was diffusion through the boundary layer. The Langmuir model expressed the adsorption isothermal data better than Freundlich model, indicating a monolayer adsorption. The maximum adsorption amounts (qm) of CHP, FZD, and DCL by GAC were 32.3, 29.3, and 9.365 mg/g, respectively. Based on the Dubinin-Radushkevich (D-R) model, the value of E (adsorption free energy) was calculated, suggesting the adsorption was physisorption in nature. Even under a wide temperature (15 degrees C-55 degrees C) and pH range (3.0-11.0). GAC still presented a relatively high adsorption performance. These results demonstrated that the prepared GAC might have application potential in the treatment of antibiotic-loaded wastewaters.