removal of ni ions from aqueous solutions using melamine-modified nano graphene oxide adsorbent

Heavy metal pollution is a serious environmental issue that poses significant risks to both human health and the environment. when heavy metals enter the human body through food consumption, they can harm various organs, including the cardiovascular system, lungs, liver, and kidneys, leading to potentially severe health effects. industrial sewage contains heavy metals such as nickel, lead, copper, zinc, and cadmium. in the present research, melamine-modified nanographene oxide was used to remove nickel from sewage. for this, the field emission microscope (fesem), the tensor fourier transform infrared spectroscopy (ftir) and the x-ray diffraction (xrd) were employed. we investigated the effects of ph (2-7), concentration (5-200) mg/g, absorbent dose (0.01-0.06) g, temperature (15-50) °c and contact time (15 to 150) minutes on the adsorption process. to determine the adsorption mechanism, thermodynamics, pseudo first and second-order kinetics, and freundlich and langmuir adsorption isotherms on the adsorption process were performed. nickel concentration was measured by atomic absorption spectrometry. the results showed that the adsorption rate is consistent with the freundlich isotherm model and the pseudo-second-order kinetic equation. thermodynamic studies also showed that the adsorption process is associated with increasing irregularities and is endothermic. the highest absorption rate at a concentration of 200 mg /l, and the highest percentage of removal occurs in 150 minutes, which is equal to 1915.75 mg/g and 99.825%, respectively. based on the results, melamine-modified nanographene oxide can be used as a suitable adsorbent to remove nickel from aqueous environments due to its high adsorption capacity and convenient and cost-effective performance.