Application of Fe-filled multi-walled carbon nanotubes for removal of antibiotics from aqueous solution

Abstract

The aim of this research is to investigate the feasibility of utilizing Fe-filled multi-wall carbon nanotubes synthesized by co-pyrolysis of glycerol and ferrocene as an adsorbent for removal of antibiotics from aqueous solution. Then synthesized Fe-filled MWCNTs were also treated by H[subscript 2]SO[subscript 4]/HNO[subscript 3]. It was found that the carboxylic acid was produced on surface of acid treated Fe-filled MWCNTs, thereby improving negatively charged on their surface. Synthesized Fe-filled MWCNTs were employed for adsorption of antibiotics included tetracycline and enrofloxacin. From the results, pristine Fe-filled MWCNTs could better adsorb tetracycline than acid treated Fe-filled MWCNTs, about 92%. The adsorption efficiency of both tetracycline and enrofloxacin onto pristine Fe-filled MWCNTs increased when pH was increased from 5 – 7 and then decreased significantly as the pH lower or higher than this range. Both adsorption capacity of tetracycline and enrofloxacin increased with temperature increased. In addition, tetracycline could reach equilibrium within 1 hr while adsorption capacity of enrofloxacin did not change significantly after 3 hr. Langmuir model and the pseudo-second-order kinetic model are well used to describe the adsorption for tetracycline and enrofloxacin onto pristine Fe-filled MWCNTs. The nature of adsorption process is the endothermic and spontaneous that was described by thermodynamic parameters.