Removal of Cadmium Ion from Aqueous Solutions Using Magnetic Graphene Oxide Nanoparticles

Industrial and agricultural processes have resulted in the release of cadmium metal into the ecosystem. One way to remove this heavy metal is adsorption. This research aimed to determine the efficiency of magnetic nanographene for removing cadmium ions from aqueous solution., This research was done in a discontinuous system at a laboratory scale. For this purpose, the effect of effective parameters such as pH, concentration, contact time, ambient temperature, adsorbent dose, and other factors was investigated. The results showed that the maximum amount of cadmium absorption occurred in the conditions of pH=6, concentration 100 mg/l, contact time 120 min, ambient temperature 45 ° C and adsorbent dose 0.01 g.  Thermodynamic parameters showed that the absorption process of cadmium metal was spontaneous and endothermic in the temperature range of 288 to 318 K The pseudo-second-order model with adsorption rate constant (K2 = 0.0092) and coefficient of determination (R2 = 0.99) showed that it describes the laboratory data better. Also, the examination of adsorption isotherms showed that the Freundlich isotherm (R2 = 0.96) was more suitable for describing the adsorption process and was more consistent with the laboratory data. According to the results of this research, magnetic oxide nanographene adsorbent with 92.8% efficiency can be used to remove cadmium from aqueous solutions.