Synthesis of Dendritic Magnetic Graphene Oxide By Radical Polymerization As Adsorbent For Rapid Removal of Malachite Green From Aqueous Solutions

Disposal of Malachite green containing sewage from related industries has resulted in global concern. Thus, removing Malachite green from aqueous solutions is highly significant and necessary. during this study, magnetic graphene oxide coated with dendrimer (G (1) -MGO-chitosan) was prepared successfully and applied for removing cationic malachite green in various conditions. The properties of the synthesized adsorbent (G (1) -MGO-chitosan) were evaluated using XRD, FTIR, BET, FESEM, TEM and TGA. Furthermore, the effect of different parameters on malachite green removal was studied. The results indicated that at pH = 8, temperature of 40 °C, initial concentration 600 µg mL-1 and contact time 10 min were obtained as optimal values for removing malachite green with nanoadsorbent (G (1) -MGO-chitosan) with maximum adsorption capacity of malachite green was obtained at 38.71 µg mg-1. The high correlation coefficient (R2 = 0.9947) for the Freundlich model confirmed that the Freundlich model is appropriate for fitting laboratory data. Based on the model, Temkin heat adsorption for malachite green j mol-1 is B = 8.1447, indicating that the process of dye adsorption with Nano adsorbent is of physical type. Based on the results of fitting the kinetic models of Malachite green adsorption by Nano adsorbent, Hu and McKay’s model with higher correlation coefficient (R2 = 0.9994) is more consistent with experimental data than other models. Since no large decrease is observed in Malachite green removal in seven consecutive recovery cycles, thus Nano adsorbent has a high stability and can be used several times.