Enhanced adsorption behavior of amended EDTA-graphene oxide for methylene blue and heavy metal ions

Here, edetic acid (EDTA) structure was chemically modified by aspartic acid and lysine (two alpha -amino acids) over covalent functionalization. The obtained modified EDTA (m-EDTA) was used to functionalize graphene oxide (GO) surface for effective removal of dyes from waste waters. The methylene blue dye was adsorbed on the hybrid sorbent through -pi interactions with GO conjugated surface and also electrostatic interactions with multivalent chelating m-EDTA sites. The synthesized hybrid sorbent has been characterized with X-ray powder diffraction, scanning electron microscope, Fourier transform infrared spectroscopy, and ultraviolet-visible spectroscopy. 0.03 g of synthesized hybrid sorbent has been used for treatment of 30 mL of pollutant (1 g/L). The results indicate high removal efficiency was obtained in first 20 min that verify the modification of the GO has a positive effect on removal efficiency.Graphical abstract