Efficiently removing Pb(II) from wastewater by graphene oxide using foam flotation

The removal of Pb(II) from wastewater by graphene oxide (GO) using foam flotation was first investigated. Effects of initial solution pH, and the dosage of GO, emulsified kerosene and terpenic oil on the Pb(II) removal and turbidity of the residual solution were systematically examined. The experimental results showed that the initial solution pH and dosage of GO significantly affected the removal of Pb(II), and more than 99% of Pb(II) could be removed under the optimum conditions. The turbidity of the residual solution could decrease to 1.4 NTU at the optimal dosage of emulsified kerosene and terpenic oil. Moreover, the flotation-desorption cycles were carried out to evaluate the practical reusability of GO, and the Pb(II) removal maintained as high as 84.9% in the sixth regeneration. It indicated that GO could be efficiently reused in the process of foam flotation. This study provides an effective strategy for the selection of an optimized method to remove the spent GO from solution compared with the conventional methods including sedimentation, centrifugation and filtration, etc.