Nanospace engineering and functionalization of MCM-48 mesoporous silica with dendrimer amines based on [1,3,5]-triazines for selective and pH-independent sorption of silver ions from aqueous solution and electroplating industry wastewater

Abstract

In this study, MCM-48 mesoporous silica was functionalized with dendrimer amines based on [1,3,5]-triazines (DA-S-Triazines), characterized by FT-IR, XRD, TEM and N2 sorption-desorption isotherm. The results confirmed the successful graft of organic functional groups on the MCM-48 surface. Then, it was used for the selective sorption of Ag (I) from aqueous solution and real wastewater in the batch system. The effect of main parameters on equilibrium sorption capacity and removal percentage including sorbent dose, pH, contact time, initial metal ion concentration and temperature was investigated. The results showed that the sorption of Ag (I) by DA-S-Triazines@MCM-48 was pH independent in the range of 3–8. The sorption capacity of MCM-48 strongly increases from 7.23 to 123 and 169.49mg/g for HDA-S-Triazines@MCM-48 and DA-S-Triazines@MCM-48, respectively. The equilibrium data were fitted to nonlinear Freundlich, Temkin and Langmuir models, while a better fit was obtained by Freundlich model. According to the kinetic parameters, the sorption process was rapid. To selective sorption of Ag (I) from aqueous solution and real wastewater, the pore size of MCM-48 was exactly adjusted by changing the amount of DA-S-Triazines ligand. The results illustrated that the selective sorption of Ag (I) increased by increasing the amount of DA-S-Triazines ligand grafted on MCM-48 mesoporous silica. The results of sorption-desorption proved the economic synthesis and practical application of DA-S-Triazines@MCM-48 for sorption of Ag (I) from wastewater. DA-S-Triazines@MCM-48 as a potential sorbent showed high sorption capacity for sorption of Ag (I) from electroplating industry wastewater.