Performance evaluation and efficiency of functionalized cellulose nanocomposites for the removal of pharmaceutical contaminants from the aqueous environment

Water pollution caused by pharmaceuticals has raised many concerns about the potential risks to human health and living organisms. Therefore, it is important to develop a high-efficiency adsorbent for the removal of organic pollutants from wastewater. Cellulose-based nanomaterials can be effectively used for wastewater treatment. In the present work, new nanocomposites are designed through the functionalization of cellulose with beta-cyclo-dextrin (beta-CD/Cell), cucurbit [6] (CUR/Cell), and calixarene (CAL/Cell) groups with Tetrafluoroterephthalonitrile (TFP) linker. Then, the adsorption of pharmaceutical agents such as propranolol (PRO), levofloxacin (LEV), and metformin (MET) is examined on nanocomposites as efficient adsorbents. The obtained results show that the systems containing the beta-CD functional group have a higher adsorption for all three types of drugs compared to the other two nanocomposites. It should be noted that both types of interactions (Van der Waals and electrostatic) between beta-CD/Cell and CAL/Cell nanocomposites with micropollutant molecules are significant, whereas, between CUR/Cell and drugs, the electrostatic interaction is dominant. Also, the most number of hydrogen bonds exist between the MET drug and nanocomposite membranes, which leads to stronger electrostatic interactions. In addition, our findings confirm that the system containing beta-CD/Cell nanocomposite and LEV drug has the highest number of contacts (2300) at the beginning of the simulation and the most interaction energy (368.5 kJ/mol). It is worth mentioning that the negative values of the interaction energies show that all of the investigated drug molecules exothermically and spontaneously adsorbed on the surface of cellulose nanocomposites.