Preparation of Graphene - Like Carbon Composites (GCC) by Hummers Method Using Fly Ash as Carbon Source and Its Removal of Lead from Wastewater

In this paper, fly ash (FA) was successfully prepared into graphene-like carbon composite materials (GCC) with good adsorption properties for heavy metals by alkali activation-Hummer oxidation method. What's more, the sulfate in the waste liquid can be collected by concentration, and sulfuric acid can be recycled several times after treatment. FA has been fully recycled in an inexpensive and environmentally friendly way. Compared with FA, the specific surface area of GCC increased about 50 times, and the pore size decreased from 9.49 nm to 4.5 nm. The adsorbing amount of GCC could attain 79.38 mg g(-1)within 90 min at pH=6. The experimental data of lead adsorption by GCC showed that the results were very consistent with the Freundlich adsorption model. The adsorbent prepared in this work has a good application prospect in water pollution control, which provides a new approach for resource recovery of FA.