Multifunctional crosslinked chitosan/nitrogen-doped graphene quantum dot for wastewater treatment

The fabrication of multifunctional nanomaterial for the adsorption of different types of pollutants is a challenge and could be a solution for many problems associated with wastewater treatment. This current study propose the use of crosslinked chitosan/nitrogen doped-graphene quantum dot nanocomposites (CS/NGQD) synthesized via glutaraldehyde as cross-linker to remove various pollutants including bacteria, proteins, fluoride, dyes, and pharmaceuticals. This nanomaterial was characterized using different techniques (FT-IR, XRD, SEM, TEM, and Raman spectroscopy). This nanocomposite offered higher pollutants removal efficiencies compared to its component parts. Using CS/NGQD the removal reached 60% for proteins and 88% for the bacterial load. A significant removal enhancement was also obtained for pharmaceuticals (63% for chlorothiazide, 81% for carbamazepine, and 89% ranitidine), dyes (82% for Azo blue, 84% for methylene blue and 94% for orange G), and fluoride (42%). Interestingly, after 5 cycles of reuse, the nanocomposite remains efficient for the removal of pollutants from water. (C) 2021 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Ain Shams University.