Surface modification of peanut shell by UV-induced graft polymerization for enriching and recycling rare earth metals (Ce(III)) from aqueous solution

In order to develop a low-cost and high efficient absorbent for enriching and recycling rare earth metals from wastewater, surface of peanut shells was grafted with the poly acrylic acid by "grafting from" polymerization based on UV -induced grafting technology. The modified peanut shells (PS-g-PAA) were characterized by SEM, FTIR and zeta potential analysis. For Ce3+ adsorption, the adsorption properties as well as the regeneration of the PS-g-PAA were investigated. Results show that the ideal adsorption capacity of PS-g-PAA could be acquired at pH 4-7 and slightly affected by ionic strength. The Langmuir model was more suitable than the Freundlich model to describe the adsorption of Ce(III), which followed pseudo -second -order kinetics. The maximum adsorption capacity is calculated to be 134.59 mg/g and the absorption capacity kept upon 88% in five consecutive cycles. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.