kinetics and thermodynamics of uranium adsorption using impregnated magnetic graphene oxide

Magnetic graphene oxide (mgo) impregnated di(2-ethyl hexyl)phosphoric acid (d2ehpa) (dmgo) was prepared by multi-impregnation. the structures of go and dmgo were characterized by ft-ir, tga, edx, sem, and xrd. the adsorption capacities for u(vi) from aqueous solution is 154.4 mg/g at ph 5. the essential factors that affected u(vi) adsorption such as initial ph, contact time, and temperature were investigated. the adsorption is highly dependent on the solution ph. in addition, the adsorption isotherm and thermodynamics were investigated. the adsorptions of u(vi) from aqueous solution on dmgo was fitted to the langmuir adsorption isotherms. the adsorption of u(vi) on dmgo is remarkably improved by go impregnated with d2ehpa. thermodynamic parameters further show that the sorption is an endothermic and spontaneous process. dmgo is a powerful promising sorbent for the efficient removal of u(vi) from aqueous solutions.