Green, Sustainable Synthesis of γ-Fe2O3/MWCNT/Ag Nano-Composites Using the Viscum album Leaf Extract and Waste Car Tire for Removal of Sulfamethazine and Bacteria from Wastewater Streams

Multi-walled carbon nanotubes (MWCNTs) decorated with Ag nanoparticles (NPs) are bifunctional adsorbent nanomaterials with antibacterial activity. They can be magnetically recovered from wastewater in case of coupling with gamma-Fe2O3. In this study, for the first time, an environmentally friendly technique was applied to prepare a nanocomposite (NC) material composed of gamma-Fe2O3/MWCNT/Ag by using Bridgestone disposable tires and Viscum album leaves extract. gamma-Fe2O3/MWCNTs/Ag NC was employed for the removal of sulfamethazine (SMT) from aqueous solutions. Under the optimized conditions determined via the Taguchi method, the highest SMT adsorption capacity of the gamma-Fe2O3/MWCNT/Ag NC was measured to be 47.6 mg/g. The experimental data fitted well with the pseudo-second-order kinetic model and the Langmuir isotherm. The thermodynamic parameters implied that the adsorption process was endothermic. In addition to adsorption of the drug pollutant, the NC demonstrated a superior antibacterial activity against Gram-positive bacteria. The reusability test also showed that over 79% SMT can be removed using gamma-Fe2O3/MWCNTs/Ag NC even after four adsorption cycles. Taken together, gamma-Fe2O3/MWCNTs/Ag NC was proven to be a promising antibacterial nano-adsorbent for wastewater treatment.

Automated summary

In this study, a nanocomposite material composed of γ-Fe2O3/MWCNT/Ag was successfully prepared using an environmentally friendly technique. The nanocomposite material showed excellent adsorption capacity for the removal of sulfamethazine from aqueous solutions and exhibited superior antibacterial activity. It also demonstrated good reusability in the adsorption process.