A high-efficiency and plane-enhanced chitosan film for cefotaxime adsorption compared with chitosan particles in water

It is well known that the adsorption capacity of particles is stronger than that of film due to the high specific surface area. Nonetheless, it is a bit different in some cases because of the plane enhancement effect of film. The third-generation cephalosporin are commonly used for either prevention or treatment of bacterial infections. These antibiotics, which have been discharged into various water environment, have created a lot of serious problems in our world. Adsorption of cefotaxime (CTX) in water by the chitosan particles (CSp) and films (CSf) were explored. The samples were characterized by scanning electron microscopy, the nitrogen adsorption isotherms, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and others. Various experimental conditions (pH, adsorption time, molecular weight of CSf, initial antibiotic concentrations, the number of films and foreign ions) presented an important influence on CTX removal. The pseudo-secondorder kinetics and Freundlich isotherm models better illustrated the adsorption behavior of CTX on CSf, and the highest adsorption capacity was 1003.64 mg g-1, far above CSp (648.05 mg g-1) and these reported adsorbents. The reusability experiments revealed that CSf had passable regeneration and continuous usage performance. Multiple analysis factors suggested that the mechanism of CTX adsorption on CSf was mainly based on plane strengthening effect, electrostatic attraction, nucleophilic addition reaction and hydrogen bonding. These findings showed that CSf was an efficient and reusable adsorbent for antibiotics elimination in water.