Highly efficient removal of antibiotic rifampicin from aqueous solution using green synthesis of recyclable nano-Fe3O4

Antibiotics in water and soil are persistent, bioaccumulative and toxic to aquatic organisms and human health. To address it, as one of the new technologies , green synthesized magnetic Fe 3 O 4 nanoparticles by Excoecaria cochinchinensis extract used to remove rifampicin (RIF) was investigated in this study. Results showed the adsorption efficiency of RIF reached 98.4% and the maximum adsorption capacity is 84.8 mg/g when 20 mL of RIF at a concentration of 20 M was adsorbed by 10 mg Fe 3 O 4 at a temperature of 303 K. The morphology of the green Fe 3 O 4 characterized by SEM demonstrated the dimensions ranging from 20 to 30 nm. The N 2 adsorption/desorption isotherms revealed that the surface area of Fe 3 O 4 was 111.8 m 2 /g. In addition, adsorption studies indicated that the kinetics fitted the pseudo second-order and isothermal adsorption conformed to the Langmuir isotherm. Furthermore, due to their magnetic properties, the Fe 3 O 4 nanoparticles were easily separated and reused and the mechanism for removing RIF occurred through adsorption rather than chemical redox reaction. Finally, the reusability of Fe 3 O 4 for adsorption of RIF showed that the removal efficiency decreased to 61.5% after five cycles.