▎ 摘 要
Graphene oxide (GO) as an important derivative of graphene is potential toxic to cells and animals. In this study, MgAl-mixed metal oxide (MgAl-MMO) prepared by one-step calcination of MgAl-layered double hydroxide (MgAl-LDH) at 500 degrees C was employed to remove GO from aqueous solution. The effect of contact time, sorbent dosage, initial GO solution pH and co-existing anions on the removal capacity of MgAl-MMO composite was investigated in detail. The results showed that the sorbent dosage and the initial solution pH had significant effect on the adsorption process. MgAl-LDH composite exhibited ultrahigh GO adsorption capacity (984.2 mg/g at pH = 2) with low dosage (25 mg/L) and fast GO-eliminating rate (within 5 h). MgAl-MMO composite could be recycled by simply calcining the rehydrated production and reused for 5 times without significant loss of the removal capacity. This adsorption process could be well fitted by the pseudo-second-order model. The mechanism study further showed that the excellent removal performance of MgAl-MMO composite came from the memory effect of calcined LDH and pH-induced aggregation of GO.