Adsorption of aspirin and paracetamol from aqueous solution using Fe/N-CNT/β-cyclodextrin nanocomopsites synthesized via a benign microwave assisted method

• A greener microwave polyol method is used to prepare Fe/N-CNTs-β-CD nanocomposite.
• Iron is dispersed uniformly into N-CNTs-βCD nanocomposite.
• The material is stable in leaching tests and hence applicable for water treatment.
• Sorption is quite rapid and metal loaded onto N-CNTs-β-CD enhances sorption.
• The material has higher affinity for aspirin and paracetamol compared to other sorbents.

Aspirin and paracetamol are used as drugs by animals and humans but are not totally metabolized inside their bodies and hence they often find way into the raw wastewaters. This study presents kinetic and thermodynamic studies of the sorption and removal of aspirin and paracetamol from aqueous solutions using N-CNT/β-CD and Fe/N-CNT/β-CD nanocomposite polymers and the parameters that determine the sorption process. The polymers were prepared via a benign method of microwave-assisted synthesis of the nanocomposites and characterized using Spectrum 100 Fourier transform infrared spectroscopy (FTIR) and focused ion beam scanning electron microscopy (FIB-SEM). The sorption process for aspirin and paracetamol was described by Freundlich and Langmuir isotherms, respectively. The maximum sorption capacities of aspirin and paracetamol onto N-CNTs-β-CD were 71.9 and 41.0 mg g−1 and Fe/N-CNTs-β-CD were 101.0 and 75.2 mg g−1, respectively, at 298 K. The nanocomposites effectively removed aspirin and paracetamol within 30 min of contact time, suggesting that the materials are effective and economically viable. Furthermore, the sorption kinetics of aspirin and paracetamol onto the N-CNT/β-CD and Fe/N-CNT/β-CD sorbents well fitted onto the pseudo second order and Elovich kinetic models, respectively as a minimum SSE was observed. Sorption thermodynamics indicated that the sorption process was feasible, spontaneous and exothermic in nature.