Synthesis of graphene oxide grafted by diazanyl groups and its application in recovery of lead from lead-acid wastewater

Abstract

Heavy metal ion (HMI) in wastewater is a kind of resource that is wrongly placed. Recovery of heavy metal from lead-acid wastewater desires efficient and reusable functional materials. In this paper, graphene oxide-like with diazanyl groups (GOLA) was synthesized by a nucleophilic substitution reaction of graphene oxide-like with hydroxyl groups (GOLH) with diazane. GOLA exhibited good stability and recyclability in wastewater. The maximal adsorption capacity (q_max) values of GOLA for Pb(II), Cd(II), Cu(II), Ni(II), and Cr(III) ions were 505.80, 401.99, 83.48, 82.29, and 147.77 mg/g, respectively. The equilibrium time of GOLA adsorbing HMIs was 20 min. GOLA was employed to recover lead ions from lead-acid wastewater to give Pb(OH)₂ and reusable water. Therefore, this paper provides a useful method of recycling lead from lead-acid wastewater.

Keywords: Diazanyl group; Graphene oxide; Heavy metal ion; Lead-acid wastewater; Recovery; Recyclability; Reusable water; Stability.