An aminated rosin-based resin (ARBR) was synthesized as a novel environmentally-friendly adsorbent for removal of Norfloxacin (NOR) from aqueous solutions. Its features were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and surface area measurements (BET). The effects of resin dosage, pH, and ionic strength on the ARBR adsorption properties of NOR were investigated by batch experiments. Results showed that the NOR adsorption amounts increased with pH in the range from 2.0 to 6.0, but decreased at higher pH (8-10). The adsorption process of NOR followed a pseudo-second rate model and could be fitted to the Langmuir isotherm, with calculated maximum monolayer adsorption capacity of 30.29 mg·g-1 at pH 6.0 and 20℃. Thermodynamic calculations showed that the adsorption of NOR was a spontaneous and endothermic process and could be attributed to a combination of electrostatic interactions and hydrogen bonding. Furthermore, the adsorbed NOR on ARBR could be efficiently desorbed by 0.1 mol·L-1 HCl to regenerate the resin. After five adsorption-desorption recycles, ARBR had a stable adsorption performance and could be recycled. The adsorption performance is better than that of various commercial resins, and these research results contribute to the development of applications of rosin derivatives and their utilization in the environmental control of micro pollutants.
Keywords: adsorption; aminated rosin-based resin; interaction mechanisms; norfloxacin; thermodynamics.