Improvement of amoxicillin removal from aqueous environment by applying functionalized carbon nanotube

Multiwalled carbon nanotubes (MWCNTs) were applied for amoxicillin removal from aqueous environment. To enhance the adsorption capacity of adsorbent, MWCNT with modified surface was applied. A functional group as 8-hydroxyquinoline (8-HQ) and carboxyl group were selected to modify the surface of MWCNT. Fourier transform infrared spectroscopy and scanning electron microscopy confirmed the successful surface modification of MWCNTs. Some important parameters associated with the adsorption capacity such as pH, initial concentration of amoxicillin and equilibrium time of adsorption were investigated for pristine and functionalized MWCNTs. Adsorption results suggested that the maximsum removal efficiency of pollutant was achieved at pH = 5 for pristine and 8-HQ functionalized carbon nanotube (CNT) and pH = 3 for the functionalized CNT with carboxylic groups. The equilibrium time of adsorption was 4 h for the pristine and 2 h for the functionalized CNTs. The maximum adsorption capacity of 8-HQ CNTs was nearly 50% higher than that of pristine MWCNT. The modeling of adsorption process suggested that adsorption of amoxicillin on pristine and functionalized MWCNTs was best fitted with Langmuir model. Moreover, pseudo-second-order kinetic model was found to be the best kinetic model for the adsorption process. In conclusion, functionalized MWCNT with 8-HQ functional groups offers a novel alternative for removing amoxicillin from water.