Highly efficient adsorption of three antibiotics from aqueous solutions using glucose-based mesoporous carbon

In the present study, the adsorption of three common types of antibiotics, tetracycline (TC), ciprofloxacin (CIP), and sulfadiazine (SDZ), from aqueous solutions using glucose-based mesoporous carbon (GMC) were conducted to investigate its performance and mechanisms. The physicochemical property results indicate that the GMC adsorbent had an average pore size of 7.27 nm, a high specific surface area (S-BET) of 1126.46 m(2)/g, and a total pore volume of 2.05 cm(3)/g. The maximum capacity of GMC for TC, CIP, and SDZ were 297.91, 369.85, and 246.73 mg/g, respectively. Moreover, the adsorption process reached equilibrium after 2 h and fit well to a pseudo-second-order model. The pH had a significant effect on the amount of antibiotics adsorbed, with the optimal pH for removal of TC, CIP, and SDZ being 6, 6, and 4, respectively. Ionic strength of NaCl, CaCl2 and MgCl2 barely influenced the adsorption efficiency. Increasing the temperature from 288 to 308 K promoted the amount of target antibiotics adsorbed. Moreover, the thermodynamics results show that the adsorption process of the target antibiotics using GMC was spontaneous and exothermic in nature. Furthermore, several mechanisms, including electrostatic interactions, hydrophobic effect, hydrogen bonding, or pi-pi interactions, for the adsorption of antibiotics have been proposed.